In certain task lifecycles the taskrunner service deregister call
could be called three times for a task that is exiting. Whilst
each hook caller of deregister has its own purpose, we should try
and ensure it is only called once during the shutdown lifecycle of
a task.
This change therefore tracks when deregister has been called, so
that subsequent calls are noop. In the event the task is
restarting, the deregister value is reset to ensure proper
operation.
Update the logic in the Nomad client's alloc health tracker which
erroneously marks existing healthy allocations with dead poststart ephemeral
tasks as unhealthy even if they were already successful during a previous
deployment.
This PR replaces use of time.After with a safe helper function
that creates a time.Timer to use instead. The new function returns
both a time.Timer and a Stop function that the caller must handle.
Unlike time.NewTimer, the helper function does not panic if the duration
set is <= 0.
Previously we copied this library by hand to avoid vendor-ing a bunch of
files related to minimock. Now that we no longer vendor, just import the
library normally.
Also we might use more of the library for handling `time.After` uses,
for which this library provides a Context-based solution.
When an allocation stops, the `csi_hook` makes an unpublish RPC to the
servers to unpublish via the CSI RPCs: first to the node plugins and
then the controller plugins. The controller RPCs must happen after the
node RPCs so that the node has had a chance to unmount the volume
before the controller tries to detach the associated device.
But the client has local access to the node plugins and can
independently determine if it's safe to send unpublish RPC to those
plugins. This will allow the server to treat the node plugin as
abandoned if a client is disconnected and `stop_on_client_disconnect`
is set. This will let the server try to send unpublish RPCs to the
controller plugins, under the assumption that the client will be
trying to unmount the volume on its end first.
Note that the CSI `NodeUnpublishVolume`/`NodeUnstageVolume` RPCs can
return ignorable errors in the case where the volume has already been
unmounted from the node. Handle all other errors by retrying until we
get success so as to give operators the opportunity to reschedule a
failed node plugin (ex. in the case where they accidentally drained a
node without `-ignore-system`). Fan-out the work for each volume into
its own goroutine so that we can release a subset of volumes if only
one is stuck.
This PR tweaks the TestCpusetManager_AddAlloc unit test to not break
when being run on a machine using cgroupsv2. The behavior of writing
an empty cpuset.cpu changes in cgroupv2, where such a group now inherits
the value of its parent group, rather than remaining empty.
The test in question was written such that a task would consume all available
cores shared on an alloc, causing the empty set to be written to the shared
group, which works fine on cgroupsv1 but breaks on cgroupsv2. By adjusting
the test to consume only 1 core instead of all cores, it no longer triggers
that edge case.
The actual fix for the new cgroupsv2 behavior will be in #11933
Templates in nomad jobs make use of the vault token defined in
the vault stanza when issuing credentials like client certificates.
When using change_mode "noop" in the vault stanza, consul-template
is not informed in case a vault token is re-issued (which can
happen from time to time for various reasons, as described
in https://www.nomadproject.io/docs/job-specification/vault).
As a result, consul-template will keep using the old vault token
to renew credentials and - once the token expired - stop renewing
credentials. The symptom of this problem is a vault_token
file that is newer than the issued credential (e.g., TLS certificate)
in a job's /secrets directory.
This change corrects this, so that h.updater.updatedVaultToken(token)
is called, which will inform stakeholders about the new
token and make sure, the new token is used by consul-template.
Example job template fragment:
vault {
policies = ["nomad-job-policy"]
change_mode = "noop"
}
template {
data = <<-EOH
{{ with secret "pki_int/issue/nomad-job"
"common_name=myjob.service.consul" "ttl=90m"
"alt_names=localhost" "ip_sans=127.0.0.1"}}
{{ .Data.certificate }}
{{ .Data.private_key }}
{{ .Data.issuing_ca }}
{{ end }}
EOH
destination = "${NOMAD_SECRETS_DIR}/myjob.crt"
change_mode = "noop"
}
This fix does not alter the meaning of the three change modes of vault
- "noop" - Take no action
- "restart" - Restart the job
- "signal" - send a signal to the task
as the switch statement following line 232 contains the necessary
logic.
