Add a helper docker-build.sh script for manual builds

Author: yhabteab

tools/container/docker-build.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+
+# This script is used to build a Docker image for Icinga 2.
+
+# Action defines the type of build to perform. It can be one of:
+#
+# - load: Build the image for the building platform and load it into the local Docker engine image storage.
+# - push: Build the image for all specified platforms and push them to the Docker registry (icinga/icinga2:<TAG>).
+# - cache: Build the image for all specified platforms using the default Buildx's exporter (cacheonly) and will just
+#   create a cache for each platform. There will be no images that you can use but any subsequent build will use the
+#   cache and speed up the build process.
+#
+# If no action is provided, it defaults to "load", and any specified platforms will be ignored.
+ACTION="${1:-load}"
+# Tag defines the tag to use for the built image. If not provided, it defaults to "test".
+# The resulting image will be tagged as "icinga/icinga2:<TAG>".
+TAG="${2:-test}"
+# Platform defines the platforms to build the image for. It defaults to "linux/amd64,linux/arm64/v8".
+PLATFORM="${3:-linux/amd64,linux/arm64/v8}"
+# ROOT_DIR is the root directory of the Icinga 2 source code repository and where the Containerfile is located.
+# It's also used to determine the build context for the Docker build, so that every file referenced in the
+# Containerfile can be found relative to this directory by Docker.
+ROOT_DIR="$(dirname "$(realpath "$0")")/../.."
+
+if ! command -v docker &> /dev/null; then
+    echo "Docker is not installed. Please install Docker to build the image." >&2
+    exit 1
+fi
+
+if ! command -v docker buildx &> /dev/null; then
+    echo "Docker Buildx is not installed. Please install Docker Buildx to build the image." >&2
+    exit 1
+fi
+
+# Set up the buildx command with the specified platform.
+BuildX=(docker buildx build --platform "${PLATFORM}")
+BUILD_ARGS=(-t "icinga/icinga2:${TAG}" -f "${ROOT_DIR}"/Containerfile "${ROOT_DIR}")
+
+# Check the action and perform the appropriate build command.
+case "$ACTION" in
+    push)
+        "${BuildX[@]}" --push "${BUILD_ARGS[@]}"
+        ;;
+    load)
+        docker buildx build --load "${BUILD_ARGS[@]}"
+        ;;
+    cache)
+        "${BuildX[@]}" "${BUILD_ARGS[@]}"
+        ;;
+    *)
+        echo "Unknown action: ${ACTION}. Valid actions are: push, load, cache." >&2
+        exit 1
+esac