Larger changes

DOC.md

@@ -3,3 +3,6 @@
 Command for checking the docker node status: ```docker node ls```
 
 Command for using and attaching to LXC container (e.g. to 'worker1'): ```lxc-attach --name worker1```. 
+
+One possible limitation of this process, is that static ip assignments [are missing in docker
+swarm](https://forums.docker.com/t/docker-swarm-1-13-static-ips-for-containers/28060/13).

Makefile

@@ -1,4 +1,4 @@
-all: preautomation provision config swarm_deploy
+all: preautomation provision swarm_deploy
 
 preautomation:
 	/bin/bash ./ansible_install.sh
@@ -6,8 +6,5 @@ preautomation:
 provision:
 	/bin/bash ./ansible_provisioning.sh
 
-config:
-	/bin/bash ./ansible_swarm_config.sh
-
 swarm_deploy:
-	docker stack deploy -c swarm-galera.yml stack
+	/bin/bash ./ansible_swarm_config.sh

README.md

@@ -5,6 +5,9 @@
  * Ansible for automatic deployment
  * Galera-inside-docker for MariaDB clustering
 
+As an operating system we used the same for all docker nodes (Host machine & LXC containers):
+ * Debian 9.3 (Stretch) with Linux Kernel 4.9.0-5-amd64
+ 
 In more detail, the manager node is running on the host machine itself, while the provisioning of LXC containers permits the creation of multiple worker nodes on which the galera cluster runs, running on the same host without the need for separate worker machines.
 
 Ansible is used for the total automation of the deployment process, which is constituted after by the usage of Makefile, in the specific case of the combination of LXC with Docker swarm and Galera cluster, provided that all the necessary modules are available with the latest version of ansible which is installed automatically by make.

ansible.cfg

@@ -1,4 +1,5 @@
 [defaults]
 #added parameters for actual management of LXC nodes with ansible because of bridged networking packet loss
 gather_timeout = 30
-timeout = 30
+timeout = 45
+host_key_checking = False

roles/lxc_swarm/tasks/deploy.yml

@@ -0,0 +1,3 @@
+---
+- name: Deploy swarm stack
+  shell: docker stack deploy -c stack.yaml stack

roles/lxc_swarm/tasks/lxc_nodes.yml

@@ -18,6 +18,10 @@
     - "worker2"
   when: inventory_hostname in groups['manager']
 
+- name: Pause execution for 20 seconds
+  pause:
+    seconds: 20
+
 - name: Start lxc containers
   shell: lxc-start --name {{ item }}
   with_items:

roles/lxc_swarm/tasks/main.yml

@@ -20,3 +20,7 @@
 - include: Dockerfile.yml
   when: inventory_hostname in groups['workers']
   tags: swarm
+
+- include: deploy.yml
+  when: inventory_hostname in groups['manager']
+  tags: swarm

roles/lxc_swarm/tasks/swarm.yml

@@ -23,7 +23,8 @@
   file: 
      path: /var/container_data/mysql
      state: directory
-     mode: '0755'
+     mode: '0777'
+     recurse: true
   when: inventory_hostname in groups['workers']
 
 - name: Add docker labels for galera master and secondary nodes

roles/lxc_swarm/templates/Dockerfile.j2

@@ -6,6 +6,6 @@ RUN add-apt-repository "deb [arch=amd64,arm64,i386,ppc64el] http://mirrors.corei
 RUN apt-get update
 RUN apt install -y rsync mariadb-server-10.4 galera-4 mariadb-client-10.4
 RUN systemctl unmask mariadb
-COPY /opt/galera.cnf /etc/mysql/conf.d/galera.cnf
-RUN echo "wsrep_node_address=`ip a s eth0|grep inet|head -1|awk '{print $2}'|cut -d "/" -f 1`" >> /etc/mysql/conf.d/galera.cnf
+COPY galera.cnf /etc/mysql/conf.d/galera.cnf
+#RUN echo "wsrep_node_address=`ip a s eth0|grep inet|head -1|awk '{print $2}'|cut -d "/" -f 1`" >> /etc/mysql/conf.d/galera.cnf
 ENTRYPOINT ["mysqld","{{ extra_docker_options }}"]

roles/lxc_swarm/templates/galera.cnf.j2

@@ -10,7 +10,8 @@ wsrep_provider=/usr/lib/galera/libgalera_smm.so
 
 # Galera Cluster Configuration
 wsrep_cluster_name="galera_cluster"
-wsrep_cluster_address="gcomm://{% for host in groups['workers'] %} {{hostvars[host]['ansible_default_ipv4']['address']}} {% endfor %}"
+#wsrep_cluster_address="gcomm://{% for host in groups['workers'] %} {{hostvars[host]['ansible_default_ipv4']['address']}} {% endfor %}"
+wsrep_cluster_address="gcomm://{% for address in container_address %} {{address}} {% endfor %}"
 
 # Galera Synchronization Configuration
 wsrep_sst_method=rsync
@@ -18,4 +19,6 @@ wsrep_sst_method=rsync
 # Galera Node Configuration
 #wsrep_node_address="{{ ansible_default_ipv4.address }}"
 #wsrep_node_name="{{ ansible_hostname }}"
+
+wsrep_node_address="{{ container_address[0] if ansible_hostname in groups['workers'][0] else container_address[1] }}
 wsrep_node_name="{{ nodes[0] if ansible_hostname in groups['workers'][0] else nodes[1] }}"

roles/lxc_swarm/vars/main.yml

@@ -7,3 +7,6 @@ workers:
 nodes:
   - "node1"
   - "node2"
+container_address:
+  - "10.0.3.10"
+  - "10.0.3.11"

stack.yaml

@@ -14,22 +14,27 @@ services:
 #     - TASKID={{.Task.ID}}
 #     - TASKNAME={{.Task.Name}}
 #     - TASKREPID={{.Task.Slot}}
+
     hostname: node1
 
+    # Storage volume
     volumes:
 
       - /var/container_data/mysql:/var/lib/mysql
     
     networks:
       galera_net:
-
+        ipv4_address: 10.0.3.10
     deploy:
+      # Replicated mode
+      mode: replicated 
       replicas: 1
       restart_policy:
         delay: 10s
         max_attempts: 10
         window: 60s
       placement:
+        # Services must run only on workers with one service per container
         constraints:
           - node.labels.node1 == true
           - node.role == worker
@@ -54,22 +59,35 @@ services:
 
     image: ubuntu:galera-node-worker2
 
+#    environment:
+#     - NODENAME={{.Node.Hostname}}
+#     - NODEID={{.Node.ID}}
+#     - SERVICEID={{.Service.ID}}
+#     - SERVICENAME={{.Service.Name}}
+#     - TASKID={{.Task.ID}}
+#     - TASKNAME={{.Task.Name}}
+#     - TASKREPID={{.Task.Slot}}
+
     hostname: node2
 
+    # Storage volume
     volumes:
 
       - /var/container_data/mysql:/var/lib/mysql
 
     networks:
       galera_net:
-
+        ipv4_address: 10.0.3.11
     deploy:
+      # Replicated mode
+      mode: replicated
       replicas: 1
       restart_policy:
         delay: 10s
         max_attempts: 10
         window: 60s
       placement:
+        # Services must run only on workers with one service per container
         constraints:
           - node.labels.node2 == true
           - node.role == worker