Quick startup with Docker Compose

Overview:

Docker Compose - is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application's services.

Installation:

Download the Docker Compose version 1.23.2:

sudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

Apply executable permission:

sudo chmod +x /usr/local/bin/docker-compose

Test the installation:
```
docker-compose --version
```

Basic commands:

To create a compose service and startup in the background (before that create docker-compose.yml file):
```
docker-compose up -d
```
To list the containers created by Docker compose use:
```
docker-compose  ps
```
To specify compose file use -f flag:
```
docker-compose -f [filepath] up -d
```
To stop a service:
```
docker-compose stop
```
To start service:
```
docker-compose start
```
To restart a service:
```
docker-compose restart
```
To delete a service:
```
docker-compose down
```

Docker Compose file:

By default the docker-compose.yml is used to create compose services. You can specify any other file with -f flag
There are four types of top level keys in Docker compose file:
- version
- services
- networks
- volumes
Docker compose file format (version) is dependent on which version of Docker you are using

Example of docker-compose.yml file which utilizes the Dockerfile. To specify usage of Dockerfile use: build: context::

version: '3'
services:
my-service: # --> Name of the service
 build: # --> Specifies build context
   context: . # --> Path to the Dockerfile (both files in the same directory)
   args:
     - VERSION=v4.1
 ports:
   - "8080:4000"
 environment:
   - ENV=development

If changes were made into Dockerfile, before starting up a compose service you need to build it again:
```
docker-compose build
```
To bypass using the cache layers from previous built images use --no-cache flag:
```
docker-compose build --no-cache
```