It is assumed that "take no action" was never meant to mean "don't tell
consul-template about the new vault token".
Successfully tested in a staging cluster consisting of multiple
nomad client nodes.
This PR exposes the following existing`consul-template` configuration options to Nomad jobspec authors in the `{job.group.task.template}` stanza.
- `wait`
It also exposes the following`consul-template` configuration to Nomad operators in the `{client.template}` stanza.
- `max_stale`
- `block_query_wait`
- `consul_retry`
- `vault_retry`
- `wait`
Finally, it adds the following new Nomad-specific configuration to the `{client.template}` stanza that allows Operators to set bounds on what `jobspec` authors configure.
- `wait_bounds`
Co-authored-by: Tim Gross <tgross@hashicorp.com>
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
The task runner prestart hooks take a `joincontext` so they have the
option to exit early if either of two contexts are canceled: from
killing the task or client shutdown. Some tasks exit without being
shutdown from the server, so neither of the joined contexts ever gets
canceled and we leak the `joincontext` (48 bytes) and its internal
goroutine. This primarily impacts batch jobs and any task that fails
or completes early such as non-sidecar prestart lifecycle tasks.
Cancel the `joincontext` after the prestart call exits to fix the
leak.
Some operators use very long group/task `shutdown_delay` settings to
safely drain network connections to their workloads after service
deregistration. But during incident response, they may want to cause
that drain to be skipped so they can quickly shed load.
Provide a `-no-shutdown-delay` flag on the `nomad alloc stop` and
`nomad job stop` commands that bypasses the delay. This sets a new
desired transition state on the affected allocations that the
allocation/task runner will identify during pre-kill on the client.
Note (as documented here) that using this flag will almost always
result in failed inbound network connections for workloads as the
tasks will exit before clients receive updated service discovery
information and won't be gracefully drained.
The `consul.client_auto_join` configuration block tells the Nomad
client whether to use Consul service discovery to find Nomad
servers. By default it is set to `true`, but contrary to the
documentation it was only respected during the initial client
registration. If a client missed a heartbeat, failed a
`Node.UpdateStatus` RPC, or if there was no Nomad leader, the client
would fallback to Consul even if `client_auto_join` was set to
`false`. This changeset returns early from the client's trigger for
Consul discovery if the `client_auto_join` field is set to `false`.
* debug: refactor Consul API collection
* debug: refactor Vault API collection
* debug: cleanup test timing
* debug: extend test to multiregion
* debug: save cmdline flags in bundle
* debug: add cli version to output
* Add changelog entry
Enhance the CLI in order to return the host network in two flavors
(default, verbose) of the `node status` command.
Fixes: #11223.
Signed-off-by: Alessandro De Blasis <alex@deblasis.net>
Fixes#2522
Skip embedding client.alloc_dir when building chroot. If a user
configures a Nomad client agent so that the chroot_env will embed the
client.alloc_dir, Nomad will happily infinitely recurse while building
the chroot until something horrible happens. The best case scenario is
the filesystem's path length limit is hit. The worst case scenario is
disk space is exhausted.
A bad agent configuration will look something like this:
```hcl
data_dir = "/tmp/nomad-badagent"
client {
enabled = true
chroot_env {
# Note that the source matches the data_dir
"/tmp/nomad-badagent" = "/ohno"
# ...
}
}
```
Note that `/ohno/client` (the state_dir) will still be created but not
`/ohno/alloc` (the alloc_dir).
While I cannot think of a good reason why someone would want to embed
Nomad's client (and possibly server) directories in chroots, there
should be no cause for harm. chroots are only built when Nomad runs as
root, and Nomad disables running exec jobs as root by default. Therefore
even if client state is copied into chroots, it will be inaccessible to
tasks.
