How should I run thumbd as a service inside a Docker container?

Question

I'd like to run thumbd as a service inside a node Docker image! At the moment I'm just running it before I start my app, which is no use to me! Is there a way I could setup my Dockerfile to run it as an init.d service on startup without blocking any of my other docker commands?

My Dockerfile goes as follows:

FROM node:6.2.0

# Create app directory
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

# Install app dependencies
COPY package.json /usr/src/app/
RUN npm install

# Thumbd
RUN npm install -g thumbd
RUN mkdir -p /var/log/
RUN echo "" > /var/log/thumbd.log
RUN thumbd server --aws_key=<KEY> --aws_secret=<SECRET> --sqs_queue=<QUEUE> --bucket=<BUCKET> --aws_region=us-west-1 --s3_acl=public-read

# Bundle app source
COPY . /usr/src/app

EXPOSE 8080

CMD npm run build && npm start

Answer 1

It's probably easiest to run thumbd in it's own container due to the way it works without direct links to your application. Docker likes to push the idea of a single process per container too.

FROM node:6.2.0

# Thumbd
RUN set -uex; \
    npm install -g thumbd; \
    mkdir -p /var/log/; \
    touch /var/log/thumbd.log

CMD thumbd server --aws_key=<KEY> --aws_secret=<SECRET> --sqs_queue=<QUEUE> --bucket=<BUCKET> --aws_region=us-west-1 --s3_acl=public-read

You can use Docker Compose to orchestrate running multiple containers in your project.

If you really want to run multiple processes in a container, use an init system like s6 or possibly supervisord .