* fingerprint: add node attr for reserverable cores
Add an attribute for the number of reservable CPU cores as they may
differ from the existing `cpu.numcores` due to client configuration or
OS support.
Hopefully clarifies some confusion in #14676
* add changelog
* num_reservable_cores -> reservablecores
The artifact getter uses the go-getter library to fetch files from
different sources. Any bug in this library that results in a panic can
cause the entire Nomad client to crash due to a single file download
attempt.
This change aims to guard against this types of crashes by recovering
from panics when the getter attempts to download an artifact. The
resulting panic is converted to an error that is stored as a task event
for operator visibility and the panic stack trace is logged to the
client's log.
Extension of #14673
Once Vault is initially fingerprinted, extend the period since changes
should be infrequent and the fingerprint is relatively expensive since
it is contacting a central Vault server.
Also move the period timer reset *after* the fingerprint. This is
similar to #9435 where the idea is to ensure the retry period starts
*after* the operation is attempted. 15s will be the *minimum* time
between fingerprints now instead of the *maximum* time between
fingerprints.
In the case of Vault fingerprinting, the original behavior might cause
the following:
1. Timer is reset to 15s
2. Fingerprint takes 16s
3. Timer has already elapsed so we immediately Fingerprint again
Even if fingerprinting Vault only takes a few seconds, that may very
well be due to excessive load and backing off our fingerprints is
desirable. The new bevahior ensures we always wait at least 15s between
fingerprint attempts and should allow some natural jittering based on
server load and network latency.
Clients periodically fingerprint Vault and Consul to ensure the server has
updated attributes in the client's fingerprint. If the client can't reach
Vault/Consul, the fingerprinter clears the attributes and requires a node
update. Although this seems like correct behavior so that we can detect
intentional removal of Vault/Consul access, it has two serious failure modes:
(1) If a local Consul agent is restarted to pick up configuration changes and the
client happens to fingerprint at that moment, the client will update its
fingerprint and result in evaluations for all its jobs and all the system jobs
in the cluster.
(2) If a client loses Vault connectivity, the same thing happens. But the
consequences are much worse in the Vault case because Vault is not run as a
local agent, so Vault connectivity failures are highly correlated across the
entire cluster. A 15 second Vault outage will cause a new `node-update`
evalution for every system job on the cluster times the number of nodes, plus
one `node-update` evaluation for every non-system job on each node. On large
clusters of 1000s of nodes, we've seen this create a large backlog of evaluations.
This changeset updates the fingerprinting behavior to keep the last fingerprint
if Consul or Vault queries fail. This prevents a storm of evaluations at the
cost of requiring a client restart if Consul or Vault is intentionally removed
from the client.
* cleanup: refactor MapStringStringSliceValueSet to be cleaner
* cleanup: replace SliceStringToSet with actual set
* cleanup: replace SliceStringSubset with real set
* cleanup: replace SliceStringContains with slices.Contains
* cleanup: remove unused function SliceStringHasPrefix
* cleanup: fixup StringHasPrefixInSlice doc string
* cleanup: refactor SliceSetDisjoint to use real set
* cleanup: replace CompareSliceSetString with SliceSetEq
* cleanup: replace CompareMapStringString with maps.Equal
* cleanup: replace CopyMapStringString with CopyMap
* cleanup: replace CopyMapStringInterface with CopyMap
* cleanup: fixup more CopyMapStringString and CopyMapStringInt
* cleanup: replace CopySliceString with slices.Clone
* cleanup: remove unused CopySliceInt
* cleanup: refactor CopyMapStringSliceString to be generic as CopyMapOfSlice
* cleanup: replace CopyMap with maps.Clone
* cleanup: run go mod tidy
The concurrent gate access test is flaky since it depends on the order
of operations of two concurrent goroutines. Despite the heavy bias
towards one of the results, it's still possible to end the execution
with a closed gate.
