This change updates tests to honor `BootstrapExpect` exclusively when
forming test clusters and removes test only knobs, e.g.
`config.DevDisableBootstrap`.
Background:
Test cluster creation is fragile. Test servers don't follow the
BootstapExpected route like production clusters. Instead they start as
single node clusters and then get rejoin and may risk causing brain
split or other test flakiness.
The test framework expose few knobs to control those (e.g.
`config.DevDisableBootstrap` and `config.Bootstrap`) that control
whether a server should bootstrap the cluster. These flags are
confusing and it's unclear when to use: their usage in multi-node
cluster isn't properly documented. Furthermore, they have some bad
side-effects as they don't control Raft library: If
`config.DevDisableBootstrap` is true, the test server may not
immediately attempt to bootstrap a cluster, but after an election
timeout (~50ms), Raft may force a leadership election and win it (with
only one vote) and cause a split brain.
The knobs are also confusing as Bootstrap is an overloaded term. In
BootstrapExpect, we refer to bootstrapping the cluster only after N
servers are connected. But in tests and the knobs above, it refers to
whether the server is a single node cluster and shouldn't wait for any
other server.
Changes:
This commit makes two changes:
First, it relies on `BootstrapExpected` instead of `Bootstrap` and/or
`DevMode` flags. This change is relatively trivial.
Introduce a `Bootstrapped` flag to track if the cluster is bootstrapped.
This allows us to keep `BootstrapExpected` immutable. Previously, the
flag was a config value but it gets set to 0 after cluster bootstrap
completes.
Fix a bug where consul service definitions would not be updated if changes
were made to the service in the Nomad job. Currently this only fixes the
bug for cases where the fix is a matter of updating consul agent's service
registration. There is related bug where destructive changes are required
(see #6877) which will be fixed in another PR.
The enable_tag_override configuration setting for the parent service is
applied to the sidecar service.
Fixes#6459
Consul CLI uses CONSUL_HTTP_TOKEN, so Nomad should use the same.
Note that consul-template uses CONSUL_TOKEN, which Nomad also uses,
so be careful to preserve any reference to that in the consul-template
context.
Consul provides a feature of Service Definitions where the tags
associated with a service can be modified through the Catalog API,
overriding the value(s) configured in the agent's service configuration.
To enable this feature, the flag enable_tag_override must be configured
in the service definition.
Previously, Nomad did not allow configuring this flag, and thus the default
value of false was used. Now, it is configurable.
Because Nomad itself acts as a state machine around the the service definitions
of the tasks it manages, it's worth describing what happens when this feature
is enabled and why.
Consider the basic case where there is no Nomad, and your service is provided
to consul as a boring JSON file. The ultimate source of truth for the definition
of that service is the file, and is stored in the agent. Later, Consul performs
"anti-entropy" which synchronizes the Catalog (stored only the leaders). Then
with enable_tag_override=true, the tags field is available for "external"
modification through the Catalog API (rather than directly configuring the
service definition file, or using the Agent API). The important observation
is that if the service definition ever changes (i.e. the file is changed &
config reloaded OR the Agent API is used to modify the service), those
"external" tag values are thrown away, and the new service definition is
once again the source of truth.
In the Nomad case, Nomad itself is the source of truth over the Agent in
the same way the JSON file was the source of truth in the example above.
That means any time Nomad sets a new service definition, any externally
configured tags are going to be replaced. When does this happen? Only on
major lifecycle events, for example when a task is modified because of an
updated job spec from the 'nomad job run <existing>' command. Otherwise,
Nomad's periodic re-sync's with Consul will now no longer try to restore
the externally modified tag values (as long as enable_tag_override=true).
Fixes#2057
The default RPC addr was a global which is fine for normal runtime use
when it only has a single user.
However many tests modify it and cause races. Follow our convention of
returning defaults from funcs instead of using globals.
MultiplexV2 is a new connection multiplex header that supports multiplex both
RPC and streaming requests over the same Yamux connection.
MultiplexV2 was added in 0.8.0 as part of
https://github.com/hashicorp/nomad/pull/3892 . So Nomad 0.11 can expect it to
be supported. Though, some more rigorous testing is required before merging
this.
