HashiConf 2024 Now streaming live from Boston! Attend for free
Nomad
Nomad Home

You are viewing documentation for version v1.6.x. View latest version.

Command: job dispatch

The job dispatch command is used to create new instances of a parameterized job. The parameterized job captures a job's configuration and runtime requirements in a generic way and dispatch is used to provide the input for the job to run against. A parameterized job is similar to a function definition, and dispatch is used to invoke the function.

Each time a job is dispatched, a unique job ID is generated. This allows a caller to track the status of the job, much like a future or promise in some programming languages.

Usage

nomad job dispatch [options] <parameterized job> [input source]

Dispatch creates an instance of a parameterized job. A data payload to the dispatched instance can be provided via stdin by using "-" for the input source or by specifying a path to a file. Metadata can be supplied by using the meta flag one or more times.

The payload has a size limit of 16384 bytes (16KiB).

An optional idempotency token can be specified to prevent dispatching more than one instance of the same job. The token can have any value and will be matched with existing jobs. If an instance with the same token already exists, the job will not be dispatched.

Upon successful creation, the dispatched job ID will be printed and the triggered evaluation will be monitored. This can be disabled by supplying the detach flag.

On successful job submission and scheduling, exit code 0 will be returned. If there are job placement issues encountered (unsatisfiable constraints, resource exhaustion, etc), then the exit code will be 2. Any other errors, including client connection issues or internal errors, are indicated by exit code 1.

When ACLs are enabled, this command requires a token with the dispatch-job capability for the job's namespace. The list-jobs capability is required to run the command with a job prefix instead of the exact job ID. The read-job capability is required to monitor the resulting evaluation when -detach is not used.

See the multiregion documentation for additional considerations when dispatching parameterized jobs.

General Options

  • -address=<addr>: The address of the Nomad server. Overrides the NOMAD_ADDR environment variable if set. Defaults to http://127.0.0.1:4646.

  • -region=<region>: The region of the Nomad server to forward commands to. Overrides the NOMAD_REGION environment variable if set. Defaults to the Agent's local region.

  • -namespace=<namespace>: The target namespace for queries and actions bound to a namespace. Overrides the NOMAD_NAMESPACE environment variable if set. If set to '*', subcommands which support this functionality query all namespaces authorized to user. Defaults to the "default" namespace.

  • -no-color: Disables colored command output. Alternatively, NOMAD_CLI_NO_COLOR may be set. This option takes precedence over -force-color.

  • -force-color: Forces colored command output. This can be used in cases where the usual terminal detection fails. Alternatively, NOMAD_CLI_FORCE_COLOR may be set. This option has no effect if -no-color is also used.

  • -ca-cert=<path>: Path to a PEM encoded CA cert file to use to verify the Nomad server SSL certificate. Overrides the NOMAD_CACERT environment variable if set.

  • -ca-path=<path>: Path to a directory of PEM encoded CA cert files to verify the Nomad server SSL certificate. If both -ca-cert and -ca-path are specified, -ca-cert is used. Overrides the NOMAD_CAPATH environment variable if set.

  • -client-cert=<path>: Path to a PEM encoded client certificate for TLS authentication to the Nomad server. Must also specify -client-key. Overrides the NOMAD_CLIENT_CERT environment variable if set.

  • -client-key=<path>: Path to an unencrypted PEM encoded private key matching the client certificate from -client-cert. Overrides the NOMAD_CLIENT_KEY environment variable if set.

  • -tls-server-name=<value>: The server name to use as the SNI host when connecting via TLS. Overrides the NOMAD_TLS_SERVER_NAME environment variable if set.

  • -tls-skip-verify: Do not verify TLS certificate. This is highly not recommended. Verification will also be skipped if NOMAD_SKIP_VERIFY is set.

  • -token: The SecretID of an ACL token to use to authenticate API requests with. Overrides the NOMAD_TOKEN environment variable if set.

Dispatch Options

  • -meta: Meta takes a key/value pair separated by "=". The metadata key will be merged into the job's metadata. The job may define a default value for the key which is overridden when dispatching. The flag can be provided more than once to inject multiple metadata key/value pairs. Arbitrary keys are not allowed. The parameterized job must allow the key to be merged.

  • -detach: Return immediately instead of monitoring. A new evaluation ID will be output, which can be used to examine the evaluation using the eval status command

  • -idempotency-token: Optional identifier used to prevent more than one instance of the job from being dispatched.

  • -id-prefix-template: Optional prefix added to dispatched job IDs.

  • -verbose: Show full information.

Examples

Dispatch against a parameterized job with the ID "video-encode" and passing in a configuration payload via stdin:

$ cat << EOF | nomad job dispatch video-encode -
{
  "s3-input": "https://video-bucket.s3-us-west-1.amazonaws.com/cb31dabb1",
  "s3-output": "https://video-bucket.s3-us-west-1.amazonaws.com/a149adbe3",
  "input-codec": "mp4",
  "output-codec": "webm",
  "quality": "1080p"
}
EOF
Dispatched Job ID = video-encode/dispatch-1485379325-cb38d00d
Evaluation ID     = 31199841

==> Monitoring evaluation "31199841"
    Evaluation triggered by job "example/dispatch-1485379325-cb38d00d"
    Allocation "8254b85f" created: node "82ff9c50", group "cache"
    Evaluation status changed: "pending" -> "complete"
==> Evaluation "31199841" finished with status "complete"

Dispatch against a parameterized job with the ID "video-encode" and passing in a configuration payload via a file:

$ nomad job dispatch video-encode video-config.json
Dispatched Job ID = video-encode/dispatch-1485379325-cb38d00d
Evaluation ID     = 31199841

==> Monitoring evaluation "31199841"
    Evaluation triggered by job "example/dispatch-1485379325-cb38d00d"
    Allocation "8254b85f" created: node "82ff9c50", group "cache"
    Evaluation status changed: "pending" -> "complete"
==> Evaluation "31199841" finished with status "complete"

Dispatch against a parameterized job with the ID "video-encode" using the detach flag:

$ nomad job dispatch -detach video-encode video-config.json
Dispatched Job ID = example/dispatch-1485380684-c37b3dba
Evaluation ID     = d9034c4e

Dispatch with an idempotency token for the first time:

$ nomad job dispatch -idempotency-token=prod video-encode video-config.json
Dispatched Job ID = video-encode/dispatch-1485379325-cb38d00d
Evaluation ID     = 31199841

==> Monitoring evaluation "31199841"
    Evaluation triggered by job "example/dispatch-1485379325-cb38d00d"
    Allocation "8254b85f" created: node "82ff9c50", group "cache"
    Evaluation status changed: "pending" -> "complete"
==> Evaluation "31199841" finished with status "complete"

Dispatch with the same idempotency token:

$ nomad job dispatch -idempotency-token=prod video-encode video-config.json
Job "video-encode/dispatch-1485379325-cb38d00d" already dispatched with idempotency token "prod".

Dispatch with an id prefix:

$ nomad job dispatch -id-prefix-template=config1 video-encode video-config1.json
Jb
Dispatched Job ID = video-encode/dispatch-config1-1485379325-cb38d00d
Evaluation ID     = 31199841

==> Monitoring evaluation "31199841"
    Evaluation triggered by job "example/dispatch-config1-1485379325-cb38d00d"
    Allocation "8254b85f" created: node "82ff9c50", group "cache"
    Evaluation status changed: "pending" -> "complete"
==> Evaluation "31199841" finished with status "complete"