add docker multistage build

.dockerignore

@@ -0,0 +1,6 @@
+/build*
+/.vscode
+/cpm_modules
+.DS_Store
+/.github
+/standalone/Dockerfile

.github/workflows/docker-cd.yml

@@ -0,0 +1,94 @@
+name: run Docker CD
+
+on:
+  push:
+    tags:
+      - "v*.*.*"
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Test scenario tag"
+        required: true
+        default: "test"
+      set-latest-tag:
+        description: "Also set the 'latest' tag with this run? (y/n)"
+        required: true
+        default: "n"
+
+env:
+  CPM_SOURCE_CACHE: ${{ github.workspace }}/cpm_modules
+
+jobs:
+  build:
+    name: CD build docker and push to DockerHub
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: handle manual workflow start and prepare docker image tag(s)
+        id: docker-tags
+        shell: bash
+        run: |
+          if [[ "x${{ github.event.inputs.tag }}" != "x" ]]; then
+            echo "Workflow started via workflow_dispatch! Parameters: tag=${{ github.event.inputs.tag }}, set-latest-tag=${{ github.event.inputs.set-latest-tag }}"
+            tag="${{ github.event.inputs.tag }}"
+          else
+            echo "Workflow started via push with tag! Complete tag: ${GITHUB_REF:10}"
+            tag="${GITHUB_REF:11}"
+          fi
+
+          if [[ "x${{ github.event.inputs.set-latest-tag }}" == "xy" || "x${{ github.event.inputs.tag }}" == "x" ]]; then
+            tags="${{ secrets.DOCKERHUB_USERNAME }}/greeter-webapi:$tag, ${{ secrets.DOCKERHUB_USERNAME }}/greeter-webapi:latest"
+            echo "Docker image release tags: $tags"
+          else
+            tags="${{ secrets.DOCKERHUB_USERNAME }}/greeter-webapi:$tag"
+            echo "Docker image release tag: $tags"
+          fi
+
+          echo ::set-output name=tags::$tags
+
+      #
+      # configure and build in GitHub CI as smoke test
+
+      # speed up configure step by installing boost as system lib, also use Ninja for faster builds
+      - name: speed up configure and build
+        shell: bash
+        run: sudo apt-get update && sudo apt-get install -y libboost-all-dev ninja-build
+
+      # use GitHub cache to cache dependencies
+      - uses: actions/cache@v2
+        with:
+          path: "**/cpm_modules"
+          key: ${{ github.workflow }}-cpm-modules-${{ hashFiles('**/CMakeLists.txt', '**/*.cmake') }}
+
+      - name: configure
+        run: cmake -S standalone -B build -G Ninja -D CMAKE_BUILD_TYPE=Release
+
+      - name: build
+        run: cmake --build build
+
+      #
+      # end GitHub CI local build
+
+      - name: set up Docker Buildx for multi-platform support
+        uses: docker/setup-buildx-action@v1
+
+      - name: set up QEMU for multi-platform support
+        uses: docker/setup-qemu-action@v1
+
+      - name: login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: build Docker image and push to DockerHub
+        uses: docker/build-push-action@v2
+        with:
+          file: ./standalone/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.docker-tags.outputs.tags }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