Skipping the `data_dir` and `{client,server}.state_dir` is possible, but
this PR attempts to implement the minimum viable solution to reduce risk
of unintended side effects or bugs.
When running tests as root in a vm without the fix, the following error
occurs:
```
=== RUN TestAllocDir_SkipAllocDir
alloc_dir_test.go:520:
Error Trace: alloc_dir_test.go:520
Error: Received unexpected error:
Couldn't create destination file /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/testtask/nomad/test/testtask/.../nomad/test/testtask/secrets/.nomad-mount: open /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/.../testtask/secrets/.nomad-mount: file name too long
Test: TestAllocDir_SkipAllocDir
--- FAIL: TestAllocDir_SkipAllocDir (22.76s)
```
Also removed unused Copy methods on AllocDir and TaskDir structs.
Thanks to @eveld for not letting me forget about this!
We see this error all the time
```
no handler registered for event
event.Message=, event.Annotations=, event.Timestamp=0001-01-01T00:00:00Z, event.TaskName=, event.AllocID=, event.TaskID=,
```
So we're handling an even with all default fields. I noted that this can
happen if only err is set as in
```
func (d *driverPluginClient) handleTaskEvents(reqCtx context.Context, ch chan *TaskEvent, stream proto.Driver_TaskEventsClient) {
defer close(ch)
for {
ev, err := stream.Recv()
if err != nil {
if err != io.EOF {
ch <- &TaskEvent{
Err: grpcutils.HandleReqCtxGrpcErr(err, reqCtx, d.doneCtx),
}
}
```
In this case Err fails to be serialized by the logger, see this test
```
ev := &drivers.TaskEvent{
Err: fmt.Errorf("errz"),
}
i.logger.Warn("ben test", "event", ev)
i.logger.Warn("ben test2", "event err str", ev.Err.Error())
i.logger.Warn("ben test3", "event err", ev.Err)
ev.Err = nil
i.logger.Warn("ben test4", "nil error", ev.Err)
2021-10-06T22:37:56.736Z INFO nomad.stdout {"@level":"warn","@message":"ben test","@module":"client.driver_mgr","@timestamp":"2021-10-06T22:37:56.643900Z","driver":"mock_driver","event":{"TaskID":"","TaskName":"","AllocID":"","Timestamp":"0001-01-01T00:00:00Z","Message":"","Annotations":null,"Err":{}}}
2021-10-06T22:37:56.736Z INFO nomad.stdout {"@level":"warn","@message":"ben test2","@module":"client.driver_mgr","@timestamp":"2021-10-06T22:37:56.644226Z","driver":"mock_driver","event err str":"errz"}
2021-10-06T22:37:56.736Z INFO nomad.stdout {"@level":"warn","@message":"ben test3","@module":"client.driver_mgr","@timestamp":"2021-10-06T22:37:56.644240Z","driver":"mock_driver","event err":"errz"}
2021-10-06T22:37:56.736Z INFO nomad.stdout {"@level":"warn","@message":"ben test4","@module":"client.driver_mgr","@timestamp":"2021-10-06T22:37:56.644252Z","driver":"mock_driver","nil error":null}
```
Note in the first example err is set to an empty object and the error is
lost.
What we want is the last two examples which call out the err field
explicitly so we can see what it is in this case
Fix a logmon leak causing high goroutine and memory usage when a task
restarts.
Logmon `FileRotator` buffers the task stdout/stderr streams and
periodically flushing them to log files. Logmon creates a new
FileRotator for each stream for each task run. However, the
`flushPeriodically` goroutine is leaked when a task restarts,
holding a reference to a no-longer-needed `FileRotator` instance
along with its 64kb buffer.
The cause is that the code assumed `time.Ticker.Stop()` closes the
ticker channel, thereby terminating the goroutine, but the documentation
says otherwise:
> Stop turns off a ticker. After Stop, no more ticks will be sent. Stop does not close the channel, to prevent a concurrent goroutine reading from the channel from seeing an erroneous "tick".
https://pkg.go.dev/time#Ticker.Stop
