When available, we provide an environment variable `CONSUL_TOKEN` to tasks, but
this isn't the environment variable expected by the Consul CLI. Job
specifications like deploying an API Gateway become noticeably nicer if we can
instead provide the expected env var.
The `consul_hook` in the allocrunner gets a separate Consul token for each task,
even if the tasks' identities have the same name, but used the identity name as
the key to the alloc hook resources map. This means the last task in the group
overwrites the Consul tokens of all other tasks.
Fix this by adding the task name to the key in the allocrunner's
`consul_hook`. And update the taskrunner's `consul_hook` to expect the task
name in the key.
Fixes: https://github.com/hashicorp/nomad/issues/20374
Fixes: https://hashicorp.atlassian.net/browse/NOMAD-614
Add a `Postrun` and `Destroy` hook to the allocrunner's `consul_hook` to ensure
that Consul tokens we've created via WI get revoked via the logout API when
we're done with them. Also add the logout to the `Prerun` hook if we've hit an
error.
This PR introduces a new allocrunner-level consul_hook which iterates over
services and tasks, if their provider is consul, fetches consul tokens for all of
them, stores them in AllocHookResources and in task secret dirs.
Ref: hashicorp/team-nomad#404
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Co-authored-by: Tim Gross <tgross@hashicorp.com>
