Dockerfile

Sample Dockerfile

FROM alpine  
LABEL maintainer="example@gmail.com"  
RUN apk add --update nodejs nodejs-npm  
COPY . /src  
WORKDIR /src  
RUN npm install  
EXPOSE 8080  
ENTRYPOINT ["node", "./app.js"]  

Details

• FROM: The base layer of the image.
• LABEL: Simple key-value pairs and are an excellent way of adding custom metadata to an image.
• RUN: Uses apk package manager to create a layer on top of base layer and installs packages on it.
• COPY: The COPY . /src instruction creates another new layer and copies in the application and dependency files from the build context.
• WORKDIR: Set the working directory inside the image filesystem for the rest of the instructions in the file.
• RUN: RUN npm install instruction creates a new layer and uses npm to install application dependencies listed in the package.json file in the build context.
• EXPOSE: The application exposes a web service on TCP port 8080, so the Dockerfile documents this with the EXPOSE 8080 instruction.
• ENTRYPOINT: The ENTRYPOINT instruction is used to set the main application that the image (container) should run.

Pushing to docker registry - TL;DR

• docker image build -t web:latest .
• docker login
• docker image tag web:latest {{username}}/web:latest
• docker image push {{username}}/web:latest
• docker container run -d –name c1 -p 8000:8080 web:latest