This commit converts the previous error into just a Warn-level log
message. By returning an error when the requested service was not a
gateway, we did not appropriately update envoy because the cache Fetch
returned an error and thus did not propagate the update through proxycfg
and xds packages.
Previously this happened to be using the method on the Server/Client that was meant to allow the ACLResolver to locally resolve tokens. On Servers that had tokens (primary or secondary dc + token replication) this function would lookup the token from raft and return the ACLIdentity. On clients this was always a noop. We inadvertently used this function instead of creating a new one when we added logging accessor ids for permission denied RPC requests.
With this commit, a new method is used for resolving the identity properly via the ACLResolver which may still resolve locally in the case of being on a server with tokens but also supports remote token resolution.
* Return early from updateGatewayServices if nothing to update
Previously, we returned an empty slice of gatewayServices, which caused
us to accidentally delete everything in the memdb table
* PR comment and better formatting
We require any non-wildcard services to match the protocol defined in
the listener on write, so that we can maintain a consistent experience
through ingress gateways. This also helps guard against accidental
misconfiguration by a user.
- Update tests that require an updated protocol for ingress gateways
This now requires some type of protocol setting in ingress gateway tests
to ensure the services are not filtered out.
- small refactor to add a max(x, y) function
- Use internal configEntryTxn function and add MaxUint64 to lib
- Validate that this cannot be set on a 'tcp' listener nor on a wildcard
service.
- Add Hosts field to api and test in consul config write CLI
- xds: Configure envoy with user-provided hosts from ingress gateways
This commit adds the necessary changes to allow an ingress gateway to
route traffic from a single defined port to multiple different upstream
services in the Consul mesh.
To do this, we now require all HTTP requests coming into the ingress
gateway to specify a Host header that matches "<service-name>.*" in
order to correctly route traffic to the correct service.
- Differentiate multiple listener's route names by port
- Adds a case in xds for allowing default discovery chains to create a
route configuration when on an ingress gateway. This allows default
services to easily use host header routing
- ingress-gateways have a single route config for each listener
that utilizes domain matching to route to different services.
This is a collection of refactors that make upcoming PRs easier to digest.
The main change is the introduction of the authmethod.Identity struct.
In the one and only current auth method (type=kubernetes) all of the
trusted identity attributes are both selectable and projectable, so they
were just passed around as a map[string]string.
When namespaces were added, this was slightly changed so that the
enterprise metadata can also come back from the login operation, so
login now returned two fields.
Now with some upcoming auth methods it won't be true that all identity
attributes will be both selectable and projectable, so rather than
update the login function to return 3 pieces of data it seemed worth it
to wrap those fields up and give them a proper name.
Also ensure that WatchSets in tests are reset between calls to watchFired.
Any time a watch fires, subsequent calls to watchFired on the same WatchSet
will also return true even if there were no changes.
Previously, if a blocking query called CheckConnectServiceNodes
before the gateway-services memdb table had any entries,
a nil watchCh would be returned when calling serviceTerminatingGatewayNodes.
This means that the blocking query would not fire if a gateway config entry
was added after the watch started.
In cases where the blocking query started on proxy registration,
the proxy could potentially never become aware of an upstream endpoint
if that upstream was going to be represented by a gateway.
On every service registration, we check to see if a service should be
assassociated to a wildcard gateway-service. This fixes an issue where
we did not correctly check to see if the service being registered was a
"typical" service or not.
* Implements a simple, tcp ingress gateway workflow
This adds a new type of gateway for allowing Ingress traffic into Connect from external services.
Co-authored-by: Chris Piraino <cpiraino@hashicorp.com>
Also reduce the log level of some version checking messages on the server as they can be pretty noisy during upgrades and really are more for debugging purposes.
The test had two racy bugs related to memdb references.
The first was when we initially populated data and retained the FederationState objects in a slice. Due to how the `inmemCodec` works these were actually the identical objects passed into memdb.
The second was that the `checkSame` assertion function was reading from memdb and setting the RaftIndexes to zeros to aid in equality checks. This was mutating the contents of memdb which is a no-no.
With this fix, the command:
```
i=0; while /usr/local/bin/go test -count=1 -timeout 30s github.com/hashicorp/consul/agent/consul -run '^(TestReplication_FederationStates)$'; do i=$((i + 1)); printf "$i "; done
```
That used to break on my machine in less than 20 runs is now running 150+ times without any issue.
Might also fix#7575
* Enable filtering language support for the v1/connect/intentions listing API
* Update website for filtering of Intentions
* Update website/source/api/connect/intentions.html.md
This config entry will be used to configure terminating gateways.
It accepts the name of the gateway and a list of services the gateway will represent.
For each service users will be able to specify: its name, namespace, and additional options for TLS origination.
Co-authored-by: Kyle Havlovitz <kylehav@gmail.com>
Co-authored-by: Chris Piraino <cpiraino@hashicorp.com>
* Add Ingress gateway config entry and other relevant structs
* Add api package tests for ingress gateways
* Embed EnterpriseMeta into ingress service struct
* Add namespace fields to api module and test consul config write decoding
* Don't require a port for ingress gateways
* Add snakeJSON and camelJSON cases in command test
* Run Normalize on service's ent metadata
Sadly cannot think of a way to test this in OSS.
* Every protocol requires at least 1 service
* Validate ingress protocols
* Update agent/structs/config_entry_gateways.go
Co-authored-by: Chris Piraino <cpiraino@hashicorp.com>
Co-authored-by: Freddy <freddygv@users.noreply.github.com>
These changes are necessary to ensure advertisement happens correctly even when datacenters are connected via network areas in Consul enterprise.
This also changes how we check if ACLs can be upgraded within the local datacenter. Previously we would iterate through all LAN members. Now we just use the ServerLookup type to iterate through all known servers in the DC.
This is like a Möbius strip of code due to the fact that low-level components (serf/memberlist) are connected to high-level components (the catalog and mesh-gateways) in a twisty maze of references which make it hard to dive into. With that in mind here's a high level summary of what you'll find in the patch:
There are several distinct chunks of code that are affected:
* new flags and config options for the server
* retry join WAN is slightly different
* retry join code is shared to discover primary mesh gateways from secondary datacenters
* because retry join logic runs in the *agent* and the results of that
operation for primary mesh gateways are needed in the *server* there are
some methods like `RefreshPrimaryGatewayFallbackAddresses` that must occur
at multiple layers of abstraction just to pass the data down to the right
layer.