I believe this case was created to test an earlier implementation where
the gate state was stored and mutated internally, so the access had to
be protected by a lock. However, the final implementation changed this
approach to be only channel-based, so there is no need for this flaky
test anymore.
This PR implements support for check_restart for checks registered
in the Nomad service provider.
Unlike Consul, Nomad service checks never report a "warning" status,
and so the check_restart.ignore_warnings configuration is not valid
for Nomad service checks.
This PR refactors agent/consul/check_watcher into client/serviceregistration,
and abstracts away the Consul-specific check lookups.
In doing so we should be able to reuse the existing check watcher logic for
also watching NSD checks in a followup PR.
A chunk of consul/unit_test.go is removed - we'll cover that in e2e tests
in a follow PR if needed. In the long run I'd like to remove this whole file.
Running `make check` on macOS identifies some dead code because the code is used
only with the Linux build tag. Move this code into appropriately-tagged code
files.
When configuring Consul Service Mesh, it's sometimes necessary to
provide dynamic value that are only known to Nomad at runtime. By
interpolating configuration values (in addition to configuration keys),
user are able to pass these dynamic values to Consul from their Nomad
jobs.
Log lines which include an error should use the full term "error"
as the context key. This provides consistency across the codebase
and avoids a Go style which operators might not be aware of.
* Update Consul Template dep to support Nomad vars
* Remove `Peering` config for Consul Testservers
Upgrading to the 1.14 Consul SDK introduces and additional default
configuration—`Peering`—that is not compatible with versions of Consul
before v1.13.0. because Nomad tests against Consul v1.11.1, this
configuration has to be nil'ed out before passing it to the Consul
binary.
Neither the `os.Setenv` nor `t.Setenv` helper are safe to use in parallel tests
because environment variables are process-global. The stdlib panics if you try
to do this. Remove the `ci.Parallel()` call from all tests where we're setting
environment variables.
This PR refactors the cgroups v2 group kill code path to use the
cgroups.kill interface file for destroying the cgroup. Previously
we copied the freeze + sigkill + unfreeze pattern from the v1 code,
but v2 provides a more efficient and more race-free way to handle
this.
Closes#14371
This PR refactors the code path in Client startup for setting up the cpuset
cgroup manager (non-linux systems not affected).
Before, there was a logic bug where we would try to read the cpuset.cpus.effective
cgroup interface file before ensuring nomad's parent cgroup existed. Therefor that
file would not exist, and the list of useable cpus would be empty. Tasks started
thereafter would not have a value set for their cpuset.cpus.
The refactoring fixes some less than ideal coding style. Instead we now bootstrap
each cpuset manager type (v1/v2) within its own constructor. If something goes
awry during bootstrap (e.g. cgroups not enabled), the constructor returns the
noop implementation and logs a warning.
Fixes#14229
* allocrunner: handle lifecycle when all tasks die
When all tasks die the Coordinator must transition to its terminal
state, coordinatorStatePoststop, to unblock poststop tasks. Since this
could happen at any time (for example, a prestart task dies), all states
must be able to transition to this terminal state.
* allocrunner: implement different alloc restarts
Add a new alloc restart mode where all tasks are restarted, even if they
have already exited. Also unifies the alloc restart logic to use the
implementation that restarts tasks concurrently and ignores
ErrTaskNotRunning errors since those are expected when restarting the
allocation.
* allocrunner: allow tasks to run again
Prevent the task runner Run() method from exiting to allow a dead task
to run again. When the task runner is signaled to restart, the function
will jump back to the MAIN loop and run it again.
The task runner determines if a task needs to run again based on two new
task events that were added to differentiate between a request to
restart a specific task, the tasks that are currently running, or all
tasks that have already run.
* api/cli: add support for all tasks alloc restart
Implement the new -all-tasks alloc restart CLI flag and its API
counterpar, AllTasks. The client endpoint calls the appropriate restart
method from the allocrunner depending on the restart parameters used.
