Add dynatrace provider

Signed-off-by: GregoireW <24318548+GregoireW@users.noreply.github.com>

charts/flagger/crds/crd.yaml

@@ -1108,6 +1108,7 @@ spec:
                         - cloudwatch
                         - newrelic
                         - graphite
+                        - dynatrace
                     address:
                       description: API address of this provider
                       type: string

docs/gitbook/usage/metrics.md

@@ -561,3 +561,51 @@ spec:
     |> count()
     |> yield(name: "count")
 ```
+
+## Dynatrace
+
+You can create custom metric checks using the Dynatrace provider.
+
+Create a secret with your Dynatrace token:
+
+```yaml
+apiVersion: v1
+kind: Secret
+metadata:
+  name: dynatrace
+  namespace: istio-system
+data:
+  dynatrace_token: ZHQwYz...
+```
+
+Dynatrace metric template example:
+
+```yaml
+apiVersion: flagger.app/v1beta1
+kind: MetricTemplate
+metadata:
+  name: response-time-95pct
+  namespace: istio-system
+spec:
+  provider:
+    type: dynatrace
+    address: https://xxxxxxxx.live.dynatrace.com
+    secretRef:
+      name: dynatrace
+  query: |
+    builtin:service.response.time:filter(eq(dt.entity.service,SERVICE-ABCDEFG0123456789)):percentile(95)
+```
+
+Reference the template in the canary analysis:
+
+```yaml
+  analysis:
+    metrics:
+      - name: "response-time-95pct"
+        templateRef:
+          name: response-time-95pct
+          namespace: istio-system
+        thresholdRange:
+          max: 1000
+        interval: 1m
+```

kustomize/base/flagger/crd.yaml

@@ -1108,6 +1108,7 @@ spec:
                         - cloudwatch
                         - newrelic
                         - graphite
+                        - dynatrace
                     address:
                       description: API address of this provider
                       type: string

pkg/metrics/providers/dynatrace.go

@@ -0,0 +1,181 @@
+/*
+Copyright 2020 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package providers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"time"
+
+	flaggerv1 "github.com/fluxcd/flagger/pkg/apis/flagger/v1beta1"
+)
+
+// https://www.dynatrace.com/support/help/dynatrace-api/environment-api/metric-v2/get-all-metrics/
+const (
+	dynatraceMetricsQueryPath = "/api/v2/metrics/query"
+	dynatraceValidationPath   = "/api/v2/metrics?pageSize=1"
+
+	dynatraceAPITokenSecretKey       = "dynatrace_token"
+	dynatraceAuthorizationHeaderKey  = "Authorization"
+	dynatraceAuthorizationHeaderType = "Api-Token"
+
+	dynatraceDeltaMultiplierOnMetricInterval = 10
+)
+
+// DynatraceProvider executes dynatrace queries
+type DynatraceProvider struct {
+	metricsQueryEndpoint  string
+	apiValidationEndpoint string
+
+	timeout   time.Duration
+	token     string
+	fromDelta int64
+}
+
+type dynatraceResponse struct {
+	Result []struct {
+		Data []struct {
+			Timestamps []int64   `json:"timestamps"`
+			Values     []float64 `json:"values"`
+		} `json:"data"`
+	} `json:"result"`
+}
+
+// NewDynatraceProvider takes a canary spec, a provider spec and the credentials map, and
+// returns a Dynatrace client ready to execute queries against the API
+func NewDynatraceProvider(metricInterval string,
+	provider flaggerv1.MetricTemplateProvider,
+	credentials map[string][]byte) (*DynatraceProvider, error) {
+
+	address := provider.Address
+	if address == "" {
