Monitor NGINX logs for errors & NGINX worker processes after a NGINX reload

Makefile

@@ -97,7 +97,6 @@ build/nginx-agent:
 build: build/nginx-agent ## Build agent executable
 
 deps: ## Update dependencies in vendor folders
-	git diff --quiet || { echo "Local changes found. Please commit or stash your changes." >&2; exit 1; }
 	cd sdk && make generate
 	for dir in ${VENDOR_LOCATIONS}; do \
 		(cd "$$dir" && echo "Running vendor commands on $$dir" && go mod tidy && go mod vendor && cd "$$OLDPWD" || exit) \
@@ -264,14 +263,14 @@ image: ## Build agent container image for NGINX Plus, need nginx-repo.crt and ng
 oss-image: ## Build agent container image for NGINX OSS
 	@echo Building image with $(CONTAINER_CLITOOL); \
 	$(CONTAINER_BUILDENV) $(CONTAINER_CLITOOL) build -t ${IMAGE_TAG} . \
-	--no-cache -f ./scripts/docker/nginx-oss/${OS_RELEASE}/Dockerfile \
+	--no-cache -f ./scripts/docker/nginx-oss/${CONTAINER_OS_TYPE}/Dockerfile \
 	--build-arg PACKAGE_NAME=${PACKAGE_NAME} \
 	--build-arg BASE_IMAGE=${BASE_IMAGE} \
-	--build-arg ENTRY_POINT=./scripts/docker/nginx-oss/entrypoint.sh
+	--build-arg ENTRY_POINT=./scripts/docker/entrypoint.sh
 
 run-container: ## Run container from specified IMAGE_TAG
 	@echo Running ${IMAGE_TAG} with $(CONTAINER_CLITOOL); \
-		$(CONTAINER_CLITOOL) run --mount type=bind,source=${PWD}/nginx-agent.conf,target=/etc/nginx-agent/nginx-agent.conf ${IMAGE_TAG}
+		$(CONTAINER_CLITOOL) run -p 127.0.0.1:8081:8081/tcp --mount type=bind,source=${PWD}/nginx-agent.conf,target=/etc/nginx-agent/nginx-agent.conf ${IMAGE_TAG}
 
 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
 # Grafana Example Dashboard Targets                                                                               #

src/core/config/config.go

@@ -78,6 +78,7 @@ func SetDefaults() {
 
 	// NGINX DEFAULTS
 	Viper.SetDefault(NginxClientVersion, Defaults.Nginx.NginxClientVersion)
+	Viper.SetDefault(NginxConfigReloadMonitoringPeriod, Defaults.Nginx.ConfigReloadMonitoringPeriod)
 }
 
 func setFlagDeprecated(name string, usageMessage string) {
@@ -284,10 +285,12 @@ func getDataplane() Dataplane {
 
 func getNginx() Nginx {
 	return Nginx{
-		ExcludeLogs:         Viper.GetString(NginxExcludeLogs),
-		Debug:               Viper.GetBool(NginxDebug),
-		NginxCountingSocket: Viper.GetString(NginxCountingSocket),
-		NginxClientVersion:  Viper.GetInt(NginxClientVersion),
+		ExcludeLogs:                  Viper.GetString(NginxExcludeLogs),
+		Debug:                        Viper.GetBool(NginxDebug),
+		NginxCountingSocket:          Viper.GetString(NginxCountingSocket),
+		NginxClientVersion:           Viper.GetInt(NginxClientVersion),
+		ConfigReloadMonitoringPeriod: Viper.GetDuration(NginxConfigReloadMonitoringPeriod),
+		TreatWarningsAsErrors:        Viper.GetBool(NginxTreatWarningsAsErrors),
 	}
 }
 

src/core/config/config_test.go

@@ -148,6 +148,7 @@ func TestGetConfig(t *testing.T) {
 		assert.Equal(t, Defaults.Server.Metrics, config.Server.Metrics)
 
 		assert.Equal(t, Defaults.AgentAPI.Port, config.AgentAPI.Port)
+		assert.Equal(t, Defaults.Nginx.ConfigReloadMonitoringPeriod, config.Nginx.ConfigReloadMonitoringPeriod)
 
 		assert.True(t, len(config.AllowedDirectoriesMap) > 0)
 		assert.Equal(t, Defaults.ConfigDirs, config.ConfigDirs)

