step9

Objectives

In this step, we will deploy the application on Docker Swarm.

What we will do

• Create a 2 nodes Swarm
• Run the Docker Compose application as a Stack

Creation of the Docker Swarm

We will use Docker Machine, with the virtualbox driver to create 2 hosts

Note: feel free to use the driver of your choice (aws, digitalocean,...).

docker-machine create --driver virtualbox node1
docker-machine create --driver virtualbox node2

Let's create the Swarm from node1, which make this guy the Leader of the future managers.

$ eval $(docker-machine env node1)

$ docker swarm init --advertise-addr eth1
Swarm initialized: current node (r6dr61umtoybvjtzk4etw8ffk) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-6bkjrg17vocrzi767d1wd6px586dy719vutigejlnt4jqq2hvc-4slm5bpf0cydkwq4up1jggh9n \
    192.168.99.100:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Following the instruction provided above, we can add node2 as a worker

$ eval $(docker-machine env node2)

$ docker swarm join \
     --token SWMTKN-1-6bkjrg17vocrzi767d1wd6px586dy719vutigejlnt4jqq2hvc-4slm5bpf0cydkwq4up1jggh9n \
     192.168.99.100:2377
This node joined a swarm as a worker.

Run the application

From Docker version 1.13, a Docker Compose application can be ran on a Swarm using the docker stack deploy command and specifying the docker-compose file. Let's deploy our application.

$ docker stack deploy -c docker-compose.yml iot
Creating network iot_default
Creating service iot_dashboard
Creating service iot_db
Creating service iot_api

The stack named iot has been created and contains 3 services

$ docker stack ls
NAME  SERVICES
iot   3

Let's have some additional details on the running services

$ docker service ls
ID            NAME           MODE        REPLICAS  IMAGE
gjrt9ox21epb  iot_db         replicated  1/1       influxdb:latest
wgyu3jvec8yc  iot_api        replicated  1/1       lucj/iot-api:v3
yyzjng3vk8d8  iot_dashboard  replicated  1/1       grafana/grafana:latest

The services are present, and seem to be running fine, we now check on which node each one is running.

$ docker service ps iot_db
ID            NAME      IMAGE            NODE   DESIRED STATE  CURRENT STATE          ERROR  PORTS
d72piw9k0fia  iot_db.1  influxdb:latest  node2  Running        Running 5 minutes ago

$ docker service ps iot_api
ID            NAME       IMAGE            NODE   DESIRED STATE  CURRENT STATE          ERROR  PORTS
ud2m9j1d3y3n  iot_api.1  lucj/iot-api:v3  node1  Running        Running 5 minutes ago

$ docker service ps iot_dashboard
ID            NAME             IMAGE                   NODE   DESIRED STATE  CURRENT STATE          ERROR  PORTS
l9j2va01ysuh  iot_dashboard.1  grafana/grafana:latest  node1  Running        Running 5 minutes ago

We can see from those outputs that instances (read containers) of both dashboard and api services are running on node1. The instance of db is running on node2.

Create the database

The routing mesh feature of Docker Swarm makes each port, published by a service, available on any node. As the InfluxDB is running on node2, let's access the administration interface from node1 and create the iot database.

Run the simulator

To verify once again the routing mesh feature, let's run the simulator towards node2 (as the API is running on node1).

./simulator.sh -h $(docker-machine ip node2) -p 1337

Visualize the data

As we did several times, we need to create a datasource and a dashboard form Grafana web interface. Once this is done, we should see the data sent by the simulator.

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