Add liveness probe to created container if otelcol configuration supp…

…orts a health_check. (open-telemetry#574)

* Add liveness probe to created container if otelcol configuration supports a health_check.
Fixes open-telemetry#571

Signed-off-by: Adrian Kostrubiak <adrian.kostrubiak@tomtom.com>

pkg/collector/adapters/config_to_probe.go

@@ -0,0 +1,158 @@
+// Copyright The OpenTelemetry 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 adapters
+
+import (
+	"errors"
+	"strings"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+)
+
+var (
+	errNoService    = errors.New("no service available as part of the configuration")
+	errNoExtensions = errors.New("no extensions available as part of the configuration")
+
+	errServiceNotAMap    = errors.New("service property in the configuration doesn't contain valid services")
+	errExtensionsNotAMap = errors.New("extensions property in the configuration doesn't contain valid extensions")
+
+	errNoExtensionHealthCheck = errors.New("extensions property in the configuration does not contain the expected health_check extension")
+
+	errNoServiceExtensions = errors.New("service property in the configuration doesn't contain extensions")
+
+	errServiceExtensionsNotSlice     = errors.New("service extensions property in the configuration does not contain valid extensions")
+	errNoServiceExtensionHealthCheck = errors.New("no healthcheck extension available in service extension configuration")
+)
+
+type probeConfiguration struct {
+	path string
+	port intstr.IntOrString
+}
+
+const (
+	defaultHealthCheckPath = "/"
+	defaultHealthCheckPort = 13133
+)
+
+// ConfigToContainerProbe converts the incoming configuration object into a container probe or returns an error.
+func ConfigToContainerProbe(config map[interface{}]interface{}) (*corev1.Probe, error) {
+	serviceProperty, ok := config["service"]
+	if !ok {
+		return nil, errNoService
+	}
+	service, ok := serviceProperty.(map[interface{}]interface{})
+	if !ok {
+		return nil, errServiceNotAMap
+	}
+
+	serviceExtensionsProperty, ok := service["extensions"]
+	if !ok {
+		return nil, errNoServiceExtensions
+	}
+
+	serviceExtensions, ok := serviceExtensionsProperty.([]interface{})
+	if !ok {
+		return nil, errServiceExtensionsNotSlice
+	}
+	healthCheckServiceExtensions := make([]string, 0)
+	for _, ext := range serviceExtensions {
+		parsedExt, ok := ext.(string)
+		if ok && strings.HasPrefix(parsedExt, "health_check") {
+			healthCheckServiceExtensions = append(healthCheckServiceExtensions, parsedExt)
+		}
+	}
+
+	if len(healthCheckServiceExtensions) == 0 {
+		return nil, errNoServiceExtensionHealthCheck
+	}
+
+	extensionsProperty, ok := config["extensions"]
+	if !ok {
+		return nil, errNoExtensions
+	}
+	extensions, ok := extensionsProperty.(map[interface{}]interface{})
+	if !ok {
+		return nil, errExtensionsNotAMap
+	}
+	// in the event of multiple health_check service extensions defined, we arbitrarily take the first one found
+	for _, healthCheckForProbe := range healthCheckServiceExtensions {
+		healthCheckExtension, ok := extensions[healthCheckForProbe]
+		if ok {
+			return createProbeFromExtension(healthCheckExtension)
+		}
+	}
+
+	return nil, errNoExtensionHealthCheck
+}
+
+func createProbeFromExtension(extension interface{}) (*corev1.Probe, error) {
+	probeCfg := extractProbeConfigurationFromExtension(extension)
+	return &corev1.Probe{
+		Handler: corev1.Handler{
+			HTTPGet: &corev1.HTTPGetAction{
+				Path: probeCfg.path,
+				Port: probeCfg.port,
+			},
+		},
+	}, nil
+}
+
+func extractProbeConfigurationFromExtension(ext interface{}) probeConfiguration {
+	extensionCfg, ok := ext.(map[interface{}]interface{})
+	if !ok {
+		return defaultProbeConfiguration()
+	}
+	return probeConfiguration{
+		path: extractPathFromExtensionConfig(extensionCfg),
+		port: extractPortFromExtensionConfig(extensionCfg),
+	}
+}
+
+func defaultProbeConfiguration() probeConfiguration {
+	return probeConfiguration{
+		path: defaultHealthCheckPath,
+		port: intstr.FromInt(defaultHealthCheckPort),
+	}
+}
+
+func extractPathFromExtensionConfig(cfg map[interface{}]interface{}) string {
+	if path, ok := cfg["path"]; ok {
+		if parsedPath, ok := path.(string); ok {
+			return parsedPath
+		}
+	}
+	return defaultHealthCheckPath
+}
+
+func extractPortFromExtensionConfig(cfg map[interface{}]interface{}) intstr.IntOrString {
+	endpoint, ok := cfg["endpoint"]
+	if !ok {
+		return defaultHealthCheckEndpoint()
+	}
+	parsedEndpoint, ok := endpoint.(string)
+	if !ok {
+		return defaultHealthCheckEndpoint()
+	}
+	endpointComponents := strings.Split(parsedEndpoint, ":")
+	if len(endpointComponents) != 2 {
+		return defaultHealthCheckEndpoint()
+	}
+	return intstr.Parse(endpointComponents[1])
+}
+
+func defaultHealthCheckEndpoint() intstr.IntOrString {
+	return intstr.FromInt(defaultHealthCheckPort)
+}

