open-nomad/website/source/docs/job-specification/job.html.md
Seth Hoenig f030a22c7c command, docs: create and document consul token configuration for connect acls (gh-6716)
This change provides an initial pass at setting up the configuration necessary to
enable use of Connect with Consul ACLs. Operators will be able to pass in a Consul
Token through `-consul-token` or `$CONSUL_TOKEN` in the `job run` and `job revert`
commands (similar to Vault tokens).

These values are not actually used yet in this changeset.
2020-01-31 19:02:53 -06:00

261 lines
8 KiB
Markdown

---
layout: "docs"
page_title: "job Stanza - Job Specification"
sidebar_current: "docs-job-specification-job"
description: |-
The "job" stanza is the top-most configuration option in the job
specification. A job is a declarative specification of tasks that Nomad
should run.
---
# `job` Stanza
<table class="table table-bordered table-striped">
<tr>
<th width="120">Placement</th>
<td>
<code>**job**</code>
</td>
</tr>
</table>
The `job` stanza is the top-most configuration option in the job specification.
A job is a declarative specification of tasks that Nomad should run. Jobs have
one or more task groups, which are themselves collections of one or more tasks.
Job names are unique per [region][region] or [namespace][namespace] (if Nomad
Enterprise is used).
```hcl
job "docs" {
constraint {
# ...
}
datacenters = ["us-east-1"]
group "example" {
# ...
}
meta {
"my-key" = "my-value"
}
parameterized {
# ...
}
periodic {
# ...
}
priority = 100
region = "north-america"
task "docs" {
# ...
}
update {
# ...
}
}
```
## `job` Parameters
- `all_at_once` `(bool: false)` - Controls whether the scheduler can make
partial placements if optimistic scheduling resulted in an oversubscribed
node. This does not control whether all allocations for the job, where all
would be the desired count for each task group, must be placed atomically.
This should only be used for special circumstances.
- `constraint` <code>([Constraint][constraint]: nil)</code> -
This can be provided multiple times to define additional constraints. See the
[Nomad constraint reference][constraint] for more
details.
- `affinity` <code>([Affinity][affinity]: nil)</code> -
This can be provided multiple times to define preferred placement criteria. See the
[Nomad affinity reference][affinity] for more
details.
- `spread` <code>([Spread][spread]: nil)</code> - This can be provided multiple times
to define criteria for spreading allocations across a node attribute or metadata.
See the [Nomad spread reference][spread] for more details.
- `datacenters` `(array<string>: <required>)` - A list of datacenters in the region which are eligible
for task placement. This must be provided, and does not have a default.
- `group` <code>([Group][group]: \<required\>)</code> - Specifies the start of a
group of tasks. This can be provided multiple times to define additional
groups. Group names must be unique within the job file.
- `meta` <code>([Meta][]: nil)</code> - Specifies a key-value map that annotates
with user-defined metadata.
- `migrate` <code>([Migrate][]: nil)</code> - Specifies the groups strategy for
migrating off of draining nodes. If omitted, a default migration strategy is
applied. Only service jobs with a count greater than 1 support migrate stanzas.
- `namespace` `(string: "default")` - The namespace in which to execute the job.
Values other than default are not allowed in non-Enterprise versions of Nomad.
- `parameterized` <code>([Parameterized][parameterized]: nil)</code> - Specifies
the job as a parameterized job such that it can be dispatched against.
- `periodic` <code>([Periodic][]: nil)</code> - Allows the job to be scheduled
at fixed times, dates or intervals.
- `priority` `(int: 50)` - Specifies the job priority which is used to
prioritize scheduling and access to resources. Must be between 1 and 100
inclusively, with a larger value corresponding to a higher priority.
- `region` `(string: "global")` - The region in which to execute the job.
- `reschedule` <code>([Reschedule][]: nil)</code> - Allows to specify a
rescheduling strategy. Nomad will then attempt to schedule the task on another
