[BUILD] add CMake support to build docker images based on Ubuntu 20.04

5 files changed, 113 insertions, 1 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6cf891d..4dcbcef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -131,7 +131,7 @@ if(CMAKE_BUILD_TYPE MATCHES Release)
     set(CPACK_RESOURCE_FILE_README ${CMAKE_CURRENT_SOURCE_DIR}/README.md)
 
     # set DEB generator specific packaging options
-    set(CPACK_DEBIAN_PACKAGE_DEPENDS "libc6, libfuse2, libjansson")
+    set(CPACK_DEBIAN_PACKAGE_DEPENDS "libc6, libfuse2, libjansson4")
     if(DNBD3_KERNEL_MODULE)
         file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postinst "depmod -a\n")
         file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/package/deb/postrm "depmod -a\n")
@@ -191,6 +191,17 @@ if(CMAKE_BUILD_TYPE MATCHES Release)
                                                -P ${PROJECT_MODULES_DIR}/PostVersionPackaging.cmake
                       COMMENT "Cleanup version.h"
                       DEPENDS package_source_main)
+
+    # include target to make docker image
+    if(NOT DNBD3_KERNEL_MODULE)
+        find_package(Docker REQUIRED)
+        include(DockerImage)
+        set(DOCKER_FILE ${CMAKE_SOURCE_DIR}/pkg/docker/Dockerfile)
+        set(DOCKER_TAG ${CPACK_PACKAGE_NAME}:${REPOSITORY_VERSION_FULL})
+        set(PACKAGE_FILE ${CPACK_PACKAGE_NAME}_${REPOSITORY_VERSION_FULL}_${CMAKE_SYSTEM_PROCESSOR}.deb)
+        set(DOCKER_IMAGE ${CPACK_PACKAGE_NAME}_${REPOSITORY_VERSION_FULL}_${CMAKE_SYSTEM_PROCESSOR}_ubuntu-20-04_docker.tar)
+        add_docker_image(docker-ubuntu-20-04 ${DOCKER_IMAGE} ${DOCKER_FILE} ${DOCKER_TAG} ${PACKAGE_FILE} ${CMAKE_BINARY_DIR})
+    endif(NOT DNBD3_KERNEL_MODULE)
 endif(CMAKE_BUILD_TYPE MATCHES Release)
 
 # add all dnbd3 related projects from the source code directory
diff --git a/README.md b/README.md
index aae3426..41a80d6 100644
--- a/README.md
+++ b/README.md
@@ -143,6 +143,34 @@ make source
 This target creates compressed archives (\*_source.tar.gz and \*_source.zip) containing the source code of this repository for code distribution purposes.
 
 
+### Docker image
+A docker image of the built dnbd3 components can be created in the `Release` build configuration with the option `DNBD3_KERNEL_MODULE=OFF`.
+
+Make sure that your docker daemon runs and you are a member of the `docker` group to access the docker deamon without any super user privileges. Then build the docker image by calling the following Make target:
+
+```
+make docker-ubuntu-20-04
+```
+
+The built docker image is saved as archive file (\*_ubuntu-20-04_docker.tar) and can be deployed to other machines and can be loaded with the following docker client call:
+
+```shell
+docker image load -i *_ubuntu-20-04_docker.tar
+```
+
+After the loading of an image, a docker container named `NAME` and with the IPv4 adrress `IPv4_ADDRESS` can be created with the following docker client call:
+
+```
+docker container create --name <NAME> --ip <IPv4_ADDRESS> <IMAGE_TAG>
+```
+
+Note that the image is already tagged with a `IMAGE_TAG` that is set to the current dnbd3 package version number. The image tag `IMAGE_TAG` can be reused to create a container. Finally, this container can be started to execute the dnbd3-server in this container with the following docker client call:
+
+```
+docker container start -a <NAME>
+```
+
+
 ## Configuration of _dnbd3-server_
 The dnbd3-server is started according to the following command line call.
 