pkg/collector/adapters/config_to_probe_test.go

@@ -0,0 +1,187 @@
+// Copyright The OpenTelemetry 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 adapters
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfigToProbeShouldCreateProbeFor(t *testing.T) {
+	tests := []struct {
+		desc         string
+		config       string
+		expectedPort int32
+		expectedPath string
+	}{
+		{
+			desc:         "SimpleHappyPath",
+			expectedPort: int32(13133),
+			expectedPath: "/",
+			config: `extensions:
+  health_check:
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "CustomEndpointAndPath",
+			expectedPort: int32(1234),
+			expectedPath: "/checkit",
+			config: `extensions:
+  health_check:
+    endpoint: localhost:1234
+    path: /checkit
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "CustomEndpointAndDefaultPath",
+			expectedPort: int32(1234),
+			expectedPath: "/",
+			config: `extensions:
+  health_check:
+    endpoint: localhost:1234
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "CustomEndpointWithJustPortAndDefaultPath",
+			expectedPort: int32(1234),
+			expectedPath: "/",
+			config: `extensions:
+  health_check:
+    endpoint: :1234
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "DefaultEndpointAndCustomPath",
+			expectedPort: int32(13133),
+			expectedPath: "/checkit",
+			config: `extensions:
+  health_check:
+    path: /checkit
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "DefaultEndpointForUnexpectedEndpoint",
+			expectedPort: int32(13133),
+			expectedPath: "/",
+			config: `extensions:
+  health_check:
+    endpoint: 0:0:0"
+service:
+  extensions: [health_check]`,
+		}, {
+			desc:         "DefaultEndpointForUnparseablendpoint",
+			expectedPort: int32(13133),
+			expectedPath: "/",
+			config: `extensions:
+  health_check:
+    endpoint:
+      this: should-not-be-a-map"
+service:
+  extensions: [health_check]`,
+		}, {
+			desc: "WillUseSecondServiceExtension",
+			config: `extensions:
+  health_check:
+service:
+  extensions: [health_check/1, health_check]`,
+			expectedPort: int32(13133),
+			expectedPath: "/",
+		},
+	}
+
+	for _, test := range tests {
+		// prepare
+		config, err := ConfigFromString(test.config)
+		require.NoError(t, err, test.desc)
+		require.NotEmpty(t, config, test.desc)
+
+		// test
+		actualProbe, err := ConfigToContainerProbe(config)
+		assert.NoError(t, err)
+		assert.Equal(t, test.expectedPath, actualProbe.HTTPGet.Path, test.desc)
+		assert.Equal(t, test.expectedPort, actualProbe.HTTPGet.Port.IntVal, test.desc)
+		assert.Equal(t, "", actualProbe.HTTPGet.Host, test.desc)
+	}
+}
+
+func TestConfigToProbeShouldErrorIf(t *testing.T) {
+	tests := []struct {
+		desc        string
+		config      string
+		expectedErr error
+	}{
+		{
+			desc: "NoHealthCheckExtension",
+			config: `extensions:
+  pprof:
+service:
+  extensions: [health_check]`,
+			expectedErr: errNoExtensionHealthCheck,
+		}, {
+			desc: "BadlyFormattedExtensions",
+			config: `extensions: [hi]
+service:
+  extensions: [health_check]`,
+			expectedErr: errExtensionsNotAMap,
+		}, {
+			desc: "NoExtensions",
+			config: `service:
+  extensions: [health_check]`,
+			expectedErr: errNoExtensions,
+		}, {
+			desc: "NoHealthCheckInServiceExtensions",
+			config: `service:
+  extensions: [pprof]`,
+			expectedErr: errNoServiceExtensionHealthCheck,
+		}, {
+			desc: "BadlyFormattedServiceExtensions",
+			config: `service:
+  extensions:
+    this: should-not-be-a-map`,
+			expectedErr: errServiceExtensionsNotSlice,
+		}, {
+			desc: "NoServiceExtensions",
+			config: `service:
+  pipelines:
+    traces:
+      receivers: [otlp]`,
+			expectedErr: errNoServiceExtensions,
+		}, {
+			desc: "BadlyFormattedService",
+			config: `extensions:
+  health_check:
+service: [hi]`,
+			expectedErr: errServiceNotAMap,
+		}, {
+			desc: "NoService",
+			config: `extensions:
+  health_check:`,
+			expectedErr: errNoService,
+		},
+	}
+
+	for _, test := range tests {
+		// prepare
+		config, err := ConfigFromString(test.config)
+		require.NoError(t, err, test.desc)
+		require.NotEmpty(t, config, test.desc)
+
+		// test
+		_, err = ConfigToContainerProbe(config)
+		assert.Equal(t, test.expectedErr, err, test.desc)
+	}
+}

pkg/collector/container.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
 	"github.com/open-telemetry/opentelemetry-operator/internal/config"
+	"github.com/open-telemetry/opentelemetry-operator/pkg/collector/adapters"
 	"github.com/open-telemetry/opentelemetry-operator/pkg/naming"
 )
 
@@ -77,6 +78,13 @@ func Container(cfg config.Config, logger logr.Logger, otelcol v1alpha1.OpenTelem
 		},
 	})
 
+	var livenessProbe *corev1.Probe
+	if config, err := adapters.ConfigFromString(otelcol.Spec.Config); err == nil {
+		if probe, err := adapters.ConfigToContainerProbe(config); err == nil {
+			livenessProbe = probe
+		}
+	}
+
 	return corev1.Container{
 		Name:            naming.Container(),
 		Image:           image,
@@ -87,5 +95,6 @@ func Container(cfg config.Config, logger logr.Logger, otelcol v1alpha1.OpenTelem
 		EnvFrom:         otelcol.Spec.EnvFrom,
 		Resources:       otelcol.Spec.Resources,
 		SecurityContext: otelcol.Spec.SecurityContext,
+		LivenessProbe:   livenessProbe,
 	}
 }