docker-asterisk

A set of Dockerfiles for running asterisk (and a FastAGI, one for PHP as it stands)

Also checkout my blog article @ dougbtv.com.

You can pull the image from dockerhub.

Which is as simple as running:

docker pull dougbtv/asterisk

What is it based on?

Asterisk 13 has been released!

• The Dockerfile is in asterisk/13/Dockerfile & available with docker pull dougbtv/asterisk13

Dockerfile in the root directory is:

• Based on Centos 6.5 base image
• Latest current available version of Asterisk 11, certified branch
  • ...More branches to come in the future.
• Available with docker pull dougbtv/asterisk

Check out the latest build!

The image is backed by bowline (a Docker build server, which I wrote) which watches for the latest tarball from downloads.asterisk.org, builds it into this docker image and then automatically pushes it to dockerhub.

Whenever a new build is created, the bot creates a pull request here, you can check out the latest merged pull requests, and you'll find a link to the results of the build posted on a paste bin. Here's an example automatically generated pull request, and here's an example log.

Bowline is under-work, but, was inspired by my Asterisk dockerfiles, seeing, it takes a while to compile Asterisk. (which is why it's nice to have an up-to-date image available)

Running it.

Asterisk with SIP tends to use a wide range of UDP ports (for RTP), so we have chosen to run the main aster container with --net=host option. We can now expose a range of ports with --expose=10000-20000, however, it can be very slow for a large number of ports.

We publish the port for the FastAGI container (which is running xinetd), and then we call the loopback address from AGI. You could separate these and run them on different hosts, should you choose.

An important function is that we need to access the CLI, which we use nsenter for, a shortcut script you'll run from the host is included here as tools/asterisk-cli.sh

This gist of how we get it going (and also memorialized in the tools/run.sh script) is:

NAME_ASTERISK=asterisk
NAME_FASTAGI=fastagi

# Run the fastagi container.
docker run \
    -p 4573:4573 \
    --name $NAME_FASTAGI
    -d -t dougbtv/fastagi

# Run the main asterisk container.
docker run \
    --name $NAME_ASTERISK \
    --net=host \
    -d -t dougbtv/asterisk

Building it.

Just issue, with your current-working-dir as the clone:

docker build -t dougbtv/asterisk .
docker build -t dougbtv/fastagi fastagi/.

About it.

Let's inspect the important files in the clone

.
|-- Dockerfile
|-- extensions.conf
|-- fastagi/
|   |-- agiLaunch.sh
|   |-- agi.php
|   |-- Dockerfile
|   `-- xinetd_agi
|-- iax.conf
|-- modules.conf
|-- README.md
`-- tools/
    |-- asterisk-cli.sh
    |-- clean.sh
    `-- run.sh

In the root dir:

• Dockerfile what makes the dockerhub image dougbtv/asterisk
• extensions.conf a very simple dialplan
• iax.conf a sample iax.conf which sets up an IAX2 client (for testing, really)

The fastagi/ dir:

• Dockerfile creates a Docker image that runs xinetd
• xinetd_agi the configuration for xinetd to run agiLaunch.sh
• agiLaunch.sh a shell script to kick off our xinetd process (a php script)
• agi.php a sample AGI script, replace this with your main AGI php processes

In the tools/ dir are some utilities I find myself using over and over:

• asterisk-cli.sh runs the nsenter command (note: image name must contain "asterisk" for it to detect it, easy enough to modify to fit your needs)
• clean.sh kills all containers, and removes them.
• run.sh a suggested way to run the Docker container.

...Not listed is the asterisk/ dir, where there's a sample build for Asterisk 13 beta. This Dockerfile works. Just getting the ducks in a row for when it's released.

Bowline

This bot is backed by bowline, which is a Docker build server / application, that I also wrote. It's actually while making these files I was inspired to build this.

This ensures there's a fresh image built and available on Dockerhub. There used to be a prototype here, alas, I have removed it -- I recommend checking out bowline if you're interested.

Lessons Learned

• I needed to disable the BUILD_NATIVE compiler flag. Without asterisk would throw an illegal instruction when run in a new place.
  • This stackexchange answer helped. Thanks arheops
  • Also this note about Asterisk 11 release provides some reference, too.