This changeset fixes a long-standing point of confusion in metrics emitted by
the eval broker. The eval broker has a queue of "blocked" evals that are waiting
for an in-flight ("unacked") eval of the same job to be completed. But this
"blocked" state is not the same as the `blocked` status that we write to raft
and expose in the Nomad API to end users. There's a second metric
`nomad.blocked_eval.total_blocked` that refers to evaluations in that
state. This has caused ongoing confusion in major customer incidents and even in
our own documentation! (Fixed in this PR.)
There's little functional change in this PR aside from the name of the metric
emitted, but there's a bit refactoring to clean up the names in `eval_broker.go`
so that there aren't name collisions and multiple names for the same
state. Changes included are:
* Everything that was previously called "pending" referred to entities that were
associated witht he "ready" metric. These are all now called "ready" to match
the metric.
* Everything named "blocked" in `eval_broker.go` is now named "pending", except
for a couple of comments that actually refer to blocked RPCs.
* Added a note to the upgrade guide docs for 1.5.0.
* Fixed the scheduling performance metrics docs because the description for
`nomad.broker.total_blocked` was actually the description for
`nomad.blocked_eval.total_blocked`.
* Add config elements
* Wire in snapshot configuration to raft
* Add hot reload of raft config
* Add documentation for new raft settings
* Add changelog
The description for the `nomad.nomad.blocked_evals.total_blocked` states that this could include evals blocked due to reached quota limits, but the `total_quota_limit` mentions being exclusive to its own metric. I personally interpret `total_blocked` as encompassing any blocked evals for any reason, as written in the docs. Though someone will have to verify the validity of that statement and possibly rectify the other metric description.
Fixed a typo: `limtis` vs `limits`.
This PR adds support for configuring `proxy.upstreams[].config` for
Consul Connect upstreams. This is an opaque config value to Nomad -
the data is passed directly to Consul and is unknown to Nomad.
* [no ci] first pass at plumbing grpc_ca_file
* consul: add support for grpc_ca_file for tls grpc connections in consul 1.14+
This PR adds client config to Nomad for specifying consul.grpc_ca_file
These changes combined with https://github.com/hashicorp/consul/pull/15913 should
finally enable Nomad users to upgrade to Consul 1.14+ and use tls grpc connections.
* consul: add cl entgry for grpc_ca_file
* docs: mention grpc_tls changes due to Consul 1.14
Devices are fingerprinted as groups of similar devices. This prevented
specifying specific device by their ID in constraint and affinity rules.
This commit introduces the `${device.ids}` attribute that returns a
comma separated list of IDs that are part of the device group. Users can
then use the set operators to write rules.
* 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
The `plugin status` command supports displaying CSI capabilities and topology
accessibility, but this was missing from the documentation. Extend the
`-verbose` example to show that info.
* 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.
After Deployments were added in Nomad 0.6.0, the `AllocUpdateRequestType` raft
log entry was no longer in use. Mark this as deprecated, remove the associated
dead code, and remove references to the metrics it emits from the docs. We'll
leave the entry itself just in case we encounter old raft logs that we need to
be able to safely load.
During unusual outage recovery scenarios on large clusters, a backlog of
millions of evaluations can appear. In these cases, the `eval delete` command can
put excessive load on the cluster by listing large sets of evals to extract the
IDs and then sending larges batches of IDs. Although the command's batch size
was carefully tuned, we still need to be JSON deserialize, re-serialize to
MessagePack, send the log entries through raft, and get the FSM applied.
To improve performance of this recovery case, move the batching process into the
RPC handler and the state store. The design here is a little weird, so let's
look a the failed options first:
* A naive solution here would be to just send the filter as the raft request and
let the FSM apply delete the whole set in a single operation. Benchmarking with
1M evals on a 3 node cluster demonstrated this can block the FSM apply for
several minutes, which puts the cluster at risk if there's a leadership
failover (the barrier write can't be made while this apply is in-flight).
* A less naive but still bad solution would be to have the RPC handler filter
and paginate, and then hand a list of IDs to the existing raft log
entry. Benchmarks showed this blocked the FSM apply for 20-30s at a time and
took roughly an hour to complete.
Instead, we're filtering and paginating in the RPC handler to find a page token,
and then passing both the filter and page token in the raft log. The FSM apply
recreates the paginator using the filter and page token to get roughly the same
page of evaluations, which it then deletes. The pagination process is fairly
cheap (only abut 5% of the total FSM apply time), so counter-intuitively this
rework ends up being much faster. A benchmark of 1M evaluations showed this
blocked the FSM apply for 20-30ms at a time (typical for normal operations) and
completes in less than 4 minutes.
Note that, as with the existing design, this delete is not consistent: a new
evaluation inserted "behind" the cursor of the pagination will fail to be
deleted.
The exec driver and other drivers derived from the shared executor check the
path of the command before handing off to libcontainer to ensure that the
command doesn't escape the sandbox. But we don't check any host volume mounts,
which should be safe to use as a source for executables if we're letting the
user mount them to the container in the first place.
Check the mount config to verify the executable lives in the mount's host path,
but then return an absolute path within the mount's task path so that we can hand
that off to libcontainer to run.
Includes a good bit of refactoring here because the anchoring of the final task
path has different code paths for inside the task dir vs inside a mount. But
I've fleshed out the test coverage of this a good bit to ensure we haven't
created any regressions in the process.
This PR updates template and meta docs pages to give examples of accessing
meta values in templates. To do so one must use the environment variable form
of the meta key name, which isn't obvious and wasn't yet documented.
* Fix s3 URLs so that they work
Unfortunately, s3 urls prefixed with https:// do NOT work with the underlying go-getter library. As such, this fixes the examples so that they are working examples that won't cause problems for people reading the docs.
See discussion in https://github.com/hashicorp/nomad/issues/1113 circa 2016.
* Use s3:// protocol schema for artifact examples
Per the discussion in https://github.com/hashicorp/nomad/pull/15123,
we're going to use the explicit s3 protocol in the examples since that
is the likeliest to work in all scenarios
Add a new `Eval.Count` RPC and associated HTTP API endpoints. This API is
designed to support interactive use in the `nomad eval delete` command to get a
count of evals expected to be deleted before doing so.
The state store operations to do this sort of thing are somewhat expensive, but
it's cheaper than serializing a big list of evals to JSON. Note that although it
seems like this could be done as an extra parameter and response field on
`Eval.List`, having it as its own endpoint avoids having to change the response
body shape and lets us avoid handling the legacy filter params supported by
`Eval.List`.
