Huge tests refactoring. Reduce running time 2-3x times

4 files changed, 808 insertions, 0 deletions

diff --git a/tests/plugins/metrics/.rr-test.yaml b/tests/plugins/metrics/.rr-test.yaml
new file mode 100644
index 00000000..37c50395
--- /dev/null
+++ b/tests/plugins/metrics/.rr-test.yaml
@@ -0,0 +1,16 @@
+rpc:
+  listen: tcp://127.0.0.1:6001
+  disabled: false
+
+metrics:
+  # prometheus client address (path /metrics added automatically)
+  address: localhost:2112
+  collect:
+    app_metric:
+      type: histogram
+      help: "Custom application metric"
+      labels: [ "type" ]
+      buckets: [ 0.1, 0.2, 0.3, 1.0 ]
+logs:
+  mode: development
+  level: error
\ No newline at end of file
diff --git a/tests/plugins/metrics/docker-compose.yml b/tests/plugins/metrics/docker-compose.yml
new file mode 100644
index 00000000..610633b4
--- /dev/null
+++ b/tests/plugins/metrics/docker-compose.yml
@@ -0,0 +1,7 @@
+version: '3.7'
+
+services:
+  prometheus:
+    image: prom/prometheus
+    ports:
+    - 9090:9090
diff --git a/tests/plugins/metrics/metrics_test.go b/tests/plugins/metrics/metrics_test.go
new file mode 100644
index 00000000..c94d51bc
--- /dev/null
+++ b/tests/plugins/metrics/metrics_test.go
@@ -0,0 +1,739 @@
+package metrics
+
+import (
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/rpc"
+	"os"
+	"os/signal"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/spiral/endure"
+	goridgeRpc "github.com/spiral/goridge/v3/pkg/rpc"
+	"github.com/spiral/roadrunner/v2/plugins/config"
+	"github.com/spiral/roadrunner/v2/plugins/logger"
+	"github.com/spiral/roadrunner/v2/plugins/metrics"
+	rpcPlugin "github.com/spiral/roadrunner/v2/plugins/rpc"
+	"github.com/stretchr/testify/assert"
+)
+
+const dialAddr = "127.0.0.1:6001"
+const dialNetwork = "tcp"
+const getAddr = "http://localhost:2112/metrics"
+
+// get request and return body
+func get() (string, error) {
+	r, err := http.Get(getAddr)
+	if err != nil {
+		return "", err
+	}
+
+	b, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return "", err
+	}
+
+	err = r.Body.Close()
+	if err != nil {
+		return "", err
+	}
+	// unsafe
+	return string(b), err
+}
+
+func TestMetricsInit(t *testing.T) {
+	cont, err := endure.NewContainer(nil, endure.SetLogLevel(endure.ErrorLevel))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cfg := &config.Viper{}
+	cfg.Prefix = "rr"
+	cfg.Path = ".rr-test.yaml"
+
+	err = cont.RegisterAll(
+		cfg,
+		&metrics.Plugin{},
+		&rpcPlugin.Plugin{},
+		&logger.ZapLogger{},
+		&Plugin1{},
+	)
+	assert.NoError(t, err)
+
+	err = cont.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ch, err := cont.Serve()
+	assert.NoError(t, err)
+
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
+
+	tt := time.NewTimer(time.Second * 5)
+
+	out, err := get()
+	assert.NoError(t, err)
+
+	assert.Contains(t, out, "go_gc_duration_seconds")
+
+	for {
+		select {
+		case e := <-ch:
+			assert.Fail(t, "error", e.Error.Error())
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+		case <-sig:
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+			return
+		case <-tt.C:
+			// timeout
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+			return
+		}
+	}
+}
+
+func TestMetricsGaugeCollector(t *testing.T) {
+	cont, err := endure.NewContainer(nil, endure.SetLogLevel(endure.ErrorLevel))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cfg := &config.Viper{}
+	cfg.Prefix = "rr"
+	cfg.Path = ".rr-test.yaml"
+
+	err = cont.RegisterAll(
+		cfg,
+		&metrics.Plugin{},
+		&rpcPlugin.Plugin{},
+		&logger.ZapLogger{},
+		&Plugin1{},
+	)
+	assert.NoError(t, err)
+
+	err = cont.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ch, err := cont.Serve()
+	assert.NoError(t, err)
+
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
+
+	time.Sleep(time.Second)
+	tt := time.NewTimer(time.Second * 5)
+
+	out, err := get()
+	assert.NoError(t, err)
+	assert.Contains(t, out, "my_gauge 100")
+	assert.Contains(t, out, "my_gauge2 100")
+
+	out, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, out, "go_gc_duration_seconds")
+
+	for {
+		select {
+		case e := <-ch:
+			assert.Fail(t, "error", e.Error.Error())
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+		case <-sig:
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+			return
+		case <-tt.C:
+			// timeout
+			err = cont.Stop()
+			if err != nil {
+				assert.FailNow(t, "error", err.Error())
+			}
+			return
+		}
+	}
+}
+
+func TestMetricsDifferentRPCCalls(t *testing.T) {
+	cont, err := endure.NewContainer(nil, endure.SetLogLevel(endure.ErrorLevel))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cfg := &config.Viper{}
+	cfg.Prefix = "rr"
+	cfg.Path = ".rr-test.yaml"
+
+	err = cont.RegisterAll(
+		cfg,
+		&metrics.Plugin{},
+		&rpcPlugin.Plugin{},
+		&logger.ZapLogger{},
+	)
+	assert.NoError(t, err)
+
+	err = cont.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ch, err := cont.Serve()