* new cache type `FederationStateListMeshGatewaysName` for use in `proxycfg/xds` layers
* the function signature for RPC dialing picked up a new required field (the
node name of the destination)
* several new RPCs for manipulating a FederationState object:
`FederationState:{Apply,Get,List,ListMeshGateways}`
* 3 read-only internal APIs for debugging use to invoke those RPCs from curl
* raft and fsm changes to persist these FederationStates
* replication for FederationStates as they are canonically stored in the
Primary and replicated to the Secondaries.
* a special derivative of anti-entropy that runs in secondaries to snapshot
their local mesh gateway `CheckServiceNodes` and sync them into their upstream
FederationState in the primary (this works in conjunction with the
replication to distribute addresses for all mesh gateways in all DCs to all
other DCs)
* a "gateway locator" convenience object to make use of this data to choose
the addresses of gateways to use for any given RPC or gossip operation to a
remote DC. This gets data from the "retry join" logic in the agent and also
directly calls into the FSM.
* RPC (`:8300`) on the server sniffs the first byte of a new connection to
determine if it's actually doing native TLS. If so it checks the ALPN header
for protocol determination (just like how the existing system uses the
type-byte marker).
* 2 new kinds of protocols are exclusively decoded via this native TLS
mechanism: one for ferrying "packet" operations (udp-like) from the gossip
layer and one for "stream" operations (tcp-like). The packet operations
re-use sockets (using length-prefixing) to cut down on TLS re-negotiation
overhead.
* the server instances specially wrap the `memberlist.NetTransport` when running
with gateway federation enabled (in a `wanfed.Transport`). The general gist is
that if it tries to dial a node in the SAME datacenter (deduced by looking
at the suffix of the node name) there is no change. If dialing a DIFFERENT
datacenter it is wrapped up in a TLS+ALPN blob and sent through some mesh
gateways to eventually end up in a server's :8300 port.
* a new flag when launching a mesh gateway via `consul connect envoy` to
indicate that the servers are to be exposed. This sets a special service
meta when registering the gateway into the catalog.
* `proxycfg/xds` notice this metadata blob to activate additional watches for
the FederationState objects as well as the location of all of the consul
servers in that datacenter.
* `xds:` if the extra metadata is in place additional clusters are defined in a
DC to bulk sink all traffic to another DC's gateways. For the current
datacenter we listen on a wildcard name (`server.<dc>.consul`) that load
balances all servers as well as one mini-cluster per node
(`<node>.server.<dc>.consul`)
* the `consul tls cert create` command got a new flag (`-node`) to help create
an additional SAN in certs that can be used with this flavor of federation.
* agent: measure blocking queries
* agent.rpc: update docs to mention we only record blocking queries
* agent.rpc: make go fmt happy
* agent.rpc: fix non-atomic read and decrement with bitwise xor of uint64 0
* agent.rpc: clarify review question
* agent.rpc: today I learned that one must declare all variables before interacting with goto labels
* Update agent/consul/server.go
agent.rpc: more precise comment on `Server.queriesBlocking`
Co-Authored-By: Paul Banks <banks@banksco.de>
* Update website/source/docs/agent/telemetry.html.md
agent.rpc: improve queries_blocking description
Co-Authored-By: Paul Banks <banks@banksco.de>
* agent.rpc: fix some bugs found in review
* add a note about the updated counter behavior to telemetry.md
* docs: add upgrade-specific note on consul.rpc.quer{y,ies_blocking} behavior
Co-authored-by: Paul Banks <banks@banksco.de>
We set RawToString=true so that []uint8 => string when decoding an interface{}.
We set the MapType so that map[interface{}]interface{} decodes to map[string]interface{}.
Add tests to ensure that this doesn't break existing usages.
Fixes#7223
* fix LeaderTest_ChangeNodeID to use StatusLeft and add waitForAnyLANLeave
* unextract the waitFor... fn, simplify, and provide a more descriptive error
Previously this happened to be validating only the chains in the default namespace. Now it will validate all chains in all namespaces when the global proxy-defaults is changed.
* Cleanup the discovery chain compilation route handling
Nothing functionally should be different here. The real difference is that when creating new targets or handling route destinations we use the router config entries name and namespace instead of that of the top level request. Today they SHOULD always be the same but that may not always be the case. This hopefully also makes it easier to understand how the router entries are handled.
* Refactor a small bit of the service manager tests in oss
We used to use the stringHash function to compute part of the filename where things would get persisted to. This has been changed in the core code to calling the StringHash method on the ServiceID type. It just so happens that the new method will output the same value for anything in the default namespace (by design actually). However, logically this filename computation in the test should do the same thing as the core code itself so I updated it here.
Also of note is that newer enterprise-only tests for the service manager cannot use the old stringHash function at all because it will produce incorrect results for non-default namespaces.
The previous value was too conservative and users with many instances
were having problems because of it. This change increases the limit to
8192 which reportedly fixed most of the issues with that.
Related: #4984, #4986, #5050.
* Updates to the Txn API for namespaces
* Update agent/consul/txn_endpoint.go
Co-Authored-By: R.B. Boyer <rb@hashicorp.com>
Co-authored-by: R.B. Boyer <public@richardboyer.net>
The backing RPC already existed but the endpoint will be useful for other service syncing processes such as consul-k8s as this endpoint can return all services registered with a node regardless of namespacing.
* Increase raft notify buffer.
Fixes https://github.com/hashicorp/consul/issues/6852.
Increasing the buffer helps recovering from leader flapping. It lowers
the chances of the flapping leader to get into a deadlock situation like
described in #6852.
Currently when using the built-in CA provider for Connect, root certificates are valid for 10 years, however secondary DCs get intermediates that are valid for only 1 year. There is no mechanism currently short of rotating the root in the primary that will cause the secondary DCs to renew their intermediates.
This PR adds a check that renews the cert if it is half way through its validity period.
In order to be able to test these changes, a new configuration option was added: IntermediateCertTTL which is set extremely low in the tests.
* Add CreateCSRWithSAN
* Use CreateCSRWithSAN in auto_encrypt and cache
* Copy DNSNames and IPAddresses to cert
* Verify auto_encrypt.sign returns cert with SAN
* provide configuration options for auto_encrypt dnssan and ipsan
* rename CreateCSRWithSAN to CreateCSR
* Renamed structs.IntentionWildcard to structs.WildcardSpecifier
* Refactor ACL Config
Get rid of remnants of enterprise only renaming.
Add a WildcardName field for specifying what string should be used to indicate a wildcard.
* Add wildcard support in the ACL package
For read operations they can call anyAllowed to determine if any read access to the given resource would be granted.
For write operations they can call allAllowed to ensure that write access is granted to everything.
* Make v1/agent/connect/authorize namespace aware
* Update intention ACL enforcement
This also changes how intention:read is granted. Before the Intention.List RPC would allow viewing an intention if the token had intention:read on the destination. However Intention.Match allowed viewing if access was allowed for either the source or dest side. Now Intention.List and Intention.Get fall in line with Intention.Matches previous behavior.
