best ci/cd tools for elixir applications in 2025

ci/cd for elixir: what makes it different

Elixir and Phoenix projects have their own CI/CD needs. Unlike a typical web framework, Phoenix ships with mix release — a built-in tool that packages your application into a self-contained tarball with the Erlang VM, your code, and all dependencies. That means your CI pipeline needs to compile Erlang and Elixir, run tests, maybe handle NIFs (native implemented functions), produce a release, and push a Docker image.

The community has converged on a few patterns: Docker-based builds, release tarballs, and increasingly, deployment via Kamal2. But the CI platform you choose determines how smoothly those patterns work.

Here's how the four main contenders stack up.

1. github actions — the default choice

If your code lives on GitHub, this is the path of least resistance. GitHub Actions has a rich marketplace of community actions specifically for Elixir — you'll find actions for setting up Erlang/OTP, caching Hex dependencies, and running mix commands with almost zero boilerplate.

Setup ease: Excellent. A working .github/workflows/elixir.yml can be written in 10 lines. The erlef/setup-beam action handles OTP and Elixir version selection.

Runner flexibility: GitHub-hosted runners cover most needs, but you can also connect self-hosted runners if you need custom hardware for NIF compilation or large test suites.

Elixir integration: The community has built mature workflows for caching deps and _build, running Credo and Dialyzer, and producing release artifacts. You can push the release tarball to a container registry or trigger a Kamal deploy directly from the workflow.

Best for: Teams already on GitHub who want the shortest setup time and access to a broad ecosystem of pre-built actions.

2. gitlab ci — best for self-hosted control

GitLab CI is a strong contender, especially for teams that want to keep their infrastructure in-house. GitLab's integrated container registry pairs naturally with Elixir's Docker-based deployment patterns1.

Setup ease: Good, but more configuration-heavy than GitHub Actions. You define your pipeline in .gitlab-ci.yml and GitLab handles the runner orchestration.

Runner flexibility: This is GitLab CI's superpower. You can spin up your own runners on any infrastructure — bare metal, Kubernetes, or cloud VMs. This matters for Elixir projects that need consistent NIF compilation environments or want to cache compiled BEAM files across pipeline runs.

Elixir integration: GitLab CI works well with Docker images that include Erlang and Elixir. You can build your release inside a container, push it to the GitLab registry, and deploy from there. The auto-scaling runner groups handle variable load from different branches.

Best for: Teams that need self-hosted runners, want a built-in container registry, or prefer keeping everything inside a single GitLab instance.

3. circleci — speed for large test suites

CircleCI built its reputation on performance. For Elixir projects with large test suites — think hundreds of ExUnit tests plus property-based testing — the speed difference can be noticeable.

Setup ease: Moderate. CircleCI uses a YAML config with a slightly steeper learning curve than GitHub Actions. Their orb system (reusable config packages) includes an Elixir orb that handles the basics.

Runner flexibility: CircleCI offers both cloud and self-hosted (Server) options. Their cloud runners are consistently fast, with good caching layers for Elixir dependencies.

Elixir integration: The Elixir orb handles OTP setup, dependency caching, and test running. CircleCI's parallel execution model lets you split your test suite across multiple containers — useful when your Phoenix test suite grows beyond a few minutes.

Best for: Larger Elixir projects where test suite runtime is a bottleneck, and teams willing to invest in config for speed gains.

4. travis ci — the reliable veteran

Travis CI was one of the first CI platforms to support Elixir natively, and it still works. It's less common in new projects today, but it remains a dependable option for existing pipelines.

Setup ease: Simple for basic workflows. Travis CI's .travis.yml has direct language support for Elixir — you just specify language: elixir and the OTP/Elixir versions.

Runner flexibility: Limited. Travis CI primarily offers cloud-hosted runners. Self-hosted options exist but aren't as polished as GitLab's or CircleCI's.

Elixir integration: Native Elixir support means less boilerplate. However, the ecosystem of community integrations is smaller than GitHub Actions, and updates to the Elixir build environment can lag behind new OTP releases.

Best for: Legacy projects already on Travis CI, or simple open-source Elixir libraries that don't need complex deployment pipelines.

comparison table

handling nifs, docker, and kamal

A few practical notes for Elixir CI/CD:

NIFs: Native implemented functions (like those used by Rustler or some database drivers) need the right C compiler and system libraries in your CI environment. Both GitHub Actions and GitLab CI let you use custom Docker images where you can pre-install these dependencies.

Dockerization: Most teams now build their release inside a Docker container during CI, then push the image to a registry. This works well on all four platforms, but GitLab CI's integrated container registry makes the push step trivial1.

Kamal deployment: Kamal (formerly MRSK) deploys Docker containers to remote servers using SSH. Your CI pipeline can trigger a Kamal deploy after a successful build. The AppSignal guide covers this workflow in detail2.

which one should you pick?

• Start with GitHub Actions if you're on GitHub and want the fastest setup with the richest Elixir ecosystem.
• Choose GitLab CI if you need self-hosted runners, a built-in container registry, or want to keep everything in one platform.
• Consider CircleCI if your test suite is large and you need parallel execution speed.
• Stick with Travis CI if you have an existing pipeline that works and doesn't need new features.

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