chore: improve docker-full-build

How to use:
make build-docker-js-cache

make build-docker-full \
    PLATFORM=linux/arm64 \
    DOCKER_BUILD_ARGS="--build-arg JS_SRC=grafana-js-cache:latest"

Dockerfile

@@ -118,7 +118,7 @@ COPY pkg/codegen pkg/codegen
 COPY pkg/plugins/codegen pkg/plugins/codegen
 COPY apps/example apps/example
 
-RUN go mod download
+RUN --mount=type=cache,target=/go/pkg/mod go mod download
 
 COPY embed.go Makefile build.go package.json ./
 COPY cue.mod cue.mod
@@ -135,7 +135,9 @@ COPY .github .github
 ENV COMMIT_SHA=${COMMIT_SHA}
 ENV BUILD_BRANCH=${BUILD_BRANCH}
 
-RUN make build-go GO_BUILD_TAGS=${GO_BUILD_TAGS} WIRE_TAGS=${WIRE_TAGS}
+RUN --mount=type=cache,target=/go/pkg/mod \
+    --mount=type=cache,target=/root/.cache/go-build \
+    make build-go GO_BUILD_TAGS=${GO_BUILD_TAGS} WIRE_TAGS=${WIRE_TAGS}
 
 # From-tarball build stage
 FROM ${BASE_IMAGE} AS tgz-builder
@@ -168,7 +170,8 @@ ENV PATH="/usr/share/grafana/bin:$PATH" \
   GF_PATHS_HOME="/usr/share/grafana" \
   GF_PATHS_LOGS="/var/log/grafana" \
   GF_PATHS_PLUGINS="/var/lib/grafana/plugins" \
-  GF_PATHS_PROVISIONING="/etc/grafana/provisioning"
+  GF_PATHS_PROVISIONING="/etc/grafana/provisioning" \
+  GF_UNIFIED_STORAGE_INDEX_PATH="/var/lib/grafana-search/bleve"
 
 WORKDIR $GF_PATHS_HOME
 
@@ -225,13 +228,14 @@ RUN if [ ! $(getent group "$GF_GID") ]; then \
   "$GF_PATHS_PROVISIONING/plugins" \
   "$GF_PATHS_PROVISIONING/access-control" \
   "$GF_PATHS_PROVISIONING/alerting" \
+  "$GF_UNIFIED_STORAGE_INDEX_PATH" \
   "$GF_PATHS_LOGS" \
   "$GF_PATHS_PLUGINS" \
   "$GF_PATHS_DATA" && \
   cp conf/sample.ini "$GF_PATHS_CONFIG" && \
   cp conf/ldap.toml /etc/grafana/ldap.toml && \
-  chown -R "grafana:$GF_GID_NAME" "$GF_PATHS_DATA" "$GF_PATHS_HOME/.aws" "$GF_PATHS_LOGS" "$GF_PATHS_PLUGINS" "$GF_PATHS_PROVISIONING" && \
-  chmod -R 777 "$GF_PATHS_DATA" "$GF_PATHS_HOME/.aws" "$GF_PATHS_LOGS" "$GF_PATHS_PLUGINS" "$GF_PATHS_PROVISIONING"
+  chown -R "grafana:$GF_GID_NAME" "$GF_PATHS_DATA" "$GF_PATHS_HOME/.aws" "$GF_PATHS_LOGS" "$GF_PATHS_PLUGINS" "$GF_PATHS_PROVISIONING" "$GF_UNIFIED_STORAGE_INDEX_PATH" && \
+  chmod -R 777 "$GF_PATHS_DATA" "$GF_PATHS_HOME/.aws" "$GF_PATHS_LOGS" "$GF_PATHS_PLUGINS" "$GF_PATHS_PROVISIONING" "$GF_UNIFIED_STORAGE_INDEX_PATH"
 
 COPY --from=go-src /tmp/grafana/bin/grafana* /tmp/grafana/bin/*/grafana* ./bin/
 COPY --from=js-src /tmp/grafana/public ./public

Makefile

@@ -135,7 +135,7 @@ i18n-extract-enterprise:
 	@echo "Skipping i18n extract for Enterprise: not enabled"
 else
 i18n-extract-enterprise:
-	@echo "Extracting i18n strings for Enterprise"	
+	@echo "Extracting i18n strings for Enterprise"
 	cd public/locales/enterprise && yarn run i18next-cli extract --sync-primary
 endif
 
@@ -418,6 +418,11 @@ shellcheck: $(SH_FILES) ## Run checks for shell scripts.
 TAG_SUFFIX=$(if $(WIRE_TAGS)!=oss,-$(WIRE_TAGS))
 PLATFORM=linux/amd64
 
+# JS_SRC can be set to a pre-built JS image to skip frontend build
+# Example: make build-docker-full JS_SRC=grafana-js-cache:latest
+JS_SRC ?=
+DOCKER_JS_SRC_ARG = $(if $(JS_SRC),--build-arg JS_SRC=$(JS_SRC))
+
 # default to a production build for frontend
 #
 DOCKER_JS_NODE_ENV_FLAG = production
@@ -436,13 +441,20 @@ ifeq (${NODE_ENV}, dev)
   DOCKER_JS_YARN_BUILD_FLAG = dev
 	DOCKER_JS_YARN_INSTALL_FLAG =
 endif
+.PHONY: build-docker-js-cache
+build-docker-js-cache: ## Build and cache the frontend Docker image for faster subsequent builds.
+	@echo "building JS cache image"
+	docker buildx build . \
+	--platform $(PLATFORM) \
+	--target js-builder \
+	--tag grafana-js-cache:latest
 
 .PHONY: build-docker-full
 build-docker-full: ## Build Docker image for development.
 	@echo "build docker container mode=($(DOCKER_JS_NODE_ENV_FLAG))"
-	tar -ch . | \
-	docker buildx build - \
+	docker buildx build . \
 	--platform $(PLATFORM) \
+	$(DOCKER_JS_SRC_ARG) \
 	--build-arg NODE_ENV=$(DOCKER_JS_NODE_ENV_FLAG) \
 	--build-arg JS_NODE_ENV=$(DOCKER_JS_NODE_ENV_FLAG) \
 	--build-arg JS_YARN_INSTALL_FLAG=$(DOCKER_JS_YARN_INSTALL_FLAG) \