Due to this being done a few different places ACL enforcement for a singular intention is now done with the CanRead and CanWrite methods on the intention itself.
* Refactor Intention.Apply to make things easier to follow.
Sometimes, we have lots of errors in cross calls between DCs (several hundreds / sec)
Enrich the log in order to help diagnose the root cause of issue.
Restore a few more service-kind index updates so blocking in ServiceDump works in more cases
Namely one omission was that check updates for dumped services were not
unblocking.
Also adds a ServiceDump state store test and also fix a watch bug with the
normal dump.
Follow-on from #6916
• Renamed EnterpriseACLConfig to just Config
• Removed chained_authorizer_oss.go as it was empty
• Renamed acl.go to errors.go to more closely describe its contents
* Increase number to test ignore. Consul Enterprise has more flags and since we are trying to reduce the differences between both code bases, we are increasing the number in oss. The semantics don't change, it is just a cosmetic thing.
* Introduce agent.initEnterprise for enterprise related hooks.
* Sync test with ent version.
* Fix import order.
* revert error wording.
Ensure we close the Sentinel Evaluator so as not to leak go routines
Fix a bunch of test logging so that various warnings when starting a test agent go to the ltest logger and not straight to stdout.
Various canned ent meta types always return a valid pointer (no more nils). This allows us to blindly deref + assign in various places.
Update ACL index tracking to ensure oss -> ent upgrades will work as expected.
Update ent meta parsing to include function to disallow wildcarding.
* Implement endpoint to query whether the given token is authorized for a set of operations
* Updates to allow for remote ACL authorization via RPC
This is only used when making an authorization request to a different datacenter.
* Update AWS SDK to use PCA features.
* Add AWS PCA provider
* Add plumbing for config, config validation tests, add test for inheriting existing CA resources created by user
* Unparallel the tests so we don't exhaust PCA limits
* Merge updates
* More aggressive polling; rate limit pass through on sign; Timeout on Sign and CA create
* Add AWS PCA docs
* Fix Vault doc typo too
* Doc typo
* Apply suggestions from code review
Co-Authored-By: R.B. Boyer <rb@hashicorp.com>
Co-Authored-By: kaitlincarter-hc <43049322+kaitlincarter-hc@users.noreply.github.com>
* Doc fixes; tests for erroring if State is modified via API
* More review cleanup
* Uncomment tests!
* Minor suggested clean ups
* Change CA Configure struct to pass Datacenter through
* Remove connect/ca/plugin as we don't have immediate plans to use it.
We still intend to one day but there are likely to be several changes to the CA provider interface before we do so it's better to rebuild from history when we do that work properly.
* Rename PrimaryDC; fix endpoint in secondary DCs
* Support Connect CAs that can't cross sign
* revert spurios mod changes from make tools
* Add log warning when forcing CA rotation
* Fixup SupportsCrossSigning to report errors and work with Plugin interface (fixes tests)
* Fix failing snake_case test
* Remove misleading comment
* Revert "Remove misleading comment"
This reverts commit bc4db9cabed8ad5d0e39b30e1fe79196d248349c.
* Remove misleading comment
* Regen proto files messed up by rebase
* pass logger through to provider
* test for proper operation of NeedsLogger
* remove public testServer function
* Ooops actually set the logger in all the places we need it - CA config set wasn't and causing segfault
* Fix all the other places in tests where we set the logger
* Allow CA Providers to persist some state
* Update CA provider plugin interface
* Fix plugin stubs to match provider changes
* Update agent/connect/ca/provider.go
Co-Authored-By: R.B. Boyer <rb@hashicorp.com>
* Cleanup review comments
* add NeedsLogger to Provider interface
* implements NeedsLogger in default provider
* pass logger through to provider
* test for proper operation of NeedsLogger
* remove public testServer function
* Switch test to actually assert on logging output rather than reflection.
--amend
* Ooops actually set the logger in all the places we need it - CA config set wasn't and causing segfault
* Fix all the other places in tests where we set the logger
* Add TODO comment
* Allow RSA CA certs for consul and vault providers to correctly sign EC leaf certs.
* Ensure key type ad bits are populated from CA cert and clean up tests
* Add integration test and fix error when initializing secondary CA with RSA key.
* Add more tests, fix review feedback
* Update docs with key type config and output
* Apply suggestions from code review
Co-Authored-By: R.B. Boyer <rb@hashicorp.com>
Main Changes:
• method signature updates everywhere to account for passing around enterprise meta.
• populate the EnterpriseAuthorizerContext for all ACL related authorizations.
• ACL resource listings now operate like the catalog or kv listings in that the returned entries are filtered down to what the token is allowed to see. With Namespaces its no longer all or nothing.
• Modified the acl.Policy parsing to abstract away basic decoding so that enterprise can do it slightly differently. Also updated method signatures so that when parsing a policy it can take extra ent metadata to use during rules validation and policy creation.
Secondary Changes:
• Moved protobuf encoding functions out of the agentpb package to eliminate circular dependencies.
• Added custom JSON unmarshalers for a few ACL resource types (to support snake case and to get rid of mapstructure)
• AuthMethod validator cache is now an interface as these will be cached per-namespace for Consul Enterprise.
• Added checks for policy/role link existence at the RPC API so we don’t push the request through raft to have it fail internally.
• Forward ACL token delete request to the primary datacenter when the secondary DC doesn’t have the token.
• Added a bunch of ACL test helpers for inserting ACL resource test data.
If acls have not yet replicated to the secondary then authz requests
will be remotely resolved by the primary. Now these tests explicitly
wait until replication has caught up first.
* ACL Authorizer overhaul
To account for upcoming features every Authorization function can now take an extra *acl.EnterpriseAuthorizerContext. These are unused in OSS and will always be nil.
Additionally the acl package has received some thorough refactoring to enable all of the extra Consul Enterprise specific authorizations including moving sentinel enforcement into the stubbed structs. The Authorizer funcs now return an acl.EnforcementDecision instead of a boolean. This improves the overall interface as it makes multiple Authorizers easily chainable as they now indicate whether they had an authoritative decision or should use some other defaults. A ChainedAuthorizer was added to handle this Authorizer enforcement chain and will never itself return a non-authoritative decision.
* Include stub for extra enterprise rules in the global management policy
* Allow for an upgrade of the global-management policy
* Implement leader routine manager
Switch over the following to use it for go routine management:
• Config entry Replication
• ACL replication - tokens, policies, roles and legacy tokens
• ACL legacy token upgrade
• ACL token reaping
• Intention Replication
• Secondary CA Roots Watching
• CA Root Pruning
Also added the StopAll call into the Server Shutdown method to ensure all leader routines get killed off when shutting down.
