Starting from and extending the mechanism introduced in #12110 we can specially handle the 3 main special Consul RPC endpoints that react to many config entries in a single blocking query in Connect:
- `DiscoveryChain.Get`
- `ConfigEntry.ResolveServiceConfig`
- `Intentions.Match`
All of these will internally watch for many config entries, and at least one of those will likely be not found in any given query. Because these are blends of multiple reads the exact solution from #12110 isn't perfectly aligned, but we can tweak the approach slightly and regain the utility of that mechanism.
### No Config Entries Found
In this case, despite looking for many config entries none may be found at all. Unlike #12110 in this scenario we do not return an empty reply to the caller, but instead synthesize a struct from default values to return. This can be handled nearly identically to #12110 with the first 1-2 replies being non-empty payloads followed by the standard spurious wakeup suppression mechanism from #12110.
### No Change Since Last Wakeup
Once a blocking query loop on the server has completed and slept at least once, there is a further optimization we can make here to detect if any of the config entries that were present at specific versions for the prior execution of the loop are identical for the loop we just woke up for. In that scenario we can return a slightly different internal sentinel error and basically externally handle it similar to #12110.
This would mean that even if 20 discovery chain read RPC handling goroutines wakeup due to the creation of an unrelated config entry, the only ones that will terminate and reply with a blob of data are those that genuinely have new data to report.
### Extra Endpoints
Since this pattern is pretty reusable, other key config-entry-adjacent endpoints used by `agent/proxycfg` also were updated:
- `ConfigEntry.List`
- `Internal.IntentionUpstreams` (tproxy)
Otherwise when the query times out we might incorrectly send a value for
the reply, when we should send an empty reply.
Also document errNotFound and how to handle the result in that case.
By using the query results as state.
Blocking queries are efficient when the query matches some results,
because the ModifyIndex of those results, returned as queryMeta.Mindex,
will never change unless the items themselves change.
Blocking queries for non-existent items are not efficient because the
queryMeta.Index can (and often does) change when other entities are
written.
This commit reduces the churn of these queries by using a different
comparison for "has changed". Instead of using the modified index, we
use the existence of the results. If the previous result was "not found"
and the new result is still "not found", we know we can ignore the
modified index and continue to block.
This is done by setting the minQueryIndex to the returned
queryMeta.Index, which prevents the query from returning before a state
change is observed.
This will both save on unnecessary raft operations as well as
unnecessarily incrementing the raft modify index of config entries
subject to no-op updates.
There are two restrictions:
- Writes from the primary DC which explicitly target a secondary DC.
- Writes to a secondary DC that do not explicitly target the primary DC.
The first restriction is because the config entry is not supported in
secondary datacenters.
The second restriction is to prevent the scenario where a user writes
the config entry to a secondary DC, the write gets forwarded to the
primary, but then the config entry does not apply in the secondary.
This makes the scope more explicit.
The prior solution to call reply.Reset() aged poorly since newer fields
were added to the reply, but not added to Reset() leading serial
blocking query loops on the server to blend replies.
This could manifest as a service-defaults protocol change from
default=>http not reverting back to default after the config entry
reponsible was deleted.
Also fixes a bug with listing kind=mesh config entries. ValidateConfigEntryKind was only being used by
the List endpoint, and was yet another place where we have to enumerate all the kinds.
This commit removes ValidateConfigEntryKind and uses MakeConfigEntry instead. This change removes
the need to maintain two separate functions at the cost of creating an instance of the config entry which will be thrown away immediately.
Previously we were inconsistently checking the response for errors. This
PR moves the response-is-error check into raftApply, so that all callers
can look at only the error response, instead of having to know that
errors could come from two places.
This should expose a few more errors that were previously hidden because
in some calls to raftApply we were ignoring the response return value.
Also handle errors more consistently. In some cases we would log the
error before returning it. This can be very confusing because it can
result in the same error being logged multiple times. Instead return
a wrapped error.
This PR replaces the original boolean used to configure transparent
proxy mode. It was replaced with a string mode that can be set to:
- "": Empty string is the default for when the setting should be
defaulted from other configuration like config entries.
- "direct": Direct mode is how applications originally opted into the
mesh. Proxy listeners need to be dialed directly.
- "transparent": Transparent mode enables configuring Envoy as a
transparent proxy. Traffic must be captured and redirected to the
inbound and outbound listeners.
This PR also adds a struct for transparent proxy specific configuration.
Initially this is not stored as a pointer. Will revisit that decision
before GA.
This is needed in case the client proxy is in TransparentProxy mode.
Typically they won't have explicit configuration for every upstream, so
this ensures the settings can be applied to all of them when generating
xDS config.
New clients in transparent proxy mode can send requests for service
config resolution without any upstream args because they do not have
explicitly defined upstreams.
Old clients on the other hand will never send requests without the
Upstreams args unless they don't have upstreams, in which case we do not
send back upstream config.
ResolveServiceConfig is called by service manager before the proxy
registration is in the catalog. Therefore we should pass proxy
registration flags in the request rather than trying to fetch
them from the state store (where they may not exist yet).
This is done because after removing ID and NodeName from
ServiceConfigRequest we will no longer know whether a request coming in
is for a Consul client earlier than v1.10.
- Upgrade the ConfigEntry.ListAll RPC to be kind-aware so that older
copies of consul will not see new config entries it doesn't understand
replicate down.
- Add shim conversion code so that the old API/CLI method of interacting
with intentions will continue to work so long as none of these are
edited via config entry endpoints. Almost all of the read-only APIs will
continue to function indefinitely.
- Add new APIs that operate on individual intentions without IDs so that
the UI doesn't need to implement CAS operations.
- Add a new serf feature flag indicating support for
intentions-as-config-entries.
- The old line-item intentions way of interacting with the state store
will transparently flip between the legacy memdb table and the config
entry representations so that readers will never see a hiccup during
migration where the results are incomplete. It uses a piece of system
metadata to control the flip.
- The primary datacenter will begin migrating intentions into config
entries on startup once all servers in the datacenter are on a version
of Consul with the intentions-as-config-entries feature flag. When it is
complete the old state store representations will be cleared. We also
record a piece of system metadata indicating this has occurred. We use
this metadata to skip ALL of this code the next time the leader starts
up.
- The secondary datacenters continue to run the old intentions
replicator until all servers in the secondary DC and primary DC support
intentions-as-config-entries (via serf flag). Once this condition it met
the old intentions replicator ceases.
- The secondary datacenters replicate the new config entries as they are
migrated in the primary. When they detect that the primary has zeroed
it's old state store table it waits until all config entries up to that
point are replicated and then zeroes its own copy of the old state store
table. We also record a piece of system metadata indicating this has
occurred. We use this metadata to skip ALL of this code the next time
the leader starts up.
* 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
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.
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.
R.B. Boyer