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.
Now that alloc.Canonicalize() is called in all alloc sources in the
client (i.e. on state restore and RPC fetching), we no longer need to
check alloc.TaskResources.
alloc.AllocatedResources is always non-nil through alloc runner.
Though, early on, we check for alloc validity, so NewTaskRunner and
TaskEnv must still check. `TestClient_AddAllocError` test validates
that behavior.
In 0.10.2 (specifically 387b016) we added interpolation to group
service blocks and centralized the logic for task environment
interpolation. This wasn't also added to script checks, which caused a
regression where the IDs for script checks for services w/
interpolated fields (ex. the service name) didn't match the service ID
that was registered with Consul.
This changeset calls the same taskenv interpolation logic during
`script_check` configuration, and adds tests to reduce the risk of
future regressions by comparing the IDs of service hook and the check hook.
Operators commonly have docker logs aggregated using various tools and
don't need nomad to manage their docker logs. Worse, Nomad uses a
somewhat heavy docker api call to collect them and it seems to cause
problems when a client runs hundreds of log collections.
Here we add a knob to disable log aggregation completely for nomad.
When log collection is disabled, we avoid running logmon and
docker_logger for the docker tasks in this implementation.
The downside here is once disabled, `nomad logs ...` commands and API
no longer return logs and operators must corrolate alloc-ids with their
aggregated log info.
This is meant as a stop gap measure. Ideally, we'd follow up with at
least two changes:
First, we should optimize behavior when we can such that operators don't
need to disable docker log collection. Potentially by reverting to
using pre-0.9 syslog aggregation in linux environments, though with
different trade-offs.
Second, when/if logs are disabled, nomad logs endpoints should lookup
docker logs api on demand. This ensures that the cost of log collection
is paid sparingly.
* client: improve group service stanza interpolation and check_restart support
Interpolation can now be done on group service stanzas. Note that some task runtime specific information
that was previously available when the service was registered poststart of a task is no longer available.
The check_restart stanza for checks defined on group services will now properly restart the allocation upon
check failures if configured.
makeAllocTaskServices did not do a nil check on AllocatedResources
which causes a panic when upgrading directly from 0.8 to 0.10. While
skipping 0.9 is not supported we intend to fix serious crashers caused
by such upgrades to prevent cluster outages.
I did a quick audit of the client package and everywhere else that
accesses AllocatedResources appears to be properly guarded by a nil
check.
fixes https://github.com/hashicorp/nomad/issues/6382
The prestart hook for templates blocks while it resolves vault secrets.
If the secret is not found it continues to retry. If a task is shutdown
during this time, the prestart hook currently does not receive
shutdownCtxCancel, causing it to hang.
This PR joins the two contexts so either killCtx or shutdownCtx cancel
and stop the task.
Currently, there is an issue when running on Windows whereby under some
circumstances the Windows stats API's will begin to return errors (such
as internal timeouts) when a client is under high load, and potentially
other forms of resource contention / system states (and other unknown
cases).
When an error occurs during this collection, we then short circuit
further metrics emission from the client until the next interval.
This can be problematic if it happens for a sustained number of
intervals, as our metrics aggregator will begin to age out older
metrics, and we will eventually stop emitting various types of metrics
including `nomad.client.unallocated.*` metrics.
However, when metrics collection fails on Linux, gopsutil will in many cases
(e.g cpu.Times) silently return 0 values, rather than an error.
Here, we switch to returning empty metrics in these failures, and
logging the error at the source. This brings the behaviour into line
with Linux/Unix platforms, and although making aggregation a little
sadder on intermittent failures, will result in more desireable overall
behaviour of keeping metrics available for further investigation if
things look unusual.
Currently, using a Volume in a job uses the following configuration:
```
volume "alias-name" {
type = "volume-type"
read_only = true
config {
source = "host_volume_name"
}
}
```
This commit migrates to the following:
```
volume "alias-name" {
type = "volume-type"
source = "host_volume_name"
read_only = true
}
```
The original design was based due to being uncertain about the future of storage
plugins, and to allow maxium flexibility.