This should be mostly unnecessary as `revokeLeadership` should manually stop each one but just in case we really want these to go away (eventually).
This fixes an issue where leaf certificates issued in secondary
datacenters would be reissued very frequently (every ~20 seconds)
because the logic meant to detect root rotation was errantly triggering
because a hash of the ultimate root (in the primary) was being compared
against a hash of the local intermediate root (in the secondary) and
always failing.
In a previous PR I made it so that we had interfaces that would work enough to allow blockingQueries to work. However to complete this we need all fields to be settable and gettable.
Notes:
• If Go ever gets contracts/generics then we could get rid of all the Getters/Setters
• protoc / protoc-gen-gogo are going to generate all the getters for us.
• I copied all the getters/setters from the protobuf funcs into agent/structs/protobuf_compat.go
• Also added JSON marshaling funcs that use jsonpb for protobuf types.
Fixes: #5396
This PR adds a proxy configuration stanza called expose. These flags register
listeners in Connect sidecar proxies to allow requests to specific HTTP paths from outside of the node. This allows services to protect themselves by only
listening on the loopback interface, while still accepting traffic from non
Connect-enabled services.
Under expose there is a boolean checks flag that would automatically expose all
registered HTTP and gRPC check paths.
This stanza also accepts a paths list to expose individual paths. The primary
use case for this functionality would be to expose paths for third parties like
Prometheus or the kubelet.
Listeners for requests to exposed paths are be configured dynamically at run
time. Any time a proxy, or check can be registered, a listener can also be
created.
In this initial implementation requests to these paths are not
authenticated/encrypted.
The fields in the certs are meant to hold the original binary
representation of this data, not some ascii-encoded version.
The only time we should be colon-hex-encoding fields is for display
purposes or marshaling through non-TLS mediums (like RPC).
* Add build system support for protobuf generation
This is done generically so that we don’t have to keep updating the makefile to add another proto generation.
Note: anything not in the vendor directory and with a .proto extension will be run through protoc if the corresponding namespace.pb.go file is not up to date.
If you want to rebuild just a single proto file you can do so with: make proto-rebuild PROTOFILES=<list of proto files to rebuild>
Providing the PROTOFILES var will override the default behavior of finding all the .proto files.
* Start adding types to the agent/proto package
These will be needed for some other work and are by no means comprehensive.
* Add ability to resolve/fixup the agentpb.ACLLinks structure in the state store.
* Use protobuf marshalling of raft requests instead of msgpack for protoc generated types.
This does not change any encoding of existing types.
* Removed structs package automatically encoding with protobuf marshalling
Instead the caller of raftApply that wants to opt-in to protobuf encoding will have to call `raftApplyProtobuf`
* Run update-vendor to fixup modules.txt
Nothing changed as far as dependencies go but the ordering of modules in that file depends on the time they are first seen and its not alphabetical.
* Rename some things and implement the structs.RPCInfo interface bits
agentpb.QueryOptions and agentpb.WriteRequest implement 3 of the 4 RPCInfo funcs and the new TargetDatacenter message type implements the fourth.
* Use the right encoding function.
* Renamed agent/proto package to agent/agentpb to prevent package name conflicts
* Update modules.txt to fix ordering
* Change blockingQuery to take in interfaces for the query options and meta
* Add %T to error output.
* Add/Update some comments
This should cut down on test flakiness.
Problems handled:
- If you had enough parallel test cases running, the former circular
approach to handling the port block could hand out the same port to
multiple cases before they each had a chance to bind them, leading to
one of the two tests to fail.
- The freeport library would allocate out of the ephemeral port range.
This has been corrected for Linux (which should cover CI).
- The library now waits until a formerly-in-use port is verified to be
free before putting it back into circulation.
* Store primaries root in secondary after intermediate signature
This ensures that the intermediate exists within the CA root stored in raft and not just in the CA provider state. This has the very nice benefit of actually outputting the intermediate cert within the ca roots HTTP/RPC endpoints.
This change means that if signing the intermediate fails it will not set the root within raft. So far I have not come up with a reason why that is bad. The secondary CA roots watch will pull the root again and go through all the motions. So as soon as getting an intermediate CA works the root will get set.
* Make TestAgentAntiEntropy_Check_DeferSync less flaky
I am not sure this is the full fix but it seems to help for me.
When there is an node name conflicts, such messages are displayed within Consul:
`consul.fsm: EnsureRegistration failed: failed inserting node: Error while renaming Node ID: "e1d456bc-f72d-98e5-ebb3-26ae80d785cf": Node name node001 is reserved by node 05f10209-1b9c-b90c-e3e2-059e64556d4a with name node001`
While it is easy to find the node that has reserved the name, it is hard to find
the node trying to aquire the name since it is not registered, because it
is not part of `consul members` output
This PR will display the IP of the offender and solve far more easily those issues.
AutoEncrypt needs the server-port because it wants to talk via RPC. Information from gossip might not be available at that point and thats why the server-port is being used.
Compiling this will set an optional SNI field on each DiscoveryTarget.
When set this value should be used for TLS connections to the instances
of the target. If not set the default should be used.
Setting ExternalSNI will disable mesh gateway use for that target. It also
disables several service-resolver features that do not make sense for an
external service.
If the entry is updated for reasons other than protocol it is surprising
that the value is explicitly persisted as 'tcp' rather than leaving it
empty and letting it fall back dynamically on the proxy-defaults value.
Add parameter local-only to operator keyring list requests to force queries to only hit local servers (no WAN traffic).
HTTP API: GET /operator/keyring?local-only=true
CLI: consul keyring -list --local-only
Sending the local-only flag with any non-GET/list request will result in an error.
Failover is pushed entirely down to the data plane by creating envoy
clusters and putting each successive destination in a different load
assignment priority band. For example this shows that normally requests
go to 1.2.3.4:8080 but when that fails they go to 6.7.8.9:8080:
- name: foo
load_assignment:
cluster_name: foo
policy:
overprovisioning_factor: 100000
endpoints:
- priority: 0
lb_endpoints:
- endpoint:
address:
socket_address:
address: 1.2.3.4
port_value: 8080
- priority: 1
lb_endpoints:
- endpoint:
address:
socket_address:
address: 6.7.8.9
port_value: 8080
Mesh gateways route requests based solely on the SNI header tacked onto
the TLS layer. Envoy currently only lets you configure the outbound SNI
header at the cluster layer.
If you try to failover through a mesh gateway you ideally would
configure the SNI value per endpoint, but that's not possible in envoy
today.
