Declare a Nomad job

Developers deploy and manage their applications in Nomad via jobs. This section provides guidance for declaring a Nomad job with a job specification.

In Nomad, a job is a user-specified state for a workload. The user expresses the job that should be running, but not where it should run. Nomad allocates resources and ensures that the actual state matches the user's desired state. A job consists of one or more tasks that you can organize into task groups.

Declare the desired state of your job in a job specification, or jobspec, that describes the tasks and resources necessary for the job to run. You can also include job constraints to control which clients Nomad runs the job on.

When you submit your job specification, Nomad automatically allocates resources to run it. Nomad also makes sure that the actual job state matches your desired state.

Deploy a new Nomad job

The general flow for operating a job in Nomad is:

1. Author the job file according to the job specification.
2. Plan and review the changes with a Nomad server.
3. Submit the job file to a Nomad server.
4. (Optional) Review job status and logs.

Update a running job

When updating a job, there are a number of built-in update strategies which may be defined in the job file. The general flow for updating an existing job in Nomad is:

1. Modify the existing job file with the desired changes.
2. Plan and review the changes with a Nomad server.
3. Submit the job file to a Nomad server.
4. (Optional) Review job status and logs.

Because the job file defines the update strategy (blue-green, rolling updates, etc.), the workflow remains the same regardless of whether this is an initial deployment or a long-running job.

Resources

• Refer to the Job concept page for more information on Nomad jobs.
• Nomad job specification