Docker image with curl

Why was this image created?

As you may know, curl comprises two components: the library with the same name and a dynamically linked executable file. When using curl in Docker images based on scratch (empty file system), we have two options:

• Include all required libraries for curl in the image.
• Compile curl as a static binary.

This repository contains a Dockerfile using the second approach (the main idea was found here).

Important note: Some curl features (such as gopher, imap, proxy, and others) have been disabled for binary file size reasons.

Another important change is that when the --fail flag is used, the exit code on error is 1 (instead of 22). You can find more details about the patch here. This change was made for use in Docker health checks (the possible exit codes for Docker health checks are: 0 for success, indicating the container is healthy and ready for use, and 1 for unhealthy, indicating the container is not working correctly):

$ docker run --rm tarampampam/curl -s --fail --show-error https://httpbin.org/status/401
curl: (22) The requested URL returned error: 401

$ echo "Exit code: $?"
Exit code: 1

Image

Registry	Image
GitHub Container Registry	ghcr.io/tarampampam/curl
Docker Hub	tarampampam/curl

Images, based on the alpine image has a postfix -alpine in the tag name, e.g.: tarampampam/curl:8.0.1-alpine.

Following platforms for this image are available:

$ docker run --rm mplatform/mquery tarampampam/curl:latest
Image: tarampampam/curl:latest
 * Manifest List: Yes (Image type: application/vnd.docker.distribution.manifest.list.v2+json)
 * Supported platforms:
   - linux/amd64
   - linux/386
   - linux/arm64
   - linux/arm/v6
   - linux/arm/v7

How can I use this?

For example - as a docker healthcheck (note - we use scratch as a base):

# use empty filesystem
FROM scratch

# import some executable application
COPY --from=docker.io/containous/whoami:v1.5.0 /whoami /whoami

# import curl from current repository image
COPY --from=ghcr.io/tarampampam/curl:8.6.0 /bin/curl /bin/curl

# Docs: <https://docs.docker.com/engine/reference/builder/#healthcheck>
HEALTHCHECK --interval=5s --timeout=2s --retries=2 --start-period=2s CMD [ \
    "curl", "--fail", "http://127.0.0.1:80/" \
]

ENTRYPOINT ["/whoami"]

After that you can build this image, run, and watch the state:

$ docker build --tag healthcheck-test:local .
...
Successfully built 72bf22424af7
Successfully tagged healthcheck-test:local

$ docker run --rm -d --name healthcheck-test healthcheck-test:local
b3f20332ac19b42dfed03021c0b90b3650b9a7efbaea7c8800d35551e43d35d7

$ docker ps --filter 'name=healthcheck-test' --format '{{.Status}}'
Up 1 minutes (healthy)

$ docker kill healthcheck-test

Releasing

New versions publishing is very simple - just make required changes in this repository and "publish" new release using repo releases page.

Docker images will be build and published automatically.

The new release will overwrite the latest and latest-alpine docker image tags in both registers.

Support

If you find any package errors, please, make an issue in current repository.

License

WTFPL. Use anywhere for your pleasure.