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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
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.
EDIT:
Previous documentation source now leads to version history, you'll have to select the version of compose you're using and look for the reference.
For the lazy – v3 / v2 / v1
Side note: Syntax remains the same for all versions as of this edit
–
–
–
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:
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.
–
–
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/compose-file-v3/#driver
https://docs.docker.com/compose/compose-file/compose-file-v3/#driver_opts
–
–
–
–
- ./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
we have to create your own docker volume mapped with the host directory before we mention in the docker-compose.yml as external
1.Create volume named share
docker volume create --driver local \
--opt type=none \
--opt device=/home/mukundhan/share \
--opt o=bind share
2.Use it in your docker-compose
version: "3"
volumes:
share:
external: true
services:
workstation:
container_name: "workstation"
image: "ubuntu"
stdin_open: true
tty: true
volumes:
- share:/share:consistent
- ./source:/source:consistent
working_dir: /source
ipc: host
privileged: true
shm_size: '2gb'
container_name: "db"
image: "ubuntu"
stdin_open: true
tty: true
volumes:
- share:/share:consistent
working_dir: /source
ipc: host
This way we can share the same directory with many services running in different containers
In docker-compose.yml you can use this format:
volumes:
- host directory:container directory
according to their documentation
Here is my working example for Node.js application and MongoDB database :
docker-compose.yml
version: '3'
services:
my-app:
container_name: my-app-container
restart: always
build: .
volumes:
- './storage:/usr/src/app/storage'
ports:
- "3000:3000"
links:
- my-app-db
my-app-db:
container_name: my-app-db-container
image: mongo
restart: always
volumes:
- './data:/data/db'
ports:
- "27017:27017"
Dockerfile
FROM node:16.13.2
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY package.json ./
RUN npm install
COPY . /usr/src/app/
EXPOSE 3000
CMD [ "npm", "start"]
Sharing redis golang docker-compose.yaml. Using bind-mount I've achieved it.
version: '3.0'
services:
redisdb:
image: redis:6.0
restart: always
ports:
- "6379:6379"
container_name: redisdb-container
command: ["redis-server", "--bind", "redisdb", "--port", "6379"]
urlshortnerservice:
depends_on:
- redisdb
ports:
- "7777:7777"
restart: always
container_name: url-shortner-container
image: url-shortner-service
volumes:
- ../pkg/repository/filestorage:/pkg/repository/filestorage #host directory:container directory
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