feat: Harvest should support embedded exporters

cmd/harvest/harvest.go

@@ -513,7 +513,7 @@ func getPollerPrometheusPort(pollerName string, opts *options) int {
 		return opts.promPort
 	}
 
-	if promPort, err = conf.GetPrometheusExporterPorts(pollerName, false); err != nil {
+	if promPort, err = conf.GetLastPromPort(pollerName, false); err != nil {
 		fmt.Println(err)
 		return 0
 	}

cmd/poller/poller.go

@@ -839,8 +839,8 @@ func (p *Poller) newCollector(class string, object string, template *node.Node)
 	return col, err
 }
 
-// returns exporter that matches to name, if exporter is not loaded
-// tries to load and return
+// Returns the exporter with the matching name.
+// If the exporter is not loaded, load and return it.
 func (p *Poller) loadExporter(name string) exporter.Exporter {
 
 	var (

cmd/tools/generate/generate.go

@@ -188,7 +188,7 @@ func generateDocker(kind int) {
 	filesd := make([]string, 0, len(conf.Config.PollersOrdered))
 
 	for _, v := range conf.Config.PollersOrdered {
-		port, _ := conf.GetPrometheusExporterPorts(v, true)
+		port, _ := conf.GetLastPromPort(v, true)
 		pollerInfo := PollerInfo{
 			ServiceName:   normalizeContainerNames(v),
 			PollerName:    v,

harvest.cue

@@ -2,6 +2,8 @@ package harvest
 
 Exporters: [Name=_]: #Prom | #Influx
 
+#ExporterDefs: string | #Prom | #Influx
+
 label: [string]: string
 
 #Auth: {
@@ -77,17 +79,17 @@ Pollers: [Name=_]: #Poller
 	credentials_file?:   string
 	credentials_script?: #CredentialsScript
 	datacenter?:         string
-	exporters: [...string]
-	is_kfs?: bool
-	labels?: [...label]
-	log: [...string]
-	log_max_bytes?:    int
-	log_max_files?:    int
-	password?:         string
-	prefer_zapi?:      bool
-	ssl_cert?:         string
-	ssl_key?:          string
-	tls_min_version?:  string
-	use_insecure_tls?: bool
-	username?:         string
+	exporters:           [...#ExporterDefs]
+	is_kfs?:             bool
+	labels?:             [...label]
+	log:                 [...string]
+	log_max_bytes?:      int
+	log_max_files?:      int
+	password?:           string
+	prefer_zapi?:        bool
+	ssl_cert?:           string
+	ssl_key?:            string
+	tls_min_version?:    string
+	use_insecure_tls?:   bool
+	username?:           string
 }

integration/test/metric_test.go

@@ -31,7 +31,7 @@ func TestPollerMetrics(t *testing.T) {
 	}
 	var duplicateMetrics []string
 	for _, pollerName := range conf.Config.PollersOrdered {
-		port, _ := conf.GetPrometheusExporterPorts(pollerName, true)
+		port, _ := conf.GetLastPromPort(pollerName, true)
 		portString := strconv.Itoa(port)
 		var validCounters = 0
 		uniqueSetOfMetricLabels := make(map[string]bool)

pkg/conf/conf.go

@@ -128,7 +128,7 @@ func LoadHarvestConfig(configPath string) (string, error) {
 		return "", errors.Join(duplicates...)
 	}
 
-	// After processing all the configuration files, check if Config.Pollers is still empty.
+	// After processing all the configuration files, check if the Config.Pollers parameter is still empty.
 	if len(Config.Pollers) == 0 {
 		return "", errs.New(errs.ErrConfig, "[Pollers] section not found")
 	}
@@ -137,9 +137,27 @@ func LoadHarvestConfig(configPath string) (string, error) {
 	for i, name := range Config.PollersOrdered {
 		Config.Pollers[name].promIndex = i
 	}
+
+	fixupExporters()
 	return configPath, nil
 }
 
+func fixupExporters() {
+	for _, pollerName := range Config.PollersOrdered {
+		poller := Config.Pollers[pollerName]
+		for i, e := range poller.ExporterDefs {
+			exporterName := e.name
+			if exporterName == "" {
+				// This is an embedded exporter, synthesize a name for it
+				exporterName = fmt.Sprintf("%s-%d", pollerName, i)
+				Config.Exporters[exporterName] = e.Exporter
+			}
+
+			poller.Exporters = append(poller.Exporters, exporterName)
+		}
+	}
+}
+
 func unmarshalConfig(contents []byte) (*HarvestConfig, error) {
 	var (
 		cfg           HarvestConfig
@@ -285,8 +303,9 @@ func GetHarvestLogPath() string {
 	return cmp.Or(os.Getenv("HARVEST_LOGS"), "/var/log/harvest/")
 }
 
