feat: add support for specifying stack builders for builder-cnb

plugins/builder-cnb/builder-build

@@ -13,7 +13,13 @@ trigger-builder-cnb-builder-build() {
     return
   fi
 
-  dokku_log_info1 "Building $APP from cnb (experimental)..."
+
+  local stack="$(plugn trigger buildpack-stack-name "$APP")"
+  if [[ -z "$stack" ]]; then
+    DOKKU_CNB_STACK="$stack"
+  fi
+
+  dokku_log_info1 "Building $APP from cnb stack $DOKKU_CNB_STACK (experimental)..."
 
   if ! command -v "pack" &>/dev/null; then
     dokku_log_fail "Missing pack, install it"
@@ -30,7 +36,7 @@ trigger-builder-cnb-builder-build() {
 
   plugn trigger pre-build-cnb "$APP" "$SOURCECODE_WORK_DIR"
 
-  pack build "$IMAGE" --builder heroku/buildpacks --path "$SOURCECODE_WORK_DIR" --default-process web
+  pack build "$IMAGE" --builder "$DOKKU_CNB_BUILDER" --path "$SOURCECODE_WORK_DIR" --default-process web
 
   echo "FROM $IMAGE" | suppress_output "$DOCKER_BIN" image build --label=com.dokku.image-stage=build --label=org.label-schema.schema-version=1.0 --label=org.label-schema.vendor=dokku --label=com.dokku.app-name=$APP --label=dokku -t "$IMAGE" -
 

plugins/builder-herokuish/builder-build

@@ -20,7 +20,6 @@ trigger-builder-herokuish-builder-build() {
     dokku_log_info1 "Building $APP from herokuish"
   fi
 
-
   local IMAGE=$(get_app_image_name "$APP")
   local DOKKU_APP_CACHE_DIR="$DOKKU_ROOT/$APP/cache"
   local DOKKU_APP_HOST_CACHE_DIR="$DOKKU_HOST_ROOT/$APP/cache"