chore: add update functionality

Signed-off-by: Stephan Wendel <me@stephanwe.de>

scripts/crowsnest.sh

@@ -194,4 +194,49 @@ function compare_crowsnest_versions() {
   fi
 
   echo "${versions}"
-}
+}
+
+function update_crowsnest() {
+  ## Helper Func
+  function install_crowsnest_dependencies() {
+    local packages
+    local install_script="${CROWSNEST_DIR}/tools/install.sh"
+
+    ### read PKGLIST from official install-script
+    status_msg "Reading dependencies..."
+    # shellcheck disable=SC2016
+    packages="$(grep "PKGLIST=" "${install_script}" | cut -d'"' -f2 | sed 's/\${PKGLIST}//g' | tr -d '\n')"
+
+    echo "${cyan}${packages}${white}" | tr '[:space:]' '\n'
+    read -r -a packages <<< "${packages}"
+
+    ### Update system package info
+    status_msg "Updating package lists..."
+    if ! sudo apt-get update --allow-releaseinfo-change; then
+      log_error "failure while updating package lists"
+      error_msg "Updating package lists failed!"
+      exit 1
+    fi
+
+    ### Install required packages
+    status_msg "Installing required packages..."
+    if ! sudo apt-get install --yes "${packages[@]}"; then
+      log_error "failure while installing required crowsnest packages"
+      error_msg "Installing required packages failed!"
+      exit 1
+    fi
+  }
+
+  do_action_service "stop" "crowsnest"
+
+  if [[ ! -d ${CROWSNEST_DIR} ]]; then
+    clone_moonraker "${CROWSNEST_REPO}"
+  else
+    status_msg "Updating Crowsnest ..."
+    cd "${CROWSNEST_DIR}" && git pull
+    ### read PKGLIST and install possible new dependencies
+    install_crowsnest_dependencies
+  fi
+  ok_msg "Update complete!"
+  do_action_service "restart" "crowsnest"
+}