diff --git a/cmake/DockerImage.cmake b/cmake/DockerImage.cmake
new file mode 100644
index 0000000..54751e4
--- /dev/null
+++ b/cmake/DockerImage.cmake
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020 Manuel Bentele <development@manuel-bentele.de>
+#
+
+# macro to build a docker image based on a provided Dockerfile and an installation package
+macro(add_docker_image TARGET_NAME DOCKER_IMAGE DOCKER_FILE DOCKER_TAG PACKAGE_FILE BUILD_DIR)
+    get_filename_component(PACKAGE_FILE_PATH ${PACKAGE_FILE} PATH)
+    get_filename_component(PACKAGE_FILE_NAME ${PACKAGE_FILE} NAME)
+
+    # create a pseudo target to do packaging before docker image is built
+    add_custom_target(package_docker
+                      COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target package
+                      VERBATIM)
+
+    # commands and target to build docker image
+    add_custom_command(OUTPUT ${DOCKER_IMAGE}
+                       COMMAND docker image build -t ${DOCKER_TAG} --file ${DOCKER_FILE} --build-arg DNBD3_PACKAGE_FILE_NAME=${PACKAGE_FILE_NAME} ${BUILD_DIR}
+                       COMMAND docker image save -o ${DOCKER_IMAGE} ${DOCKER_TAG}
+                       COMMAND docker image rm ${DOCKER_TAG}
+                       DEPENDS ${DOCKER_FILE}
+                               package_docker)
+    add_custom_target(${TARGET_NAME}
+                      DEPENDS ${DOCKER_IMAGE})    
+endmacro(add_docker_image TARGET_NAME DOCKER_IMAGE DOCKER_FILE PACKAGE_FILE)
diff --git a/cmake/FindDocker.cmake b/cmake/FindDocker.cmake
new file mode 100644
index 0000000..ef3046d
--- /dev/null
+++ b/cmake/FindDocker.cmake
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020 Manuel Bentele <development@manuel-bentele.de>
+#
+
+find_program(Docker_EXECUTABLE NAMES docker)
+
+if(Docker_EXECUTABLE)
+    execute_process(COMMAND docker version --format "{{.Server.Version}}"
+                    OUTPUT_VARIABLE Docker_VERSION
+                    OUTPUT_STRIP_TRAILING_WHITESPACE)
+endif(Docker_EXECUTABLE)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Docker
+                                  FOUND_VAR Docker_FOUND
+                                  REQUIRED_VARS Docker_EXECUTABLE
+                                  VERSION_VAR Docker_VERSION
+                                  FAIL_MESSAGE "Docker is not available! Please install docker to build and run containers!")
+
diff --git a/pkg/docker/Dockerfile b/pkg/docker/Dockerfile
new file mode 100644
index 0000000..ad2adcb
--- /dev/null
+++ b/pkg/docker/Dockerfile
@@ -0,0 +1,28 @@
+# use Ubuntu 20.04 as base image
+FROM ubuntu:focal
+
+# declare arguments that should be set by 'docker build --build-arg ...'
+ARG DNBD3_PACKAGE_FILE_NAME
+
+# copy built package file from host to docker image
+COPY ${DNBD3_PACKAGE_FILE_NAME} /tmp
+
+# install required dependencies
+RUN apt-get update
+RUN apt-get install -y libfuse2 libjansson4
+
+# install installation package
+RUN dpkg -i /tmp/${DNBD3_PACKAGE_FILE_NAME}
+
+# use default config for dnbd3-server
+RUN ln -s /etc/dnbd3-server/sample/server.conf /etc/dnbd3-server
+RUN ln -s /etc/dnbd3-server/sample/alt-servers /etc/dnbd3-server
+
+# make default storage point for dnbd3-server
+RUN mkdir -p /mnt/storage
+
+# expose the port of the dnbd3-server to the host
+EXPOSE 5003
+
+# run dnbd3-server
+CMD [ "dnbd3-server", "-n" ]