node if any of its allocation statuses become "failed".
- `type` `(string: "service")` - Specifies the [Nomad scheduler][scheduler] to
use. Nomad provides the `service`, `system` and `batch` schedulers.
- `update` <code>([Update][update]: nil)</code> - Specifies the task's update
strategy. When omitted, rolling updates are disabled.
- `vault` <code>([Vault][]: nil)</code> - Specifies the set of Vault policies
required by all tasks in this job.
- `vault_token` `(string: "")` - Specifies the Vault token that proves the
submitter of the job has access to the specified policies in the
[`vault`][vault] stanza. This field is only used to transfer the token and is
not stored after job submission.
!> It is **strongly discouraged** to place the token as a configuration
parameter like this, since the token could be checked into source control
accidentally. Users should set the `VAULT_TOKEN` environment variable when
running the job instead.
- `consul_token` `(string: "")` - Specifies the Consul token that proves the
submitter of the job has access to the Service Identity policies associated
with the job's Consul Connect enabled services. This field is only used to
transfer the token and is not stored after job submission.
!> It is **strongly discouraged** to place the token as a configuration
parameter like this, since the token could be checked into source control
accidentally. Users should set the `CONSUL_TOKEN` environment variable when
running the job instead.
## `job` Examples
The following examples only show the `job` stanzas. Remember that the
`job` stanza is only valid in the placements listed above.
### Docker Container
This example job starts a Docker container which runs as a service. Even though
the type is not specified as "service", that is the default job type.
```hcl
job "docs" {
datacenters = ["default"]
group "example" {
task "server" {
driver = "docker"
config {
image = "hashicorp/http-echo"
args = ["-text", "hello"]
}
resources {
memory = 128
}
}
}
}
```
### Batch Job
This example job executes the `uptime` command on 10 Nomad clients in the fleet,
restricting the eligible nodes to Linux machines.
```hcl
job "docs" {
datacenters = ["default"]
type = "batch"
constraint {
attribute = "${attr.kernel.name}"
value = "linux"
}
group "example" {
count = 10
task "uptime" {
driver = "exec"
config {
command = "uptime"
}
}
}
}
```
### Consuming Secrets
This example shows a job which retrieves secrets from Vault and writes those
secrets to a file on disk, which the application then consumes. Nomad handles
all interactions with Vault.
```hcl
job "docs" {
datacenters = ["default"]
group "example" {
task "cat" {
driver = "exec"
config {
command = "cat"
args = ["local/secrets.txt"]
}
template {
data = "{{ secret \"secret/data\" }}"
destination = "local/secrets.txt"
}
vault {
policies = ["secret-readonly"]
}
}
}
}
```
When submitting this job, you would run:
```
$ VAULT_TOKEN="..." nomad job run example.nomad
```
[affinity]: /docs/job-specification/affinity.html "Nomad affinity Job Specification"
[constraint]: /docs/job-specification/constraint.html "Nomad constraint Job Specification"
[group]: /docs/job-specification/group.html "Nomad group Job Specification"
[meta]: /docs/job-specification/meta.html "Nomad meta Job Specification"
[migrate]: /docs/job-specification/migrate.html "Nomad migrate Job Specification"
[namespace]: https://learn.hashicorp.com/nomad/governance-and-policy/namespaces
[parameterized]: /docs/job-specification/parameterized.html "Nomad parameterized Job Specification"
[periodic]: /docs/job-specification/periodic.html "Nomad periodic Job Specification"
[region]: /guides/operations/federation.html
[reschedule]: /docs/job-specification/reschedule.html "Nomad reschedule Job Specification"
[scheduler]: /docs/schedulers.html "Nomad Scheduler Types"
[spread]: /docs/job-specification/spread.html "Nomad spread Job Specification"
[task]: /docs/job-specification/task.html "Nomad task Job Specification"
[update]: /docs/job-specification/update.html "Nomad update Job Specification"
[vault]: /docs/job-specification/vault.html "Nomad vault Job Specification"