Do not allow missed attachments with a strict check

Makefile

@@ -22,10 +22,12 @@ GO_LDFLAGS_VARS := -X $(BUILD_VAR_PREFIX).Version=$(BUILD_VERSION) \
 
 CLANG_FORMAT_FILES = ${wildcard examples/*.c examples/*.h benchmark/probes/*.c benchmark/probes/*.h}
 
+# * cachestat fails to attach in newer kernels (see code)
 # * kfree_skb doesn't load in ci, possibly due to older verifier
+# * llcstat requires real hardware to attach perf events, which is not present in ci
 # * pci doesn't load in ci, possibly due to older verifier
 # * unix-socket-backlog requires a newer kernel than we have in ci
-CONFIGS_TO_IGNORE_IN_CHECK := kfree_skb pci unix-socket-backlog
+CONFIGS_TO_IGNORE_IN_CHECK := cachestat kfree_skb llcstat pci unix-socket-backlog
 CONFIGS_TO_CHECK := $(filter-out $(CONFIGS_TO_IGNORE_IN_CHECK), ${patsubst examples/%.yaml, %, ${wildcard examples/*.yaml}})
 
 export CGO_LDFLAGS := -l bpf
@@ -61,7 +63,7 @@ test-privileged:
 
 .PHONY: config-check
 config-check:
-	sudo ./ebpf_exporter --config.check --config.dir=examples --config.names=$(shell echo $(CONFIGS_TO_CHECK) | tr ' ' ',')
+	sudo ./ebpf_exporter --capabilities.keep=none --config.check --config.strict --config.dir=examples --config.names=$(shell echo $(CONFIGS_TO_CHECK) | tr ' ' ',')
 
 .PHONY: build
 build: build-static

cmd/ebpf_exporter/main.go

@@ -23,6 +23,7 @@ func main() {
 	configDir := kingpin.Flag("config.dir", "Config dir path.").Required().ExistingDir()
 	configNames := kingpin.Flag("config.names", "Comma separated names of configs to load.").Required().String()
 	configCheck := kingpin.Flag("config.check", "Check whether configs attach and exit.").Bool()
+	configStrict := kingpin.Flag("config.strict", "Make sure every probe registered.").Bool()
 	debug := kingpin.Flag("debug", "Enable debug.").Bool()
 	noLogTime := kingpin.Flag("log.no-timestamps", "Disable timestamps in log.").Bool()
 	listenAddress := kingpin.Flag("web.listen-address", "The address to listen on for HTTP requests (fd://0 for systemd activation).").Default(":9435").String()
@@ -74,6 +75,13 @@ func main() {
 
 	log.Printf("Started with %d programs found in the config in %dms", len(configs), time.Since(started).Milliseconds())
 
+	if *configStrict {
+		missed := e.MissedAttachments()
+		if len(missed) > 0 {
+			log.Fatalf("Missed attachments (module:prog): %v", strings.Join(missed, ", "))
+		}
+	}
+
 	if *configCheck {
 		log.Printf("Config check successful, exiting")
 		return

exporter/exporter.go

@@ -167,6 +167,23 @@ func (e *Exporter) Attach() error {
 	return nil
 }
 
+// MissedAttachments returns the list of module:prog names that failed to attach
+func (e *Exporter) MissedAttachments() []string {
+	missed := []string{}
+
+	for name, progs := range e.attachedProgs {
+		for prog, attached := range progs {
+			if attached {
+				continue
+			}
+
+			missed = append(missed, fmt.Sprintf("%s:%s", name, prog.Name()))
+		}
+	}
+
+	return missed
+}
+
 func (e *Exporter) passKaddrs(module *libbpfgo.Module, cfg config.Config) error {
 	if len(e.kaddrs) == 0 {
 		if err := e.populateKaddrs(); err != nil {