This PR introduces a simpler way around the problem for now:
1. We identify any target of failover that will use mesh gateway mode local or
remote and then further isolate any resolver node in the compiled discovery
chain that has a failover destination set to one of those targets.
2. For each of these resolvers we will perform a small measurement of
comparative healths of the endpoints that come back from the health API for the
set of primary target and serial failover targets. We walk the list of targets
in order and if any endpoint is healthy we return that target, otherwise we
move on to the next target.
3. The CDS and EDS endpoints both perform the measurements in (2) for the
affected resolver nodes.
4. For CDS this measurement selects which TLS SNI field to use for the cluster
(note the cluster is always going to be named for the primary target)
5. For EDS this measurement selects which set of endpoints will populate the
cluster. Priority tiered failover is ignored.
One of the big downsides to this approach to failover is that the failover
detection and correction is going to be controlled by consul rather than
deferring that entirely to the data plane as with the prior version. This also
means that we are bound to only failover using official health signals and
cannot make use of data plane signals like outlier detection to affect
failover.
In this specific scenario the lack of data plane signals is ok because the
effectiveness is already muted by the fact that the ultimate destination
endpoints will have their data plane signals scrambled when they pass through
the mesh gateway wrapper anyway so we're not losing much.
Another related fix is that we now use the endpoint health from the
underlying service, not the health of the gateway (regardless of
failover mode).
In addition to exposing compilation over the API cleaned up the structures that would be exchanged to be cleaner and easier to support and understand.
Also removed ability to configure the envoy OverprovisioningFactor.
This should make them better for sending over RPC or the API.
Instead of a chain implemented explicitly like a linked list (nodes
holding pointers to other nodes) instead switch to a flat map of named
nodes with nodes linking other other nodes by name. The shipped
structure is just a map and a string to indicate which key to start
from.
Other changes:
* inline the compiler option InferDefaults as true
* introduce compiled target config to avoid needing to send back
additional maps of Resolvers; future target-specific compiled state
can go here
* move compiled MeshGateway out of the Resolver and into the
TargetConfig where it makes more sense.
* connect: reconcile how upstream configuration works with discovery chains
The following upstream config fields for connect sidecars sanely
integrate into discovery chain resolution:
- Destination Namespace/Datacenter: Compilation occurs locally but using
different default values for namespaces and datacenters. The xDS
clusters that are created are named as they normally would be.
- Mesh Gateway Mode (single upstream): If set this value overrides any
value computed for any resolver for the entire discovery chain. The xDS
clusters that are created may be named differently (see below).
- Mesh Gateway Mode (whole sidecar): If set this value overrides any
value computed for any resolver for the entire discovery chain. If this
is specifically overridden for a single upstream this value is ignored
in that case. The xDS clusters that are created may be named differently
(see below).
- Protocol (in opaque config): If set this value overrides the value
computed when evaluating the entire discovery chain. If the normal chain
would be TCP or if this override is set to TCP then the result is that
we explicitly disable L7 Routing and Splitting. The xDS clusters that
are created may be named differently (see below).
- Connect Timeout (in opaque config): If set this value overrides the
value for any resolver in the entire discovery chain. The xDS clusters
that are created may be named differently (see below).
If any of the above overrides affect the actual result of compiling the
discovery chain (i.e. "tcp" becomes "grpc" instead of being a no-op
override to "tcp") then the relevant parameters are hashed and provided
to the xDS layer as a prefix for use in naming the Clusters. This is to
ensure that if one Upstream discovery chain has no overrides and
tangentially needs a cluster named "api.default.XXX", and another
Upstream does have overrides for "api.default.XXX" that they won't
cross-pollinate against the operator's wishes.
Fixes#6159
Secondary CA initialization steps are:
• Wait until the primary will be capable of signing intermediate certs. We use serf metadata to check the versions of servers in the primary which avoids needing a token like the previous implementation that used RPCs. We require at least one alive server in the primary and the all alive servers meet the version requirement.
• Initialize the secondary CA by getting the primary to sign an intermediate
When a primary dc is configured, if no existing CA is initialized and for whatever reason we cannot initialize a secondary CA the secondary DC will remain without a CA. As soon as it can it will initialize the secondary CA by pulling the primaries roots and getting the primary to sign an intermediate.
This also fixes a segfault that can happen during leadership revocation. There was a spot in the secondaryCARootsWatch that was getting the CA Provider and executing methods on it without nil checking. Under normal circumstances it wont be nil but during leadership revocation it gets nil'ed out. Therefore there is a period of time between closing the stop chan and when the go routine is actually stopped where it could read a nil provider and cause a segfault.
Auto-encrypt meant to fallback to the default port when it wasn't provided, but it hadn't been because of an issue with the error handling. We were checking against an incomplete error value:
"missing port in address" vs "address $HOST: missing port in address"
Additionally, all RPCs to AutoEncrypt.Sign were using a.config.ServerPort, so those were updated to use ports resolved by resolveAddrs, if they are available.
All these changes should have no side-effects or change behavior:
- Use bytes.Buffer's String() instead of a conversion
- Use time.Since and time.Until where fitting
- Drop unnecessary returns and assignment
I can only assume we want to check for the retrieved `updatedToken` to not be
nil, before accessing it below.
`token` can't possibly be nil at this point, as we accessed `token.AccessorID`
just before.
* Ensure the mesh gateway configuration comes back in the api within each upstream
* Add a test for the MeshGatewayConfig in the ToAPI functions
* Ensure we don’t use gateways for dc local connections
* Update the svc kind index for deletions
* Replace the proxycfg.state cache with an interface for testing
Also start implementing proxycfg state testing.
* Update the state tests to verify some gateway watches for upstream-targets of a discovery chain.
Also:
- add back an internal http endpoint to dump a compiled discovery chain for debugging purposes
Before the CompiledDiscoveryChain.IsDefault() method would test:
- is this chain just one resolver step?
- is that resolver step just the default?
But what I forgot to test:
- is that resolver step for the same service that the chain represents?
This last point is important because if you configured just one config
entry:
kind = "service-resolver"
name = "web"
redirect {
service = "other"
}
and requested the chain for "web" you'd get back a **default** resolver
for "other". In the xDS code the IsDefault() method is used to
determine if this chain is "empty". If it is then we use the
pre-discovery-chain logic that just uses data embedded in the Upstream
object (and still lets the escape hatches function).
In the example above that means certain parts of the xDS code were going
to try referencing a cluster named "web..." despite the other parts of
the xDS code maintaining clusters named "other...".
* Retry the creation of the test server three times.
* Reduce the retry timeout for the API wait to 2 seconds, opting to fail faster and start over.
* Remove wait for leader from server creation. This wait can be added on a test by test basis now that the function is being exported.
