#!/bin/bash
# Clones the NetBox repository with git from Github and builds the Dockerfile

echo "▶️ $0 $*"

set -e

if [ "${1}x" == "x" ] || [ "${1}" == "--help" ] || [ "${1}" == "-h" ]; then
cat <<END_OF_DOCS
Usage: ${0} <branch> [--push|--push-only]
  branch       The branch or tag to build. Required.
  --push       Pushes the built Docker image to the registry.
  --push-only  Only pushes the Docker image to the registry, but does not build it.

You can use the following ENV variables to customize the build:
  SRC_ORG     Which fork of netbox to use (i.e. github.com/\${SRC_ORG}/\${SRC_REPO}).
              Default: netbox-community
  SRC_REPO    The name of the repository to use (i.e. github.com/\${SRC_ORG}/\${SRC_REPO}).
              Default: netbox
  URL         Where to fetch the code from.
              Must be a git repository. Can be private.
              Default: https://github.com/\${SRC_ORG}/\${SRC_REPO}.git
  NETBOX_PATH The path where netbox will be checkout out.
              Must not be outside of the netbox-docker repository (because of Docker)!
              Default: .netbox
  SKIP_GIT    If defined, git is not invoked and \${NETBOX_PATH} will not be altered.
              This may be useful, if you are manually managing the NETBOX_PATH.
              Default: undefined
  TAG         The version part of the docker tag.
              Default:
                When <branch>=master:  latest
                When <branch>=develop: snapshot
                Else:                  same as <branch>
  DOCKER_REGISTRY  The Docker repository's registry (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: docker.io
  DOCKER_ORG  The Docker repository's organisation (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: netboxcommunity
  DOCKER_REPO The Docker repository's name (i.e. '\${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}'')
              Used for tagging the image.
              Default: netbox
  DOCKER_TAG  The name of the tag which is applied to the image.
              Useful for pushing into another registry than hub.docker.com.
              Default: \${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}:\${TAG}
  DOCKER_SHORT_TAG  The name of the short tag which is applied to the
              image. This is used to tag all patch releases to their
              containing version e.g. v2.5.1 -> v2.5
              Default: \${DOCKER_REGISTRY}/\${DOCKER_ORG}/\${DOCKER_REPO}:<MAJOR>.<MINOR>
  DOCKERFILE  The name of Dockerfile to use.
              Default: Dockerfile
  DOCKER_FROM The base image to use.
              Default: 'alpine:3.14'
  DOCKER_TARGET  A specific target to build.
              It's currently not possible to pass multiple targets.
              Default: main ldap
  BUILDX_PLATFORMS  Specifies the platform(s) to build the image for.
              Example: linux/amd64,linux/arm64
              Default: linux/amd64
  BUILDX_BUILDER_NAME  If defined, the image build will be assigned to the given builder.
              If you specify this variable, make sure that the builder exists.
              If this value is not defined, a new builx builder with the directory name of the
              current directory (i.e. '$(basename "${PWD}")') is created.
              Example: clever_lovelace
              Default: undefined
  BUILDX_KEEP_BUILDER  If defined and if BUILDX_BUILDER_NAME is undefined, then the
              buildx builder created by this script is not removed.
              This is useful if you want to re-use the builder in a later build on the
              same system.
              By default, all buildx builders created by this script are removed at the end.
              Default: undefined
  HTTP_PROXY  The proxy to use for http requests.
              Example: http://proxy.domain.tld:3128
              Default: undefined
  NO_PROXY    Comma-separated list of domain extensions proxy should not be used for.
              Example: .domain1.tld,.domain2.tld
              Default: undefined
  DEBUG       If defined, the script does not stop when certain checks are unsatisfied.
              Default: undefined
  DRY_RUN     Prints all build statements instead of running them.
              Default: undefined
  GH_ACTION   If defined, special 'echo' statements are enabled that set the
              following environment variables in Github Actions:
              - FINAL_DOCKER_TAG: The final value of the DOCKER_TAG env variable
              Default: undefined

