Description:
- https://docs.docker.com/engine/reference/builder/
- Works layer by layer, data are used in the next layer
- Start from the least likely to be changed first
- Next update uses a last update and add the differences as a layer
- much smaller file size
Overview:
Format
Parser directives
Environment replacement
dockerignore
Shell and Exect form
Dockerfile FROM
Dockerfile RUN
Dockerfile CMD
Dockerfile ADD
COPY
- Copy individual file from source code to image or COPY . .
WORKDIR
- Equivalent to
cd - The
WORKDIRinstruction sets the working directory for anyRUN,CMD,ENTRYPOINT,COPYandADDinstructions that follow it in the Dockerfile. - If the
WORKDIRdoesn’t exist, it will be created even if it’s not used in any subsequent Dockerfile instruction.WORKDIR /app
RUN
- Run in shell
ENV
- Environment variable