I want to call out some implementation details:
First, the current connection pool reuses the Yamux stream for multiple RPC calls,
and doesn't close them until an error is encountered. This commit doesn't
change it, and sets the `RpcNomad` byte only at stream creation.
Second, the StreamingRPC session gets closed by callers and cannot be reused.
Every StreamingRPC opens a new Yamux session.
This is from a merge conflict resolution that went the wrong direction.
I assumed the block had been added, but really it had been removed. Now,
it is removed once again.
Apply smaller suggestions like doc strings, variable names, etc.
Co-Authored-By: Nick Ethier <nethier@hashicorp.com>
Co-Authored-By: Michael Schurter <mschurter@hashicorp.com>
Nomad jobs may be configured with a TaskGroup which contains a Service
definition that is Consul Connect enabled. These service definitions end
up establishing a Consul Connect Proxy Task (e.g. envoy, by default). In
the case where Consul ACLs are enabled, a Service Identity token is required
for these tasks to run & connect, etc. This changeset enables the Nomad Server
to recieve RPC requests for the derivation of SI tokens on behalf of instances
of Consul Connect using Tasks. Those tokens are then relayed back to the
requesting Client, which then injects the tokens in the secrets directory of
the Task.
When a job is configured with Consul Connect aware tasks (i.e. sidecar),
the Nomad Client should be able to request from Consul (through Nomad Server)
Service Identity tokens specific to those tasks.
Enable any Server to lookup the unique ClusterID. If one has not been
generated, and this node is the leader, generate a UUID and attempt to
apply it through raft.
The value is not yet used anywhere in this changeset, but is a prerequisite
for gh-6701.
This change provides an initial pass at setting up the configuration necessary to
enable use of Connect with Consul ACLs. Operators will be able to pass in a Consul
Token through `-consul-token` or `$CONSUL_TOKEN` in the `job run` and `job revert`
commands (similar to Vault tokens).
These values are not actually used yet in this changeset.
Introduce limits to prevent unauthorized users from exhausting all
ephemeral ports on agents:
* `{https,rpc}_handshake_timeout`
* `{http,rpc}_max_conns_per_client`
The handshake timeout closes connections that have not completed the TLS
handshake by the deadline (5s by default). For RPC connections this
timeout also separately applies to first byte being read so RPC
connections with TLS enabled have `rpc_handshake_time * 2` as their
deadline.
The connection limit per client prevents a single remote TCP peer from
exhausting all ephemeral ports. The default is 100, but can be lowered
to a minimum of 26. Since streaming RPC connections create a new TCP
connection (until MultiplexV2 is used), 20 connections are reserved for
Raft and non-streaming RPCs to prevent connection exhaustion due to
streaming RPCs.
All limits are configurable and may be disabled by setting them to `0`.
This also includes a fix that closes connections that attempt to create
TLS RPC connections recursively. While only users with valid mTLS
certificates could perform such an operation, it was added as a
safeguard to prevent programming errors before they could cause resource
exhaustion.
Allows addressing servers with nomad monitor using the servers name or
ID.
Also unifies logic for addressing servers for client_agent_endpoint
commands and makes addressing logic region aware.
rpc getServer test
Fixes a deadlock in leadership handling if leadership flapped.
Raft propagates leadership transition to Nomad through a NotifyCh channel.
Raft blocks when writing to this channel, so channel must be buffered or
aggressively consumed[1]. Otherwise, Raft blocks indefinitely in `raft.runLeader`
until the channel is consumed[1] and does not move on to executing follower
related logic (in `raft.runFollower`).
While Raft `runLeader` defer function blocks, raft cannot process any other
raft operations. For example, `run{Leader|Follower}` methods consume
`raft.applyCh`, and while runLeader defer is blocked, all raft log applications
or config lookup will block indefinitely.
Sadly, `leaderLoop` and `establishLeader` makes few Raft calls!
`establishLeader` attempts to auto-create autopilot/scheduler config [3]; and
`leaderLoop` attempts to check raft configuration [4]. All of these calls occur
without a timeout.
