A Job Definition is a reusable template that tells Daestro exactly how to run a specific task. Think of it as a detailed recipe for your job. It includes everything Daestro needs to know, such as what code to run, what software to use, and how long the task is allowed to take.
Once you create a Job Definition, you can use it over and over again to run jobs without having to re-enter the same settings every time.
Daestro supports two types of Job Definitions:
- Docker: For running jobs using a specific Docker container image.
- Bash Script: For running simple jobs using a standard Linux shell script.
Table of Contents
How to Create a Job Definition
- Go to the Job Definition page in the Daestro Console.
- Click on Create Job Definition and choose either Docker or Bash Script.
For a Docker Job
This is the most common type and gives you the most flexibility.
- Name: A unique name for your definition (e.g.,
process-daily-reports). - Docker Image: The name of the Docker image to use (e.g.,
ubuntu:24.04 or my-app:latest). - Container Registry Auth (Optional): If you are using a private Docker image, select the credentials you saved earlier.
- Execution Timeout (in seconds): The maximum time the job is allowed to run before it is automatically stopped. Use
0 for no time limit. - Command (Optional): The specific command to run inside the Docker container. You can use placeholders like
Param::<key> to pass in custom values when the job runs. - Command Parameters (Optional): Define default values for the placeholders you used in the Command. These can be overridden when you submit a job.
- Environment Variables (Optional): Add any secret keys or configuration values your application needs. For security, these are always encrypted.
- Privileged (Checkbox): Grants the container extra permissions on the host machine. Only use this if you are sure you need it.
For a Bash Script Job
This is a simpler option for running shell commands without needing a custom Docker image.
- Name: A unique name for your definition.
- Bash Script: Write or paste the shell script you want to run. Daestro will execute it inside a default
ubuntu:24.04 container. - Execution Timeout (in seconds): The maximum time the job is allowed to run.
- Environment Variables (Optional): Add any secret keys or configuration values your script needs.
- Privileged (Checkbox): Grants the container extra permissions on the host machine. Only use this if you are sure you need it.
How to Update a Job Definition (Revisions)
For safety and consistency, you cannot directly edit a Job Definition after it has been created. Instead, you create a revision.
A revision is a new version of the Job Definition. It copies all the settings from the original, allowing you to make changes and save it as a new version (e.g., process-daily-reports:2). This is a great way to update your jobs without breaking any tasks that are currently running with the old version.
How to Delete a Job Definition
You can delete a Job Definition if it is no longer needed, but only if it meets these conditions:
- There are no jobs currently running that are based on this definition.
- No scheduled Cron Job is set to use this definition.