Custom Docker Builds

When you need full control over the build environment — a specific base image, complex system dependencies, or custom steps that Salus buildpacks can’t express — build your project from your own Dockerfile instead.

1. In Build Configurations, enable Custom Docker builds.
2. Set the Dockerfile path, relative to the project root (for example Dockerfile or docker/Dockerfile). A leading slash is optional — Salus trims it. The path can’t contain commas or trailing spaces.

Salus then builds your image straight from that Dockerfile, giving you complete control over how the app is compiled and packaged.

The build context is the repository root, even when the project builds from a subfolder. In a repository with several apps, write COPY paths from the root: COPY api/requirements.txt ., not COPY requirements.txt ..

Troubleshooting

• Docker build can’t find the Dockerfile. Confirm the Dockerfile path is relative to the project root and free of commas and trailing spaces.
• COPY fails with a file not found. The build context is the repository root, so paths in the Dockerfile start from there, not from the project’s subfolder.