Thus, if leadership flapped quickly while `leaderLoop/establishLeadership` is
invoked and hit any of these Raft calls, Raft handler _deadlock_ forever.
Depending on how many times it flapped and where exactly we get stuck, I suspect
it's possible to get in the following case:
* Agent metrics/stats http and RPC calls hang as they check raft.Configurations
* raft.State remains in Leader state, and server attempts to handle RPC calls
(e.g. node/alloc updates) and these hang as well
As we create goroutines per RPC call, the number of goroutines grow over time
and may trigger a out of memory errors in addition to missed updates.
[1] d90d6d6bda/config.go (L190-L193)
[2] d90d6d6bda/raft.go (L425-L436)
[3] 2a89e47746/nomad/leader.go (L198-L202)
[4] 2a89e47746/nomad/leader.go (L877)
Passes in agent enable_debug config to nomad server and client configs.
This allows for rpc endpoints to have more granular control if they
should be enabled or not in combination with ACLs.
enable debug on client test
This commit ensures that Alloc.AllocatedResources is properly populated
when read from persistence stores (namely Raft and client state store).
The alloc struct may have been written previously by an arbitrary old
version that may only populate Alloc.TaskResources.
When parsing a config file which had the consul.timeout param set,
Nomad was reporting an error causing startup to fail. This seems
to be caused by the HCL decoder interpreting the timeout type as
an int rather than a string. This is caused by the struct
TimeoutHCL param having a hcl key of timeout alongside a Timeout
struct param of type time.Duration (int). Ensuring the decoder
ignores the Timeout struct param ensure the decoder runs
correctly.
copy struct values
ensure groupserviceHook implements RunnerPreKillhook
run deregister first
test that shutdown times are delayed
move magic number into variable
Avoid logging in the `watch` function as much as possible, since
it is not waited on during a server shutdown. When the logger
logs after a test passes, it may or may not cause the testing
framework to panic.
More info in:
https://github.com/golang/go/issues/29388#issuecomment-453648436
Fixes#6853
Canonicalize jobs first before adding any sidecars. This fixes a bug
where sidecar tasks were added without interpolated names and broke
validation. Sidecar tasks must be canonicalized independently.
Also adds a group network to the mock connect job because it wasn't a
valid connect job before!
It has been decided we're going to live in a many core world.
Let's take advantage of that and parallelize these state store
tests which all run in memory and are largely CPU bound.
An unscientific benchmark demonstrating the improvement:
[mp state (master)] $ go test
PASS
ok github.com/hashicorp/nomad/nomad/state 5.162s
[mp state (f-parallelize-state-store-tests)] $ go test
PASS
ok github.com/hashicorp/nomad/nomad/state 1.527s
Copy the updated version of freeport (sdk/freeport), and tweak it for use
in Nomad tests. This means staying below port 10000 to avoid conflicts with
the lib/freeport that is still transitively used by the old version of
consul that we vendor. Also provide implementations to find ephemeral ports
of macOS and Windows environments.
Ports acquired through freeport are supposed to be returned to freeport,
which this change now also introduces. Many tests are modified to include
calls to a cleanup function for Server objects.
This should help quite a bit with some flakey tests, but not all of them.
Our port problems will not go away completely until we upgrade our vendor
version of consul. With Go modules, we'll probably do a 'replace' to swap
out other copies of freeport with the one now in 'nomad/helper/freeport'.
If ACL Request is unauthenticated, we should honor the anonymous token.
This PR makes few changes:
* `GetPolicy` endpoints may return policy if anonymous policy allows it,
or return permission denied otherwise.
* `ListPolicies` returns an empty policy list, or one with anonymous
policy if one exists.
Without this PR, the we return an incomprehensible error.
Before:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
acl token lookup failed: index error: UUID must be 36 characters
$ curl http://localhost:4646/v1/acl/policies; echo
acl token lookup failed: index error: UUID must be 36 characters
```
After:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
Permission denied
$ curl http://localhost:4646/v1/acl/policies; echo
[]
```