* Remove wait for anti-entropy sync. This is built into the existing WaitForSerfCheck func, so that can be used if the anti-entropy wait is needed
Previously a sequence of events like:
Start
Stop
Start
Stop
would segfault on the second stop because the original ctx and cancel func were only initialized during the constructor and not during Start.
* Make cluster names SNI always
* Update some tests
* Ensure we check for prepared query types
* Use sni for route cluster names
* Proper mesh gateway mode defaulting when the discovery chain is used
* Ignore service splits from PatchSliceOfMaps
* Update some xds golden files for proper test output
* Allow for grpc/http listeners/cluster configs with the disco chain
* Update stats expectation
maxIndexWatchTxn was only watching the IndexEntry of the max index of all the entries. It needed to watch all of them regardless of which was the max.
Also plumbed the query source through in the proxy config to help better track requests.
The general problem was that a the CA config which contained the trust domain was happening outside of the blocking mechanism so if the client started the blocking query before the primary dcs roots had been set then a state trust domain was being pushed down.
This was fixed here but in the future we should probably fixup the CA initialization code to not initialize the CA config twice when it doesn’t need to.
* Prune Servers from WAN and LAN
* cleaned up and fixed LAN to WAN
* moving things around
* force-leave remove from serfWAN, create pruneSerfWAN
* removed serfWAN remove, reduced complexity, fixed comments
* add another place to remove from serfWAN
* add nil check
* Update agent/consul/server.go
Co-Authored-By: Paul Banks <banks@banksco.de>
With this you should be able to fetch all of the relevant discovery
chain config entries from the state store in one query and then feed
them into the compiler outside of a transaction.
There are a lot of TODOs scattered through here, but they're mostly
around handling fun edge cases and can be deferred until more of the
plumbing works completely.
With ACLs enabled if an agent is wiped and restarted without a leave
it can no longer deregister the services it had previously registered
because it no longer has the tokens the services were registered with.
To remedy that we allow service deregistration from tokens with node
write permission.
* Support for maximum size for Output of checks
This PR allows users to limit the size of output produced by checks at the agent
and check level.
When set at the agent level, it will limit the output for all checks monitored
by the agent.
When set at the check level, it can override the agent max for a specific check but
only if it is lower than the agent max.
Default value is 4k, and input must be at least 1.
If a KVSet is performed but does not update the entry, do not trigger
watches for this key.
This avoids releasing blocking queries for KV values that did not
actually changed.
* Add integration test for central config; fix central config WIP
* Add integration test for central config; fix central config WIP
* Set proxy protocol correctly and begin adding upstream support
* Add upstreams to service config cache key and start new notify watcher if they change.
This doesn't update the tests to pass though.
* Fix some merging logic get things working manually with a hack (TODO fix properly)
* Simplification to not allow enabling sidecars centrally - it makes no sense without upstreams anyway
* Test compile again and obvious ones pass. Lots of failures locally not debugged yet but may be flakes. Pushing up to see what CI does
* Fix up service manageer and API test failures
* Remove the enable command since it no longer makes much sense without being able to turn on sidecar proxies centrally
* Remove version.go hack - will make integration test fail until release
* Remove unused code from commands and upstream merge
* Re-bump version to 1.5.0
* Add HTTP endpoints for config entry management
* Finish implementing decoding in the HTTP Config entry apply endpoint
* Add CAS operation to the config entry apply endpoint
Also use this for the bootstrapping and move the config entry decoding function into the structs package.
* First pass at the API client for the config entries
* Fixup some of the ConfigEntry APIs
Return a singular response object instead of a list for the ConfigEntry.Get RPC. This gets plumbed through the HTTP API as well.
Dont return QueryMeta in the JSON response for the config entry listing HTTP API. Instead just return a list of config entries.
* Minor API client fixes
* Attempt at some ConfigEntry api client tests
These don’t currently work due to weak typing in JSON
* Get some of the api client tests passing
* Implement reflectwalk magic to correct JSON encoding a ProxyConfigEntry
Also added a test for the HTTP endpoint that exposes the problem. However, since the test doesn’t actually do the JSON encode/decode its still failing.
* Move MapWalk magic into a binary marshaller instead of JSON.
* Add a MapWalk test
* Get rid of unused func
* Get rid of unused imports
* Fixup some tests now that the decoding from msgpack coerces things into json compat types
* Stub out most of the central config cli
Fully implement the config read command.
* Basic config delete command implementation
* Implement config write command
* Implement config list subcommand
Not entirely sure about the output here. Its basically the read output indented with a line specifying the kind/name of each type which is also duplicated in the indented output.
* Update command usage
* Update some help usage formatting
* Add the connect enable helper cli command
* Update list command output
* Rename the config entry API client methods.
* Use renamed apis
* Implement config write tests
Stub the others with the noTabs tests.
* Change list output format
Now just simply output 1 line per named config
* Add config read tests
* Add invalid args write test.
* Add config delete tests
* Add config list tests
* Add connect enable tests
* Update some CLI commands to use CAS ops
This also modifies the HTTP API for a write op to return a boolean indicating whether the value was written or not.
* Fix up the HTTP API CAS tests as I realized they weren’t testing what they should.
* Update config entry rpc tests to properly test CAS
* Fix up a few more tests
* Fix some tests that using ConfigEntries.Apply
* Update config_write_test.go
* Get rid of unused import
When receiving a serf faild message for a node which is not in the
catalog, do not perform a register request to set is serf heath to
critical as it could overwrite the node information and services if it
was renamed.
Fixes : #5518
Roles are named and can express the same bundle of permissions that can
currently be assigned to a Token (lists of Policies and Service
Identities). The difference with a Role is that it not itself a bearer
token, but just another entity that can be tied to a Token.
This lets an operator potentially curate a set of smaller reusable
Policies and compose them together into reusable Roles, rather than
always exploding that same list of Policies on any Token that needs
similar permissions.
This also refactors the acl replication code to be semi-generic to avoid
3x copypasta.
This is mainly to avoid having the API return "0001-01-01T00:00:00Z" as
a value for the ExpirationTime field when it is not set. Unfortunately
time.Time doesn't respect the json marshalling "omitempty" directive.
These act like a special cased version of a Policy Template for granting
a token the privileges necessary to register a service and its connect
proxy, and read upstreams from the catalog.
Fixes: #4222
# Data Filtering
This PR will implement filtering for the following endpoints:
## Supported HTTP Endpoints
- `/agent/checks`
- `/agent/services`
- `/catalog/nodes`
- `/catalog/service/:service`
- `/catalog/connect/:service`
- `/catalog/node/:node`
- `/health/node/:node`
- `/health/checks/:service`
- `/health/service/:service`
- `/health/connect/:service`
- `/health/state/:state`
- `/internal/ui/nodes`
- `/internal/ui/services`
More can be added going forward and any endpoint which is used to list some data is a good candidate.
