FROM docker.io/library/alpine:3.12 ARG NODEJS_VERSION=12.22.6-r0 ARG MARKDOWNLINT_VERSION RUN set -ex && \ apk add --no-cache nodejs=${NODEJS_VERSION} nodejs-npm=${NODEJS_VERSION} RUN if [ ! -z "${MARKDOWNLINT_VERSION}" ]; then set -ex; npm install -g markdownlint-cli@${MARKDOWNLINT_VERSION}; fi RUN if [ -z "${MARKDOWNLINT_VERSION}" ]; then set -ex; npm install -g markdownlint-cli; fi RUN set -ex && \ npm cache clean --force && \ apk del nodejs-npm WORKDIR /work ENTRYPOINT ["/usr/bin/markdownlint"] CMD ["."]