Docker compose just new containers - docker

Question

I have a docker-compose.yml file which brings up several services (redis, db, mongo, app). I made a script to bring up Docker environment up, but forcing you to forward environment variable which will act as a subdomain for the app (which is a PHP web app).
So for the app container I have:
app:
build:
context: .
dockerfile: ./docker/app/Dockerfile
image: xxx:xxx
container_name:my-app-${ENV}
restart: always
depends_on:
...
Now what I would like is to be able to fire up several apps which all depend on already brought up containers (for example app1.com and app2.com using the same DB).
So I was trying to bring it up by using:
ENV=$1 VIRTUAL_HOST=$1.com docker-compose up -d --build app
(I am using nginx container to enable virtual hosts, and $1 comes from bash script). But what this does is just rebuilds already existing app container and adds a new name.
Can I run docker-compose while building completely new app container, leaving others intact if they already exist?

Answer 1

You can run docker-compose up -d [NEW APPNAME] to build/run a specific app in the compose file
try...
docker-compose build [appName]
docker-compose up --no-deps -d [appName]
The first command builds the new container with [appName]
The 2nd command stops, destroys, and recreates just the [appName] container.
The --no-deps flag prevents Compose from recreating any services which [appName] depends on
your apps have to have different names since compose is going to build, stop, create all containers with that name.
so your compose file should be similar to:
app:
build:
context: .
dockerfile: ./docker/app/Dockerfile
image: xxx:xxx
container_name:my-app-${ENV}
restart: always
depends_on: ...
app2:
build:
context: .
dockerfile: ./docker/app/Dockerfile
image: xxx:xxx
container_name:my-app2-${ENV}
restart: always
depends_on: ...
app3:
build:
context: .
dockerfile: ./docker/app/Dockerfile
image: xxx:xxx
container_name:my-app3-${ENV}
restart: always
depends_on: ...
the above is using the same Dockerfile for app containers.
to use different dockerfiles for each app just change path of dockerfile