Examples:
  ${0} master
              This will fetch the latest 'master' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:latest'.
  ${0} develop
              This will fetch the latest 'develop' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:snapshot'.
  ${0} v2.6.6
              This will fetch the 'v2.6.6' tag, build a Docker Image and tag it
              'netboxcommunity/netbox:v2.6.6' and 'netboxcommunity/netbox:v2.6'.
  ${0} develop-2.7
              This will fetch the 'develop-2.7' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:develop-2.7'.
  SRC_ORG=cimnine ${0} feature-x
              This will fetch the 'feature-x' branch from https://github.com/cimnine/netbox.git,
              build a Docker Image and tag it 'netboxcommunity/netbox:feature-x'.
  SRC_ORG=cimnine DOCKER_ORG=cimnine ${0} feature-x
              This will fetch the 'feature-x' branch from https://github.com/cimnine/netbox.git,
              build a Docker Image and tag it 'cimnine/netbox:feature-x'.
  PLATFORMS=linux/amd64,linux/arm64 ${0} master
              This will fetch the latest 'master' branch, build a Docker Image and tag it
              'netboxcommunity/netbox:latest'.
              It will produce an ARM64 and an AMD64 version of the image.
END_OF_DOCS

  if [ "${1}x" == "x" ]; then
    exit 1
  else
    exit 0
  fi
fi

###
# Enabling dry-run mode
###
if [ -z "${DRY_RUN}" ]; then
  DRY=""
else
  echo "⚠️ DRY_RUN MODE ON ⚠️"
  DRY="echo"
fi

###
# Variables for fetching the NetBox source
###
SRC_ORG="${SRC_ORG-netbox-community}"
SRC_REPO="${SRC_REPO-netbox}"
NETBOX_BRANCH="${1}"
URL="${URL-https://github.com/${SRC_ORG}/${SRC_REPO}.git}"
NETBOX_PATH="${NETBOX_PATH-.netbox}"

###
# Fetching the NetBox source
###
if [ "${2}" != "--push-only" ] && [ -z "${SKIP_GIT}" ]; then
  REMOTE_EXISTS=$(git ls-remote --heads --tags "${URL}" "${NETBOX_BRANCH}" | wc -l)
  if [ "${REMOTE_EXISTS}" == "0" ]; then
    echo "❌ Remote branch '${NETBOX_BRANCH}' not found in '${URL}'; Nothing to do"
    if [ -n "${GH_ACTION}" ]; then
      echo "::set-output name=skipped::true"
    fi
    exit 0
  fi
  echo "🌐 Checking out '${NETBOX_BRANCH}' of NetBox from the url '${URL}' into '${NETBOX_PATH}'"
  if [ ! -d "${NETBOX_PATH}" ]; then
    $DRY git clone -q --depth 10 -b "${NETBOX_BRANCH}" "${URL}" "${NETBOX_PATH}"
  fi

  (
    $DRY cd "${NETBOX_PATH}"
    # shellcheck disable=SC2030
    if [ -n "${HTTP_PROXY}" ]; then
      git config http.proxy "${HTTP_PROXY}"
    fi

    $DRY git remote set-url origin "${URL}"
    $DRY git fetch -qp --depth 10 origin "${NETBOX_BRANCH}"
    $DRY git checkout -qf FETCH_HEAD
    $DRY git prune
  )
  echo "✅ Checked out NetBox"
fi

###
# Determining the value for DOCKERFILE
# and checking whether it exists
###
DOCKERFILE="${DOCKERFILE-Dockerfile}"
if [ ! -f "${DOCKERFILE}" ]; then
  echo "🚨 The Dockerfile ${DOCKERFILE} doesn't exist."

  if [ -z "${DEBUG}" ]; then
    exit 1
  else
    echo "⚠️ Would exit here with code '1', but DEBUG is enabled."
  fi
fi

