Dockerfile Environment Variables

Dockerfile Environment Variables

To make new software easier to run, you can use ENV to update the PATH environment variable for the software that your container installs.

Setup your environment:

Step 1: Make the env Directory

mkdir env

cd env

Use the --env flag to pass an environment variable when building an image:

--env [KEY]=[VALUE]

Use the ENV instruction in the Dockerfile:

ENV [KEY]=[VALUE] ENV [KEY] [VALUE]

Step 1: Clone the weather-app:

git clone https://github.com/nishanthkumarpathi/content-weather-app.git src

Step 2: Create the Dockerfile

vi Dockerfile

Create an image for the weather-app

Step 3: Dockerfile contents:

FROM node
LABEL org.label-schema.version=v1.1
ENV NODE_ENV="development"
ENV PORT 3000

RUN mkdir -p /var/node
ADD src/ /var/node/
WORKDIR /var/node
RUN npm install
EXPOSE $PORT
CMD ./bin/www

Step 4: Create the weather-app container:

docker image build -t nishanthkp/weather-app:v2 .

Step 5: Inspect the container to see the environment variables:

docker image inspect nishanthkp/weather-app:v2

Step 6: Deploy the weather-dev application:

docker container run -d --name weather-dev -p 8082:3001 --env PORT=3001 nishanthkp/weather-app:v2

Step 7: Inspect the development container to see the environment variables:

docker container inspect weather-dev

Step 8: Deploy the weather-app to production:

docker container run -d --name weather-app2 -p 8083:3001 --env PORT=3001 --env NODE_ENV=production nishanthkp/weather-app:v2

Step 9: Inspect the production container to see the environment variables:

docker container inspect weather-app2

Step 10: Get the logs for weather-app2:

docker container logs weather-app2

docker container run -d --name weather-prod -p 8084:3000 --env NODE_ENV=production nishanthkp/weather-app:v2