git rev-parse Command: Resolve Refs in CI

git rev-parse turns refs, branch names, and shorthand into the full object IDs Git uses internally.

rev-parse is the workhorse for scripts that need a commit SHA, the current branch name, or the repo root. It powers most CI build-tagging and image-labeling steps.

Common flags

HEAD - resolve the current commit to its full 40-character SHA
--short - print an abbreviated (default 7-char) SHA
--abbrev-ref HEAD - print the current branch name (or "HEAD" if detached)
--show-toplevel - print the absolute path to the repository root
--verify <ref> - verify a ref exists and print its SHA, failing if not
--is-inside-work-tree - print true when inside a working tree

Example

shell

# Build a short SHA and branch for image tags
SHA="$(git rev-parse --short HEAD)"
BRANCH="$(git rev-parse --abbrev-ref HEAD)"
echo "Building ${BRANCH}@${SHA}"

In CI

rev-parse --short HEAD is the canonical way to derive a short commit ID for Docker tags and artifact names. Note that in detached-HEAD checkouts (common in CI) --abbrev-ref HEAD returns "HEAD"; use the platform branch variable when you need the real branch name.

Key takeaways

git rev-parse --short HEAD produces a stable short SHA for tagging artifacts.
--abbrev-ref HEAD returns "HEAD" in detached checkouts, so prefer CI env vars for branch names.
--show-toplevel reliably locates the repo root inside scripts.

Related guides

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