.github/workflows/docker-ci.yml

@@ -0,0 +1,63 @@
+name: run Docker CI
+
+on:
+  push:
+    branches:
+      - main
+      - master
+      - add-docker-build
+  pull_request:
+    branches:
+      - main
+      - master
+
+env:
+  CPM_SOURCE_CACHE: ${{ github.workspace }}/cpm_modules
+
+jobs:
+  build:
+    name: CI build docker
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      #
+      # configure and build in GitHub CI as smoke test
+
+      # speed up configure step by installing boost as system lib, also use Ninja for faster builds
+      - name: speed up configure and build
+        shell: bash
+        run: sudo apt-get update && sudo apt-get install -y libboost-all-dev ninja-build
+
+      # use GitHub cache to cache dependencies
+      - uses: actions/cache@v2
+        with:
+          path: "**/cpm_modules"
+          key: ${{ github.workflow }}-cpm-modules-${{ hashFiles('**/CMakeLists.txt', '**/*.cmake') }}
+
+      - name: configure
+        run: cmake -S standalone -B build -G Ninja -D CMAKE_BUILD_TYPE=Release
+
+      - name: build
+        run: cmake --build build
+
+      #
+      # end GitHub CI local build
+
+      - name: set up Docker Buildx for multi-platform support
+        uses: docker/setup-buildx-action@v1
+
+      - name: set up QEMU for multi-platform support
+        uses: docker/setup-qemu-action@v1
+
+      # build image but do NOT push to DockerHub
+      - name: build Docker image
+        uses: docker/build-push-action@v2
+        with:
+          file: ./standalone/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: false
+          tags: ${{ secrets.DOCKERHUB_USERNAME }}/greeter-webapi:ci
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

.github/workflows/standalone.yml

@@ -32,4 +32,4 @@ jobs:
         run: cmake --build build -j4
 
       - name: run
-        run: ./build/Greeter
+        run: ./build/GreeterStandalone

.gitignore

@@ -1,4 +1,4 @@
 /build*
 /.vscode
 /cpm_modules
-.DS_Store
+.DS_Store

standalone/CMakeLists.txt

@@ -1,6 +1,10 @@
 cmake_minimum_required(VERSION 3.14...3.22)
 
-project(GreeterStandalone LANGUAGES CXX)
+project(
+  GreeterStandalone
+  DESCRIPTION "A standalone minimal webapi application using the Crow framework"
+  LANGUAGES CXX
+)
 
 # --- Import tools ----
 
@@ -10,20 +14,44 @@ include(../cmake/tools.cmake)
 
 include(../cmake/CPM.cmake)
 
+# Crow needs Boost 1.64 and does not provide CPM.cmake integration itself, so we have to get Boost
+# first
+find_package(Boost 1.64 QUIET)
+if(NOT Boost_FOUND)
+  # Use CPM.cmake to get Boost from the official repo if not provided as system lib
+  message(STATUS "GreeterStandalone: Boost system lib NOT found")
+  CPMAddPackage(
+    NAME Boost
+    GITHUB_REPOSITORY boostorg/boost
+    GIT_TAG boost-1.78.0
+    VERSION 1.78.0
+  )
+  # Ugly workaround: Boost cmake support is still experimental, the Boost::boost target is not
+  # provided if downloaded via FetchContent_declare / CPM.cmake. Crow uses it for asio, so we fake
+  # the Boost:boost target as asio
+  if(NOT TARGET Boost::boost)
+    add_library(Boost::boost INTERFACE IMPORTED)
+    target_link_libraries(Boost::boost INTERFACE Boost::asio)
+  endif()
+else()
+  message(STATUS "GreeterStandalone: Boost system lib found")
+endif()
+# add Crow
 CPMAddPackage(
-  GITHUB_REPOSITORY jarro2783/cxxopts
-  VERSION 3.0.0
-  OPTIONS "CXXOPTS_BUILD_EXAMPLES NO" "CXXOPTS_BUILD_TESTS NO" "CXXOPTS_ENABLE_INSTALL YES"
+  NAME Crow
+  GITHUB_REPOSITORY CrowCpp/Crow
+  GIT_TAG v1.0+1
+  VERSION 1.0.1
+  OPTIONS "CROW_INSTALL OFF"
 )
 
+# get the Greeter lib
 CPMAddPackage(NAME Greeter SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/..)
 
