How to route specific Jobs to Ephemeral agents while keeping default Jobs on Host agents without mod

Question

Hello Atlassian Support Team,

We are currently expanding our Bamboo build infrastructure by introducing Ephemeral agents (Kubernetes Pods / Container Agents) alongside our existing static Host agents (Local/Static VMs).

In our build setup, a single Plan typically contains multiple Jobs. Our goal is to run heavy or environment-specific tasks (like standard Build jobs) on our Host agents, while offloading specific analysis tasks (like Coverity) to Ephemeral agents.

However, we are encountering an agent assignment routing issue:

* Current Issue:* When a Job has no explicit Requirement set, newly provisioned Ephemeral agents tend to pick up the job first instead of the Host agents.
* As a result, standard Build jobs run inside Ephemeral containers and fail due to environment mismatches.

* Our Question & Architecture Dilemma:* While we can update our Plans via REST API or scripts to explicitly assign Requirements to each Job, we want to know if manually attaching Requirements to every Job across all Plans is truly Atlassian's recommended Best Practice.
* Is there a cleaner, agent-side or global configuration option to achieve this? For example:* Restricting Ephemeral agents so they only accept Jobs with explicit Requirements, leaving all default (un-required) Jobs to run naturally on Host agents.
* Setting priority or routing rules at the Agent, Project, or Global level so that specific Jobs like Coverity can be directed to Ephemeral agents without needing to reconfigure every other Job across all Plans.

We would appreciate Atlassian's guidance on the recommended architectural approach for seamlessly integrating Ephemeral agents into existing Host agent-based workflows.

Thank you.

Mihai_LeanZero · Answer

Hi @Jae Gon Yeo,

To confirm Josh's option 1, ephemeral agent templates can be dedicated: Administration > Overview > Ephemeral agents > Templates, select the template, pick Type and Name, then Add (https://confluence.atlassian.com/bamboo/dedicating-ephemeral-agent-templates-1236444150.html).

Dedicate it to the Coverity job, not the plan. Your Build jobs are in the same plan, so a plan dedication would send them to pods again.

Dedication works both ways. The template only takes Coverity and Coverity only runs on that template, so it waits in the queue if the cluster is down. If you have more than one template, dedicate each of them, because an undedicated one still takes requirement-less jobs.

The ephemeral-first default is BAM-22321 (https://jira.atlassian.com/browse/BAM-22321), which is worth a vote.

Josh · Answer

Hi @Jae Gon Yeo, as far as I know Bamboo does not have a global "only take jobs with requirements" switch for agents. Bamboo matches a job to any agent whose capabilities meet the job's requirements. A job with no requirements can run on any agent that is free, so new ephemeral agents pick them up.

There are two native ways to steer this without editing every job by hand.

1. Dedicate the agents. In Bamboo administration, an agent can be dedicated to specific projects, plans, jobs or deployment environments. A dedicated agent only builds what it is dedicated to. Check whether your Bamboo version allows this for your ephemeral agent template. If it does, dedicate it to the Coverity jobs and the default jobs will stay on the host agents.

2. Use a capability only the host agents have. Add a custom capability (for example "agent.type = host") to the host agents, then add it as a requirement to the jobs that must run there. You can do this in bulk with Bamboo Specs or the REST API, which is the usual way to handle many plans.

Requirements on each job are the documented way to route jobs, so option 2 is a normal setup and not a hack. If option 1 works for your ephemeral template, it is less work.

Docs: https://confluence.atlassian.com/bamboo/agents-and-capabilities-289277114.html