Fix some docstring typos and fix noisy log message during client restarts.
A log for the common case where the plugin socket isn't ready yet
isn't actionable by the operator so having it at info is just noise.
* client/allocrunner/csi_hook: tag errors
* nomad/client_csi_endpoint: tag errors
* nomad/client_rpc: remove an unnecessary error tag
* nomad/state/state_store: ControllerRequired fix intent
We use ControllerRequired to indicate that a volume should use the
publish/unpublish workflow, rather than that it has a controller. We
need to check both RequiresControllerPlugin and SupportsAttachDetach
from the fingerprint to check that.
* nomad/csi_endpoint: tag errors
* nomad/csi_endpoint_test: longer error messages, mock fingerprints
Derive a provider name and version for plugins (and the volumes that
use them) from the CSI identity API `GetPluginInfo`. Expose the vendor
name as `Provider` in the API and CLI commands.
* structs: CSIInfo include AllocID, CSIPlugins no Jobs
* state_store: eliminate plugin Jobs, delete an empty plugin
* nomad/structs/csi: detect empty plugins correctly
* client/allocrunner/taskrunner/plugin_supervisor_hook: option AllocID
* client/pluginmanager/csimanager/instance: allocID
* client/pluginmanager/csimanager/fingerprint: set AllocID
* client/node_updater: split controller and node plugins
* api/csi: remove Jobs
The CSI Plugin API will map plugins to allocations, which allows
plugins to be defined by jobs in many configurations. In particular,
multiple plugins can be defined in the same job, and multiple jobs can
be used to define a single plugin.
Because we now map the allocation context directly from the node, it's
no longer necessary to track the jobs associated with a plugin
directly.
* nomad/csi_endpoint_test: CreateTestPlugin & register via fingerprint
* client/dynamicplugins: lift AllocID into the struct from Options
* api/csi_test: remove Jobs test
* nomad/structs/csi: CSIPlugins has an array of allocs
* nomad/state/state_store: implement CSIPluginDenormalize
* nomad/state/state_store: CSIPluginDenormalize npe on missing alloc
* nomad/csi_endpoint_test: defer deleteNodes for clarity
* api/csi_test: disable this test awaiting mocks:
https://github.com/hashicorp/nomad/issues/7123
CSI Plugins that manage devices need not just access to the CSI
directory, but also to manage devices inside `/dev`.
This commit introduces a `/dev:/dev` mount to the container so that they
may do so.
This commit is the initial implementation of claiming volumes from the
server and passes through any publishContext information as appropriate.
There's nothing too fancy here.
The CSI Spec requires us to attach and stage volumes based on different
types of usage information when it may effect how they are bound. Here
we pass through some basic usage options in the CSI Hook (specifically
the volume aliases ReadOnly field), and the attachment/access mode from
the volume. We pass the attachment/access mode seperately from the
volume as it simplifies some handling and doesn't necessarily force
every attachment to use the same mode should more be supported (I.e if
we let each `volume "foo" {}` specify an override in the future).
This commit introduces initial support for unmounting csi volumes.
It takes a relatively simplistic approach to performing
NodeUnpublishVolume calls, optimising for cleaning up any leftover state
rather than terminating early in the case of errors.
This is because it happens during an allocation's shutdown flow and may
not always have a corresponding call to `NodePublishVolume` that
succeeded.
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.
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 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 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.
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
