This PR adds validation during job submission that Connect proxy upstreams
within a task group are using different listener addresses. Otherwise, a
duplicate envoy listener will be created and not be able to bind.

Closes #7833

e2e: fix a couple recent e2e bugs

This PR changes the e2e helper thingy to set -detach option
when registering a job with the CLI instead of the API. This is
necessary for jobs which never become healthy, as the deployment
never finishes for failing jobs and the command never returns,
causing the test to timeout after 10 minutes.

This PR fixes a bug introduced in a refactoring

https://github.com/hashicorp/nomad/pull/10764/files#diff-56b3c82fcbc857f8fb93a903f1610f6e6859b3610a4eddf92bad9ea27fdc85ec

where task level service checks would inherent the task name
field, when they shouldn't.

Fixes #10781

Running the `client/allocrunner` tests fail to compile on macOS because the
CNI test file depends on the CNI network configurator, which is in a
Linux-only file.

consul/connect: in-place update service definition when connect upstreams are modified

This PR fixes a bug where modifying the upstreams of a Connect sidecar proxy
would not result Consul applying the changes, unless an additional change to
the job would trigger a task replacement (thus replacing the service definition).

The fix is to check if upstreams have been modified between Nomad's view of the
sidecar service definition, and the service definition for the sidecar that is
actually registered in Consul.

Fixes #8754

When `network.mode = "bridge"`, we create a pause container in Docker with no
networking so that we have a process to hold the network namespace we create
in Nomad. The default `/etc/hosts` file of that pause container is then used
for all the Docker tasks that share that network namespace. Some applications
rely on this file being populated.

This changeset generates a `/etc/hosts` file and bind-mounts it to the
container when Nomad owns the network, so that the container's hostname has an
IP in the file as expected. The hosts file will include the entries added by
the Docker driver's `extra_hosts` field.

In this changeset, only the Docker task driver will take advantage of this
option, as the `exec`/`java` drivers currently copy the host's `/etc/hosts`
file and this can't be changed without breaking backwards compatibility. But
the fields are available in the task driver protobuf for community task
drivers to use if they'd like.

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.35 to 7.0.36.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.35...7.0.36

)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
...
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [ws](https://github.com/websockets/ws) from 7.3.1 to 7.4.6.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](https://github.com/websockets/ws/compare/7.3.1...7.4.6

)
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

client/fingerprint/java: improve java version string regex matching

This PR improves the regular expression used for matching the java
version string, which varies a lot depending on the java vendor and
version.

These are the example strings we now test for:

java version "1.7.0_80"
openjdk version "11.0.1" 2018-10-16
openjdk version "11.0.1" 2018-10-16
java version "1.6.0_36"
openjdk version "1.8.0_192"
openjdk 11.0.11 2021-04-20 LTS

The last one is a new test added on behalf of #6081, which is
still broken on today's CentOS 7 default JDK package.

openjdk 11.0.11 2021-04-20 LTS
OpenJDK Runtime Environment 18.9 (build 11.0.11+9-LTS)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.11+9-LTS, mixed mode, sharing)

==> Evaluation "21c6caf7" finished with status "complete" but failed to place all allocations:
    Task Group "example" (failed to place 1 allocation):
      * Constraint "${driver.java.version} >= 11.0.0": 1 nodes excluded by filter
    Evaluation "2b737d48" waiting for additional capacity to place r...

consul: make failures_before_critical and success_before_passing work with group services

This PR fixes some job submission plumbing to make sure the Consul Check parameters
- failure_before_critical
- success_before_passing

work with group-level services. They already work with task-level services.

docs: update changelog

plugins: fix test data race.

System and batch jobs don't create deployments, which means nomad tries
to monitor a non-existent deployment when it runs a job and outputs an
error message. This adds a check to make sure a deployment exists before
monitoring. Also fixes some formatting.
Co-authored-by: Tim Gross <tgross@hashicorp.com>

Fix deployment watchers to avoid creating unnecessary deployment watcher goroutines and blocking queries. `deploymentWatcher.getAllocsCh` creates a new goroutine that makes a blocking query to fetch updates of deployment allocs.