###
# Determining the value for DOCKER_FROM
###
if [ -z "$DOCKER_FROM" ]; then
  DOCKER_FROM="alpine:3.14"
fi

###
# Variables for labelling the docker image
###
BUILD_DATE="$(date -u '+%Y-%m-%dT%H:%M+00:00')"

if [ -d ".git" ]; then
  GIT_REF="$(git rev-parse HEAD)"
fi

# Read the project version from the `VERSION` file and trim it, see https://stackoverflow.com/a/3232433/172132
PROJECT_VERSION="${PROJECT_VERSION-$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' VERSION)}"

# Get the Git information from the netbox directory
if [ -d "${NETBOX_PATH}/.git" ]; then
  NETBOX_GIT_REF=$(
    cd "${NETBOX_PATH}"
    git rev-parse HEAD
  )
  NETBOX_GIT_BRANCH=$(
    cd "${NETBOX_PATH}"
    git rev-parse --abbrev-ref HEAD
  )
  NETBOX_GIT_URL=$(
    cd "${NETBOX_PATH}"
    git remote get-url origin
  )
fi

###
# Variables for tagging the docker image
###
DOCKER_REGISTRY="${DOCKER_REGISTRY-docker.io}"
DOCKER_ORG="${DOCKER_ORG-netboxcommunity}"
DOCKER_REPO="${DOCKER_REPO-netbox}"
case "${NETBOX_BRANCH}" in
master)
  TAG="${TAG-latest}"
  ;;
develop)
  TAG="${TAG-snapshot}"
  ;;
*)
  TAG="${TAG-$NETBOX_BRANCH}"
  ;;
esac

###
# Determine targets to build
###
DEFAULT_DOCKER_TARGETS=("main" "ldap")
DOCKER_TARGETS=("${DOCKER_TARGET:-"${DEFAULT_DOCKER_TARGETS[@]}"}")
echo "🏭 Building the following targets:" "${DOCKER_TARGETS[@]}"

###
# Build each target
###
export DOCKER_BUILDKIT=${DOCKER_BUILDKIT-1}
for DOCKER_TARGET in "${DOCKER_TARGETS[@]}"; do
  echo "🏗 Building the target '${DOCKER_TARGET}'"

  ###
  # composing the final TARGET_DOCKER_TAG
  ###
  TARGET_DOCKER_TAG="${DOCKER_TAG-${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:${TAG}}"
  if [ "${DOCKER_TARGET}" != "main" ]; then
    TARGET_DOCKER_TAG="${TARGET_DOCKER_TAG}-${DOCKER_TARGET}"
  fi
  if [ -n "${GH_ACTION}" ]; then
    echo "FINAL_DOCKER_TAG=${TARGET_DOCKER_TAG}" >>"$GITHUB_ENV"
    echo "::set-output name=skipped::false"
  fi

  ###
  # composing the additional DOCKER_SHORT_TAG,
  # i.e. "v2.6.1" becomes "v2.6",
  # which is only relevant for version tags
  # Also let "latest" follow the highest version
  ###
  if [[ "${TAG}" =~ ^v([0-9]+)\.([0-9]+)\.[0-9]+$ ]]; then
    MAJOR=${BASH_REMATCH[1]}
    MINOR=${BASH_REMATCH[2]}

    TARGET_DOCKER_SHORT_TAG="${DOCKER_SHORT_TAG-${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:v${MAJOR}.${MINOR}}"
    TARGET_DOCKER_LATEST_TAG="${DOCKER_REGISTRY}/${DOCKER_ORG}/${DOCKER_REPO}:latest"

    if [ "${DOCKER_TARGET}" != "main" ]; then
      TARGET_DOCKER_SHORT_TAG="${TARGET_DOCKER_SHORT_TAG}-${DOCKER_TARGET}"
      TARGET_DOCKER_LATEST_TAG="${TARGET_DOCKER_LATEST_TAG}-${DOCKER_TARGET}"
    fi
  fi

