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

问题

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 <amin@gilani.me>

# 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

回答1:

Checkout their documentation

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

volumes:
    - ./:/app

回答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.

回答3:

If you would like to mount a particular host directory (/disk1/prometheus-data in the following example) as a volume in the volumes section of the Docker Compose YAML file, you can do it as below, e.g.:

version: '3'

services:
  prometheus:
    image: prom/prometheus
    volumes:
      - prometheus-data:/prometheus

volumes:
  prometheus-data:
    driver: local
    driver_opts:
      o: bind
      type: none
      device: /disk1/prometheus-data

By the way, in prometheus's Dockerfile, You may find the VOLUME instruction as below, which marks it as holding externally mounted volumes from native host, etc. (Note however: this instruction is not a must though to mount a volume into a container.):

Dockerfile

...
VOLUME ["/prometheus"]
...

Refs:

• https://docs.docker.com/compose/compose-file/#driver
• https://docs.docker.com/compose/compose-file/#driver_opts

回答4:

It was two things:

I added the volume in docker-compose.yml:

node:
    volumes:
        - ./node:/app

I moved the npm install && nodemon app.js pieces into a CMD because RUN adds things to the Union File System, and my volume isn't part of UFS.

# Set the base image to Ubuntu
FROM    node:boron

# File Author / Maintainer
MAINTAINER Amin Shah Gilani <amin@gilani.me>

# Install nodemon
RUN npm install -g nodemon

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

# Define working directory
WORKDIR /app

# Expose port
EXPOSE  8080

# Run npm install
CMD npm install && nodemon app.js

来源：https://stackoverflow.com/questions/40905761/how-do-i-mount-a-host-directory-as-a-volume-in-docker-compose