Install skydns and skydock

* Skydns servers are configured in a cluster. This requires a new `dns_leader` Ansible variable. * Skydock is run on each server and talks to the master skydns (it should talk to the local one, but a bug in the skydns code prevents it, see comments) * Some updates to the README
1uptalent · Feb 11, 2014 · e226b0b · e226b0b
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diff --git a/README.md b/README.md
@@ -14,8 +14,8 @@ WIP for managing a collection of docker hosts
 
 ```
 host1 ansible_ssh_port=2251 host_id=1 other_hosts="192.168.50.102 192.168.50.103"
-host2 ansible_ssh_port=2252 host_id=2 other_hosts="192.168.50.101"
-host3 ansible_ssh_port=2253 host_id=3 other_hosts="192.168.50.101"
+host2 ansible_ssh_port=2252 host_id=2 other_hosts="192.168.50.101" dns_leader=10.10.1.1
+host3 ansible_ssh_port=2253 host_id=3 other_hosts="192.168.50.101" dns_leader=10.10.1.1
 ```
 
 ##Configure the servers as docker's hosts
@@ -38,8 +38,8 @@ ANSIBLE_HOST_KEY_CHECKING=False ansible-playbook --user=vagrant --private-key=~/
 
 ```
 public_ip_address_host_1 host_id=1 other_hosts="private_ip_address_host_2 private_ip_address_host_3"
-public_ip_address_host_2 host_id=2 other_hosts="private_ip_address_host_1"
-public_ip_address_host_3 host_id=3 other_hosts="private_ip_address_host_1"
+public_ip_address_host_2 host_id=2 other_hosts="private_ip_address_host_1" dns_leader=10.10.1.1
+public_ip_address_host_3 host_id=3 other_hosts="private_ip_address_host_1" dns_leader=10.10.1.1
 ```
 
 ##Prepare the servers
@@ -54,10 +54,11 @@ ANSIBLE_HOST_KEY_CHECKING=False ansible-playbook --inventory-file=docker_hosts a
 ANSIBLE_HOST_KEY_CHECKING=False ansible-playbook --user=ubuntu --inventory-file=docker_hosts ansible-playbooks/docker.yml
 ```
 
-##Notes
+#Notes
 
 * The host 1 will act as *network concentrator*, all traffic will pass through it.
 * The docker service will be available in IP address 10.10.X.1, X is the `host_id`
 * The containers in host X will have an IP address like 10.10.X.Y, X is the `host_id`
+* The `dns_leader` parameter must point point to the ip of the docker bridge
 
 **ENJOY!**
diff --git a/ansible-playbooks/docker.yml b/ansible-playbooks/docker.yml
@@ -88,7 +88,99 @@
       apt_repository: repo='deb http://get.docker.io/ubuntu docker main' state=present
       tags: docker repo
 
+    - name: Create the docker group
+      user: name=docker state=present
+
+    - name: Add ansible user to the docker group
+      user: name={{ ansible_ssh_user }} groups=docker append=true
+
     - name: Install docker
       apt: pkg=lxc-docker state=present update_cache=yes cache_valid_time=14400
       tags: docker repo
 
+    - name: Refresh facts to learn about the new network interfaces
+      setup: ''
+
+    - name: Reconfigure docker
+      lineinfile: >
+        dest=/etc/init/docker.conf
+        state=present
+        regexp='( *DOCKER_OPTS=).*' 
+        line='\1"--dns {{ facter_ipaddress_docker0 }}"'
+        backrefs=yes
+
+    - name: Apply docker configuration
+      shell: stop docker ; start docker
+
+    - name: Pull Skydns
+      command: docker pull crosbymichael/skydns
+
+    - name: Pull Skydock
+      command: docker pull crosbymichael/skydock
+
+    - name: Install skydns master
+      command: >
+        docker run -d 
+                   -p {{ facter_ipaddress_docker0 }}:53:53/udp 
+                   -p {{ facter_ipaddress_docker0 }}:8080:8080/tcp 
+                   -name skydns
+                   --entrypoint /bin/bash
+                   crosbymichael/skydns
+                   -c 'skydns -http $(hostname -i):8080 -dns $(hostname -i):53 -nameserver 8.8.8.8:53 -domain docker'
+      when: dns_leader is not defined
+
+    - name: Wait for master
+      wait_for: host={{ facter_ipaddress_docker0 }} port=8080 timeout=30
+      when: dns_leader is not defined
+
+    - name: Install skydock on master
+      command: >
+        docker run -d -v /var/run/docker.sock:/docker.sock 
+                   -name skydock 
+                   -link skydns:skydns 
+                   crosbymichael/skydock 
+                   -ttl 30 
+                   -s /docker.sock 
+                   -environment dev 
+                   -domain docker
+      when: dns_leader is not defined
+
+    - name: Install skydns on slaves
+      command: >
+        docker run -d -p {{ facter_ipaddress_docker0 }}:53:53/udp 
+                   -name skydns
+                   --dns {{ dns_leader }}
+                   --entrypoint bash
+                   crosbymichael/skydns
+                   -c 'skydns -http $(hostname -i):8080 -dns $(hostname -i):53 -nameserver 8.8.8.8:53 -domain docker -join master.docker:8080'
+      when: dns_leader is defined
+
+    - name: Install skydock on slaves
+      #
+      # BUG: This should work, but the skydns api client does not handle the redirection to the master
+      # See: https://github.com/skynetservices/skydns/pull/79
+      #
+      # command: >
+      #   docker run -d -v /var/run/docker.sock:/docker.sock 
+      #              -name skydock 
+      #              -link skydns:skydns 
+      #              crosbymichael/skydock 
+      #              -ttl 30 
+      #              -s /docker.sock 
+      #              -environment dev 
+      #              -domain docker
+
+      #
+      # WORKAROUND: Set the skydnsUrl to the master. I guess this can break if a new master is elected
+      command: >
+        docker run -d -v /var/run/docker.sock:/docker.sock 
+                   -name skydock 
+                   crosbymichael/skydock 
+                   --skydns http://master.docker:8080
+                   -ttl 30 
+                   -s /docker.sock 
+                   -environment dev 
+                   -domain docker
+      when: dns_leader is defined
+
+