+		return nil, fmt.Errorf("dynatrace endpoint is not set")
+	}
+
+	dt := DynatraceProvider{
+		timeout:               5 * time.Second,
+		metricsQueryEndpoint:  address + dynatraceMetricsQueryPath,
+		apiValidationEndpoint: address + dynatraceValidationPath,
+	}
+
+	if b, ok := credentials[dynatraceAPITokenSecretKey]; ok {
+		dt.token = string(b)
+	} else {
+		return nil, fmt.Errorf("dynatrace credentials does not contain dynatrace_token")
+	}
+
+	md, err := time.ParseDuration(metricInterval)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing metric interval: %w", err)
+	}
+
+	dt.fromDelta = int64(dynatraceDeltaMultiplierOnMetricInterval * md.Milliseconds())
+	return &dt, nil
+}
+
+// RunQuery executes the dynatrace query against DynatraceProvider.metricsQueryEndpoint
+// and returns the the first result as float64
+func (p *DynatraceProvider) RunQuery(query string) (float64, error) {
+
+	req, err := http.NewRequest("GET", p.metricsQueryEndpoint, nil)
+	if err != nil {
+		return 0, fmt.Errorf("error http.NewRequest: %w", err)
+	}
+
+	req.Header.Set(dynatraceAuthorizationHeaderKey, fmt.Sprintf("%s %s", dynatraceAuthorizationHeaderType, p.token))
+
+	now := time.Now().Unix() * 1000
+	q := req.URL.Query()
+	q.Add("metricSelector", query)
+	q.Add("resolution", "Inf")
+	q.Add("from", strconv.FormatInt(now-p.fromDelta, 10))
+	q.Add("to", strconv.FormatInt(now, 10))
+	req.URL.RawQuery = q.Encode()
+
+	ctx, cancel := context.WithTimeout(req.Context(), p.timeout)
+	defer cancel()
+	r, err := http.DefaultClient.Do(req.WithContext(ctx))
+	if err != nil {
+		return 0, fmt.Errorf("request failed: %w", err)
+	}
+
+	defer r.Body.Close()
+	b, err := io.ReadAll(r.Body)
+	if err != nil {
+		return 0, fmt.Errorf("error reading body: %w", err)
+	}
+
+	if r.StatusCode != http.StatusOK {
+		return 0, fmt.Errorf("error response: %s: %w", string(b), err)
+	}
+
+	var res dynatraceResponse
+	if err := json.Unmarshal(b, &res); err != nil {
+		return 0, fmt.Errorf("error unmarshaling result: %w, '%s'", err, string(b))
+	}
+
+	if len(res.Result) < 1 {
+		return 0, fmt.Errorf("invalid response: %s: %w", string(b), ErrNoValuesFound)
+	}
+
+	data := res.Result[0].Data
+	if len(data) < 1 {
+		return 0, fmt.Errorf("invalid response: %s: %w", string(b), ErrNoValuesFound)
+	}
+
+	vs := data[len(data)-1]
+	if len(vs.Values) < 1 {
+		return 0, fmt.Errorf("invalid response: %s: %w", string(b), ErrNoValuesFound)
+	}
+
+	return vs.Values[0], nil
+}
+
+// IsOnline calls the Dynatrace's metrics endpoint with token
+// and returns an error if the endpoint fails
+func (p *DynatraceProvider) IsOnline() (bool, error) {
+	req, err := http.NewRequest("GET", p.apiValidationEndpoint, nil)
+	if err != nil {
+		return false, fmt.Errorf("error http.NewRequest: %w", err)
+	}
+
+	req.Header.Set(dynatraceAuthorizationHeaderKey, fmt.Sprintf("%s %s", dynatraceAuthorizationHeaderType, p.token))
+
+	ctx, cancel := context.WithTimeout(req.Context(), p.timeout)
+	defer cancel()
+	r, err := http.DefaultClient.Do(req.WithContext(ctx))
+	if err != nil {
+		return false, fmt.Errorf("request failed: %w", err)
+	}
+
+	defer r.Body.Close()
+
+	b, err := io.ReadAll(r.Body)
+	if err != nil {
+		return false, fmt.Errorf("error reading body: %w", err)
+	}
+
+	if r.StatusCode != http.StatusOK {
+		return false, fmt.Errorf("error response: %s", string(b))
+	}
+
+	return true, nil
+}