Add environment specific data to the influxdb data.

pkg/monitoring/influxdb2_middleware.go

@@ -0,0 +1,146 @@
+package monitoring
+
+import (
+	"bytes"
+	"context"
+	"github.com/gorilla/mux"
+	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
+	influxdb2API "github.com/influxdata/influxdb-client-go/v2/api"
+	"github.com/influxdata/influxdb-client-go/v2/api/write"
+	"github.com/openHPI/poseidon/internal/environment"
+	"github.com/openHPI/poseidon/internal/runner"
+	"github.com/openHPI/poseidon/pkg/dto"
+	"github.com/openHPI/poseidon/pkg/logging"
+	"io"
+	"net/http"
+	"reflect"
+	"strconv"
+	"time"
+)
+
+var log = logging.GetLogger("monitoring")
+
+const (
+	// influxdbContextKey is a key to reference the influxdb data point in the request context.
+	influxdbContextKey runner.ContextKey = "influxdb data point"
+	// influxdbMeasurementPrefix allows easier filtering in influxdb.
+	influxdbMeasurementPrefix = "poseidon_"
+
+	// The keys for the monitored tags and fields.
+	influxKeyRunnerID                      = "runner_id"
+	influxKeyEnvironmentID                 = "environment_id"
+	influxKeyEnvironmentType               = "environment_type"
+	influxKeyEnvironmentIdleRunner         = "idle_runner"
+	influxKeyEnvironmentPrewarmingPoolSize = "prewarming_pool_size"
+	influxKeyRequestSize                   = "request_size"
+)
+
+// InfluxDB2Middleware is a middleware to send events to an influx database.
+func InfluxDB2Middleware(influxClient influxdb2API.WriteAPI, manager environment.Manager) mux.MiddlewareFunc {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			route := mux.CurrentRoute(r).GetName()
+			p := influxdb2.NewPointWithMeasurement(influxdbMeasurementPrefix + route)
+
+			start := time.Now().UTC()
+			p.SetTime(time.Now())
+
+			ctx := context.WithValue(r.Context(), influxdbContextKey, p)
+			requestWithPoint := r.WithContext(ctx)
+			lrw := logging.NewLoggingResponseWriter(w)
+			next.ServeHTTP(lrw, requestWithPoint)
+
+			p.AddField("duration", time.Now().UTC().Sub(start).Nanoseconds())
+			p.AddTag("status", strconv.Itoa(lrw.StatusCode))
+
+			environmentID, err := strconv.Atoi(getEnvironmentID(p))
+			if err == nil && manager != nil {
+				addEnvironmentData(p, manager, dto.EnvironmentID(environmentID))
+			}
+
+			if influxClient != nil {
+				influxClient.WritePoint(p)
+			}
+		})
+	}
+}
+
+// AddRunnerMonitoringData adds the data of the runner we want to monitor.
+func AddRunnerMonitoringData(request *http.Request, r runner.Runner) {
+	addRunnerID(request, r.ID())
+	addEnvironmentID(request, r.Environment())
+}
+
+// addRunnerID adds the runner id to the influx data point for the current request.
+func addRunnerID(r *http.Request, id string) {
+	addInfluxDBTag(r, influxKeyRunnerID, id)
+}
+
+// addEnvironmentID adds the environment id to the influx data point for the current request.
+func addEnvironmentID(r *http.Request, id dto.EnvironmentID) {
+	addInfluxDBTag(r, influxKeyEnvironmentID, strconv.Itoa(int(id)))
+}
+
+// AddRequestSize adds the size of the request body to the influx data point for the current request.
+func AddRequestSize(r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		log.WithError(err).Warn("Failed to read request body")
+	}
+
+	err = r.Body.Close()
+	if err != nil {
+		log.WithError(err).Warn("Failed to close request body")
+	}
+	r.Body = io.NopCloser(bytes.NewBuffer(body))
+
+	addInfluxDBField(r, influxKeyRequestSize, len(body))
+}
+
+// addInfluxDBTag adds a tag to the influxdb data point in the request.
+func addInfluxDBTag(r *http.Request, key, value string) {
+	dataPointFromRequest(r).AddTag(key, value)
+}
+
+// addInfluxDBField adds a field to the influxdb data point in the request.
+func addInfluxDBField(r *http.Request, key string, value interface{}) {
+	dataPointFromRequest(r).AddField(key, value)
+}
+
+// dataPointFromRequest returns the data point in the passed request.
+func dataPointFromRequest(r *http.Request) *write.Point {
+	p, ok := r.Context().Value(influxdbContextKey).(*write.Point)
+	if !ok {
+		log.Error("All http request must contain an influxdb data point!")
+	}
+	return p
+}
+
+// getEnvironmentID tries to find the environment id in the influxdb data point.
+func getEnvironmentID(p *write.Point) string {
+	for _, tag := range p.TagList() {
+		if tag.Key == influxKeyEnvironmentID {
+			return tag.Value
+		}
+	}
+	return ""
+}
+
+// addEnvironmentData adds environment specific data to the influxdb data point.
+func addEnvironmentData(p *write.Point, manager environment.Manager, id dto.EnvironmentID) {
+	e, err := manager.Get(id, false)
+	if err == nil {
+		p.AddTag(influxKeyEnvironmentType, getType(e))
+		p.AddField(influxKeyEnvironmentIdleRunner, e.IdleRunnerCount())
+		p.AddField(influxKeyEnvironmentPrewarmingPoolSize, e.PrewarmingPoolSize())
+	}
+}
+
+// Get type returns the type of the passed execution environment.
+func getType(e runner.ExecutionEnvironment) string {
+	if t := reflect.TypeOf(e); t.Kind() == reflect.Ptr {
+		return t.Elem().Name()
+	} else {
+		return t.Name()
+	}
+}