-// GetPrometheusExporterPorts returns the Prometheus port for the given poller
-func GetPrometheusExporterPorts(pollerName string, validatePortInUse bool) (int, error) {
+// GetLastPromPort returns the Prometheus port for the given poller
+// If multiple Prometheus exporters are configured for a poller, the port for the last exporter is returned.
+func GetLastPromPort(pollerName string, validatePortInUse bool) (int, error) {
 	var port int
 	var isPrometheusExporterConfigured bool
 
@@ -299,29 +318,28 @@ func GetPrometheusExporterPorts(pollerName string, validatePortInUse bool) (int,
 	}
 
 	exporters := poller.Exporters
-	if len(exporters) > 0 {
-		for _, e := range exporters {
-			exporter := Config.Exporters[e]
-			if exporter.Type == "Prometheus" {
-				isPrometheusExporterConfigured = true
-				if exporter.PortRange != nil {
-					ports := promPortRangeMapping[e]
-					preferredPort := exporter.PortRange.Min + poller.promIndex
-					_, isFree := ports.freePorts[preferredPort]
-					if isFree {
-						port = preferredPort
-						delete(ports.freePorts, preferredPort)
-						break
-					}
-					for k := range ports.freePorts {
-						port = k
-						delete(ports.freePorts, k)
-						break
-					}
-				} else if exporter.Port != nil && *exporter.Port != 0 {
-					port = *exporter.Port
+	for i := len(exporters) - 1; i >= 0; i-- {
+		e := exporters[i]
+		exporter := Config.Exporters[e]
+		if exporter.Type == "Prometheus" {
+			isPrometheusExporterConfigured = true
+			if exporter.PortRange != nil {
+				ports := promPortRangeMapping[e]
+				preferredPort := exporter.PortRange.Min + poller.promIndex
+				_, isFree := ports.freePorts[preferredPort]
+				if isFree {
+					port = preferredPort
+					delete(ports.freePorts, preferredPort)
+					break
+				}
+				for k := range ports.freePorts {
+					port = k
+					delete(ports.freePorts, k)
 					break
 				}
+			} else if exporter.Port != nil && *exporter.Port != 0 {
+				port = *exporter.Port
+				break
 			}
 		}
 	}
@@ -458,6 +476,25 @@ type CertificateScript struct {
 	Timeout string `yaml:"timeout,omitempty"`
 }
 
+type ExportDef struct {
+	name string
+	Exporter
+}
+
+func (e *ExportDef) UnmarshalYAML(n *yaml.Node) error {
+	if n.Kind == yaml.MappingNode {
+		var aExporter *Exporter
+		err := n.Decode(&aExporter)
+		if err != nil {
+			return fmt.Errorf("error unmarshalling embedded exporter: %w", err)
+		}
+		e.Exporter = *aExporter
+	} else if n.Kind == yaml.ScalarNode && n.ShortTag() == "!!str" {
+		e.name = n.Value
+	}
+	return nil
+}
+
 type Poller struct {
 	Addr              string               `yaml:"addr,omitempty"`
 	APIVersion        string               `yaml:"api_version,omitempty"`
@@ -470,7 +507,7 @@ type Poller struct {
 	CredentialsScript CredentialsScript    `yaml:"credentials_script,omitempty"`
 	CertificateScript CertificateScript    `yaml:"certificate_script,omitempty"`
 	Datacenter        string               `yaml:"datacenter,omitempty"`
-	Exporters         []string             `yaml:"exporters,omitempty"`
+	ExporterDefs      []ExportDef          `yaml:"exporters,omitempty"`
 	IsKfs             bool                 `yaml:"is_kfs,omitempty"`
 	Labels            *[]map[string]string `yaml:"labels,omitempty"`
 	LogMaxBytes       int64                `yaml:"log_max_bytes,omitempty"`
@@ -485,6 +522,7 @@ type Poller struct {
 	Username          string               `yaml:"username,omitempty"`
 	PreferZAPI        bool                 `yaml:"prefer_zapi,omitempty"`
 	ConfPath          string               `yaml:"conf_path,omitempty"`
+	Exporters         []string             `yaml:"-"`
 	promIndex         int
 	Name              string
 }

pkg/conf/conf_test.go

@@ -4,6 +4,7 @@ import (
 	"github.com/netapp/harvest/v2/pkg/tree/node"
 	"os"
 	"reflect"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -12,7 +13,7 @@ import (
 
 var testYml = "../../cmd/tools/doctor/testdata/testConfig.yml"
 