src/core/config/defaults.go

@@ -51,9 +51,11 @@ var (
 			Token: uuid.New().String(),
 		},
 		Nginx: Nginx{
-			Debug:               false,
-			NginxCountingSocket: "unix:/var/run/nginx-agent/nginx.sock",
-			NginxClientVersion:  6,
+			Debug:                        false,
+			NginxCountingSocket:          "unix:/var/run/nginx-agent/nginx.sock",
+			NginxClientVersion:           6,
+			ConfigReloadMonitoringPeriod: 10 * time.Second,
+			TreatWarningsAsErrors:        false,
 		},
 		ConfigDirs:            "/etc/nginx:/usr/local/etc/nginx:/usr/share/nginx/modules:/etc/nms",
 		AllowedDirectoriesMap: map[string]struct{}{},
@@ -128,10 +130,12 @@ const (
 	// viper keys used in config
 	NginxKey = "nginx"
 
-	NginxExcludeLogs    = NginxKey + agent_config.KeyDelimiter + "exclude_logs"
-	NginxDebug          = NginxKey + agent_config.KeyDelimiter + "debug"
-	NginxCountingSocket = NginxKey + agent_config.KeyDelimiter + "socket"
-	NginxClientVersion  = NginxKey + agent_config.KeyDelimiter + "client_version"
+	NginxExcludeLogs                  = NginxKey + agent_config.KeyDelimiter + "exclude_logs"
+	NginxDebug                        = NginxKey + agent_config.KeyDelimiter + "debug"
+	NginxCountingSocket               = NginxKey + agent_config.KeyDelimiter + "socket"
+	NginxClientVersion                = NginxKey + agent_config.KeyDelimiter + "client_version"
+	NginxConfigReloadMonitoringPeriod = NginxKey + agent_config.KeyDelimiter + "config_reload_monitoring_period"
+	NginxTreatWarningsAsErrors        = NginxKey + agent_config.KeyDelimiter + "treat_warnings_as_errors"
 
 	// viper keys used in config
 	DataplaneKey = "dataplane"
@@ -247,6 +251,11 @@ var (
 			Usage:        "The NGINX Plus counting unix socket location.",
 			DefaultValue: Defaults.Nginx.NginxCountingSocket,
 		},
+		&DurationFlag{
+			Name:         NginxConfigReloadMonitoringPeriod,
+			Usage:        "The duration the NGINX Agent will monitor error logs after a NGINX reload",
+			DefaultValue: Defaults.Nginx.ConfigReloadMonitoringPeriod,
+		},
 		// Metrics
 		&DurationFlag{
 			Name:         MetricsCollectionInterval,

src/core/config/types.go

@@ -88,10 +88,12 @@ type TLSConfig struct {
 
 // Nginx settings
 type Nginx struct {
-	ExcludeLogs         string `mapstructure:"exclude_logs" yaml:"-"`
-	Debug               bool   `mapstructure:"debug" yaml:"-"`
-	NginxCountingSocket string `mapstructure:"socket" yaml:"-"`
-	NginxClientVersion  int    `mapstructure:"client_version" yaml:"-"`
+	ExcludeLogs                  string        `mapstructure:"exclude_logs" yaml:"-"`
+	Debug                        bool          `mapstructure:"debug" yaml:"-"`
+	NginxCountingSocket          string        `mapstructure:"socket" yaml:"-"`
+	NginxClientVersion           int           `mapstructure:"client_version" yaml:"-"`
+	ConfigReloadMonitoringPeriod time.Duration `mapstructure:"config_reload_monitoring_period" yaml:"-"`
+	TreatWarningsAsErrors        bool          `mapstructure:"treat_warnings_as_errors" yaml:"-"`
 }
 
 type Dataplane struct {

src/core/metrics/sources/nginx_access_log.go

@@ -20,7 +20,7 @@ import (
 	"github.com/nginx/agent/sdk/v2/proto"
 	"github.com/nginx/agent/v2/src/core"
 	"github.com/nginx/agent/v2/src/core/metrics"
-	"github.com/nginx/agent/v2/src/core/metrics/sources/tailer"
+	"github.com/nginx/agent/v2/src/core/tailer"
 
 	log "github.com/sirupsen/logrus"
 )

src/core/metrics/sources/nginx_error_log.go

@@ -16,7 +16,7 @@ import (
 
 	"github.com/nginx/agent/v2/src/core"
 	"github.com/nginx/agent/v2/src/core/metrics"
-	"github.com/nginx/agent/v2/src/core/metrics/sources/tailer"
+	"github.com/nginx/agent/v2/src/core/tailer"
 
 	log "github.com/sirupsen/logrus"
 )

src/core/nginx.go

@@ -269,15 +269,27 @@ func (n *NginxBinaryType) ValidateConfig(processId, bin, configLocation string,
 		return fmt.Errorf("error running nginx -t -c %v:\n%s", configLocation, response)
 	}
 
