Caddy Docker Image

Docker image with a customized build of Caddy

Features

• Caddy built from source
• DigitalOcean DNS provider
• Telemetry disabled
• Docker proxy Caddyfile loader plugin enabled, use -dockerproxy tags
• Container runs as unprivileged user (su-exec)

Usage

Run with built-in user

The image comes with a built-in unprivileged user caddy (UID 99 / GID 99) which is used by default if the container is started with the caddy command. All other commands are run as the container user, which is usually root unless started with --user.

$ docker run moccu/caddy:latest caddy

Run with host user

Caddy can be started with the UID and GID of a host user by setting $CADDYUID and $CADDYGID. This is the recommended way if certificates have to be mounted into the container.

$ id caddy
uid=123(caddy) gid=123(caddy) groups=123(caddy)

$ ls -ln /path/to/certificates
-rw------- 1 123 123 2818 Jan 01 2018 00:00 certificate.pem

$ docker run \
    -e CADDYUID=123 \
    -e CADDYGID=123 \
    -v /path/to/certificates:/certificates:ro \
    moccu/caddy:latest \
    caddy

Run as root

Caddy can be run as root although it is not recommended. Therefore $CADDYUID and $CADDYGID have to be set to 0.

$ docker run -e CADDYUID=0 -e CADDYGID=0 moccu/caddy:latest caddy

Options

$CADDYPATH

Caddy will use this folder to store assets. The default is /etc/caddy.

Note: Caddy will store Let's Encrypt certificates in a subfolder acme.

$CADDYPATH_SETOWNER

Change owner of $CADDYPATH to $CADDYUID and $CADDYGID if set to yes and container is started as root. The default is yes.

$CADDYUID

Caddy will be run in the container with this UID. The default is 99.

$CADDYGID

Caddy will be run in the container with this GID. The default is 99.

Configuration

To configure Caddy, create a configuration file according to the documentation, mount it and start caddy with the -conf attribute.

docker run \
    -v /path/to/Caddyfile:/etc/caddy/Caddyfile:ro \
    moccu/caddy:latest \
    caddy -conf /etc/caddy/Caddyfile

Alternatives

You may want to have a look at the Docker image of Abiola Ibrahim: abiosoft/caddy