* test: fix tasklifecycle Coordinator test
* allocrunner: kill taskrunners if all tasks are dead
When all non-poststop tasks are dead we need to kill the taskrunners so
we don't leak their goroutines, which are blocked in the alloc restart
loop. This also ensures the allocrunner exits on its own.
* taskrunner: fix tests that waited on WaitCh
Now that "dead" tasks may run again, the taskrunner Run() method will
not return when the task finishes running, so tests must wait for the
task state to be "dead" instead of using the WaitCh, since it won't be
closed until the taskrunner is killed.
* tests: add tests for all tasks alloc restart
* changelog: add entry for #14127
* taskrunner: fix restore logic.
The first implementation of the task runner restore process relied on
server data (`tr.Alloc().TerminalStatus()`) which may not be available
to the client at the time of restore.
It also had the incorrect code path. When restoring a dead task the
driver handle always needs to be clear cleanly using `clearDriverHandle`
otherwise, after exiting the MAIN loop, the task may be killed by
`tr.handleKill`.
The fix is to store the state of the Run() loop in the task runner local
client state: if the task runner ever exits this loop cleanly (not with
a shutdown) it will never be able to run again. So if the Run() loops
starts with this local state flag set, it must exit early.
This local state flag is also being checked on task restart requests. If
the task is "dead" and its Run() loop is not active it will never be
able to run again.
* address code review requests
* apply more code review changes
* taskrunner: add different Restart modes
Using the task event to differentiate between the allocrunner restart
methods proved to be confusing for developers to understand how it all
worked.
So instead of relying on the event type, this commit separated the logic
of restarting an taskRunner into two methods:
- `Restart` will retain the current behaviour and only will only restart
the task if it's currently running.
- `ForceRestart` is the new method where a `dead` task is allowed to
restart if its `Run()` method is still active. Callers will need to
restart the allocRunner taskCoordinator to make sure it will allow the
task to run again.
* minor fixes
This PR causes the logmon task runner to acquire the binary of the
Nomad executable in an 'init' block, so as to almost certainly get
the name while the nomad file still exists.
This is an attempt at fixing the case where a deleted Nomad file
(e.g. during upgrade) may be getting renamed with a mysterious
suffix first.
If this doesn't work, as a last resort we can literally just trim
the mystery string.
Fixes: #14079
The current implementation for the task coordinator unblocks tasks by
performing destructive operations over its internal state (like closing
channels and deleting maps from keys).
This presents a problem in situations where we would like to revert the
state of a task, such as when restarting an allocation with tasks that
have already exited.
With this new implementation the task coordinator behaves more like a
finite state machine where task may be blocked/unblocked multiple times
by performing a state transition.
This initial part of the work only refactors the task coordinator and
is functionally equivalent to the previous implementation. Future work
will build upon this to provide bug fixes and enhancements.
When a Nomad agent starts and loads jobs that already existed in the
cluster, the default template uid and gid was being set to 0, since this
is the zero value for int. This caused these jobs to fail in
environments where it was not possible to use 0, such as in Windows
clients.
In order to differentiate between an explicit 0 and a template where
these properties were not set we need to use a pointer.
In #14139 this code was changed to use the original copy of the config,
but Config.AllocDir is updated in the `Client.init()` method for dev
agents.
This uses the latest version of the alloc dir (which cannot change
further at runtime without a client restart which would reinitialize
the stats collector as well).
Before this change, Client had 2 copies of the config object: config and configCopy. There was no guidance around which to use where (other than configCopy's comment to pass it to alloc runners), both are shared among goroutines and mutated in data racy ways. At least at one point I think the idea was to have `config` be mutable and then grab a lock to overwrite `configCopy`'s pointer atomically. This would have allowed alloc runners to read their config copies in data race safe ways, but this isn't how the current implementation worked.
This change takes the following approach to safely handling configs in the client:
1. `Client.config` is the only copy of the config and all access must go through the `Client.configLock` mutex
2. Since the mutex *only protects the config pointer itself and not fields inside the Config struct:* all config mutation must be done on a *copy* of the config, and then Client's config pointer is overwritten while the mutex is acquired. Alloc runners and other goroutines with the old config pointer will not see config updates.
