fpm tests can now be run through docker.

This changes the Dockerfile to create docker images suitable for running tests (fpm rspec suite in docker) and also as a normal release (using fpm through docker).

Fixes #1682, #1453

Author: directionless

.gitignore

@@ -42,3 +42,6 @@ Gemfile.lock
 
 docs/_build
 docs/.work
+
+.docker-test-everything
+.docker-test-minimal

CONTRIBUTORS

@@ -21,6 +21,7 @@ sbuss
 Brett Gailey (github: dnbert)
 Daniel Haskin (github: djhaskin987)
 Richard Grainger (github: liger1978)
+seph (github: directionless)
 
 If you have contributed (bug reports, feature requests, help in IRC, blog
 posts, code, etc) and aren't listed here, please let me know if you wish to be

Dockerfile

@@ -1,17 +1,94 @@
-#
-# To build this Docker image: docker build -t fpm .
-#
-# To run this Docker container interactively: docker run -it fpm
-#
-FROM alpine:3.12
-
-RUN apk add --no-cache \
-        ruby \
-        ruby-dev \
-        ruby-etc \
-        gcc \
-        libffi-dev \
-        make \
-        libc-dev \
-        rpm \
-    && gem install --no-document fpm
+# Are we running against the minimal container, or the everything
+# container? Minimal is mostly the compiled package tools. Everything
+# pulls in scripting langauges.
+ARG BASE_ENV=everything
+
+# Are we running tests, or a release? Tests build and run against the
+# CWD, where release will use the downloaded gem.
+ARG TARGET=test
+
+# Container to throw an error if called with a bare `docker build .`
+FROM ubuntu:18.04 as error
+RUN echo "\n\n\nHey! Use buildkit. See the Makefile or docs\n\n\n"
+RUN false
+
+# Base container is used for various release and test things
+FROM ubuntu:18.04 as minimal-base
+
+# Runtime deps. Build deps go in the build or test containers
+RUN apt-get update \
+	&& apt-get -y dist-upgrade \
+	&& apt-get install --no-install-recommends -y \
+	ruby rubygems rubygems-integration \
+	bsdtar \
+	cpio \
+	debsigs \
+	pacman \
+	rpm  \
+	squashfs-tools \
+	xz-utils \
+	zip \
+	&& rm -rf /var/lib/apt/lists/* \
+	&& apt-get clean
+RUN adduser fpm 
+
+# everything container includes all the scripting languages. These
+# greatly embiggen the underlying docker container, so they're
+# conditionalized.
+FROM minimal-base AS everything-base
+RUN apt-get update \
+	&& apt-get install --no-install-recommends -y \
+	cpanminus \
+	npm \
+	perl \
+	python3-pip \
+	&& pip3 --no-cache-dir install setuptools \
+	&& pip3 --no-cache-dir install wheel \
+	&& pip3 --no-cache-dir install virtualenv virtualenv-tools3 \
+	&& update-alternatives --install /usr/bin/python python /usr/bin/python3 10 \
+	&& rm -rf /var/lib/apt/lists/*
+
+
+# Run tests against the current working directory. This is a bit
+# orthogonal to the container release process, but it has a lot of
+# same dependancies, so we reuse it. This uses COPY to allow rspect to
+# initall the gems, but runtime usage expects you to mount a volume
+# into /src
+FROM ${BASE_ENV}-base AS test
+WORKDIR /src
+RUN apt-get update \
+	&& apt-get install --no-install-recommends -y \
+	gcc make ruby-dev libc-dev lintian git
+# installing ffi here is a bit of an optimization for how COPY and layer reuse works
+RUN gem install --no-ri --no-rdoc ffi
+
+RUN install -d -o fpm /origsrc
+COPY --chown=fpm . /origsrc
+ENV HOME=/origsrc
+ENV BUNDLE_PATH=/origsrc/.bundle
+# Install a specific version of bundler
+WORKDIR /origsrc
+RUN gem install -v "$(grep -A1 '^BUNDLED WITH' Gemfile.lock | tail -1)" bundler
+USER fpm
+RUN bundle install
+CMD bundle exec rspec
+
+# build a container from a released gem. install build deps here, so
+# we can omit them from the final release package
+FROM ${BASE_ENV}-base AS build
+RUN apt-get update
+RUN apt-get install --no-install-recommends -y \
+	gcc make ruby-dev libc-dev
+ENV GEM_PATH /fpm
+ENV PATH "/fpm/bin:${PATH}"
+RUN gem install --no-ri --no-rdoc --install-dir=/fpm fpm
+
+FROM build as release
+COPY --from=build /fpm /fpm
+ENV GEM_PATH /fpm
+ENV PATH "/fpm/bin:${PATH}"
+WORKDIR /src
+ENTRYPOINT ["/fpm/bin/fpm"]
+
+# This target is to help docker buildkit in resolving things.
+FROM ${TARGET} as final

Makefile

@@ -52,3 +52,18 @@ clean:
 
 publish-docs:
 	$(MAKE) -C docs publish
+
+# Testing in docker.
+# The dot file is a sentinal file that will built a docker image, and tag it.
+# The normal make target runs said image, mounting CWD against it.
+SECONDARY: .docker-test-minimal .docker-test-everything
+.docker-test-%: Gemfile.lock fpm.gemspec Dockerfile
+	DOCKER_BUILDKIT=1 docker build -t fpm-test-$*  --build-arg BASE_ENV=$* --build-arg TARGET=test .
+	touch "$@"
+
+docker-test-%: .docker-test-%
+	docker run -v `pwd`:/src fpm-test-$*
+
+docker-release-%:
+	DOCKER_BUILDKIT=1 docker build -t fpm  --build-arg BASE_ENV=$* --build-arg TARGET=release --squash .
+