loom context

Generate GitLab pipeline context files from the current git branch.

GitLab-format runs evaluate workflow:rules and rules: against pipeline variables that only exist on a GitLab runner. loom context init derives a loom.gitlab-pipeline-context.v1 file from repository facts so loom check, loom compile, and loom run can select the same jobs GitLab would, without a hand-written JSON file.

Canonical command usage

Use the core CLI command reference for the exact loom context and loom context init synopsis, flags, and displayed defaults.

loom context

loom context is a command group. Invoking it without a subcommand prints help for the group and exits successfully. Today the group contains one subcommand: init.

loom context init

Write .loom/contexts/<name>.json beneath the repository root.

Behavior

• --as push|mr is required and selects the pipeline shape to mimic.
• --name <name> defaults to the --as value. Names use letters, digits, ., _, or - (max 64 characters, no leading .).
• The command fails when the file already exists unless --force is set.
• HEAD must be a branch; a detached HEAD is rejected.
• The default branch is the short name of origin/HEAD, falling back to main when the remote head is unknown.

What it writes

Field	--as push	--as mr
CI_PIPELINE_SOURCE	push	merge_request_event
CI_COMMIT_BRANCH	current branch	not set
CI_COMMIT_REF_NAME	current branch	current branch
CI_COMMIT_REF_SLUG	slug of the branch	slug of the branch
CI_DEFAULT_BRANCH	default branch	default branch
CI_COMMIT_SHA / CI_COMMIT_SHORT_SHA	HEAD	HEAD
CI_COMMIT_BEFORE_SHA	first parent of HEAD, or the zero SHA	the zero SHA
CI_MERGE_REQUEST_SOURCE_BRANCH_NAME	not set	current branch
CI_MERGE_REQUEST_TARGET_BRANCH_NAME	not set	default branch
changes	base parent, head HEAD; omitted for a root commit	base default branch, head HEAD

changes never lists paths, so rules:changes resolve through git as described for loom check. No runner_tags are written; add them by hand when a job requires tags.

Commit hashes are pinned at generation time. Re-run with --force after new commits when a rule depends on CI_COMMIT_SHA or changes.

Examples

Generate a default-branch push context and run against it:

loom context init --as push --name main
loom run --local --context main

Generate a merge request context named mr:

loom context init --as mr
loom check --context mr

Short context names

--context <name> without a path separator or .json suffix resolves to .loom/contexts/<name>.json. Any value containing / or ending in .json is read as a project-relative path exactly as before. A missing short name fails with the resolved path and the loom context init command that creates it.