Step 3
@@ -2052,3 +2056,262 @@ Now we can fetch the contents of our logfile using the usual container logging A +## 9. Simple Orchestration + + +### 9.1 Simple orchestration via docker compose + ++Step 1
+ +**Clone the source code for the app we will be working on.** + +```shell +git clone https://github.com/docker-training/orchestration-workshop + +cd orchestration-workshop/dockercoins +``` + ++Step 2
+ +**look at docker-compose.yaml file** + +```shell +vi docker-compose.yaml +``` + +```yaml +version: "3.7" + +services: + rng: + image: training/dockercoins-rng:1.0 + networks: + - dockercoins + ports: + - "8001:80" + + hasher: + image: training/dockercoins-hasher:1.0 + networks: + - dockercoins + ports: + - "8002:80" + + webui: + image: training/dockercoins-webui:1.0 + networks: + - dockercoins + ports: + - "8000:80" + redis: + image: redis + networks: + - dockercoins + + worker: + image: training/dockercoins-worker:1.0 + networks: + - dockercoins + +networks: + dockercoins: +``` + ++Step 3
+ +**Start the application** + + +```shell +docker compose up +``` + ++Step 4
+ +**Open the webui** + +```text +Open http:/+Step 5
+ +**Stop the application** + + +Hit `CTRL-C` + + +When we hit Ctrl-C, Compose tries to gracefully terminate all of the containers. + +After ten seconds (or if we press ^C again) it will forcibly kill them. + + +### 9.2 Structure of docker-compose.ym file + + +**Compose file structure :** + +A Compose file has multiple sections: + + - `version` is mandatory. (Typically use "3".) + - `services` is mandatory. Each service corresponds to a container. + - `networks` is optional and indicates to which networks containers should be connected. + (By default, containers will be connected on a private, per-compose-file network.) + - `volumes` is optional and can define volumes to be used and/or shared by the containers. + + +**Compose file versions :** + + - Version 1 is legacy and shouldn't be used. + (If you see a Compose file without version and services, it's a legacy v1 file.) + - Version 2 added support for networks and volumes. + - Version 3 added support for deployment options (scaling, rolling updates, etc). + +Typically use version: "3". + + +**Containers in docker-compose.yml :** + + - Each service in the YAML file must contain either build, or image. + - build indicates a path containing a Dockerfile. + - image indicates an image name (local, or on a registry). + + +Container parameters + - command indicates what to run (like CMD in a Dockerfile). + + - ports translates to one (or multiple) -p options to map ports. + You can specify local ports (i.e. x:y to expose public port x). + + - volumes translates to one (or multiple) -v options. + You can use relative paths here. + +**Environment variables :** + +We can use environment variables in Compose files + +(like $THIS or ${THAT}) + +We can provide default values, e.g. ${PORT-8000} + +Compose will also automatically load the environment file .env + +(it should contain VAR=value, one per line) + +This is a great way to customize build and run parameters + +(base image versions to use, build and run secrets, port numbers...) + + +### 9.3 Useful commands + +**Checking stack status** + +```shell +docker compose ps + +``` + +```text +NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS +dockercoins-hasher-1 training/dockercoins-hasher:1.0 "ruby hasher.rb" hasher 3 hours ago Up 6 seconds 0.0.0.0:8002->80/tcp, [::]:8002->80/tcp +dockercoins-redis-1 redis "docker-entrypoint.s…" redis 3 hours ago Up 6 seconds 6379/tcp +dockercoins-rng-1 training/dockercoins-rng:1.0 "python rng.py" rng 3 hours ago Up 6 seconds 0.0.0.0:8001->80/tcp, [::]:8001->80/tcp +dockercoins-webui-1 training/dockercoins-webui:1.0 "node webui.js" webui 3 hours ago Up 6 seconds 0.0.0.0:8000->80/tcp, [::]:8000->80/tcp +dockercoins-worker-1 training/dockercoins-worker:1.0 "python worker.py" worker 3 hours ago Up 6 seconds +``` + +**Cleaning up** + + +```shell +docker compose kill + +``` + +to stop application containers + + +```shell +docker compose rm + +``` +to remove containers + + +```shell +docker compose down + +``` +to stop and remove containers + + +# 10. Advanced Orchestration Swarm mode + + + +# Exercise 1 - Initialize Docker Swarm and Add Nodes to the Cluster + +In this exercise, you'll initialize Docker Swarm. Docker Swarm provides clustering and orchestration capabilities to allow you to turn a group of machines running Docker into a single, virtual Docker engine. + +## Initialize Swarm Manager Node + +1. Open a terminal in the same VM that you cloned this GitHub repository +2. Identify the IP address of your VM. In Linux, you can can open the Connection Information Prompt on the top right and find your address under the `IPv4` section. You can also use `ifconfig` to find the IP. It should look something like `192.168.x.x`. +3. Run the following command: +``` +docker swarm init --advertise-addr