3. Deep copying is implemented on the Config struct to satisfy the previous approach. The TLS Keyloader is an exception because it has its own internal locking to support mutating in place. An unfortunate complication but one I couldn't find a way to untangle in a timely fashion.
4. To facilitate deep copying I made an *internally backward incompatible API change:* our `helper/funcs` used to turn containers (slices and maps) with 0 elements into nils. This probably saves a few memory allocations but makes it very easy to cause panics. Since my new config handling approach uses more copying, it became very difficult to ensure all code that used containers on configs could handle nils properly. Since this code has caused panics in the past, I fixed it: nil containers are copied as nil, but 0-element containers properly return a new 0-element container. No more "downgrading to nil!"
This PR enables setting of the headers block on services registered
into Nomad's service provider. Works just like the existing support
in Consul checks.
This PR hopefully fixes a race condition of our little test tcp server
that the check observer is making connections against for test cases.
The tcp listener would either startup too slow or exit too soon.
* Allow specification of CSI staging and publishing directory path
* Add website documentation for stage_publish_dir
* Replace erroneous reference to csi_plugin.mount_config with csi_plugin.mount_dir
* Avoid requiring CSI plugins to be redeployed after introducing StagePublishDir
The `golang.org/x/net/context` package was merged into the stdlib as of go
1.7. Update the imports to use the identical stdlib version. Clean up import
blocks for the impacted files to remove unnecessary package aliasing.
This PR adds support for specifying checks in services registered to
the built-in nomad service provider.
Currently only HTTP and TCP checks are supported, though more types
could be added later.
In order to support implicit ACL policies for tasks to get their own
secrets, each task would need to have its own ACL token. This would
add extra raft overhead as well as new garbage collection jobs for
cleaning up task-specific ACL tokens. Instead, Nomad will create a
workload Identity Claim for each task.
An Identity Claim is a JSON Web Token (JWT) signed by the server’s
private key and attached to an Allocation at the time a plan is
applied. The encoded JWT can be submitted as the X-Nomad-Token header
to replace ACL token secret IDs for the RPCs that support identity
claims.
Whenever a key is is added to a server’s keyring, it will use the key
as the seed for a Ed25519 public-private private keypair. That keypair
will be used for signing the JWT and for verifying the JWT.
This implementation is a ruthlessly minimal approach to support the
secure variables feature. When a JWT is verified, the allocation ID
will be checked against the Nomad state store, and non-existent or
terminal allocation IDs will cause the validation to be rejected. This
is sufficient to support the secure variables feature at launch
without requiring implementation of a background process to renew
soon-to-expire tokens.
This PR fixes a bug where client configuration max_kill_timeout was
not being enforced. The feature was introduced in 9f44780 but seems
to have been removed during the major drivers refactoring.
We can make sure the value is enforced by pluming it through the DriverHandler,
which now uses the lesser of the task.killTimeout or client.maxKillTimeout.
Also updates Event.SetKillTimeout to require both the task.killTimeout and
client.maxKillTimeout so that we don't make the mistake of using the wrong
value - as it was being given only the task.killTimeout before.
Fix numerous go-getter security issues:
- Add timeouts to http, git, and hg operations to prevent DoS
- Add size limit to http to prevent resource exhaustion
- Disable following symlinks in both artifacts and `job run`
- Stop performing initial HEAD request to avoid file corruption on
retries and DoS opportunities.
**Approach**
Since Nomad has no ability to differentiate a DoS-via-large-artifact vs
a legitimate workload, all of the new limits are configurable at the
client agent level.
The max size of HTTP downloads is also exposed as a node attribute so
that if some workloads have large artifacts they can specify a high
limit in their jobspecs.
In the future all of this plumbing could be extended to enable/disable
specific getters or artifact downloading entirely on a per-node basis.
Closes#12927Closes#12958
This PR updates the version of redis used in our examples from 3.2 to 7.
