Improved building of the Docker container

Signed-off-by: Andreas Maier <[email protected]>

.dockerignore

@@ -1,3 +1,5 @@
+# Note: /dist/ is needed in the docker build to access the distribution archive
+
 # User specific configuration files
 /myconfig/
 
@@ -10,7 +12,6 @@
 
 # Make build
 /build/
-/dist/
 /*.egg-info/
 /AUTHORS
 /ChangeLog

Dockerfile

@@ -1,26 +1,77 @@
 # Dockerfile for zhmc-os-forwarder project
 #
 # This image runs the zhmc_os_forwarder command.
-# The standard metric definition file is provided in its default location, so
-# the -m option does not need to be specified.
 #
-# The HMC credentials file still needs to be made available to the container
+# The os forwarder config file needs to be made available to the container
 # using some mount option and specified with -c.
 #
-# Example docker command to run the forwarder using a locally built version of this image:
-#
-#   docker run -it --rm -v $(pwd)/myconfig:/root/myconfig -p 514:514 zhmcosforwarder -c /root/myconfig/config.yaml -v
+#   docker run --rm -v $(pwd)/myconfig:/root/myconfig -p 514:514 zhmc_os_forwarder -c /root/myconfig/config.yaml -v
+
+FROM python:3.12-alpine as builder
+
+# Path name of binary distribution archive of zhmc-os-forwarder package
+ARG bdist_file
+RUN : "${bdist_file:?Build argument bdist_file is required}"
+
+# Install some packages onto this minimal Alpine image:
+# - git - in case the Python requirements use git+https links
+# - gcc musl-dev - in case Python wheels based on C need to be built (e.g. for rpds)
+RUN apk add git gcc musl-dev
+
+# Make sure the installed Python commands are found
+ENV PATH=/root/.local/bin:$PATH
+
+# Install the Python package of this project
+COPY ${bdist_file} /tmp/${bdist_file}
+RUN pip install --user /tmp/${bdist_file}
+
+# Show the installed Linux packages
+RUN echo "Installed Linux packages:" \
+  && apk info -v
+
+# Show the installed Python packages
+RUN echo "Installed Python packages:" \
+  && pip list
+
+# Display files in 'rpds' Python package (verifying that it can be imported)
+RUN echo "Files in rpds Python package:" \
+  && python -c "import rpds, os, sys; rpds_dir=os.path.dirname(rpds.__file__); print(rpds_dir); sys.stdout.flush(); os.system(f'ls -al {rpds_dir}')"
+
+# The Python 'rpds' package (used by 'jsonschema') has a shared library that is
+# built during its installation, and thus depends on APIs of the system and
+# the C library of the builder OS used in the first stage of this Dockerfile.
+# Therefore, the OS used in the final stage needs to be compatible with the
+# builder OS. We use the same OS image to make sure.
+FROM python:3.12-alpine
+
+# Version of the zhmc-os-forwarder package
+ARG package_version
+RUN : "${package_version:?Build argument package_version is required}"
+
+# Image build date in ISO-8601 format
+ARG build_date
+RUN : "${build_date:?Build argument build_date is required}"
+
+# Git commit ID of the zhmc-os-forwarder repo used to build the image
+ARG git_commit
+RUN : "${git_commit:?Build argument git_commit is required}"
 
-FROM python:3.9-slim
+# Set image metadata
+LABEL org.opencontainers.image.title="IBM Z HMC OS Message Forwarder"
+LABEL org.opencontainers.image.version="${package_version}"
+LABEL org.opencontainers.image.authors="Andreas Maier"
+LABEL org.opencontainers.image.created="${build_date}"
+LABEL org.opencontainers.image.url="https://github.com/zhmcclient/zhmc-os-forwarder"
+LABEL org.opencontainers.image.documentation="https://zhmc-os-forwarder.readthedocs.io"
+LABEL org.opencontainers.image.source="https://github.com/zhmcclient/zhmc-os-forwarder"
+LABEL org.opencontainers.image.licenses="Apache Software License 2.0"
+LABEL org.opencontainers.image.revision="${git_commit}"
 
-# Install this package
-ENV TMP_DIR=/tmp/zhmc-os-forwarder
-WORKDIR $TMP_DIR
-COPY . $TMP_DIR
-RUN pip install . && rm -rf $TMP_DIR
+# Copy the installed Python packages from the builder image
+COPY --from=builder /root/.local /root/.local
 
-# Set the current directory when running this image
-WORKDIR /root
+# Make sure the installed Python commands are found
+ENV PATH=/root/.local/bin:$PATH
 
 EXPOSE 9291
 ENTRYPOINT ["zhmc_os_forwarder"]

Makefile

@@ -103,7 +103,9 @@ package_name := zhmc_os_forwarder
 # version indicator by 1.
 package_version := $(shell $(PYTHON_CMD) -m setuptools_scm)
 
-docker_registry := zhmcosforwarder
+# Docker image
+docker_image_name := zhmc_os_forwarder
+docker_image_tag := latest
 
 python_mn_version := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('{}.{}'.format(sys.version_info[0], sys.version_info[1]))")
 pymn := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('py{}{}'.format(sys.version_info[0], sys.version_info[1]))")
@@ -125,7 +127,7 @@ test_py_files := \
     $(wildcard $(test_dir)/*/*.py) \
 
 dist_dir := dist
-bdist_file := $(dist_dir)/$(package_name)-$(package_version)-py2.py3-none-any.whl
+bdist_file := $(dist_dir)/$(package_name)-$(package_version)-py3-none-any.whl
 sdist_file := $(dist_dir)/$(package_name)-$(package_version).tar.gz
 
