Files
nomad/website/content/docs/commands/job/action.mdx
Phil Renaud d104432cd3 Actions: API, command, and jobspec docs (#19166)
* API command and jobspec docs

* PR comments addressed

* API docs for job/jobid/action socket

* Removing a perhaps incorrect origin of job_id across the jobs api doc

* PR comments addressed
2023-11-30 14:13:37 -05:00

108 lines
3.5 KiB
Plaintext

---
layout: docs
page_title: 'Commands: job action'
description: |
The job action command is used to execute predefined actions from a job
specification in a running task context
---
# Command: job action
**Alias: `nomad action`**
The `job action` command allows operators to execute predefined actions declared
in Nomad job specifications. These actions can be defined at task level and are
intended for specific operational tasks, such as clearing a cache, or migrating
a database.
An action may self-terminate upon completion (for example, echoing a string),
or run for an indeterminate amount of time (for example, watching a blocking
query). In the latter case, an action can be terminated via escape character
(such as cmd+c / ctrl+c)
When ACLs are enabled, this command requires a token with the `alloc-exec`,
`read-job`, and `list-jobs` capabilities for the allocation's namespace. If
the task driver does not have file system isolation (as with `raw_exec`),
this command requires the `alloc-node-exec`, `alloc-exec`, `read-job`, and
`list-jobs` capabilities for the allocation's namespace.
## Usage
```plaintext
nomad job action [options] <action>
```
The `job action` command requires an action name and accepts two ways of
specifying where it should run:
- by passing the job name and known allocation ID along with the name of the action
- by passing the job, task group, and task name along with the name of the action
(when the allocation ID is not known). A random allocation will be selected if
multiple are available.
The action name provided must be defined within a task in the [job specification]
provided. With sufficient privileges, an execution context will be opened and
the defined action command will be run. No further input is possible, save for
the escape character to terminate execution, so interactive commands are not
supported.
## General Options
@include 'general_options.mdx'
## Action Options
- `-job`: (Required) Specifies the job containing the predefined action.
- `-alloc`: Specifies the allocation within which the action is to be executed.
If omitted, `-group` and `-task` must be provided, and a random
allocation for the group will be selected.
- `-task`: Specifies the task within the job where the action is defined. This
is required either if `-alloc` provided and your group has multiple tasks,
or if you specify a `-group`.
- `-group`: Specifies the task group within the job. If present, a random
allocation is selected. If omitted, `-alloc` must be provided.
- `-i`: Pass stdin to the action, defaults to `true`. Pass `-i=false` to
disable explicitly.
- `-t`: Allocate a pseudo-tty, defaults to `true` if stdin is detected to be a tty
session. Pass `-t=false` to disable explicitly.
- `-e` <escape_char>: Sets the escape character for sessions with a pty,
defaults to '~'. The escape character is only recognized at the beginning of a
line. The escape character followed by a dot (`.`) closes the connection.
Setting the character to `none` disables any escapes and makes the session
fully transparent.
## Examples
Execute an action within a specific task in a job:
```shell-session
$ nomad action \
-group=my-group \
-task=my-task \
-job=my-job \
weather
Toronto: ☁️ +3°C
```
Execute an action within a specific allocation:
```shell-session
$ nomad action \
-alloc=f200a789-6da4-504c-d131-6181764f101e \
-job=actions-demo \
echo-time
Running for 0 seconds
Running for 1 seconds
Running for 2 seconds
Running for 3 seconds
```
[job specification]: /nomad/docs/job-specification