A Docker image, based on Alpine Linux, for running Varnish HTTP Cache. This README only aims at getting you up and running with the Docker image, and documents only a very basic usage of Varnish. Consult the Varnish Documentation for more details.

For details about the image and its builds, see the Docker Hub page.

• Varnish listens on port 80.
• The default.vcl assumes a backend listening on localhost:8080.
• The default.vcl location us /etc/varnish/default.vcl

The images uses the following environmental variables. See the varnishd documentation for more details.

VCL_DIR '/etc/varnish'
VCL_FILE 'default.vcl'
VARNISH_CACHE_SIZE 64m
VARNISH_ADDRESS '0.0.0.0' 
VARNISH_PORT 80

A dummy backend JSON REST API is provided in order to ease testing:

1. Install JSON Server or any other equivalent dummy backend tool.
2. Serve the file using:

json-server --watch backend/db.json

The default JSON server port is 3000, so access the resouce on http://localhost:3000/posts, or change to another port using json-server --watch db.json --port 8080. The latter is reccomended since the default.vcl-file assumes a backend listening on port 8080. Verify that the dummy backend is running with curl localhost:3000/posts or curl localhost:8080/posts.

The image can be used directly or act as a base for you own image.

Out of the box the image assumes a backend on localhost:8080, which implies that the docker image has to be on the same network as the host, which works well for testing, but be aware of port collisions.

docker run -it --rm --name myvarnish --network host njmittet/alpine-varnish

Verify that Varnish works by requesting on port 80: curl localhost/posts.

Run with a different VCL-file using bind mounts:

# Replace default.vcl.
docker run -it --rm --name myvarnish --network host -v $(pwd)/my.vcl:/etc/varnish/default.vcl:ro  njmittet/alpine-varnish

# Use a VCl file with a different name. 
docker run -it --rm --name myvarnish --network host -v $(pwd)/my.vcl:/etc/varnish/my.vcl:ro -e VCL_FILE='my.vcl' njmittet/alpine-varnish

To change the port Varnish listens on, both the Varnish port and the port exposed by Docker must be changed:

docker run -it --rm --name myvarnish --network host -e VARNISH_PORT=9000 --expose=9000 njmittet/alpine-varnish

Create a Docker image containing your own VCL-file by creating a Dockerfile with the following content:

FROM njmittet/alpine-varnish:latest
COPY my.vcl $VCL_DIR/default.vcl

Create and run the your container:

docker build -t myvarnish .
$ docker run -it --rm --name myvarnish --network host myvarnish

See examples foran example cluster VCL-file. Consult the Varnish VCL Examples for a great list of other examples.

This image does not allow configuring the exact Varnish version, and will always use the latest version provided by the current Alpine version used when building the image.