Dockerfile example

Example 1: docker ARG

$ docker build --build-arg some_variable_name=a_value

Example 2: dockerfile example

FROM ubuntu:18.04
COPY . /app
RUN make /app
CMD python /app/app.py

Example 3: dockerfile env variabes

FROM busybox
ENV foo /bar
WORKDIR ${foo}   # WORKDIR /bar
ADD . $foo       # ADD . /bar
COPY \$foo /quux # COPY $foo /quux

Example 4: how to create docker image from custom filename

cat DockerFile.debian.foo | docker build -t debian.foo -

Example 5: how run dockerfile

# Use the official image as a parent image.
FROM node:current-slim

# Set the working directory.
WORKDIR /usr/src/app

# Copy the file from your host to your current location.
COPY package.json .

# Run the command inside your image filesystem.
RUN npm install

# Inform Docker that the container is listening on the specified port at runtime.
EXPOSE 8080

# Run the specified command within the container.
CMD [ "npm", "start" ]

# Copy the rest of your app's source code from your host to your image filesystem.
COPY . .

Example 6: dockerfile run app cmd

RUN apt-get install python3
CMD echo "Hello world"
ENTRYPOINT echo "Hello world"