Docker Swarm Example

File Explanations

• setup.sh - Installs docker-machine and virtualbox for single host testing
• install-swarm-no-machine.sh - Opens TCP Ports on Ubuntu Machine
• install-swarm-vb-driver.sh - (For Use with Virtualbox Driver) - Creates 3 docker machines using VB driver and copies into master node create-master-services.sh
• create-master-services.sh - Loads Docker Registry and Portainer Services, then self destructs.
• add-example-service - (For Use with Virtualbox Driver) - Adds example python image and load-example-service.sh into the master-node or specified machine NAME.
• load-example-service.sh - (For Use with Virtualbox Driver) - Loads example service into Docker Registry Service and self destructs
• notes - Research to possibly use later
• ubuntu-16.04-fix-vb.sh - Used to fix Kernel problem when attempting to install virtualbox on Ubuntu 16.04

Without machine

Pre-requirements: Create 3 Linux Machines that have Docker Engine running on them.

• Execute on Master Node.

  • docker swarm init --advertise-addr <master node ip>
    • To create Secondary Master, run command on master to get master token
    • docker swarm join-token manager
  • install-swarm-no-machine.sh on ubuntu Machines, it opens ports below
    • Open the following ports
      • TCP port 2377 for cluster management communications
      • TCP and UDP port 7946 for communication among nodes
      • UDP port 4789 for overlay network traffic

• Execute on Worker Nodes

  • docker swarm join --token <token> <master node ip>:2377
  • install-swarm-no-machine.sh on ubuntu Machines, it opens ports below
    • Open the following ports
      • TCP port 2377 for cluster management communications
      • TCP and UDP port 7946 for communication among nodes
      • UDP port 4789 for overlay network traffic

• add-example-service.sh to create Docker Registry and Run Portainer services

• Access UI Manager http://<Master Node Ip>:9000/

• If you prefer to just use the Docker Visualizer you would run this in the swarm.

docker service create \
  --name=viz \
  --publish=8080:8080/tcp \
  --constraint=node.role==manager \
  --mount=type=bind,src=/var/run/docker.sock,dst=/var/run/docker.sock \
  dockersamples/visualizer

Using Docker Machine

• Run setup.sh
• Run install-swarm-vb-driver.sh
• List Docker Machine docker-machine ls

NAME            ACTIVE   DRIVER       STATE     URL                         SWARM   DOCKER        ERRORS
swarm-master    -        virtualbox   Running   tcp://192.168.99.100:2376           v17.10.0-ce   
swarm-node-01   -        virtualbox   Running   tcp://192.168.99.101:2376           v17.10.0-ce   
swarm-node-02   -        virtualbox   Running   tcp://192.168.99.102:2376           v17.10.0-ce  

• To get IP from running Docker Machine docker-machine ip <name>
• Next Shell into each Docker Machine and complete the Without Machine Steps
  • docker-machine ssh <name>

Create Docker Registry in SWARM

• docker service create --name registry --publish 5000:5000 registry:2

Useful Commands

• Run docker info to view the current state of the swarm:
  • docker info

Containers: 2
Running: 0
Paused: 0
Stopped: 2
  ...snip...
Swarm: active
  NodeID: dxn1zf6l61qsb1josjja83ngz
  Is Manager: true
  Managers: 1
  Nodes: 1
  ...snip...

• Run the docker node ls command to view information about nodes:
  • docker node ls

ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
dxn1zf6l61qsb1josjja83ngz *  manager1  Ready   Active        Leader

The * next to the node ID indicates that you’re currently connected on this node.

• docker-machine ls - List Docker Machines
• docker-machine ip <machine name> - Get IP address of Docker Machine
• docker-machine ssh <machinename> - SSH into Docker Machine
• docker-machine scp -r <localFile> <machinename>:<pathToRemoteFile> - Copy file into Docker Machine
• docker swarm init --advertise-addr <manager ip> - Create Swarm
• docker info - Get Current State of Swarm
• docker node ls - List connected Nodes
• docker service create --replicas 1 --name <name> <container> <parameters> * Creates a Swarm Service
• docker service create --name <SERVICE-NAME> --publish <PUBLISHED-PORT>:<TARGET-PORT> <IMAGE> - create a Swarm Service mapped to port
• docker service ls - List of running services
• docker service inspect --pretty <name> - Gets details on a service "--pretty displays info in yaml, without is JSON"
• docker service ps <name> - See which node is running service.
• docker ps - Execute on working node to see details
• docker service scale <name>=<number of tasks> - Scale a service across nodes.
• docker service rm <name> - remove the service
• docker service update --image <imagename> <service-name> - Update running service
• docker service update --publish-add <PUBLISHED-PORT>:<TARGET-PORT> <service-name> - Update port on running service