+	assert.NoError(t, err)
+
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		tt := time.NewTimer(time.Minute * 3)
+		for {
+			select {
+			case e := <-ch:
+				assert.Fail(t, "error", e.Error.Error())
+				err = cont.Stop()
+				if err != nil {
+					assert.FailNow(t, "error", err.Error())
+				}
+			case <-sig:
+				err = cont.Stop()
+				if err != nil {
+					assert.FailNow(t, "error", err.Error())
+				}
+				return
+			case <-tt.C:
+				// timeout
+				err = cont.Stop()
+				if err != nil {
+					assert.FailNow(t, "error", err.Error())
+				}
+				return
+			}
+		}
+	}()
+
+	t.Run("DeclareMetric", declareMetricsTest)
+	genericOut, err := get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "test_metrics_named_collector")
+
+	t.Run("AddMetric", addMetricsTest)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "test_metrics_named_collector 10000")
+
+	t.Run("SetMetric", setMetric)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "user_gauge_collector 100")
+
+	t.Run("VectorMetric", vectorMetric)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "gauge_2_collector{section=\"first\",type=\"core\"} 100")
+
+	t.Run("MissingSection", missingSection)
+	t.Run("SetWithoutLabels", setWithoutLabels)
+	t.Run("SetOnHistogram", setOnHistogram)
+	t.Run("MetricSub", subMetric)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "sub_gauge_subMetric 1")
+
+	t.Run("SubVector", subVector)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "sub_gauge_subVector{section=\"first\",type=\"core\"} 1")
+
+	t.Run("RegisterHistogram", registerHistogram)
+
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, `TYPE histogram_registerHistogram`)
+
+	// check buckets
+	assert.Contains(t, genericOut, `histogram_registerHistogram_bucket{le="0.1"} 0`)
+	assert.Contains(t, genericOut, `histogram_registerHistogram_bucket{le="0.2"} 0`)
+	assert.Contains(t, genericOut, `histogram_registerHistogram_bucket{le="0.5"} 0`)
+	assert.Contains(t, genericOut, `histogram_registerHistogram_bucket{le="+Inf"} 0`)
+	assert.Contains(t, genericOut, `histogram_registerHistogram_sum 0`)
+	assert.Contains(t, genericOut, `histogram_registerHistogram_count 0`)
+
+	t.Run("CounterMetric", counterMetric)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "HELP default_default_counter_CounterMetric test_counter")
+	assert.Contains(t, genericOut, `default_default_counter_CounterMetric{section="section2",type="type2"}`)
+
+	t.Run("ObserveMetric", observeMetric)
+	genericOut, err = get()
+	assert.NoError(t, err)
+	assert.Contains(t, genericOut, "observe_observeMetric")
+
+	t.Run("ObserveMetricNotEnoughLabels", observeMetricNotEnoughLabels)
+
+	close(sig)
+}
+
+func observeMetricNotEnoughLabels(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "observe_observeMetricNotEnoughLabels",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Help:      "test_observe",
+			Type:      metrics.Histogram,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	assert.Error(t, client.Call("metrics.Observe", metrics.Metric{
+		Name:   "observe_observeMetric",
+		Value:  100.0,
+		Labels: []string{"test"},
+	}, &ret))
+	assert.False(t, ret)
+}
+
+func observeMetric(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "observe_observeMetric",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Help:      "test_observe",
+			Type:      metrics.Histogram,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	assert.NoError(t, client.Call("metrics.Observe", metrics.Metric{
+		Name:   "observe_observeMetric",
+		Value:  100.0,
+		Labels: []string{"test", "test2"},
+	}, &ret))
+	assert.True(t, ret)
+}
+
+func counterMetric(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "counter_CounterMetric",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Help:      "test_counter",
+			Type:      metrics.Counter,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	assert.NoError(t, client.Call("metrics.Add", metrics.Metric{
+		Name:   "counter_CounterMetric",
+		Value:  100.0,
+		Labels: []string{"type2", "section2"},
+	}, &ret))
+	assert.True(t, ret)
+}
+
+func registerHistogram(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "histogram_registerHistogram",
+		Collector: metrics.Collector{
+			Help:    "test_histogram",
+			Type:    metrics.Histogram,
+			Buckets: []float64{0.1, 0.2, 0.5},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	m := metrics.Metric{
+		Name:   "histogram_registerHistogram",
+		Value:  10000,
+		Labels: nil,
+	}
+
+	err = client.Call("metrics.Add", m, &ret)
+	assert.Error(t, err)
+	assert.False(t, ret)
+}
+
+func subVector(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "sub_gauge_subVector",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	m := metrics.Metric{
+		Name:   "sub_gauge_subVector",
+		Value:  100000,
+		Labels: []string{"core", "first"},
+	}
+