-func TestGetPrometheusExporterPorts(t *testing.T) {
+func TestGetLastPromPort(t *testing.T) {
 	TestLoadHarvestConfig(testYml)
 	type args struct {
 		pollerNames []string
@@ -29,23 +30,23 @@ func TestGetPrometheusExporterPorts(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			for i, v := range tt.args.pollerNames {
-				got, err := GetPrometheusExporterPorts(v, true)
+				got, err := GetLastPromPort(v, true)
 				if (err != nil) != tt.wantErr[i] {
-					t.Errorf("GetPrometheusExporterPorts() error = %v, wantErr %v", err, tt.wantErr)
+					t.Errorf("GetLastPromPort() error = %v, wantErr %v", err, tt.wantErr)
 					return
 				}
 				if err == nil && got == 0 {
-					t.Errorf("GetPrometheusExporterPorts() got = %v, want %s", got, "non zero value")
+					t.Errorf("GetLastPromPort() got = %v, want %s", got, "non zero value")
 				}
 			}
 		})
 	}
 }
 
-func TestGetPrometheusExporterPortsIssue284(t *testing.T) {
+func TestGetLastPromPortIssue284(t *testing.T) {
 	TestLoadHarvestConfig("../../cmd/tools/doctor/testdata/issue-284.yml")
 	loadPrometheusExporterPortRangeMapping(false)
-	got, _ := GetPrometheusExporterPorts("issue-284", false)
+	got, _ := GetLastPromPort("issue-284", false)
 	if got != 0 {
 		t.Fatalf("expected port to be 0 but was %d", got)
 	}
@@ -464,3 +465,45 @@ func TestEmptyPoller(t *testing.T) {
 		}
 	}
 }
+
+func TestEmbeddedExporter(t *testing.T) {
+	t.Helper()
+	resetConfig()
+
+	configYaml := "testdata/issue_2852_direct_exporters.yml"
+	_, err := LoadHarvestConfig(configYaml)
+	if err != nil {
+		t.Fatalf("got error loading config: %s, want no errors", err)
+	}
+
+	p, err := PollerNamed("u2")
+	if err != nil {
+		t.Fatalf("got no poller, want poller named=u2")
+	}
+	if len(p.Exporters) != 3 {
+		t.Errorf("got %d exporters, want 3", len(p.Exporters))
+	}
+
+	port, err := GetLastPromPort("u2", false)
+	if err != nil {
+		t.Fatalf("got error: %v, want no error", err)
+	}
+	if port != 12990 {
+		t.Errorf("got port=%d, want port=12990", port)
+	}
+
+	uniqueExporters := GetUniqueExporters(p.Exporters)
+	want := []string{"u2-1", "u2-2})"}
+	if slices.Equal(uniqueExporters, want) {
+		t.Errorf("got %v, want %v", uniqueExporters, want)
+	}
+
+	// Test that the last default Prometheus exporter is used when no exporters are defined for a poller
+	port, err = GetLastPromPort("u3", false)
+	if err != nil {
+		t.Fatalf("got error: %v, want no error", err)
+	}
+	if port != 32990 {
+		t.Errorf("got port=%d, want port=32990", port)
+	}
+}

pkg/conf/testdata/issue_2852_direct_exporters.yml

@@ -0,0 +1,26 @@
+Exporters:
+  prometheus1:
+    exporter: Prometheus
+    addr: 0.0.0.0
+    port_range: 2000-2030
+
+Defaults:
+  exporters:
+    - prometheus1
+    - exporter: Prometheus
+      port: 32990
+
+Pollers:
+  u2:
+    addr: 10.193.48.11
+    exporters:
+      - prometheus1
+      - exporter: Prometheus
+        port: 12990
+      - exporter: InfluxDB
+        addr: localhost
+        bucket: harvest
+        org: harvest
+
+  u3:
+    addr: 10.0.1.1