* artifact: enable inheriting environment variables from client
This PR adds client configuration for specifying environment variables that
should be inherited by the artifact sandbox process from the Nomad Client agent.
Most users should not need to set these values but the configuration is provided
to ensure backwards compatability. Configuration of go-getter should ideally be
done through the artifact block in a jobspec task.
e.g.
```hcl
client {
artifact {
set_environment_variables = "TMPDIR,GIT_SSH_OPTS"
}
}
```
Closes#15498
* website: update set_environment_variables text to mention PATH
This PR adds the client config option for turning off filesystem isolation,
applicable on Linux systems where filesystem isolation is possible and
enabled by default.
```hcl
client{
artifact {
disable_filesystem_isolation = <bool:false>
}
}
```
Closes#15496
* client: sandbox go-getter subprocess with landlock
This PR re-implements the getter package for artifact downloads as a subprocess.
Key changes include
On all platforms, run getter as a child process of the Nomad agent.
On Linux platforms running as root, run the child process as the nobody user.
On supporting Linux kernels, uses landlock for filesystem isolation (via go-landlock).
On all platforms, restrict environment variables of the child process to a static set.
notably TMP/TEMP now points within the allocation's task directory
kernel.landlock attribute is fingerprinted (version number or unavailable)
These changes make Nomad client more resilient against a faulty go-getter implementation that may panic, and more secure against bad actors attempting to use artifact downloads as a privilege escalation vector.
Adds new e2e/artifact suite for ensuring artifact downloading works.
TODO: Windows git test (need to modify the image, etc... followup PR)
* landlock: fixup items from cr
* cr: fixup tests and go.mod file
This PR adds a secondary path for cleaning up iptables created for an allocation
when the normal CNI library fails to do so. This typically happens when the state
of the pause container is unexpected - e.g. deleted out of band from Nomad. Before,
the iptables rules would be leaked which could lead to unexpected nat routing
behavior later on (in addition to leaked resources). With this change, we scan
for the rules created on behalf of the allocation being GC'd and delete them.
Fixes#6385
* client: accommodate Consul 1.14.0 gRPC and agent self changes.
Consul 1.14.0 changed the way in which gRPC listeners are
configured, particularly when using TLS. Prior to the change, a
single listener was responsible for handling plain-text and
encrypted gRPC requests. In 1.14.0 and beyond, separate listeners
will be used for each, defaulting to 8502 and 8503 for plain-text
and TLS respectively.
The change means that Nomad’s Consul Connect integration would not
work when integrated with Consul clusters using TLS and running
1.14.0 or greater.
The Nomad Consul fingerprinter identifies the gRPC port Consul has
exposed using the "DebugConfig.GRPCPort" value from Consul’s
“/v1/agent/self” endpoint. In Consul 1.14.0 and greater, this only
represents the plain-text gRPC port which is likely to be disbaled
in clusters running TLS. In order to fix this issue, Nomad now
takes into account the Consul version and configured scheme to
optionally use “DebugConfig.GRPCTLSPort” value from Consul’s agent
self return.
The “consul_grcp_socket” allocrunner hook has also been updated so
that the fingerprinted gRPC port attribute is passed in. This
provides a better fallback method, when the operator does not
configure the “consul.grpc_address” option.
* docs: modify Consul Connect entries to detail 1.14.0 changes.
* changelog: add entry for #15309
* fixup: tidy tests and clean version match from review feedback.
* fixup: use strings tolower func.
client: fixed a bug where non-`docker` tasks with network isolation would leak network namespaces and iptables rules if the client was restarted while they were running
* client: avoid unconsumed channel in timer construction
This PR fixes a bug introduced in #11983 where a Timer initialized with 0
duration causes an immediate tick, even if Reset is called before reading the
channel. The fix is to avoid doing that, instead creating a Timer with a non-zero
initial wait time, and then immediately calling Stop.
* pr: remove redundant stop
This PR protects access to `templateHook.templateManager` with its lock. So
far we have not been able to reproduce the panic - but it seems either Poststart
is running without a Prestart being run first (should be impossible), or the
Update hook is running concurrently with Poststart, nil-ing out the templateManager
in a race with Poststart.
Fixes#15189
Allocations created before 1.4.0 will not have a workload identity token. When
the client running these allocs is upgraded to 1.4.x, the identity hook will run
and replace the node secret ID token used previously with an empty string. This
causes service discovery queries to fail.
Fallback to the node's secret ID when the allocation doesn't have a signed
identity. Note that pre-1.4.0 allocations won't have templates that read
Variables, so there's no threat that this new node ID secret will be able to
read data that the allocation shouldn't have access to.
Previously, the splay timeout was only applied if a template re-render
caused a restart or a signal action. The `change_mode = "script"` was
running after the `if restart || len(signals) != 0` check, so it was
invoked at all times.
This change refactors the logic so it's easier to notice that new
`change_mode` options should start only after `splay` is applied.
* client: protect user lookups with global lock
This PR updates Nomad client to always do user lookups while holding
a global process lock. This is to prevent concurrency unsafe implementations
of NSS, but still enabling NSS lookups of users (i.e. cannot not use osusergo).
* cl: add cl
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.
* 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.
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.
* 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
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.
* 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
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.
