The cloud-init configuration runs on boot, which can result in a race
condition between that and service startup. This has caused provisioning
failures because Nomad expects the userdata to have configured a host volume
directory. Diagnosing this was also compounded by a warning being fired by
systemd for the Nomad unit file.
* Update the location of the `StartLimitIntervalSec` field to it's
post-systemd-230 location.
* Ensure that the weekly AMI build is up-to-date to reduce the risk of
unexpected system software changes.
* Move the host volume to a directory we can set up at AMI build time rather
than in userdata.
Only `change_mode = "restart"` will result in the template environment
variables being updated in the task. Clarify the behavior of the unsupported
options.
* `nomad operator keyring` was missing the general options section
* `nomad operator metrics` was missing a page in the docs entirely
Co-authored-by: Luiz Aoqui <luiz@hashicorp.com>
Create a new "Operating Nomad" section of the docs where we can put reference
material for operators that doesn't quite fit in either configuration file /
command line documentation or a step-by-step Learn Guide. Pre-populate this
with the existing telemetry docs and some links out to the Learn Guide
sections.
* vault secrets named with `-` characters cannot be read by `consul-template`
due to limitations in golang's template rendering engine.
* environment variables are not modified in running tasks if
`change_mode.noop` is set.
The `nomad alloc logs` command does not remove terminal escape sequences for
color from the log outputs of a task. Clarify that the standard `-no-color`
flag, which does apply to Nomad's error responses from `nomad alloc logs`,
does not apply to the log output.
The CSIVolume struct "denormalizes" allocations when it's first queried from
the state store. The CSIVolumeByID method on the state store copies the volume
before denormalizing so that we don't end up with unexpected changes. The
copying has some subtle bugs that meant that Allocations (as well as
Topologies and MountOptions) were not getting copied when expected.
Also, ensure we never write allocations attached to volumes to the state store
during claims.
While Nomad v0.12.8 fixed `NOMAD_{ALLOC,TASK,SECRETS}_DIR` use in
`template.destination`, interpolating these variables in
`template.source` caused a path escape error.
**Why not apply the destination fix to source?**
The destination fix forces destination to always be relative to the task
directory. This makes sense for the destination as a destination outside
the task directory would be unreachable by the task. There's no reason
to ever render a template outside the task directory. (Using `..` does
allow destinations to escape the task directory if
`template.disable_file_sandbox = true`. That's just awkward and unsafe
enough I hope no one uses it.)
There is a reason to source a template outside a task
directory. At least if there weren't then I can't think of why we
implemented `template.disable_file_sandbox`. So v0.12.8 left the
behavior of `template.source` the more straightforward "Interpolate and
validate."
However, since outside of `raw_exec` every other driver uses absolute
paths for `NOMAD_*_DIR` interpolation, this means those variables are
unusable unless `disable_file_sandbox` is set.
**The Fix**
The variables are now interpolated as relative paths *only for the
purpose of rendering templates.* This is an unfortunate special case,
but reflects the fact that the templates view of the filesystem is
completely different (unconstrainted) vs the task's view (chrooted).
Arguably the values of these variables *should be context-specific.*
I think it's more reasonable to think of the "hack" as templating
running uncontainerized than that giving templates different paths is a
hack.
**TODO**
- [ ] E2E tests
- [ ] Job validation may still be broken and prevent my fix from
working?
**raw_exec**
`raw_exec` is actually broken _a different way_ as exercised by tests in
this commit. I think we should probably remove these tests and fix that
in a followup PR/release, but I wanted to leave them in for the initial
review and discussion. Since non-containerized source paths are broken
anyway, perhaps there's another solution to this entire problem I'm
overlooking?
This is mostly switching paragraphs to bullets to make following
instructions easier. In doing so, this also adds instructions to install
things that were previously assumed to be installed, like Vagrant,
Virtualbox, and Consul.
It also removes the expectation that Nomad is cloned to $GOPATH, as that
is not necessary.
The `nomad alloc status -verbose` command returns a 404 from CSI volumes
because the volume mount block in the task points back to the
`job.group.volume` block. So using the `Name` field to query is the "name" as
seen in the jobspec, and not the name of the volume that we need for querying.
Show both the job-specific name and the volume ID in the resulting output,
which clarifies the difference between the two fields and is more consistent
with the web UI.