 # ---- Create standalone executable ----
 
 file(GLOB sources CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/source/*.cpp)
 
 add_executable(${PROJECT_NAME} ${sources})
-
-set_target_properties(${PROJECT_NAME} PROPERTIES CXX_STANDARD 17 OUTPUT_NAME "Greeter")
-
-target_link_libraries(${PROJECT_NAME} Greeter::Greeter cxxopts)
+target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_11)
+target_link_libraries(${PROJECT_NAME} PRIVATE Greeter::Greeter Crow::Crow)

standalone/Dockerfile

@@ -0,0 +1,21 @@
+# build
+FROM buildpack-deps:bullseye as webapp-build
+RUN set -eux; \
+    apt-get update; \
+    apt-get install -y --no-install-recommends \
+    cmake \
+    ninja-build \
+    # configure/build with Boost as system lib - this should be orders of magnitude faster to configure than
+    # downloading via CPM.cmake while Boost's CMake support is still experimental
+    libboost-all-dev \
+    ;
+COPY . .
+RUN cmake -S standalone -B build -G Ninja -D CMAKE_BUILD_TYPE=Release
+RUN cmake --build build
+
+
+# deploy
+FROM debian:bullseye-slim as webapp-run
+WORKDIR /app
+COPY --from=webapp-build /build/GreeterStandalone .
+CMD ["./GreeterStandalone"]

standalone/source/main.cpp

@@ -1,53 +1,48 @@
+#include <crow.h>
 #include <greeter/greeter.h>
 #include <greeter/version.h>
 
-#include <cxxopts.hpp>
 #include <iostream>
 #include <string>
 #include <unordered_map>
 
-auto main(int argc, char** argv) -> int {
-  const std::unordered_map<std::string, greeter::LanguageCode> languages{
-      {"en", greeter::LanguageCode::EN},
-      {"de", greeter::LanguageCode::DE},
-      {"es", greeter::LanguageCode::ES},
-      {"fr", greeter::LanguageCode::FR},
-  };
-
-  cxxopts::Options options(*argv, "A program to welcome the world!");
-
-  std::string language;
-  std::string name;
-
-  // clang-format off
-  options.add_options()
-    ("h,help", "Show help")
-    ("v,version", "Print the current version number")
-    ("n,name", "Name to greet", cxxopts::value(name)->default_value("World"))
-    ("l,lang", "Language code to use", cxxopts::value(language)->default_value("en"))
-  ;
-  // clang-format on
-
-  auto result = options.parse(argc, argv);
-
-  if (result["help"].as<bool>()) {
-    std::cout << options.help() << std::endl;
-    return 0;
-  }
-
-  if (result["version"].as<bool>()) {
-    std::cout << "Greeter, version " << GREETER_VERSION << std::endl;
-    return 0;
-  }
-
-  auto langIt = languages.find(language);
-  if (langIt == languages.end()) {
-    std::cerr << "unknown language code: " << language << std::endl;
-    return 1;
-  }
-
-  greeter::Greeter greeter(name);
-  std::cout << greeter.greet(langIt->second) << std::endl;
-
-  return 0;
+int main() {
+  crow::SimpleApp app;
+
+  CROW_ROUTE(app, "/hello")
+  ([](const crow::request& req) {
+    // check params
+    std::cout << "Params: " << req.url_params << "\n";
+    std::cout << "The key 'language' was "
+              << (req.url_params.get("language") == nullptr ? "not " : "") << "found.\n";
+
+    if (req.url_params.get("language") == nullptr) {
+      // return bad request
+      return crow::response(400, "please provide a 'language' argument");
+    }
+    const auto language = req.url_params.get("language");
+
+    // see if langauge was found
+    const std::unordered_map<std::string, greeter::LanguageCode> languages{
+        {"en", greeter::LanguageCode::EN},
+        {"de", greeter::LanguageCode::DE},
+        {"es", greeter::LanguageCode::ES},
+        {"fr", greeter::LanguageCode::FR},
+    };
+    const auto langIt = languages.find(language);
+    if (langIt == languages.end()) {
+      // return bad request
+      std::cout << "Greeting for language '" << language << "' is not available\n";
+      return crow::response(400, "language not recognized");
+    }
+
+    const greeter::Greeter greeter("Crow & Greeter");
+    std::cout << "Greeting for language '" << language << "' is available, returning message\n";
+    const auto message = greeter.greet(langIt->second);
+
+    crow::json::wvalue ret({{"answer", message}});
+    return crow::response(200, ret);
+  });
+
+  app.port(3080).multithreaded().run();
 }