How to rebuild go project efficiently while using Docker Compose?

Source – stackoverflow.com

This may be a stupid question, but I’m new to using Docker-compose. So far, I love it… but I’m having some long build times. I have a project with several dependencies, and I need to obviously rebuild the source every time I make a change. Right now, I’m calling docker-compose build to rebuild the container, followed by a docker-compose up. The problem is:

1. It’s rebuilding the entire container for every change I make to the source code (which takes a long time — fetching dependencies/etc). This is significantly slowing me down.
2. I really feel like I should just be able to run a command on the container to rebuild and then re-run the executable, like-so:

   docker-compose run web go build .
   docker-compose run web ./app

   or

   docker-compose run web go build .
   docker-compose restart
   

   This should work because I’m using a volume to share code amongst the host and container. There shouldn’t be a need to refetch all the dependencies. Shouldn’t it use the freshly built executable? However, this does not reflect the built changes and port forwarding appears to break.

For reference, here is my Dockerfile:

FROM golang:1.8

COPY . /go/src/github.com/codeblooded/test1
WORKDIR /go/src/github.com/codeblooded/test1

RUN echo $PATH
RUN go get -d -v ./...
RUN go install -v ./...

RUN go build -o test1 .
CMD ["test1"]
EXPOSE 3470

And my docker-compose.yml file:

version: '3'
services:
  postgres:
    image: postgres
    volumes:
      - ./db/data/psql:/var/lib/postgresql/data
      - ./db/schema:/db/schema
  redis:
    image: redis
    volumes:
      - ./db/data/redis:/data
  server:
    build: .
    command: test1
    volumes:
      - .:/go/src/github.com/codeblooded/test1
    ports:
      - "3470:3470"
    depends_on:
      - postgres
      - redis