This commit implements support for creating driver mounts for CSI
Volumes.
It works by fetching the created mounts from the allocation resources
and then iterates through the volume requests, creating driver mount
configs as required.
It's a little bit messy primarily because there's _so_ much terminology
overlap and it's a bit difficult to follow.
This commit is an initial (read: janky) approach to forwarding state
from an allocrunner hook to a taskrunner using a similar `hookResources`
approach that tr's use internally.
It should eventually probably be replaced with something a little bit
more message based, but for things that only come from pre-run hooks,
and don't change, it's probably fine for now.
This commit introduces the first stage of volume mounting for an
allocation. The csimanager.VolumeMounter interface manages the blocking
and actual minutia of the CSI implementation allowing this hook to do
the minimal work of volume retrieval and creating mount info.
In the future the `CSIVolume.Get` request should be replaced by
`CSIVolume.Claim(Batch?)` to minimize the number of RPCs and to handle
external triggering of a ControllerPublishVolume request as required.
We also need to ensure that if pre-run hooks fail, we still get a full
unwinding of any publish and staged volumes to ensure that there are no hanging
references to volumes. That is not handled in this commit.
As part of introducing support for CSI, AllocRunner hooks need to be
able to communicate with Nomad Servers for validation of and interaction
with storage volumes. Here we create a small RPCer interface and pass
the client (rpc client) to the AR in preparation for making these RPCs.
This changeset implements the minimal structs on the client-side we
need to compile the work-in-progress implementation of the
server-to-controller RPCs. It doesn't include implementing the
`ClientCSI.DettachVolume` RPC on the client.
When providing paths to plugins, the path needs to be in the scope of
the plugins container, rather than that of the host.
Here we enable that by providing the mount point through the plugin
registration and then use it when constructing request target paths.
This commit introduces support for staging volumes when a plugin
implements the STAGE_UNSTAGE_VOLUME capability.
See the following for further reference material:
4731db0e0b/spec.md (nodestagevolume)
This commit adds helpers that create and validate the staging directory
for a given volume. It is currently missing usage options as the
interfaces are not yet in place for those.
The staging directory is only required when a volume has the
STAGE_UNSTAGE Volume capability and has to live within the plugin root
as the plugin needs to be able to create mounts inside it from within
the container.
This changeset is some pre-requisite boilerplate that is required for
introducing CSI volume management for client nodes.
It extracts out fingerprinting logic from the csi instance manager.
This change is to facilitate reusing the csimanager to also manage the
node-local CSI functionality, as it is the easiest place for us to
guaruntee health checking and to provide additional visibility into the
running operations through the fingerprinter mechanism and goroutine.
It also introduces the VolumeMounter interface that will be used to
manage staging/publishing unstaging/unpublishing of volumes on the host.
This commit introduces a new set of endpoints to a Nomad Client:
ClientCSI.
ClientCSI is responsible for mediating requests from a Nomad Server to
a CSI Plugin running on a Nomad Client. It should only really be used to
make controller RPCs.
This changeset implements the initial registration and fingerprinting
of CSI Plugins as part of #5378. At a high level, it introduces the
following:
* A `csi_plugin` stanza as part of a Nomad task configuration, to
allow a task to expose that it is a plugin.
* A new task runner hook: `csi_plugin_supervisor`. This hook does two
things. When the `csi_plugin` stanza is detected, it will
automatically configure the plugin task to receive bidirectional
mounts to the CSI intermediary directory. At runtime, it will then
perform an initial heartbeat of the plugin and handle submitting it to
the new `dynamicplugins.Registry` for further use by the client, and
then run a lightweight heartbeat loop that will emit task events
when health changes.
* The `dynamicplugins.Registry` for handling plugins that run
as Nomad tasks, in contrast to the existing catalog that requires
`go-plugin` type plugins and to know the plugin configuration in
advance.
* The `csimanager` which fingerprints CSI plugins, in a similar way to
`drivermanager` and `devicemanager`. It currently only fingerprints
the NodeID from the plugin, and assumes that all plugins are
monolithic.
Missing features
* We do not use the live updates of the `dynamicplugin` registry in
the `csimanager` yet.
* We do not deregister the plugins from the client when they shutdown
yet, they just become indefinitely marked as unhealthy. This is
deliberate until we figure out how we should manage deploying new
versions of plugins/transitioning them.
allow oss to parse sink duration
clean up audit sink parsing
ent eventer config reload
fix typo
SetEnabled to eventer interface
client acl test
rm dead code
fix failing test
In service jobs, lifecycles non-sidecar task tweak health logic a bit:
they may terminate successfully without impacting alloc health, but fail
the alloc if they fail.
Sidecars should be treated just like a normal task.
Fixes a bug where an allocation is considered healthy if some of the
tasks are being restarted and as such, their checks aren't tracked by
consul agent client.
Here, we fix the immediate case by ensuring that an alloc is healthy
only if tasks are running and the registered checks at the time are
healthy.
Previously, health tracker tracked task "health" independently from
checks and leads to problems when a task restarts. Consider the
following series of events:
1. all tasks start running -> `tracker.tasksHealthy` is true
2. one task has unhealthy checks and get restarted
3. remaining checks are healthy -> `tracker.checksHealthy` is true
4. propagate health status now that `tracker.tasksHealthy` and
`tracker.checksHealthy`.
This change ensures that we accurately use the latest status of tasks
and checks regardless of their status changes.
Also, ensures that we only consider check health after tasks are
considered healthy, otherwise we risk trusting incomplete checks.
This approach accomodates task dependencies well. Service jobs can have
prestart short-lived tasks that will terminate before main process runs.
These dead tasks that complete successfully will not negate health
status.
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.
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
Re-orient the management of the tr.kill to happen in the parent of
the spawned goroutine that is doing the actual token derivation. This
makes the code a little more straightforward, making it easier to
reason about not leaking the worker goroutine.
The derivation of an SI token needs to be safegaurded by a context
timeout, otherwise an unresponsive Consul could cause the siHook
to block forever on Prestart.
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>
The TestEnvoyBootstrapHook_maybeLoadSIToken test case only works when
running as a non-priveleged user, since it deliberately tries to read
an un-readable file to simulate a failure loading the SI token file.
Was thinking about using the testing pattern where you create executable
shell scripts as test resources which "mock" the process a bit of code
is meant to fork+exec. Turns out that wasn't really necessary in this case.
When creating the envoy bootstrap configuration, we should append
the "-token=<token>" argument in the case where the sidsHook placed
the token in the secrets directory.
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.
There is a case for always canonicalizing alloc.Job field when
canonicalizing the alloc. I'm less certain of implications though, and
the job canonicalize hasn't changed for a long time.
Here, we special case client restore from database as it's probably the
most relevant part. When receiving an alloc from RPC, the data should
be fresh enough.