## Usage
When using the HTTP API a `filter` query parameter can be used to pass a filter expression to Consul. Filter Expressions take the general form of:
```
<selector> == <value>
<selector> != <value>
<value> in <selector>
<value> not in <selector>
<selector> contains <value>
<selector> not contains <value>
<selector> is empty
<selector> is not empty
not <other expression>
<expression 1> and <expression 2>
<expression 1> or <expression 2>
```
Normal boolean logic and precedence is supported. All of the actual filtering and evaluation logic is coming from the [go-bexpr](https://github.com/hashicorp/go-bexpr) library
## Other changes
Adding the `Internal.ServiceDump` RPC endpoint. This will allow the UI to filter services better.
* First conversion
* Use serf 0.8.2 tag and associated updated deps
* * Move freeport and testutil into internal/
* Make internal/ its own module
* Update imports
* Add replace statements so API and normal Consul code are
self-referencing for ease of development
* Adapt to newer goe/values
* Bump to new cleanhttp
* Fix ban nonprintable chars test
* Update lock bad args test
The error message when the duration cannot be parsed changed in Go 1.12
(ae0c435877d3aacb9af5e706c40f9dddde5d3e67). This updates that test.
* Update another test as well
* Bump travis
* Bump circleci
* Bump go-discover and godo to get rid of launchpad dep
* Bump dockerfile go version
* fix tar command
* Bump go-cleanhttp
* Make Connect health queryies unblock correctly in all cases and use optimal number of watch chans. Fixes#5506.
* Node check test cases and clearer bug test doc
* Comment update
Refs #4984.
Watching chans for every node we touch in a health query is wasteful. In #4984 it shows that if there are more than 682 service instances we always fallback to watching all services which kills performance.
We already have a record in MemDB that is reliably update whenever the service health result should change thanks to per-service watch indexes.
So in general, provided there is at least one service instances and we actually have a service index for it (we always do now) we only ever need to watch a single channel.
This saves us from ever falling back to the general index and causing the performance cliff in #4984, but it also means fewer goroutines and work done for every blocking health query.
It also saves some allocations made during the query because we no longer have to populate a WatchSet with 3 chans per service instance which saves the internal map allocation.
This passes all state store tests except the one that explicitly checked for the fallback behaviour we've now optimized away and in general seems safe.
acl: reduce complexity of token resolution process with alternative singleflighting
Switches acl resolution to use golang.org/x/sync/singleflight. For the
identity/legacy lookups this is a drop-in replacement with the same
overall approach to request coalescing.
For policies this is technically a change in behavior, but when
considered holistically is approximately performance neutral (with the
benefit of less code).
There are two goals with this blob of code (speaking specifically of
policy resolution here):
1) Minimize cross-DC requests.
2) Minimize client-to-server LAN requests.
The previous iteration of this code was optimizing for the case of many
possibly different tokens being resolved concurrently that have a
significant overlap in linked policies such that deduplication would be
worth the complexity. While this is laudable there are some things to
consider that can help to adjust expectations:
1) For v1.4+ policies are always replicated, and once a single policy
shows up in a secondary DC the replicated data is considered
authoritative for requests made in that DC. This means that our
earlier concerns about minimizing cross-DC requests are irrelevant
because there will be no cross-DC policy reads that occur.
2) For Server nodes the in-memory ACL policy cache is capped at zero,
meaning it has no caching. Only Client nodes run with a cache. This
means that instead of having an entire DC's worth of tokens (what a
Server might see) that can have policy resolutions coalesced these
nodes will only ever be seeing node-local token resolutions. In a
reasonable worst-case scenario where a scheduler like Kubernetes has
"filled" a node with Connect services, even that will only schedule
~100 connect services per node. If every service has a unique token
there will only be 100 tokens to coalesce and even then those requests
have to occur concurrently AND be hitting an empty consul cache.
Instead of seeing a great coalescing opportunity for cutting down on
redundant Policy resolutions, in practice it's far more likely given
node densities that you'd see requests for the same token concurrently
than you would for two tokens sharing a policy concurrently (to a degree
that would warrant the overhead of the current variation of
singleflighting.
Given that, this patch switches the Policy resolution process to only
singleflight by requesting token (but keeps the cache as by-policy).
This PR introduces reloading tls configuration. Consul will now be able to reload the TLS configuration which previously required a restart. It is not yet possible to turn TLS ON or OFF with these changes. Only when TLS is already turned on, the configuration can be reloaded. Most importantly the certificates and CAs.
Node updates were not updating the service indexes, which are used for
service related queries. This caused the X-Consul-Index to stay the same
after a node update as seen from a service query even though the node
data is returned in heath queries. If that happened in between queries
the client would miss this change.
We now update the indexes of the services on the node when it is
updated.
Fixes: #5450
In TestServer_LANReap autopilot is running, so the alternate flow
through the serf reaping function is possible. In that situation the
ReconnectTimeout is not relevant so for parity also override the
TombstoneTimeout value as well.
For additional parity update the TestServer_WANReap and
TestClient_LANReap versions of this test in the same way even though
autopilot is irrelevant here .
Fix error in detecting raft replication errors.
Detect redacted token secrets and prevent attempting to insert.
Add a Redacted field to the TokenBatchRead and TokenRead RPC endpoints
This will indicate whether token secrets have been redacted.
Ensure any token with a redacted secret in secondary datacenters is removed.
Test that redacted tokens cannot be replicated.
Previously we were fixing up the token links directly on the *ACLToken returned by memdb. This invalidated some assumptions that a snapshot is immutable as well as potentially being able to cause a crash.
The fix here is to give the policy link fixing function copy on write semantics. When no fixes are necessary we can return the memdb object directly, otherwise we copy it and create a new list of links.
Eventually we might find a better way to keep those policy links in sync but for now this fixes the issue.
This PR adds two features which will be useful for operators when ACLs are in use.
1. Tokens set in configuration files are now reloadable.
2. If `acl.enable_token_persistence` is set to `true` in the configuration, tokens set via the `v1/agent/token` endpoint are now persisted to disk and loaded when the agent starts (or during configuration reload)
Note that token persistence is opt-in so our users who do not want tokens on the local disk will see no change.
Some other secondary changes:
* Refactored a bunch of places where the replication token is retrieved from the token store. This token isn't just for replicating ACLs and now it is named accordingly.
* Allowed better paths in the `v1/agent/token/` API. Instead of paths like: `v1/agent/token/acl_replication_token` the path can now be just `v1/agent/token/replication`. The old paths remain to be valid.