-	if strings.Contains(response.String(), "nginx: [warn]") {
-		return fmt.Errorf("error running nginx -t -c %v:\n%s", configLocation, response)
+	err = n.validateConfigCheckResponse(response, configLocation)
+	if err != nil  {
+		return err
 	}
 
 	log.Infof("Config validated:\n%s", response)
 
 	return nil
 }
 
+func (n *NginxBinaryType) validateConfigCheckResponse(response *bytes.Buffer, configLocation string) (error) {
+	if bytes.Contains(response.Bytes(), []byte("[emerg]")) {
+		return fmt.Errorf("error running nginx -t -c %v:\n%s", configLocation, response)
+	}
+
+	if (n.config.Nginx.TreatWarningsAsErrors && bytes.Contains(response.Bytes(), []byte("[warn]"))) {
+		return fmt.Errorf("error running nginx -t -c %v:\n%s", configLocation, response)
+	}
+	return nil
+}
+
 // Stop stops an instance of NGINX.
 func (n *NginxBinaryType) Stop(processId, bin string) error {
 	log.Info("Stopping NGINX")
@@ -330,8 +342,8 @@ func (n *NginxBinaryType) WriteConfig(config *proto.NginxConfig) (*sdk.ConfigApp
 		}
 	}
 
-	details, ok := n.nginxDetailsMap[config.ConfigData.NginxId]
-	if !ok || details == nil {
+	details := n.GetNginxDetailsByID(config.ConfigData.NginxId)
+	if details == nil {
 		return nil, fmt.Errorf("NGINX instance %s not found", config.ConfigData.NginxId)
 	}
 

