page_title: Dockerizing a Riak service page_description: Build a Docker image with Riak pre-installed page_keywords: docker, example, package installation, networking, riak
The goal of this example is to show you how to build a Docker image with Riak pre-installed.
Create an empty file called Dockerfile
:
$ touch Dockerfile
Next, define the parent image you want to use to build your image on top of. We'll use Ubuntu (tag: latest
), which is available on Docker Hub:
# Riak # # VERSION 0.1.0 # Use the Ubuntu base image provided by dotCloud FROM ubuntu:latest MAINTAINER Hector Castro hector@basho.com
Next, we update the APT cache and apply any updates:
# Update the APT cache RUN sed -i.bak 's/main$/main universe/' /etc/apt/sources.list RUN apt-get update RUN apt-get upgrade -y
After that, we install and setup a few dependencies:
curl
is used to download Basho's APT repository keylsb-release
helps us derive the Ubuntu release codenameopenssh-server
allows us to login to containers remotely and join Riak nodes to form a clustersupervisor
is used manage the OpenSSH and Riak processes# Install and setup project dependencies RUN apt-get install -y curl lsb-release supervisor openssh-server RUN mkdir -p /var/run/sshd RUN mkdir -p /var/log/supervisor RUN locale-gen en_US en_US.UTF-8 ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf RUN echo 'root:basho' | chpasswd
Next, we add Basho's APT repository:
RUN curl -s http://apt.basho.com/gpg/basho.apt.key | apt-key add -- RUN echo "deb http://apt.basho.com $(lsb_release -cs) main" > /etc/apt/sources.list.d/basho.list RUN apt-get update
After that, we install Riak and alter a few defaults:
# Install Riak and prepare it to run RUN apt-get install -y riak RUN sed -i.bak 's/127.0.0.1/0.0.0.0/' /etc/riak/app.config RUN echo "ulimit -n 4096" >> /etc/default/riak
Almost there. Next, we add a hack to get us by the lack of initctl
:
# Hack for initctl # See: https://github.com/dotcloud/docker/issues/1024 RUN dpkg-divert --local --rename --add /sbin/initctl RUN ln -s /bin/true /sbin/initctl
Then, we expose the Riak Protocol Buffers and HTTP interfaces, along with SSH:
# Expose Riak Protocol Buffers and HTTP interfaces, along with SSH EXPOSE 8087 8098 22
Finally, run supervisord
so that Riak and OpenSSH are started:
CMD ["/usr/bin/supervisord"]
Create an empty file called supervisord.conf
. Make sure it's at the same directory level as your Dockerfile
:
touch supervisord.conf
Populate it with the following program definitions:
[supervisord] nodaemon=true [program:sshd] command=/usr/sbin/sshd -D stdout_logfile=/var/log/supervisor/%(program_name)s.log stderr_logfile=/var/log/supervisor/%(program_name)s.log autorestart=true [program:riak] command=bash -c ". /etc/default/riak && /usr/sbin/riak console" pidfile=/var/log/riak/riak.pid stdout_logfile=/var/log/supervisor/%(program_name)s.log stderr_logfile=/var/log/supervisor/%(program_name)s.log
Now you should be able to build a Docker image for Riak:
$ docker build -t "<yourname>/riak" .
Riak is a distributed database. Many production deployments consist of at least five nodes. See the docker-riak project details on how to deploy a Riak cluster using Docker and Pipework.