Extend prisma Docker image with another layer of node express image - docker

Question

I have got a prisma server image from dockerhub which is
prismagraphql/prisma:1.34
The above prisma image in order to run on PORT 4466 requires database connection string and the same is passed as an environment variable using a docker-compose file like shown below
prisma:
image: prismagraphql/prisma:1.34
ports:
- "4466:4466"
environment:
PRISMA_CONFIG: |
port: 4466
databases:
default:
connector: mongo
uri: mongodb://mongodb
I am trying to extend the above prisma server image like shown below.
FROM prismagraphql/prisma:1.34
RUN apk add --no-cache --repository http://dl-cdn.alpinelinux.org/alpine/v3.7/main/ nodejs=8.9.3-r1
WORKDIR /project
COPY . .
# To handle 'not get uid/gid' error in alpine linux set unsafe-perm true
RUN apk update && apk upgrade \
&& npm config set unsafe-perm true \
&& npm install --g yarn \
&& npm install -g prisma \
&& yarn install \
&& chmod +x ./entrypoint.sh \
&& chmod +x ./wait-for-it.sh
EXPOSE 4466 4000
ENTRYPOINT ["./entrypoint.sh"]
The entrypoint.sh file is like this
#!/bin/bash
# wait for the prisma service to start.
# then run prisma deploy (more on that later)
./wait-for-it.sh prisma:4466 -- prisma deploy
# go into the project...
cd /project
# run an npm command to use nodemon to start/watch the server
npm run start
In the above Dockerfile
I try installing nodejs app on existing prisma image from dockerhub.
This nodejs application is called prisma nexus. nexus requires to be connected to prisma on
localhost:4466 and nexus runs on port 4000.
When I run the below below image I get this error. i.e nexus(nodejs app) is not able to connect to prisma
Could not connect to server at http://localhost:4466. Please check if your server is running.
Finally I run the extended image like this
mongodb:
image: mongo:4.2
container_name: mongodb
volumes:
- ./mongo-volume:/data/db
ports:
- "27017:27017"
networks:
- prisma
prisma:
image: extended-image-here:1.0
container_name: prisma-server
restart: always
ports:
- "4466:4466"
- "4000:4000"
environment:
PRISMA_CONFIG: |
port: 4466
databases:
default:
connector: mongo
uri: mongodb://mongodb
What am I doing here? Please help.

Answer 1

I guess the reason why it does not work is because the image prismagraphql/prisma:1.34 has an entrypoint and at the end of the Dockerfile there is another entrypoint. Docker accepts only a single entrypoint in a Dockerfile...

Answer 2

First: In your code, you put the MongoDB container on a specific named network called prisma but you do not do the same thing with the prisma container. When using compose, containers on the same overlay network are resolved by name, but requests will only be routed between containers if they're on the same network.
Next: you shouldn't be running two servers in the same container. It's better to not build your app on top of the prisma image at all, but to build it instead on top of alpine or ubuntu (or anything else really). It should connect to another container where the prisma server is running. In the comments you say that you really want to do this, but you really shouldn't. It's not much harder to run a compose configuration on a client's server rather than a single container, but it is that much harder to run 2 servers in a single container.
Finally: The localhost reference (nexus you say?) should be configurable in some way. Find out how, and have it address something like 'http://prisma:4466'. In this way you'll have 3 containers -- mongodb, prisma, and your own app.