Minimal ZNC Docker image

Dockerfile

Image size: <12 MB.

How to run

As with any Docker image, you can run it in a number of ways, some of these are shown below.

Note that you have to bind port 6667 on the container to a port on your host (3030 in the examples) to be able to connect your IRC client to ZNC and to be able to access the web interface.

Default webadmin username / password is admin / admin. Don't forget to change this before you expose the container to the world.

Examples:

All examples will assume that your container is named 'znc'.

Run the container straight up, this will create an unnamed data volume:

docker run -d --restart=unless-stopped --name znc -p 3030:6667 towb/znc

Create a named data volume and mount it to the container:

docker volume create --name zncdata
docker run -d --restart=unless-stopped --name znc -p 3030:6667 -v zncdata:/znc-data towb/znc

Mount a directory from your host to the container:

docker run -d --restart=unless-stopped --name znc -p 3030:6667 -v ~/.znc:/znc-data towb/znc

How to install modules

ZNC comes with a bunch of useful modules by default. There are a few ways you can add more modules if you need extra functionality.

This is what the ZNC wiki says about modules:

ZNC modules are written in C++ natively. There are also a couple of modules that embed an interpreter to allow you to load Perl, Python, or Tcl modules.

List of available ZNC modules you may want to install

Modules from znc-extra

Alpine Linux has a package called znc-extra that currently (2016-06-11) contains these mods

imapauth send_raw log shell notify_connect ctcoflood block_motd autovoice listsockets flooddetach clearbufferonmsg

All you have to do to install these mods is to execute the following on your main ZNC container:

docker exec znc sh -c "apk add --update znc-extra"

Install C++ modules:

To install and compile a C++ module a bunch of dependencies are needed. To avoid making the main ZNC container grow a lot in size we can compile the modules from a temporary container, like this:

# spin up a temporary container and mount it to your ZNC data volume
docker run --rm -it --volumes-from znc towb/znc sh
# install necessary dependencies
apk add --update znc-dev g++ openssl-dev wget
mkdir -p $ZNCMOD && cd &ZNCMOD
# now find a module you want to install and use wget to download it
wget https://raw.githubusercontent.com/FruitieX/znc-backlog/master/backlog.cpp
# ... and compile it
znc-buildmod backlog.cpp
# done! remove the source file if you care...
rm backlog.cpp
exit

The temporary container with many megabytes of dependencies are automatically removed, while the compiled module still exists on your main data volume. Use /znc loadmod or the webadmin to load your newly installed module.

Perl, Python and TCL modules

If you want to use any of these kinds of modules you have to install modperl, modpython or modtcl to your main znc container.

docker exec znc sh -c "apk add --update znc-modperl znc-modpython znc-modtcl"

Download the source code for your Perl, Python or TCL modules to your $ZNCMOD (/znc-data/modules) folder and use /znc loadmod or the webadmin to load the mod.

Backup

To create a backup run this:

docker run --rm --volumes-from znc -v $(pwd):/backup towb/znc tar zcvf /backup/backup.tar.gz /znc-data

To restore from a previous backup run this:

docker run --rm --volumes-from znc -v $(pwd):/backup towb/znc sh -c "apk add --update tar && tar zxvf /backup/backup.tar.gz -C /znc-data --strip-components=1"