exercise2

Docker Exercise: Proper Handling of Environment Variables

You are provided with the following Dockerfile:

FROM alpine:3.19.1

ARG secret_code

ENV STATUS_CODE=${secret_code} 

RUN apk update && apk add --no-cache \
    curl

RUN curl -s -o response.jpg https://http.dog/${STATUS_CODE}.jpg

RUN unset STATUS_CODE

CMD [ "sh", "-c","echo secret is ${STATUS_CODE}" ]

• It accepts a secret_code as a build argument, this argument will be set as an environment variable
• It downloads an image using the environment variable value,
• It unsets the environment variable.

However, there is an issue with the Dockerfile. Even after unsetting the environment variable using unset STATUS_CODE, the container still prints the environment variable value as shown in below screenshot. Your task is to fix this issue while still making use of the environment variable.

Instructions:

1. Change the directory to Dockerfile-exercises/exercise2/

2. Build the Docker image using the following command:

docker build --build-arg=secret_code=201 -t envtest:0.2 .

3. Once the image is built, run the container using the following command:

docker run envtest:0.2

Expected Outcome:

When you run the container, it shouldn't print the secret value.