  ###
  # If `--push-only` is passed, just push and then quit
  ###
  if [ "${2}" == "--push-only" ]; then
    source ./build-functions/docker-functions.sh
    push_image_to_registry "${TARGET_DOCKER_TAG}"

    if [ -n "${TARGET_DOCKER_SHORT_TAG}" ]; then
      push_image_to_registry "${TARGET_DOCKER_SHORT_TAG}"
      push_image_to_registry "${TARGET_DOCKER_LATEST_TAG}"
    fi
    exit 1
  fi

  ###
  # Checking if the build is necessary,
  # meaning build only if one of those values changed:
  # - Python base image digest (Label: PYTHON_BASE_DIGEST)
  # - netbox git ref (Label: NETBOX_GIT_REF)
  # - netbox-docker git ref (Label: org.label-schema.vcs-ref)
  ###
  # Load information from registry (only for docker.io)
  SHOULD_BUILD="false"
  BUILD_REASON=""
  if [ -z "${GH_ACTION}" ]; then
    # Asuming non Github builds should always proceed
    SHOULD_BUILD="true"
    BUILD_REASON="${BUILD_REASON} interactive"
  elif [ "$DOCKER_REGISTRY" = "docker.io" ]; then
    source ./build-functions/get-public-image-config.sh
    IFS=':' read -ra DOCKER_FROM_SPLIT <<<"${DOCKER_FROM}"
    if ! [[ ${DOCKER_FROM_SPLIT[0]} =~ .*/.* ]]; then
      # Need to use "library/..." for images the have no two part name
      DOCKER_FROM_SPLIT[0]="library/${DOCKER_FROM_SPLIT[0]}"
    fi
    PYTHON_LAST_LAYER=$(get_image_last_layer "${DOCKER_FROM_SPLIT[0]}" "${DOCKER_FROM_SPLIT[1]}")
    mapfile -t IMAGES_LAYERS_OLD < <(get_image_layers "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")
    NETBOX_GIT_REF_OLD=$(get_image_label NETBOX_GIT_REF "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")
    GIT_REF_OLD=$(get_image_label org.label-schema.vcs-ref "${DOCKER_ORG}"/"${DOCKER_REPO}" "${TAG}")

    if ! printf '%s\n' "${IMAGES_LAYERS_OLD[@]}" | grep -q -P "^${PYTHON_LAST_LAYER}\$"; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} alpine"
    fi
    if [ "${NETBOX_GIT_REF}" != "${NETBOX_GIT_REF_OLD}" ]; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} netbox"
    fi
    if [ "${GIT_REF}" != "${GIT_REF_OLD}" ]; then
      SHOULD_BUILD="true"
      BUILD_REASON="${BUILD_REASON} netbox-docker"
    fi
  else
    SHOULD_BUILD="true"
    BUILD_REASON="${BUILD_REASON} no-check"
  fi

  ###
  # Building the docker image
  ###
  if [ "${SHOULD_BUILD}" != "true" ]; then
    echo "Build skipped because sources didn't change"
    echo "::set-output name=skipped::true"
  else
    ###
    # Composing all arguments for `docker build`
    ###
    DOCKER_BUILD_ARGS=(
      --pull
      --output=type=image
      --target "${DOCKER_TARGET}"
      -f "${DOCKERFILE}"
      -t "${TARGET_DOCKER_TAG}"
    )
    if [ -n "${TARGET_DOCKER_SHORT_TAG}" ]; then
      DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_SHORT_TAG}")
      DOCKER_BUILD_ARGS+=(-t "${TARGET_DOCKER_LATEST_TAG}")
    fi

    # --label
    DOCKER_BUILD_ARGS+=(
      --label "ORIGINAL_TAG=${TARGET_DOCKER_TAG}"

      --label "org.label-schema.build-date=${BUILD_DATE}"
      --label "org.opencontainers.image.created=${BUILD_DATE}"

