scottslowe-learning-tools/openstack-cli/README.md

Running an etcd-Backed Docker Swarm Cluster in Vagrant

These files were created to allow users to use Vagrant (http://www.vagrantup.com) quickly and relatively easily spin up a Docker Swarm (URL) cluster backed by etcd (URL). The configuration was tested using Vagrant 1.7.2, VMware Fusion 6.0.5, and the Vagrant VMware plugin.

Contents

• README.md: This file you're currently reading.

• servers.yml: This YAML file contains a list of VM definitions and associated configuration data. It is referenced by Vagrantfile when Vagrant instantiates the VMs.

• Vagrantfile: This file is used by Vagrant to spin up the virtual machines. This file is fairly extensively commented to help explain what's happening. You should be able to use this file unchanged; all the VM configuration options are stored outside this file.

• user_data: This file is used by the CoreOS cloud-init process to customize the CoreOS VMs upon instantiation. This file disables etcd and fleet, and configures Docker to listen on TCP port 2375.

Instructions

These instructions assume you've already installed VMware Fusion, Vagrant, and the Vagrant VMware plugin. Please refer to the documentation for those products for more information on installation or configuration.

NOT YET COMPLETE

1. Use vagrant box add to install an Ubuntu 14.04 x64 box for the vmware_fusion provider. I have a base box you can use for this purpose; to use my Ubuntu 14.04 x64 base box, add the box with vagrant box add slowe/ubuntu-trusty-x64.

2. Use vagrant box add to install a CoreOS base box. The Vagrantfile assumes you are using the Stable release of CoreOS (the box named coreos-stable). If the box name is different, you'll need to edit the Vagrantfile accordingly. You'll need to be sure to use a version of CoreOS that comes with Docker 1.4.0 or later, as Swarm requires Docker => 1.4.0. Note that CoreOS Stable 557.2.0 comes with Docker 1.4.1.

3. Place the files from the docker-swarm directory of this GitHub repository into a directory on your local system. You can clone the entire "learning-tools" repository (using git clone) or just download the specific files from the the docker-swarm folder.

4. Optionally, edit the servers.yml file to provide the specific details on the VMs that Vagrant should create. The Vagrantfile expects five values for each VM: name (the user-friendly name of the VM, which will also be used as the hostname for the guest OS inside the VM); box (the name of an Ubuntu 14.04 base box); ram (the amount of memory to be assigned to the VM); vcpu (the number of vCPUs that should be assigned to the VM); and priv_ip (an IP address to be statically assigned to the VM and is used for Consul cluster communications). It is not required to edit this file. You can use it without any modifications if desired.

5. Once you have edited servers.yml (and server.json, if you changed the IP addresses in servers.yml), use vagrant up to bring up the 6 systems. Three VMs will run the Consul cluster; the other 3 VMs will be running CoreOS and will make up the Docker Swarm cluster.

6. Once Vagrant has finished bringing up the VMs, simply use vagrant ssh consul-01 (where consul-01 is the value assigned to the first VM from servers.yml) to connect to the VM. No password should be required; it should use the default (insecure) SSH key. Once you are logged into the first VM, start the Consul agent with this command:

    sudo service consul start
   

   Repeat this process with the other two Consul nodes (consul-02 and consul-03 if you are using the default values in servers.yml). Once Consul has been started on all three nodes, verify Consul is running correctly by running this command:

    consul members
   

   Consul should report three members, using the IP addresses specified in servers.yml. If Consul does not report three members (a minimum to bootstrap the cluster) or if it reports an error, you'll need to resolve this before continuing.

7. Use vagrant ssh coreos-01 to log into the first CoreOS system (coreos-01 is the default name supplied in servers.yml; if you've changed the default name, modify your command appropriately). On this system, launch a Dockerized Consul client using the following command:

    docker run -d -p 8300:8300 -p 8301:8301 -p 8301:8301/udp -p 8302:8302 -p 8302:8302/udp -p 8400:8400 -p 8500:8500 -p 8600:8600/udp --name consul-coreos-01 -h coreos-01 progrium/consul -rejoin -advertise 192.168.1.104 -join 192.168.1.101
   

   If you've changed the IP addresses in servers.yml, be sure to modify the command above with the correct IP addresses (-advertise needs to specify the IP address assigned to the first CoreOS node, and -join needs to provide the IP address of one of the Consul nodes).

8. While still logged into the first CoreOS system, launch an instance of Registrator:

    docker run -d --name reg-coreos-01 -h coreos-01 -v /var/run/docker.sock:/tmp/docker.sock progrium/registrator consul://192.168.1.104:8500
   

   The IP address in this command must correspond to the IP address assigned to the CoreOS node as specified in servers.yml.

9. While still logged into the first CoreOS system, add it as the first node to a new Docker Swarm cluster using this command:

    docker run -d swarm join --addr=192.168.1.104:2375 consul://192.168.1.104:8500/swarm
   

10. Log out of the first CoreOS system and use vagrant ssh to log into the second and third CoreOS systems, repeating steps 7, 8, and 9 on each system. Be sure to change values for the --name and -h parameters on each system. Also be sure that the -advertise parameter for the Consul container maps to the IP address assigned to the host CoreOS VM (as provided in servers.yml). Make sure the consul:// parameter for the Registrator container points to the CoreOS VM's IP address as provided in servers.yml as well.

11. On the first CoreOS system (the one named coreos-01 by default), run a Docker container that will serve as the manager of the Swarm cluster. Launch the Swarm manager with this command:

    docker run -d -p 8333:2375 swarm manage consul://192.168.1.104:8500/swarm
    

    The IP address specified in the consul:// URL should correspond to the IP address assigned from servers.yml to this node. Make note of the port exposed by the -p command and the IP address of the node on which you're running the Swarm manager. This will be the endpoint against which you will run Docker commands against the cluster.

12. Verify the operation of the Swarm cluster by running this command (from any system that has connectivity to the CoreOS system running the Swarm manager container launched in the previous step):

    docker -H tcp://192.168.1.104:8333 info
    

    Docker should return information indicating that there are 10 containers running across 3 nodes, and then provide more information about each node and the containers running on that node.

13. Launch an Nginx container somewhere on the cluster with this command:

    docker -H tcp://192.168.1.104:8333 run -d --name www -p 80:80 nginx
    

If everything is working as expected, Docker will launch an Nginx container on one of the CoreOS nodes in the Swarm cluster, and Registrator will register the presence of the container in Consul for service discovery.

Enjoy!