ts-node app running using docker run but not docker compose - node.js

Question

Using this Dockerfile:
FROM node:14-alpine
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD ["npm", "start"]
docker build -t ts-node-api .
docker run -it --entrypoint sh --expose 3000 -it ts-node-api
or
docker run --expose 3000 -it steve/ts-node-api
works correctly, apart from not connected to the db, which is a later problem.
However, run the same Dockerfile as such:
version: "3"
services:
mongo:
image: mongo
volumes:
- ./data:/data/db
ports:
- "27017:27017"
ts-node-api:
depends_on:
- mongo
build:
context: .
dockerfile: services/ts-node-api/Dockerfile
ports:
- 3000:3000
using docker compose results in:
=> ERROR [6/6] RUN npm run build 0.3s
------
> [6/6] RUN npm run build:
#9 0.244 npm ERR! code ENOENT
#9 0.244 npm ERR! syscall open
#9 0.244 npm ERR! path /usr/src/app/package.json
#9 0.245 npm ERR! errno -2
#9 0.246 npm ERR! enoent ENOENT: no such file or directory, open '/usr/src/app/package.json'
#9 0.246 npm ERR! enoent This is related to npm not being able to find a file.
#9 0.246 npm ERR! enoent
#9 0.248
#9 0.249 npm ERR! A complete log of this run can be found in:
#9 0.249 npm ERR! /root/.npm/_logs/2022-08-26T18_29_26_477Z-debug.log
Any help would be greatly appreciated, thank you.

Answer 1

Your two build setups are different. The docker build command you show is equivalent to
build:
context: .
# dockerfile: Dockerfile
which has a shorthand
build: .
If the Compose file is in an ancestor directory of the service, so you cd into that subdirectory and then run the docker build . command, you need to use that subdirectory name as the context directory
build: services/ts-node-api
The Compose block you show is equivalent to
docker build -f services/ts-node-api/Dockerfile .
which causes COPY commands to be interpreted relative to the root of your tree, not the directory containing your application (compare the two context: directories), which is why it doesn't work as expected.