However, this causes a few issues, namely:
- We frequently need to parse this configuration during submission,
scheduling, and mounting
- It complicates the configuration from and end users perspective
- It complicates the ability to do validation
As we understand the problem space of CSI a little more, it has become
clear that we won't need the `source` to be in config, as it will be
used in the majority of cases:
- Host Volumes: Always need a source
- Preallocated CSI Volumes: Always needs a source from a volume or claim name
- Dynamic Persistent CSI Volumes*: Always needs a source to attach the volumes
to for managing upgrades and to avoid dangling.
- Dynamic Ephemeral CSI Volumes*: Less thought out, but `source` will probably point
to the plugin name, and a `config` block will
allow you to pass meta to the plugin. Or will
point to a pre-configured ephemeral config.
*If implemented
The new design simplifies this by merging the source into the volume
stanza to solve the above issues with usability, performance, and error
handling.
Splitting the immutable and mutable components of the scriptCheck led
to a bug where the environment interpolation wasn't being incorporated
into the check's ID, which caused the UpdateTTL to update for a check
ID that Consul didn't have (because our Consul client creates the ID
from the structs.ServiceCheck each time we update).
Task group services don't have access to a task environment at
creation, so their checks get registered before the check can be
interpolated. Use the original check ID so they can be updated.
In Nomad prior to Consul Connect, all Consul checks work the same
except for Script checks. Because the Task being checked is running in
its own container namespaces, the check is executed by Nomad in the
Task's context. If the Script check passes, Nomad uses the TTL check
feature of Consul to update the check status. This means in order to
run a Script check, we need to know what Task to execute it in.
To support Consul Connect, we need Group Services, and these need to
be registered in Consul along with their checks. We could push the
Service down into the Task, but this doesn't work if someone wants to
associate a service with a task's ports, but do script checks in
another task in the allocation.
Because Nomad is handling the Script check and not Consul anyways,
this moves the script check handling into the task runner so that the
task runner can own the script check's configuration and
lifecycle. This will allow us to pass the group service check
configuration down into a task without associating the service itself
with the task.
When tasks are checked for script checks, we walk back through their
task group to see if there are script checks associated with the
task. If so, we'll spin off script check tasklets for them. The
group-level service and any restart behaviors it needs are entirely
encapsulated within the group service hook.
* connect: add unix socket to proxy grpc for envoy
Fixes#6124
Implement a L4 proxy from a unix socket inside a network namespace to
Consul's gRPC endpoint on the host. This allows Envoy to connect to
Consul's xDS configuration API.
* connect: pointer receiver on structs with mutexes
* connect: warn on all proxy errors
* adds meta object to service in job spec, sends it to consul
* adds tests for service meta
* fix tests
* adds docs
* better hashing for service meta, use helper for copying meta when registering service
* tried to be DRY, but looks like it would be more work to use the
helper function
Fixes#6041
Unlike all other Consul operations, boostrapping requires Consul be
available. This PR tries Consul 3 times with a backoff to account for
the group services being asynchronously registered with Consul.
When rendering a task template, the `plugin` function is no longer
permitted by default and will raise an error. An operator can opt-in
to permitting this function with the new `template.function_blacklist`
field in the client configuration.
When rendering a task template, path parameters for the `file`
function will be treated as relative to the task directory by
default. Relative paths or symlinks that point outside the task
directory will raise an error. An operator can opt-out of this
protection with the new `template.disable_file_sandbox` field in the
client configuration.
When rendering a task consul template, ensure that only task environment
variables are used.
Currently, `consul-template` always falls back to host process
environment variables when key isn't a task env var[1]. Thus, we add
an empty entry for each host process env-var not found in task env-vars.
[1] bfa5d0e133/template/funcs.go (L61-L75)