The old version is very not supported anymore, and we should be setting
a good example by using a supported version.
The long-form example job is now fixed so that the service stanza uses
nomad as the service discovery provider, and so now the job runs without
a requirement of having Consul running and configured.
* test: use `T.TempDir` to create temporary test directory
This commit replaces `ioutil.TempDir` with `t.TempDir` in tests. The
directory created by `t.TempDir` is automatically removed when the test
and all its subtests complete.
Prior to this commit, temporary directory created using `ioutil.TempDir`
needs to be removed manually by calling `os.RemoveAll`, which is omitted
in some tests. The error handling boilerplate e.g.
defer func() {
if err := os.RemoveAll(dir); err != nil {
t.Fatal(err)
}
}
is also tedious, but `t.TempDir` handles this for us nicely.
Reference: https://pkg.go.dev/testing#T.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
* test: fix TestLogmon_Start_restart on Windows
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
* test: fix failing TestConsul_Integration
t.TempDir fails to perform the cleanup properly because the folder is
still in use
testing.go:967: TempDir RemoveAll cleanup: unlinkat /tmp/TestConsul_Integration2837567823/002/191a6f1a-5371-cf7c-da38-220fe85d10e5/web/secrets: device or resource busy
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
This PR modifies raw_exec and exec to ensure the cgroup for a task
they are driving still exists during a task restart. These drivers
have the same bug but with different root cause.
For raw_exec, we were removing the cgroup in 2 places - the cpuset
manager, and in the unix containment implementation (the thing that
uses freezer cgroup to clean house). During a task restart, the
containment would remove the cgroup, and when the task runner hooks
went to start again would block on waiting for the cgroup to exist,
which will never happen, because it gets created by the cpuset manager
which only runs as an alloc pre-start hook. The fix here is to simply
not delete the cgroup in the containment implementation; killing the
PIDs is enough. The removal happens in the cpuset manager later anyway.
For exec, it's the same idea, except DestroyTask is called on task
failure, which in turn calls into libcontainer, which in turn deletes
the cgroup. In this case we do not have control over the deletion of
the cgroup, so instead we hack the cgroup back into life after the
call to DestroyTask.
All of this only applies to cgroups v2.
Fixes#10200
**The bug**
A user reported receiving the following error when an alloc was placed
that needed to preempt existing allocs:
```
[ERROR] client.alloc_watcher: error querying previous alloc:
alloc_id=28... previous_alloc=8e... error="rpc error: alloc lookup
failed: index error: UUID must be 36 characters"
```
The previous alloc (8e) was already complete on the client. This is
possible if an alloc stops *after* the scheduling decision was made to
preempt it, but *before* the node running both allocations was able to
pull and start the preemptor. While that is hopefully a narrow window of
time, you can expect it to occur in high throughput batch scheduling
heavy systems.
However the RPC error made no sense! `previous_alloc` in the logs was a
valid 36 character UUID!
**The fix**
The fix is:
```
- prevAllocID: c.Alloc.PreviousAllocation,
+ prevAllocID: watchedAllocID,
```
The alloc watcher new func used for preemption improperly referenced
Alloc.PreviousAllocation instead of the passed in watchedAllocID. When
multiple allocs are preempted, a watcher is created for each with
watchedAllocID set properly by the caller. In this case
Alloc.PreviousAllocation="" -- which is where the `UUID must be 36 characters`
error was coming from! Sadly we were properly referencing
watchedAllocID in the log, so it made the error make no sense!
**The repro**
I was able to reproduce this with a dev agent with [preemption enabled](https://gist.github.com/schmichael/53f79cbd898afdfab76865ad8c7fc6a0#file-preempt-hcl)
and [lowered limits](https://gist.github.com/schmichael/53f79cbd898afdfab76865ad8c7fc6a0#file-limits-hcl)
for ease of repro.