 # Dependencies of the distribution archives. Since the $(version_file) is
@@ -136,7 +138,7 @@ dist_dependent_files := \
     LICENSE \
     README.md \
     requirements.txt \
-    $(package_py_files) \
+    $(filter-out $(version_file), $(package_py_files)) \
 
 doc_dir := docs
 doc_build_dir := build_docs
@@ -205,7 +207,7 @@ help:
 	@echo "  build      - Build the distribution files in $(dist_dir)"
 	@echo "  builddoc   - Build the documentation in $(doc_build_dir)"
 	@echo "  all        - Do all of the above"
-	@echo "  docker     - Build local Docker image in registry $(docker_registry)"
+	@echo "  docker     - Build local Docker image $(docker_image_name):$(docker_image_tag)"
 	@echo "  authors    - Generate AUTHORS.md file from git log"
 	@echo "  upload     - Upload the package to Pypi"
 	@echo "  clean      - Remove any temporary files"
@@ -381,7 +383,7 @@ $(doc_build_file): $(done_dir)/develop_$(pymn)_$(PACKAGE_LEVEL).done $(doc_depen
 	sphinx-build -b html -v $(doc_dir) $(doc_build_dir)
 	@echo "Makefile: Done generating HTML documentation"
 
-$(sdist_file): $(done_dir)/develop_$(pymn)_$(PACKAGE_LEVEL).done Makefile $(dist_dependent_files)
+$(sdist_file): $(done_dir)/develop_$(pymn)_$(PACKAGE_LEVEL).done Makefile $(dist_dependent_files) $(version_file)
 	@echo "Makefile: Building the source distribution archive: $(sdist_file)"
 	$(PYTHON_CMD) -m build --sdist --outdir $(dist_dir) .
 	@echo "Makefile: Done building the source distribution archive: $(sdist_file)"
@@ -431,9 +433,11 @@ $(done_dir)/bandit_$(pymn)_$(PACKAGE_LEVEL).done: $(done_dir)/develop_$(pymn)_$(
 	echo "done" >$@
 	@echo "Makefile: Done running Bandit"
 
-$(done_dir)/docker_$(pymn)_$(PACKAGE_LEVEL).done: $(done_dir)/develop_$(pymn)_$(PACKAGE_LEVEL).done Dockerfile .dockerignore Makefile $(dist_dependent_files)
-	@echo "Makefile: Building Docker image $(docker_registry):latest"
+$(done_dir)/docker_$(pymn)_$(PACKAGE_LEVEL).done: $(done_dir)/develop_$(pymn)_$(PACKAGE_LEVEL).done Dockerfile .dockerignore $(bdist_file)
+	@echo "Makefile: Building Docker image $(docker_image_name):$(docker_image_tag)"
 	-$(call RM_FUNC,$@)
-	docker build -t $(docker_registry):latest .
+	docker build --tag $(docker_image_name):$(docker_image_tag) --build-arg bdist_file=$(bdist_file) --build-arg package_version=$(subst +,.,$(package_version)) --build-arg build_date="$(shell date -Iseconds)" --build-arg git_commit="$(shell git rev-parse HEAD)" .
+	docker run --rm $(docker_image_name):$(docker_image_tag) --version
+	docker image list --filter reference=$(docker_image_name)
 	@echo "Makefile: Done building Docker image"
 	echo "done" >$@

changes/100.feature.rst

@@ -0,0 +1 @@
+Improved building of the Docker container to reduce its size.

changes/100.incompatible.rst

@@ -0,0 +1,2 @@
+Changed mage name of Docker container image from 'zhmcosforwarder' to
+'zhmc_os_forwarder' to match the command name.

docs/usage.rst

@@ -34,10 +34,7 @@ Running in a Docker container
 -----------------------------
 
 If you want to run the forwarder in a Docker container you can create the
-container as follows, using the ``Dockerfile`` provided in the Git repository.
-
-Note that the provided ``Dockerfile`` can also be used as a starting point if
-you want to embed the forwarder in your own Docker/OCI image.
+container as follows, using the Dockerfile provided in the Git repository.
 
 * Clone the Git repository of the forwarder and switch to the clone's root
   directory:
@@ -53,8 +50,8 @@ you want to embed the forwarder in your own Docker/OCI image.
 
       $ make docker
 
-  This builds a container image named 'zhmcforwarder:latest' in your local Docker
-  environment.
+  This builds a container image named ``zhmc_os_forwarder:latest`` in your local
+  Docker environment.
 
   The image does not contain the forwarder config file, so that needs to be
   specified when starting the container.
@@ -63,7 +60,7 @@ you want to embed the forwarder in your own Docker/OCI image.
 
   .. code-block:: bash
 
-      $ docker run -it --rm -v $(pwd)/myconfig:/root/myconfig zhmcforwarder -p 514:514 -c /root/myconfig/config.yaml -v
+      $ docker run --rm -v $(pwd)/myconfig:/root/myconfig zhmc_os_forwarder -p 514:514 -c /root/myconfig/config.yaml -v
 
   In this command, the forwarder config file is provided on the local system
   as ``./myconfig/config.yaml``. The ``-v`` option of 'docker run' mounts the
@@ -73,8 +70,8 @@ you want to embed the forwarder in your own Docker/OCI image.
 
   The command above maps port 514 in the docker container to port 514 of the
   system running docker. That is the default port used by syslog. If your remote
-  syslog servers use different ports, they need to be mapped using the `-p` option
-  of the "docker run" command.
+  syslog servers use different ports, they need to be mapped using the ``-p`` option
+  of the ``docker run`` command.
 
 
 zhmc_os_forwarder command