+	err = client.Call("metrics.Add", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	m = metrics.Metric{
+		Name:   "sub_gauge_subVector",
+		Value:  99999,
+		Labels: []string{"core", "first"},
+	}
+
+	err = client.Call("metrics.Sub", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
+
+func subMetric(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "sub_gauge_subMetric",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	m := metrics.Metric{
+		Name:  "sub_gauge_subMetric",
+		Value: 100000,
+	}
+
+	err = client.Call("metrics.Add", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	m = metrics.Metric{
+		Name:  "sub_gauge_subMetric",
+		Value: 99999,
+	}
+
+	err = client.Call("metrics.Sub", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
+
+func setOnHistogram(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "histogram_setOnHistogram",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Histogram,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	m := metrics.Metric{
+		Name:  "gauge_setOnHistogram",
+		Value: 100.0,
+	}
+
+	err = client.Call("metrics.Set", m, &ret) // expected 2 label values but got 1 in []string{"missing"}
+	assert.Error(t, err)
+	assert.False(t, ret)
+}
+
+func setWithoutLabels(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "gauge_setWithoutLabels",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	m := metrics.Metric{
+		Name:  "gauge_setWithoutLabels",
+		Value: 100.0,
+	}
+
+	err = client.Call("metrics.Set", m, &ret) // expected 2 label values but got 1 in []string{"missing"}
+	assert.Error(t, err)
+	assert.False(t, ret)
+}
+
+func missingSection(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "gauge_missing_section_collector",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	m := metrics.Metric{
+		Name:   "gauge_missing_section_collector",
+		Value:  100.0,
+		Labels: []string{"missing"},
+	}
+
+	err = client.Call("metrics.Set", m, &ret) // expected 2 label values but got 1 in []string{"missing"}
+	assert.Error(t, err)
+	assert.False(t, ret)
+}
+
+func vectorMetric(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "gauge_2_collector",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+			Labels:    []string{"type", "section"},
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+
+	ret = false
+
+	m := metrics.Metric{
+		Name:   "gauge_2_collector",
+		Value:  100.0,
+		Labels: []string{"core", "first"},
+	}
+
+	err = client.Call("metrics.Set", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
+
+func setMetric(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "user_gauge_collector",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Gauge,
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+	ret = false
+
+	m := metrics.Metric{
+		Name:  "user_gauge_collector",
+		Value: 100.0,
+	}
+
+	err = client.Call("metrics.Set", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
+
+func addMetricsTest(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	m := metrics.Metric{
+		Name:   "test_metrics_named_collector",
+		Value:  10000,
+		Labels: nil,
+	}
+
+	err = client.Call("metrics.Add", m, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
+
+func declareMetricsTest(t *testing.T) {
+	conn, err := net.Dial(dialNetwork, dialAddr)
+	assert.NoError(t, err)
+	defer func() {
+		_ = conn.Close()
+	}()
+	client := rpc.NewClientWithCodec(goridgeRpc.NewClientCodec(conn))
+	var ret bool
+
+	nc := metrics.NamedCollector{
+		Name: "test_metrics_named_collector",
+		Collector: metrics.Collector{
+			Namespace: "default",
+			Subsystem: "default",
+			Type:      metrics.Counter,
+			Help:      "NO HELP!",
+			Labels:    nil,
+			Buckets:   nil,
+		},
+	}
+
+	err = client.Call("metrics.Declare", nc, &ret)
+	assert.NoError(t, err)
+	assert.True(t, ret)
+}
diff --git a/tests/plugins/metrics/plugin1.go b/tests/plugins/metrics/plugin1.go
new file mode 100644
index 00000000..ae024a8a
--- /dev/null
+++ b/tests/plugins/metrics/plugin1.go
@@ -0,0 +1,46 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/spiral/roadrunner/v2/plugins/config"
+)
+
+// Gauge //////////////
+type Plugin1 struct {
+	config config.Configurer
+}
+
+func (p1 *Plugin1) Init(cfg config.Configurer) error {
+	p1.config = cfg
+	return nil
+}
+
+func (p1 *Plugin1) Serve() chan error {
+	errCh := make(chan error, 1)
+	return errCh
+}
+
+func (p1 *Plugin1) Stop() error {
+	return nil
+}
+
+func (p1 *Plugin1) Name() string {
+	return "metrics_test.plugin1"
+}
+
+func (p1 *Plugin1) MetricsCollector() []prometheus.Collector {
+	collector := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "my_gauge",
+		Help: "My gauge value",
+	})
+
+	collector.Set(100)
+
+	collector2 := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "my_gauge2",
+		Help: "My gauge2 value",
+	})
+
+	collector2.Set(100)
+	return []prometheus.Collector{collector, collector2}
+}