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
This question is related to
docker
docker-compose
docker-volume
In docker-compose.yml you can use this format:
volumes:
- host directory:container directory
according to their documentation
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'
db:
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
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:
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 <[email protected]>
# 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
There are a few options
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
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.
Source: Stackoverflow.com