How do I mount a host directory as a volume in docker compose

I have a development environment I'm dockerizing and I would like the ability to livereload my changes without having to rebuild docker images. I'm using docker compose because redis is one of my app's dependencies and I like being able to link a redis container

I have two containers defined in my docker-compose.yml:

node:
  build: ./node
  links:
    - redis
  ports:
    - "8080"
  env_file:
    - node-app.env

redis:
  image: redis
  ports:
    - "6379"

I've gotten to the point in my node app's dockerfile where I add a volume, but how do I mount the the host's directory in the volume so that all my live edits to the code are reflected in the container?

Here's my current Dockerfile:

# Set the base image to Ubuntu
FROM    node:boron

# File Author / Maintainer
MAINTAINER Amin Shah Gilani <[email protected]>

# Install nodemon
RUN npm install -g nodemon

# Add a /app volume
VOLUME ["/app"]

# TODO: link the current . to /app

# Define working directory
WORKDIR /app

# Run npm install
RUN npm install

# Expose port
EXPOSE  8080

# Run app using nodemon
CMD ["nodemon", "/app/app.js"]

My project looks like this:

/
- docker-compose.yml
- node-app.env
- node/
  - app.js
  - Dockerfile.js

Solution 1:

Checkout their documentation

From the looks of it you could do the following on your docker-compose.yml

volumes:
    - ./:/app

Where ./ is the host directory, and /app is the target directory for the containers.

For the lazy – v3 / v2 / v1

Side note: Syntax remains the same for all versions as of this edit

Solution 2:

There are a few options

Short Syntax

Using the host : guest format you can do any of the following:

volumes:
  # Just specify a path and let the Engine create a volume
  - /var/lib/mysql

  # Specify an absolute path mapping
  - /opt/data:/var/lib/mysql

  # Path on the host, relative to the Compose file
  - ./cache:/tmp/cache

  # User-relative path
  - ~/configs:/etc/configs/:ro

  # Named volume
  - datavolume:/var/lib/mysql

Long Syntax

As of docker-compose v3.2 you can use long syntax which allows the configuration of additional fields that can be expressed in the short form such as mount type (volume, bind or tmpfs) and read_only.

version: "3.2"
services:
  web:
    image: nginx:alpine
    ports:
      - "80:80"
    volumes:
      - type: volume
        source: mydata
        target: /data
        volume:
          nocopy: true
      - type: bind
        source: ./static
        target: /opt/app/static

networks:
  webnet:

volumes:
  mydata:

Check out https://docs.docker.com/compose/compose-file/#long-syntax-3 for more info.