* Added a couple new API functions to set tokens via the new paths. Deprecated the old ones and pointed to the new names. The names are also generally better and don't imply that what you are setting is for ACLs but rather are setting ACL tokens. There is a minor semantic difference there especially for the replication token as again, its no longer used only for ACL token/policy replication. The new functions will detect 404s and fallback to using the older token paths when talking to pre-1.4.3 agents.
* Docs updated to reflect the API additions and to show using the new endpoints.
* Updated the ACL CLI set-agent-tokens command to use the non-deprecated APIs.
In order to be able to reload the TLS configuration, we need one way to generate the different configurations.
This PR introduces a `tlsutil.Configurator` which holds a `tlsutil.Config`. Afterwards it is responsible for rendering every `tls.Config`. In this particular PR I moved `IncomingHTTPSConfig`, `IncomingTLSConfig`, and `OutgoingTLSWrapper` into `tlsutil.Configurator`.
This PR is a pure refactoring - not a single feature added. And not a single test added. I only slightly modified existing tests as necessary.
Also in acl_endpoint_test.go:
* convert logical blocks in some token tests to subtests
* remove use of require.New
This removes a lot of noise in a later PR.
There was an errant early-return in PolicyDelete() that bypassed the
rest of the function. This was ok because the only caller of this
function ignores the results.
This removes the early-return making it structurally behave like
TokenDelete() and for both PolicyDelete and TokenDelete clarify the lone
callers to indicate that the return values are ignored.
We may wish to avoid the entire return value as well, but this patch
doesn't go that far.
`establishLeadership` invoked during leadership monitoring may use autopilot to do promotions etc. There was a race with doing that and having autopilot initialized and this fixes it.
Given a query like:
```
{
"Name": "tagged-connect-query",
"Service": {
"Service": "foo",
"Tags": ["tag"],
"Connect": true
}
}
```
And a Consul configuration like:
```
{
"services": [
"name": "foo",
"port": 8080,
"connect": { "sidecar_service": {} },
"tags": ["tag"]
]
}
```
If you executed the query it would always turn up with 0 results. This was because the sidecar service was being created without any tags. You could instead make your config look like:
```
{
"services": [
"name": "foo",
"port": 8080,
"connect": { "sidecar_service": {
"tags": ["tag"]
} },
"tags": ["tag"]
]
}
```
However that is a bit redundant for most cases. This PR ensures that the tags and service meta of the parent service get copied to the sidecar service. If there are any tags or service meta set in the sidecar service definition then this copying does not take place. After the changes, the query will now return the expected results.
A second change was made to prepared queries in this PR which is to allow filtering on ServiceMeta just like we allow for filtering on NodeMeta.
When tests fail, only the logs for the failing run are dumped to the
console which helps in diagnosis. This is easily added to other test
scenarios as they come up.
* Fix 2 remote ACL policy resolution issues
1 - Use the right method to fire async not found errors when the ACL.PolicyResolve RPC returns that error. This was previously accidentally firing a token result instead of a policy result which would have effectively done nothing (unless there happened to be a token with a secret id == the policy id being resolved.
2. When concurrent policy resolution is being done we single flight the requests. The bug before was that for the policy resolution that was going to piggy back on anothers RPC results it wasn’t waiting long enough for the results to come back due to looping with the wrong variable.
* Fix a handful of other edge case ACL scenarios
The main issue was that token specific issues (not able to access a particular policy or the token being deleted after initial fetching) were poisoning the policy cache.
A second issue was that for concurrent token resolutions, the first resolution to get started would go fetch all the policies. If before the policies were retrieved a second resolution request came in, the new request would register watchers for those policies but then never block waiting for them to complete. This resulted in using the default policy when it shouldn't have.
* Support rate limiting and concurrency limiting CSR requests on servers; handle CA rotations gracefully with jitter and backoff-on-rate-limit in client
* Add CSR rate limiting docs
* Fix config naming and add tests for new CA configs
* Store leaf cert indexes in raft and use for the ModifyIndex on the returned certs
This ensures that future certificate signings will have a strictly greater ModifyIndex than any previous certs signed.
## Background
When making a blocking query on a missing service (was never registered, or is not registered anymore) the query returns as soon as any service is updated.
On clusters with frequent updates (5~10 updates/s in our DCs) these queries virtually do not block, and clients with no protections againt this waste ressources on the agent and server side. Clients that do protect against this get updates later than they should because of the backoff time they implement between requests.
## Implementation
While reducing the number of unnecessary updates we still want :
* Clients to be notified as soon as when the last instance of a service disapears.
* Clients to be notified whenever there's there is an update for the service.
* Clients to be notified as soon as the first instance of the requested service is added.
To reduce the number of unnecessary updates we need to block when a request to a missing service is made. However in the following case :
1. Client `client1` makes a query for service `foo`, gets back a node and X-Consul-Index 42
2. `foo` is unregistered
3. `client1` makes a query for `foo` with `index=42` -> `foo` does not exist, the query blocks and `client1` is not notified of the change on `foo`
We could store the last raft index when each service was last alive to know wether we should block on the incoming query or not, but that list could grow indefinetly.
We instead store the last raft index when a service was unregistered and use it when a query targets a service that does not exist.
When a service `srv` is unregistered this "missing service index" is always greater than any X-Consul-Index held by the clients while `srv` was up, allowing us to immediatly notify them.
1. Client `client1` makes a query for service `foo`, gets back a node and `X-Consul-Index: 42`
2. `foo` is unregistered, we set the "missing service index" to 43
3. `client1` makes a blocking query for `foo` with `index=42` -> `foo` does not exist, we check against the "missing service index" and return immediatly with `X-Consul-Index: 43`
4. `client1` makes a blocking query for `foo` with `index=43` -> we block
5. Other changes happen in the cluster, but foo still doesn't exist and "missing service index" hasn't changed, the query is still blocked
6. `foo` is registered again on index 62 -> `foo` exists and its index is greater than 43, we unblock the query
Fixes#4897
Also apparently token deletion could segfault in secondary DCs when attempting to delete non-existant tokens. For that reason both checks are wrapped within the non-nil check.
* Avoid to have infinite recursion in DNS lookups when resolving CNAMEs
This will avoid killing Consul when a Service.Address is using CNAME
to a Consul CNAME that creates an infinite recursion.
This will fix https://github.com/hashicorp/consul/issues/4907
* Use maxRecursionLevel = 3 to allow several recursions
* bugfix: use ServiceTags to generate cahce key hash
* update unit test
* update
* remote print log
* Update .gitignore
* Completely deprecate ServiceTag field internally for clarity
* Add explicit test for CacheInfo cases
Chris Piraino