Provide alerting rule for Nextcloud updates (#129)

Author: xperimental

.bingo/Variables.mk

@@ -29,3 +29,9 @@ $(GOLANGCI_LINT): $(BINGO_DIR)/golangci-lint.mod
 	@echo "(re)installing $(GOBIN)/golangci-lint-v1.62.2"
 	@cd $(BINGO_DIR) && GOWORK=off $(GO) build -mod=mod -modfile=golangci-lint.mod -o=$(GOBIN)/golangci-lint-v1.62.2 "github.com/golangci/golangci-lint/cmd/golangci-lint"
 
+PROMTOOL := $(GOBIN)/promtool-v0.306.0
+$(PROMTOOL): $(BINGO_DIR)/promtool.mod
+	@# Install binary/ries using Go 1.14+ build command. This is using bwplotka/bingo-controlled, separate go module with pinned dependencies.
+	@echo "(re)installing $(GOBIN)/promtool-v0.306.0"
+	@cd $(BINGO_DIR) && GOWORK=off $(GO) build -mod=mod -modfile=promtool.mod -o=$(GOBIN)/promtool-v0.306.0 "github.com/prometheus/prometheus/cmd/promtool"
+

.bingo/promtool.mod

@@ -0,0 +1,15 @@
+module _ // Auto generated by https://github.com/bwplotka/bingo. DO NOT EDIT
+
+go 1.23.0
+
+toolchain go1.23.4
+
+replace github.com/fsnotify/fsnotify v1.8.0 => github.com/fsnotify/fsnotify v1.7.0
+
+exclude github.com/linode/linodego v1.0.0
+
+exclude github.com/grpc-ecosystem/grpc-gateway v1.14.7
+
+exclude google.golang.org/api v0.30.0
+
+require github.com/prometheus/prometheus v0.306.0 // cmd/promtool

.bingo/promtool.sum

@@ -12,3 +12,5 @@ BINGO="${GOBIN}/bingo-v0.9.0"
 
 GOLANGCI_LINT="${GOBIN}/golangci-lint-v1.62.2"
 
+PROMTOOL="${GOBIN}/promtool-v0.306.0"
+

.bingo/variables.env

@@ -15,3 +15,5 @@ jobs:
       uses: golangci/golangci-lint-action@v4
       with:
         version: v1.62.2
+    - name: promtool
+      run: make lint-promtool

.github/workflows/pull-request.yml

@@ -17,13 +17,20 @@ test:
 	$(GO_CMD) test -cover ./...
 
 .PHONY: lint
-lint: $(GOLANGCI_LINT)
+lint: lint-go lint-promtool
+
+.PHONY: lint-go
+lint-go: $(GOLANGCI_LINT)
 	$(GOLANGCI_LINT) run
 
-.PHONY: lint-fix
-lint-fix: $(GOLANGCI_LINT)
+.PHONY: lint-go-fix
+lint-go-fix: $(GOLANGCI_LINT)
 	$(GOLANGCI_LINT) run --fix
 
+.PHONY: lint-promtool
+lint-promtool: $(PROMTOOL) contrib/prometheus-alerts.yaml
+	$(PROMTOOL) check rules contrib/prometheus-alerts.yaml
+
 .PHONY: build-binary
 build-binary:
 	$(GO_CMD) build -tags netgo -ldflags "-w -X main.Version=$(VERSION) -X main.GitCommit=$(GIT_COMMIT)" -o nextcloud-exporter .
@@ -49,7 +56,7 @@ all-images:
 	docker buildx build -t "ghcr.io/$(DOCKER_REPO):$(DOCKER_TAG)" -t "docker.io/$(DOCKER_REPO):$(DOCKER_TAG)" --platform linux/amd64,linux/arm64 --push .
 
 .PHONY: tools
-tools: $(BINGO) $(GOLANGCI_LINT)
+tools: $(BINGO) $(GOLANGCI_LINT) $(PROMTOOL)
 	@echo Tools built.
 
 .PHONY: clean

Makefile

@@ -0,0 +1,14 @@
+groups:
+- name: nextcloud
+  rules:
+  - alert: NextcloudUpdateWarning
+    expr: |
+      sum by (instance, version, available_version) (nextcloud_system_update_available) > 0
+    for: 15m
+    annotations:
+      summary: |
+        Version {{ index $labels "available_version" }} available for Nextcloud server {{ index $labels "instance" }}.
+      description: |
+        The Nextcloud server at {{ index $labels "instance" }} can be updated to version {{ index $labels "available_version" }} (from {{ index $labels "version" }}).
+    labels:
+      severity: warning