      --label "org.label-schema.version=${PROJECT_VERSION}"
      --label "org.opencontainers.image.version=${PROJECT_VERSION}"
    )
    if [ -d ".git" ]; then
      DOCKER_BUILD_ARGS+=(
        --label "org.label-schema.vcs-ref=${GIT_REF}"
        --label "org.opencontainers.image.revision=${GIT_REF}"
      )
    fi
    if [ -d "${NETBOX_PATH}/.git" ]; then
      DOCKER_BUILD_ARGS+=(
        --label "NETBOX_GIT_BRANCH=${NETBOX_GIT_BRANCH}"
        --label "NETBOX_GIT_REF=${NETBOX_GIT_REF}"
        --label "NETBOX_GIT_URL=${NETBOX_GIT_URL}"
      )
    fi
    if [ -n "${BUILD_REASON}" ]; then
      BUILD_REASON=$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' <<<"$BUILD_REASON")
      DOCKER_BUILD_ARGS+=(--label "BUILD_REASON=${BUILD_REASON}")
    fi

    # --build-arg
    DOCKER_BUILD_ARGS+=(--build-arg "NETBOX_PATH=${NETBOX_PATH}")

    if [ -n "${DOCKER_FROM}" ]; then
      DOCKER_BUILD_ARGS+=(--build-arg "FROM=${DOCKER_FROM}")
    fi
    # shellcheck disable=SC2031
    if [ -n "${HTTP_PROXY}" ]; then
      DOCKER_BUILD_ARGS+=(--build-arg "http_proxy=${HTTP_PROXY}")
      DOCKER_BUILD_ARGS+=(--build-arg "https_proxy=${HTTPS_PROXY}")
    fi
    if [ -n "${NO_PROXY}" ]; then
      DOCKER_BUILD_ARGS+=(--build-arg "no_proxy=${NO_PROXY}")
    fi

    # --platform
    DOCKER_BUILD_ARGS+=(--platform "${BUILDX_PLATFORMS-linux/amd64}")

    # --cache-from / --cache-to
    # DOCKER_BUILD_ARGS+=("--cache-from=type=registry,ref=${TARGET_DOCKER_TAG}-cache,mode=max")
    # DOCKER_BUILD_ARGS+=("--cache-to=type=registry,ref=${TARGET_DOCKER_TAG}-cache,mode=max")

    ###
    # Pushing the docker images if `--push` is passed
    ###
    if [ "${2}" == "--push" ]; then
      DOCKER_BUILD_ARGS+=(--push)
    fi

    if [ -z "${BUILDX_BUILDER_NAME}" ]; then
      BUILDX_BUILDER_NAME="$(basename "${PWD}")"
      if ! docker buildx ls | grep --quiet --word-regexp "${BUILDX_BUILDER_NAME}"; then
        echo "👷  Creating new Buildx Builder '${BUILDX_BUILDER_NAME}'"
        $DRY docker buildx create --name "${BUILDX_BUILDER_NAME}"
        BUILDX_BUILDER_CREATED="yes"
      fi
    fi

    echo "🐳  Building the Docker image '${TARGET_DOCKER_TAG}' on '${BUILDX_BUILDER_NAME}'."
    echo "    Build reason set to: ${BUILD_REASON}"

    $DRY docker buildx \
      --builder "${BUILDX_BUILDER_NAME}" \
      build \
      "${DOCKER_BUILD_ARGS[@]}" \
      .

    echo "✅  Finished building the Docker images '${TARGET_DOCKER_TAG}'"
    echo "🔎  Inspecting labels on '${TARGET_DOCKER_TAG}'"
    $DRY docker inspect "${TARGET_DOCKER_TAG}" --format "{{json .Config.Labels}}"

    if [ -z "${BUILDX_KEEP_BUILDER}" ] && [ "${BUILDX_BUILDER_CREATED}" == "yes" ]; then
      echo "👷  Removing Buildx Builder '${BUILDX_BUILDER_NAME}'"
      $DRY docker buildx rm "${BUILDX_BUILDER_NAME}"
    fi
  fi
done