3 KiB
page_title: Running a Redis service page_description: Installing and running an redis service page_keywords: docker, example, package installation, networking, redis
Redis Service
Note
:
- This example assumes you have Docker running in daemon mode. For more information please see Check your Docker install.
- If you don’t like sudo then see Giving non-root access
Very simple, no frills, Redis service attached to a web application using a link.
Create a docker container for Redis
Firstly, we create a Dockerfile for our new Redis
image.
FROM ubuntu:12.10
RUN apt-get update
RUN apt-get -y install redis-server
EXPOSE 6379
ENTRYPOINT ["/usr/bin/redis-server"]
Next we build an image from our Dockerfile.
Replace <your username> with your own user name.
sudo docker build -t <your username>/redis .
Run the service
Use the image we’ve just created and name your container
redis.
Running the service with -d runs the container in
detached mode, leaving the container running in the background.
Importantly, we’re not exposing any ports on our container. Instead we’re going to use a container link to provide access to our Redis database.
sudo docker run --name redis -d <your username>/redis
Create your web application container
Next we can create a container for our application. We’re going to use
the -link flag to create a link to the
redis container we’ve just created with an alias
of db. This will create a secure tunnel to the
redis container and expose the Redis instance
running inside that container to only this container.
sudo docker run --link redis:db -i -t ubuntu:12.10 /bin/bash
Once inside our freshly created container we need to install Redis to
get the redis-cli binary to test our connection.
apt-get update
apt-get -y install redis-server
service redis-server stop
As we’ve used the --link redis:db option, Docker
has created some environment variables in our web application container.
env | grep DB_
# Should return something similar to this with your values
DB_NAME=/violet_wolf/db
DB_PORT_6379_TCP_PORT=6379
DB_PORT=tcp://172.17.0.33:6379
DB_PORT_6379_TCP=tcp://172.17.0.33:6379
DB_PORT_6379_TCP_ADDR=172.17.0.33
DB_PORT_6379_TCP_PROTO=tcp
We can see that we’ve got a small list of environment variables prefixed
with DB. The DB comes from
the link alias specified when we launched the container. Let’s use the
DB_PORT_6379_TCP_ADDR variable to connect to our
Redis container.
redis-cli -h $DB_PORT_6379_TCP_ADDR
redis 172.17.0.33:6379>
redis 172.17.0.33:6379> set docker awesome
OK
redis 172.17.0.33:6379> get docker
"awesome"
redis 172.17.0.33:6379> exit
We could easily use this or other environment variables in our web
application to make a connection to our redis
container.