First I started a [low priority count 3 job](https://gist.github.com/schmichael/53f79cbd898afdfab76865ad8c7fc6a0#file-preempt-lo-nomad),
then a [high priority job](https://gist.github.com/schmichael/53f79cbd898afdfab76865ad8c7fc6a0#file-preempt-hi-nomad)
that evicts 2 low priority jobs. Everything worked as expected.
However if I force it to use the [remotePrevAlloc implementation](https://github.com/hashicorp/nomad/blob/v1.3.0-beta.1/client/allocwatcher/alloc_watcher.go#L147),
it reproduces the bug because the watcher references PreviousAllocation
instead of watchedAllocID.
We enforce exactly one plugin supervisor loop by checking whether
`running` is set and returning early. This works but is fairly
subtle. It can briefly result in two goroutines where one quickly
exits before doing any work. Clarify the intent by using
`sync.Once`. The goroutine we've spawned only exits when the entire
task runner is being torn down, and not when the task driver restarts
the workload, so it should never be re-run.
The task runner hook `Prestart` response object includes a `Done`
field that's intended to tell the client not to run the hook
again. The plugin supervisor creates mount points for the task during
prestart and saves these mounts in the hook resources. But if a client
restarts the hook resources will not be populated. If the plugin task
restarts at any time after the client restarts, it will fail to have
the correct mounts and crash loop until restart attempts run out.
Fix this by not returning `Done` in the response, just as we do for
the `volume_mount_hook`.
This PR introduces the `address` field in the `service` block so that Nomad
or Consul services can be registered with a custom `.Address.` to advertise.
The address can be an IP address or domain name. If the `address` field is
set, the `service.address_mode` must be set in `auto` mode.
* add concurrent download support - resolves#11244
* format imports
* mark `wg.Done()` via `defer`
* added tests for successful and failure cases and resolved some goleak
* docs: add changelog for #11531
* test typo fixes and improvements
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
This PR is 2 fixes for the flaky TestTaskRunner_TaskEnv_Chroot test.
And also the TestTaskRunner_Download_ChrootExec test.
- Use TinyChroot to stop copying gigabytes of junk, which causes GHA
to fail to create the environment in time.
- Pre-create cgroups on V2 systems. Normally the cgroup directory is
managed by the cpuset manager, but that is not active in taskrunner tests,
so create it by hand in the test framework.
These tests have a data race where the test assertion is reading a
value that's being set in the `listenFunc` goroutines that are
subscribing to registry update events. Move the assertion into the
subscribing goroutine to remove the race. This bug was discovered
in #12098 but does not impact production Nomad code.
The plugin manager for CSI hands out instances of a plugin for callers
that need to mount a volume. The `MounterForPlugin` method accesses
the internal instances map without a lock, and can be called
concurrently from outside the plugin manager's main run-loop.
The original commit for the instances map included a warning that it
needed to be accessed only from the main loop but that comment was
unfortunately ignored shortly thereafter, so this bug has existed in
the code for a couple years without being detected until we ran tests
with `-race` in #12098. Lesson learned here: comments make for lousy
enforcement of invariants!
This PR injects the 'NOMAD_CPU_CORES' environment variable into
tasks that have been allocated reserved cpu cores. The value uses
normal cpuset notation, as found in cpuset.cpu cgroup interface files.
Note this value is not necessiarly the same as the content of the actual
cpuset.cpus interface file, which will also include shared cpu cores when
using cgroups v2. This variable is a workaround for users who used to be
able to read the reserved cgroup cpuset file, but lose the information
about distinct reserved cores when using cgroups v2.
Side discussion in: https://github.com/hashicorp/nomad/issues/12374
When a service is updated, the service hooks update a number of
internal fields which helps generate the new workload. This also
needs to update the namespace for the service provider. It is
possible for these to be different, and in the case of Nomad and
Consul running OSS, this is to be expected.
This change modifies the template task runner to utilise the
new consul-template which includes Nomad service lookup template
funcs.
In order to provide security and auth to consul-template, we use
a custom HTTP dialer which is passed to consul-template when
setting up the runner. This method follows Vault implementation.
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
