Dockle
Dockle is free, open-source software for linting container images on Linux, macOS and Windows.
What Dockle is
Dockle is free, open-source software for linting container images on Linux, macOS and Windows. It scans images for vulnerabilities and checks Docker and Linux settings against image best practices, including checkpoints from the CIS Docker Image Benchmarks. Checks include issues such as empty passwords and duplicate user or group IDs. Results can be displayed or saved as JSON or SARIF. Users can change exit levels or ignore selected checkpoints through command options, environment variables or a `.dockleignore` file. Dockle supports CI workflows with a GitHub Action and examples for Travis CI, CircleCI and GitLab CI. It documents access to private images in Docker Hub, Amazon ECR, Google Container Registry and self-hosted registries. An image archive created with `docker save` can be scanned with `--input`. Installation options include package managers, binaries, source builds, version managers and Docker. It is licensed under Apache-2.0.
Good
- Scans vulnerabilities and Docker best practices
- JSON and SARIF output
- GitHub Action and CI examples
- Private registry access documented
- Can scan saved image archives
Watch out
- Self-hosted operation is required
- Private registry credentials use environment variables
- Checks may require configuration to ignore checkpoints
Who it suits
It suits teams and developers who need self-hosted container image checks in local workflows or continuous integration across major desktop platforms.
Verdict
Dockle offers configurable image linting with registry, archive and CI workflows. Its cross-platform installation and structured outputs make it practical for teams managing container images in their own environments.
Plans and prices
From Dockle's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Dockle | Free | Open-source container image linter |
The facts
Each one read from Dockle's own pages, with the date it was checked.
What it does
- CIS benchmarks
- Its security checkpoints include CIS Docker Image Benchmarks.checked 8 Oct 2026
- CI support
- The project documents CI usage and provides a GitHub Action, with examples for Travis CI, CircleCI, and GitLab CI.checked 8 Oct 2026
- Configurable checks
- Users can change the exit level and ignore selected checkpoints using command options, environment variables, or a .dockleignore file.checked 8 Oct 2026
- Image checks
- It checks container images for vulnerabilities and Docker image best practices.checked 8 Oct 2026
- Image files
- Dockle can scan an image archive created with docker save by using its --input option.checked 8 Oct 2026
- Installation
- Installation options include Homebrew, RHEL/CentOS, Debian/Ubuntu, Arch Linux, Windows binaries, version managers, source builds, and Docker.checked 8 Oct 2026
- License
- The repository lists the project under the Apache-2.0 license.checked 8 Oct 2026
- Other checkpoints
- Dockle also checks Docker-specific and Linux-specific image settings, including empty passwords and duplicate UIDs or groups.checked 8 Oct 2026
- Output formats
- It can display or save results in JSON and SARIF formats.checked 8 Oct 2026
- Private registry credentials
- For private registry access, the documentation describes configuring credentials through environment variables and advises against using them on a local machine.checked 8 Oct 2026
- Purpose
- Dockle is a container image linter for security that helps build best-practice Docker images.checked 8 Oct 2026
- Registry integrations
- Dockle documents access to private images in Docker Hub, Amazon ECR, Google Container Registry, and self-hosted registries.checked 8 Oct 2026
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