src/core/nginx_test.go

@@ -386,7 +386,7 @@ func TestWriteBackup(t *testing.T) {
 	}{
 		{
 			name:        "enabled test",
-			config:      config.Config{Nginx: config.Nginx{Debug: true}},
+			config:      config.Config{Nginx: config.Nginx{Debug: true, TreatWarningsAsErrors: true}},
 			nginxConfig: &proto.NginxConfig{Zconfig: zippedFile, Zaux: zippedFile},
 			confFiles: []*proto.File{
 				{
@@ -402,7 +402,7 @@ func TestWriteBackup(t *testing.T) {
 		},
 		{
 			name:           "not enabled test",
-			config:         config.Config{Nginx: config.Nginx{Debug: false}},
+			config:         config.Config{Nginx: config.Nginx{Debug: false, TreatWarningsAsErrors: false}},
 			nginxConfig:    &proto.NginxConfig{},
 			confFiles:      []*proto.File{},
 			auxFiles:       []*proto.File{},
@@ -945,3 +945,39 @@ func TestNginxBinaryType_sanitizeProcessPath(t *testing.T) {
 		})
 	}
 }
+
+func TestNginxBinaryType_validateConfigCheckResponse(t *testing.T) {
+	type testDef struct {
+		name                  string
+		response              string
+		expected              interface{}
+		treatWarningsAsErrors bool
+	}
+
+	// no test case for process lookup, that would require running nginx or proc somewhere
+	for _, test := range []testDef{
+		{name: "validation fails, emerg respected", response: "nginx [emerg]", treatWarningsAsErrors: false, expected: errors.New("error running nginx -t -c :\nnginx [emerg]")},
+		{name: "validation fails, emerg respected, config irrelevant", response: "nginx [emerg]", treatWarningsAsErrors: true, expected: errors.New("error running nginx -t -c :\nnginx [emerg]")},
+		{name: "validation passes, warn ignored", response: "nginx [warn]", treatWarningsAsErrors: false, expected: nil},
+		{name: "validation fails, warn respected", response: "nginx [warn]", treatWarningsAsErrors: true, expected: errors.New("error running nginx -t -c :\nnginx [warn]")},
+		{name: "validation passes, info irrelevant", response: "nginx [info]", treatWarningsAsErrors: false, expected: nil},
+		{name: "validation passes, info irrelevant, config irrelevant", response: "nginx [info]", treatWarningsAsErrors: true, expected: nil},
+		{name: "validation fails unknown directive", response: "nginx: [emerg] unknown directive \"location/\" in /etc/nginx/sites-enabled/someapp:5", treatWarningsAsErrors: false, expected: errors.New("error running nginx -t -c :\nnginx: [emerg] unknown directive \"location/\" in /etc/nginx/sites-enabled/someapp:5")},
+		{name: "validation fails conflicting server name", response: "nginx: [warn] conflicting server name \"example.com\" on 0.0.0.0:80, ignored", treatWarningsAsErrors: true, expected: errors.New("error running nginx -t -c :\nnginx: [warn] conflicting server name \"example.com\" on 0.0.0.0:80, ignored")},
+		{name: "validation fails limit_req", response: "nginx: [emerg] 96300#96300: limit_req \"default\" uses the \"$binary_remote_addr\" key while previously it used the \"$http_apiKey\" key", treatWarningsAsErrors: true, expected: errors.New("error running nginx -t -c :\nnginx: [emerg] 96300#96300: limit_req \"default\" uses the \"$binary_remote_addr\" key while previously it used the \"$http_apiKey\" key")},
+		{name: "validation fails host not found in upstream", response: "nginx: [emerg] 5191#5191: host not found in upstream \"example.com:80\" in /etc/nginx/nginx.conf:111", treatWarningsAsErrors: false, expected: errors.New("error running nginx -t -c :\nnginx: [emerg] 5191#5191: host not found in upstream \"example.com:80\" in /etc/nginx/nginx.conf:111")},
+		{name: "validation fails worker_connections", response: "nginx: [warn] 2048 worker_connections exceed open file resource limit: 1024", treatWarningsAsErrors: true, expected: errors.New("error running nginx -t -c :\nnginx: [warn] 2048 worker_connections exceed open file resource limit: 1024")},
+		{name: "validation passes worker_connections", response: "nginx: [warn] 2048 worker_connections exceed open file resource limit: 1024", treatWarningsAsErrors: false, expected: nil},
+	} {
+		t.Run(test.name, func(tt *testing.T) {
+			binary := NginxBinaryType{
+				env: &EnvironmentType{},
+				config: &config.Config{Nginx: config.Nginx{Debug: true, TreatWarningsAsErrors: test.treatWarningsAsErrors}},
+
+			}
+			buffer := bytes.NewBuffer([]byte(test.response))
+			err := binary.validateConfigCheckResponse(buffer, "")
+			assert.Equal(tt, test.expected, err)
+		})
+	}
+}

src/core/metrics/sources/tailer/tailer.go → src/core/tailer/tailer.go

@@ -19,9 +19,10 @@ import (
 
 var (
 	tailConfig = tail.Config{
-		Follow: true,
-		ReOpen: true,
-		Poll:   true,
+		Follow:    true,
+		ReOpen:    true,
+		MustExist: true,
+		Poll:      true,
 		Location: &tail.SeekInfo{
 			Whence: io.SeekEnd,
 		},
@@ -108,11 +109,14 @@ func (t *Tailer) Tail(ctx context.Context, data chan<- string) {
 			data <- line.Text
 
 		case <-ctx.Done():
-			err := ctx.Err()
-			if err != nil {
-				log.Errorf("error in done context Tail %v", err)
+			ctxErr := ctx.Err()
+			switch ctxErr {
+			case context.DeadlineExceeded:
+				log.Tracef("Tailer cancelled. Deadline exceeded, %v", ctxErr)
+			case context.Canceled:
+				log.Tracef("Tailer forcibly cancelled, %v", ctxErr)
 			}
-			log.Info("tailer is done")
+			log.Trace("Tailer is done")
 			return
 		}
 	}
@@ -134,11 +138,14 @@ func (t *PatternTailer) Tail(ctx context.Context, data chan<- map[string]string)
 				data <- l
 			}
 		case <-ctx.Done():
-			err := ctx.Err()
-			if err != nil {
-				log.Errorf("error in done context Tail %v", err)
+			ctxErr := ctx.Err()
+			switch ctxErr {
+			case context.DeadlineExceeded:
+				log.Tracef("Tailer cancelled because deadline was exceeded, %v", ctxErr)
+			case context.Canceled:
+				log.Tracef("Tailer forcibly cancelled, %v", ctxErr)
 			}
-			log.Info("tailer is done")
+			log.Tracef("Tailer is done")
 			return
 		}
 	}