0.setup

Example Docker Setup

The examples in the /docs section show different aspects of Oracle Coherence functionality running in a multi-host Docker environment. The examples require a Docker environment with two Docker hosts configured to run Docker's overlay network, i.e. with a suitable key store configured. The easiest way to configure a suitable example environment is to use Docker Machine to set up temporary virtual machines that can then be disposed of afterwards.

1. Create a machine to run the key store required to use Docker's overlay network using the following command:

   $ docker-machine create -d virtualbox coh-keystore

   This creates a Docker Machine VM called coh-keystore

2. Set your local environment to the coh-keystore machine:

   $ eval "$(docker-machine env coh-keystore)"

3. Start a progrium/consul container to run the Consul key store on the coh-keystore machine:

   $ docker run -d -p "8500:8500" -h "consul" progrium/consul -server -bootstrap

4. Create a second machine to run Coherence containers:

   docker-machine create -d virtualbox \
   --engine-opt="cluster-store=consul://$(docker-machine ip coh-keystore):8500" \
   --engine-opt="cluster-advertise=eth1:2376" \
   coh-demo0
   

    This creates a Docker Machine VM called `coh-demo0` that is configured to use the Consul keystore created above.
    
5. Create a third machine to run Coherence containers:

    ```
    docker-machine create -d virtualbox \
    --engine-opt="cluster-store=consul://$(docker-machine ip coh-keystore):8500" \
    --engine-opt="cluster-advertise=eth1:2376" \
    coh-demo1
    ```

    This creates a Docker Machine VM called `coh-demo1` that is configured to use the Consul keystore created above.
    
6. Create an overlay network to use in the overlay examples. This command only needs to be executed for one of the cluster machines so the `$(docker-machine config coh-demo0)` argument is used to target the command to the `coh-demo0` machine: 
    
    ```
    $ docker $(docker-machine config coh-demo0) network create \
    --driver overlay coh-net

This creates an overlay network called `coh-net` available to both the `coh-demo0` and `coh-demo1` machines.

7. Build the Java 8 image. Change directory to the OracleJDK/java-8 directory, make sure the required JRE install (as documented in the OracleJDK section) has been downloaded to that directory, and then run these commands:

   $ eval $(docker-machine env coh-demo0)

   $ sh build.sh

   $ eval $(docker-machine env coh-demo1)

   $ sh build.sh

8. Build the Coherence image. Change directory to the OracleCoherence/dockerfiles/12.2.1 directory, make sure that the Coherence 12.2.1 Standalone installer has been downloaded to the directory and run these commands:

   $ eval $(docker-machine env coh-demo0)

   $ sh buildDockerImage.sh -s

   $ eval $(docker-machine env coh-demo1)

   $ sh buildDockerImage.sh -s

9. As these example uses Docker Machine, the virtual machines need to be configured to correctly route Coherence multicast traffic over the correct network interface. A Docker Machine VM has multiple NICs and inter-machine multicast traffic will only work over one of them. The following step would not normally be required on Docker hosts that are real physical boxes or that are configured to correctly route multicast traffic.

   Run the following commands to route multicast traffic over the eth1 interface, which is externally visible to other machines:

   docker-machine ssh coh-demo0 'route add -net 224.0.0.0 netmask 224.0.0.0 dev eth1

   docker-machine ssh coh-demo1 'route add -net 224.0.0.0 netmask 224.0.0.0 dev eth1

There should now be three Docker Machine VMs running, one running the Consul key store and two with the oracle/coherence:12.2.1.0.0-standalone image installed.