This README is the one indexed from the repository at its latest ref, not from the tag for this version.

Skedjewel

A scheduled Sidekiq job runner written in Crystal.

Usage

Create a file at config/skedjewel.yml specifying the desired jobs schedule and other configuration.

Example:

# config/skedjewel.yml

config:
  app_redis_db: 0
  sidekiq_redis_db: 1
  time_zone: America/Chicago

jobs_by_rails_env:
  all:
    DataMonitors::Launcher: '**:07' # hourly at 7 minutes after
    TruncateTables: '**:**' # every minute
  production:
    CheckLinks::LaunchPageFetches: '04:16' # daily at 4:16am in configured time zone
    CollectRedisMetrics: '**:%5' # every 5 minutes
    PgHero::CaptureQueryStats: '**:%10+2' # every 10 minutes, with an offset of 2 (2, 12, 22, ...)
    PgHero::CaptureQueryStats: '%2:07' # every 2 hours at 7 minutes after the hour
    PgHero::CaptureQueryStats: '%2+1:56' # every 2 hours (in odd hours) at 56 minutes after the hour

You can print the Skedjewel version:

$ skedjewel --version

Installation

Start by adding something like this to your Procfile:

clock: bin/skedjewel

Now, you need to download the appropriate compiled binary and put it in the bin/ directory of your Rails app. Binaries are released only for Linux. The latest release binary is available here.

In development

On your development machine (if you are using Linux), you can manually download the appropriate binary and put it in the bin/ directory of your Rails project.

You'll also want to add /bin/skedjewel to your repository's .gitignore file.

In production

To use Skedjewel in production, you'll need to download the appropriate binary as part of your deploy process.

If you use Docker to build an image that can run Skedjewel, then you can add something like this to your Dockerfile:

# Download skedjewel binary.
ARG SKEDJEWEL_VERSION=v1.1.0
RUN curl --fail -L "https://github.com/davidrunger/skedjewel/releases/download/$SKEDJEWEL_VERSION/skedjewel-$SKEDJEWEL_VERSION-linux" > skedjewel && \
  mkdir -p /app/bin && \
  mv skedjewel /app/bin/ && \
  chmod a+x /app/bin/skedjewel

Or, perhaps your deploy process invokes the assets:precompile rake task? If so, then you could enhance that rake task with the following:

# lib/tasks/assets.rake

Rake::Task['assets:precompile'].enhance do
  # install skedjewel
  bin_path = Rails.root.join('bin')
  skedjewel_url =
    'https://github.com/davidrunger/skedjewel/releases/download/v0.0.2/skedjewel-v0.0.2-linux'
  system(<<~SH.squish, exception: true)
    curl -L #{skedjewel_url} > skedjewel &&
      mv skedjewel #{bin_path}/ &&
      chmod a+x #{bin_path}/skedjewel
  SH
end

Note that a Skedjewel version is hardcoded at two places in that URL. You'll update Skedjewel by updating those version numbers.

Verifying release assets

Release binaries are built by GitHub Actions from version tags and include signed build provenance attestations. Release-level verification applies to releases published after GitHub release immutability is enabled. See RELEASING.md for the maintainer setup and release process.

After downloading a release binary, set TAG to its release tag and ASSET to the downloaded file's path, then run:

TAG=v2.2.0
ASSET=./skedjewel-v2.2.0-linux

gh release verify "$TAG" --repo davidrunger/skedjewel
gh release verify-asset "$TAG" "$ASSET" --repo davidrunger/skedjewel
gh attestation verify "$ASSET" \
  --repo davidrunger/skedjewel \
  --signer-workflow davidrunger/skedjewel/.github/workflows/release.yml \
  --source-ref "refs/tags/$TAG"

gh release verify verifies GitHub's signed attestation for the release, including its tag, commit, and asset digests. gh release verify-asset additionally verifies that the local file has the same digest as the asset published in that release. These commands establish release integrity, but do not establish how the binary was built.

gh attestation verify verifies the binary's signed SLSA build provenance. With the repository, workflow, and tag restrictions above, it verifies that the binary was attested by this repository's release workflow for the specified tag. This provides evidence that the binary was built by that GitHub Actions workflow from the source associated with that tag. It does not prove that the source code is safe or that an independent rebuild would produce identical bytes.

These commands require GitHub CLI v2.81.0 or newer. Use a current GitHub CLI release; versions before v2.93.0 contain a security issue affecting these verification commands.

An easier-to-install alternative: Schedjewel

Schedjewel is a Ruby gem with very similar functionality. It's also maintained by me, @davidrunger.

Installing Schedjewel as a gem in your project is simpler than installing the Skedjewel binaries, so if you're looking for convenience and simplicity, you might consider using Schedjewel instead. The primary downside of using Schedjewel rather than Skedjewel is that Schedjewel (the Ruby gem) uses more memory.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/davidrunger/skedjewel.

License

This library is available as open source under the terms of the MIT License.