mitmproxy docker image is not anymore based on Alpine

[ben-64]

Since this commit, mitmproxy is not anymore based on alpine, therefore the docker build fails with:

/bin/sh: 1: apk: not found
The command '/bin/sh -c apk --no-cache add --virtual .build-dependencies linux-headers build-base curl perl &&     curl -sLO https://www.openssl.org/source/openssl-${OPENSSL_VERSION}.tar.gz &&     tar xvfz "openssl-${OPENSSL_VERSION}.tar.gz" &&     apk del openssl' returned a non-zero code: 127

[penguinpowernz]

I changed it so the Dockerfile was built from tag 5.2 (July 2020) and it worked.

[CR-DMcDonald]

Also had this same issue. @penguinpowernz solution resolved the problem in the short term. Specifically, change the first line of the Dockerfile to "FROM mitmproxy/mitmproxy:5.2" instead of "FROM mitmproxy/mitmproxy:latest".