docker-swarm-environment

The goal of this project is to have some examples deployed and running in a cluster of Docker Engines in swarm mode

Examples

Prerequisite

Initializing a cluster of Docker Engines in swarm mode

In the following example, two Docker machines will be created. One will act as the Manager (Leader) and the another will be the Worker. The manager machine will be called manager1 and the worker machine, worker1. Those docker machines will act as nodes in our Docker Swarm.

The setup of the cluster can be done automatically or manually. All the commands below must be executed in a terminal.

Automatically

Open a terminal and navigate to docker-swarm-environment root folder
Run the following script
```
./setup-docker-swarm.sh
```

Manually

Open a terminal and follow the steps below

Create Docker Machines

Run the command to create manager1 Docker Machine

docker-machine create --driver virtualbox --virtualbox-memory 8192 manager1

Run the command to create worker1 Docker Machine

docker-machine create --driver virtualbox --virtualbox-memory 8192 worker1

Check the status of all the Docker machines

docker-machine ls

You should see something similar to

NAME       ACTIVE   DRIVER       STATE     URL                         SWARM   DOCKER     ERRORS
manager1   -        virtualbox   Running   tcp://192.168.99.108:2376           v19.03.5
worker1    -        virtualbox   Running   tcp://192.168.99.109:2376           v19.03.5

Initialize a swarm

Export to MANAGER1_IP environment variable the ip address of the docker machine manager1
```
export MANAGER1_IP=$(docker-machine ip manager1)
```

Create a new swarm

docker-machine ssh manager1 docker swarm init --advertise-addr $MANAGER1_IP

Get the join-token for manager and worker. In case you want another node to join as a worker or as a manager, you must use those tokens

export MANAGER_TOKEN=$(docker-machine ssh manager1 docker swarm join-token --quiet manager)
export WORKER_TOKEN=$(docker-machine ssh manager1 docker swarm join-token --quiet worker)

Join to swarm worker1 as worker node.

docker-machine ssh worker1 docker swarm join --token $WORKER_TOKEN $MANAGER1_IP:2377

Create an overlay network

docker-machine ssh manager1 docker network create --driver overlay --attachable my-swarm-net

View swarm members & info

In a terminal, to view information about Swarm nodes run

docker-machine ssh manager1 docker node ls

It will prompt something like

ID                            HOSTNAME            STATUS              AVAILABILITY        MANAGER STATUS      ENGINE VERSION
60hh6m3rqqch60u7yza9lf6f5 *   manager1            Ready               Active              Leader              19.03.12
21urc24cgvwq6vjwuizy1bnar     worker1             Ready               Active                                  19.03.12

To see the current state and more information of the Swarm, run

docker-machine ssh manager1 docker info

The output will be similar to

Client:
 Debug Mode: false

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 19.03.12
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: active
  NodeID: 60hh6m3rqqch60u7yza9lf6f5
  Is Manager: true
  ClusterID: ocflb0g33nrvh79n85lob6lhc
  Managers: 1
  Nodes: 2
  Default Address Pool: 10.0.0.0/8
  SubnetSize: 24
  Data Path Port: 4789
  Orchestration:
   Task History Retention Limit: 5
  Raft:
   Snapshot Interval: 10000
   Number of Old Snapshots to Retain: 0
   Heartbeat Tick: 1
   Election Tick: 10
  Dispatcher:
   Heartbeat Period: 5 seconds
  CA Configuration:
   Expiry Duration: 3 months
   Force Rotate: 0
  Autolock Managers: false
  Root Rotation In Progress: false
  Node Address: 192.168.99.120
  Manager Addresses:
   192.168.99.120:2377
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
 init version: fec3683
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.19.130-boot2docker
 Operating System: Boot2Docker 19.03.12 (TCL 10.1)
 OSType: linux
 Architecture: x86_64
 CPUs: 1
 Total Memory: 7.79GiB
 Name: manager1
 ID: XAYV:H4TN:VI2S:D22T:PISE:G6QA:WMXJ:YKYB:QRBV:7ZXB:IRB3:XEM5
 Docker Root Dir: /mnt/sda1/var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
  provider=virtualbox
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false
 Product License: Community Engine

Cleaning up

In a terminal, run the command below o remove manager1 and worker1 docker machines

docker-machine rm worker1 manager1

Issues

Unable to upgrade this project because, while running setup-docker-swarm.sh script, I am getting the following error while creating manager1 and worker1

Error creating machine: Error checking the host: Error checking and/or regenerating the certs: There was an error validating certificates for host "192.168.99.132:2376": dial tcp 192.168.99.132:2376: i/o timeout

Besides, after the script finishes, I cannot access docker-daemon from manager1 and worker1 machines

$ eval $(docker-machine env manager1)
Error checking TLS connection: Error checking and/or regenerating the certs: There was an error validating certificates for host "192.168.99.131:2376": dial tcp 192.168.99.131:2376: i/o timeout
You can attempt to regenerate them using 'docker-machine regenerate-certs [name]'.
Be advised that this will trigger a Docker daemon restart which might stop running containers.

ivangfr/docker-swarm-environment