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Select build, test, and deploy work in a monorepo

· 2 min read
Erik Osterman
Erik Osterman
Founder @ Cloud Posse

Build, test, and deploy what changed. In a monorepo, that means identifying the affected projects and their dependents, then running the work that matters for that change.

The Atmos Automation Language lets you turn affected components and stacks into build, test, and deployment tasks. Write your project logic once and run it locally or in CI.

Select work across your monorepo​

Monorepos bring related projects together. A single change can span an application, its shared configuration, and the components that depend on it. Knowing those relationships lets you focus validation and deployment on the parts of the repository that need them.

Atmos identifies affected components and stacks from its configuration and declared dependencies. The Atmos Automation Language puts those results in your script, where you can apply your project's build, test, and release rules.

Turn affected components into tasks​

Query the affected set, iterate over the results, and choose the commands to run for each component. You can use that set to select tests, prepare deployments, or run independent work in parallel.

The query wrappers capture output and request JSON by default. This applies to atmos.list, atmos.describe, and the config and stack config getters. Explicit formats and streaming options still take precedence.

Command results expose decoded JSON through data and retain raw stdout, stderr, and exit_code. The step library also exposes data, decoded from its primary value. Decoding happens only when accessed, so text results remain usable. Decoded collections are read-only and can be shared with parallel tasks.

How to Use It​

Run this script in an Atmos project with the comparison ref available locally:

result = atmos.describe(
    "affected",
    flags = {"base": "origin/main", "include-dependents": True},
)
for item in result.data:
    if not item.get("deleted", False):
        ui.info("{} in {}".format(item["component"], item["stack"]))

Use the records to select project commands or construct parallel tasks. Affected detection follows Atmos configuration and declared dependencies; the loop does not establish execution order between dependent components.

For individual child processes, exec.run and component.exec now accept timeout and retry directly. A timeout bounds the entire call, including retry delays. Only retry operations that are safe to repeat.

Get Involved​

Try the query defaults in your project automation and open an issue with feedback.