Snapshot enhancements for Depot CI

Snapshots in Depot CI let you bake setup steps into a reusable custom image, so later jobs start from a prepared environment instead of repeating the same work. This release brings a few improvements.

• Persist environment variables: Snapshots now persist non-sensitive environment variables, so configuration you set during the snapshot job is there when later jobs run. Sensitive and masked variables remain excluded.

• Faster registry throughput: Pushing a snapshot to the registry is much faster. We raised the throughput from 30 Mbps to 1 Gbps.

• Provenance:: Every snapshot now carries provenance information as annotations. This helps to answer questions such as which run built it and what the workflow looked like.

• Create and reuse images in a single workflow:: Add snapshot: to a job to create one. The first run builds the snapshot; later runs reuse it and skip the snapshot job. Combine it with needs: to build a snapshot before the job that depends on it. You can also use image shorthands like e2e-base, which expands to {orgId}.registry.depot.dev/depot/snapshots/e2e-base:latest.

jobs:
  setup:
    runs-on: depot-ubuntu-latest
    snapshot: your-image:v1
    steps:
      - name: Install dependencies
        run: sudo apt-get update && sudo apt-get install -y your-tool-here

  work:
    needs: setup
    runs-on:
      image: your-image
    steps:
      - uses: actions/checkout@v4
      - run: your-tool-here do-the-thing

See the custom images guide for the full details.