ac999a9cb2
Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@fosiki.com> (github: SvenDowideit)
95 lines
3 KiB
Markdown
95 lines
3 KiB
Markdown
page_title: Running a Redis service
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page_description: Installing and running an redis service
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page_keywords: docker, example, package installation, networking, redis
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# Redis Service
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Note
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- This example assumes you have Docker running in daemon mode. For
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more information please see [*Check your Docker
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install*](../hello_world/#running-examples).
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- **If you don’t like sudo** then see [*Giving non-root
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access*](../../installation/binaries/#dockergroup)
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Very simple, no frills, Redis service attached to a web application
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using a link.
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## Create a docker container for Redis
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Firstly, we create a `Dockerfile` for our new Redis
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image.
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FROM ubuntu:12.10
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RUN apt-get update
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RUN apt-get -y install redis-server
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EXPOSE 6379
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ENTRYPOINT ["/usr/bin/redis-server"]
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Next we build an image from our `Dockerfile`.
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Replace `<your username>` with your own user name.
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sudo docker build -t <your username>/redis .
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## Run the service
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Use the image we’ve just created and name your container
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`redis`.
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Running the service with `-d` runs the container in
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detached mode, leaving the container running in the background.
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Importantly, we’re not exposing any ports on our container. Instead
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we’re going to use a container link to provide access to our Redis
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database.
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sudo docker run --name redis -d <your username>/redis
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## Create your web application container
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Next we can create a container for our application. We’re going to use
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the `-link` flag to create a link to the
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`redis` container we’ve just created with an alias
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of `db`. This will create a secure tunnel to the
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`redis` container and expose the Redis instance
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running inside that container to only this container.
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sudo docker run --link redis:db -i -t ubuntu:12.10 /bin/bash
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Once inside our freshly created container we need to install Redis to
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get the `redis-cli` binary to test our connection.
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apt-get update
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apt-get -y install redis-server
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service redis-server stop
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As we’ve used the `--link redis:db` option, Docker
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has created some environment variables in our web application container.
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env | grep DB_
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# Should return something similar to this with your values
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DB_NAME=/violet_wolf/db
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DB_PORT_6379_TCP_PORT=6379
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DB_PORT=tcp://172.17.0.33:6379
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DB_PORT_6379_TCP=tcp://172.17.0.33:6379
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DB_PORT_6379_TCP_ADDR=172.17.0.33
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DB_PORT_6379_TCP_PROTO=tcp
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We can see that we’ve got a small list of environment variables prefixed
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with `DB`. The `DB` comes from
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the link alias specified when we launched the container. Let’s use the
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`DB_PORT_6379_TCP_ADDR` variable to connect to our
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Redis container.
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redis-cli -h $DB_PORT_6379_TCP_ADDR
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redis 172.17.0.33:6379>
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redis 172.17.0.33:6379> set docker awesome
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OK
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redis 172.17.0.33:6379> get docker
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"awesome"
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redis 172.17.0.33:6379> exit
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We could easily use this or other environment variables in our web
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application to make a connection to our `redis`
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container.
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