## Background

When operators submit a new or updated service job, Nomad create a new deployment by default. The deployment object controls how fast to place the allocations through [`max_parallel`](https://www.nomadproject.io/docs/job-specification/update#max_parallel) and health checks configurations.

The `scheduler` and `deploymentwatcher` package collaborate to achieve deployment logic: The scheduler only places the canaries and `max_parallel` allocations for a new deployment; the `deploymentwatcher` monitors for alloc progress and then enqueues a new evaluation whenever the scheduler should reprocess a job and places the next `max_parallel` round of allocations.

The `deploymentwatcher` package makes blocking queries against the state store, to fetch all deployments and the relevant allocs for each running deployments. If `deploymentwatcher` fails or is hindered from fetching the state, the deployments fail to make progress.

`Deploymentwatcher` logic only runs on the leader.

## Why unnecessary deployment watchers can halt cluster progress
Previously, `getAllocsCh` is called on every for loop iteration in `deploymentWatcher.watch()` function. However, the for-loop may iterate many times before the allocs get updated. In fact, whenever a new deployment is created/updated/deleted, *all* `deploymentWatcher`s get notified through `w.deploymentUpdateCh`. The `getAllocsCh` goroutines and blocking queries spike significantly and grow quadratically with respect to the number of running deployments. The growth leads to two adverse outcomes:

1. it spikes the CPU/Memory usage resulting potentially leading to OOM or very slow processing
2. it activates the [query rate limiter](https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployment_watcher.go#L896-L898), so later the watcher fails to get updates and consequently fails to make progress towards placing new allocations for the deployment!

So the cluster fails to catch up and fails to make progress in almost all deployments. The cluster recovers after a leader transition: the deposed leader stops all watchers and free up goroutines and blocking queries; the new leader recreates the watchers without the quadratic growth and remaining under the rate limiter.  Well, until a spike of deployments are created triggering the condition again.

### Relevant Code References

Path for deployment monitoring:
* [`Watcher.watchDeployments`](https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployments_watcher.go#L164-L192) loops waiting for deployment updates.
* On every deployment update, [`w.getDeploys`](https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployments_watcher.go#L194-L229) returns all deployments in the system
* `watchDeployments` calls `w.add(d)` on every active deployment
* which in turns, [updates existing watcher if one is found](https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployments_watcher.go#L251-L255).
* The deployment watcher [updates local local deployment field and trigger `deploymentUpdateCh` channel]( https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployment_watcher.go#L136-L147)
* The [deployment watcher `deploymentUpdateCh` selector is activated](https://github.com/hashicorp/nomad/blob/abaa9c5c5bd09af774fda30d76d5767b06128df4/nomad/deploymentwatcher/deployment_watcher.go#L455-L489

). Most of the time the selector clause is a no-op, because the flow was triggered due to another deployment update
* The `watch` for-loop iterates again and in the previous code we create yet another goroutine and blocking call that risks being rate limited.
Co-authored-by: Tim Gross <tgross@hashicorp.com>

consul/connect: remove unnecessary connect constraint on clients

volumewatcher: fix test data race.

The `QuotaIterator` is used as the source of nodes passed into feasibility
checking for constraints. Every node that passes the quota check counts the
allocation resources agains the quota, and as a result we count nodes which
will be later filtered out by constraints. Therefore for jobs with
constraints, nodes that are feasibility checked but fail have been counted
against quotas. This failure mode is order dependent; if all the unfiltered
nodes happen to be quota checked first, everything works as expected.

This changeset moves the `QuotaIterator` to happen last among all feasibility
checkers (but before ranking). The `QuotaIterator` will never receive filtered
nodes so it will calculate quotas correctly.

PR https://github.com/hashicorp/nomad/pull/10702 added 2 new constraints
for connect jobs - one for Consul gRPC listener, and one for Connect being
enabled on Clients. Connect does not need to be enabled on clients, only
on Consul servers. Remove the extra constraint.

Discuss:
https://discuss.hashicorp.com/t/nomad-1-1-1-and-consul-connect-enabled-on-consul-clients/25295

Fix headshot image 404

deploymentwatcher: fix test data race.

chore: remove duplicate import statements

Deflaking Test 2021 June edition

core: remove unused types pkg and PeriodicCallback type.