Add Host Metrics receiver scaffolding

receiver/README.md

@@ -12,6 +12,7 @@ Supported trace receivers (sorted alphabetically):
 - [Zipkin Receiver](#zipkin)
 
 Supported metric receivers (sorted alphabetically):
+- [Host Metrics Receiver](#hostmetrics)
 - [OpenCensus Receiver](#opencensus)
 - [Prometheus Receiver](#prometheus)
 - [VM Metrics Receiver](#vmmetrics)

receiver/hostmetricsreceiver/README.md

@@ -0,0 +1,22 @@
+# Host Metrics Receiver
+
+The Host Metrics receiver generates metrics about the host system. This is intended to be used when the collector is
+deployed as an agent.
+
+The categories of metrics scraped can be configured under the `scrapers` key, e.g. to scrape cpu, memory and disk metrics
+(note not all of these are implemented yet):
+
+```
+hostmetrics:
+  default_collection_interval: 10s
+  scrapers:
+    cpu:
+      report_per_process: true
+    memory:
+    disk:
+```
+
+## OS Support
+
+The initial implementation of the Host Metrics receiver supports Windows only. It's intended that future iterations
+of this receiver will support the collection of identical metrics (where possible) on other operating systems.

receiver/hostmetricsreceiver/config.go

@@ -0,0 +1,30 @@
+// Copyright 2020, 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 hostmetricsreceiver
+
+import (
+	"time"
+
+	"github.com/open-telemetry/opentelemetry-collector/config/configmodels"
+	"github.com/open-telemetry/opentelemetry-collector/receiver/hostmetricsreceiver/internal"
+)
+
+// Config defines configuration for HostMetrics receiver.
+type Config struct {
+	configmodels.ReceiverSettings `mapstructure:",squash"`
+
+	DefaultCollectionInterval time.Duration              `mapstructure:"default_collection_interval"`
+	Scrapers                  map[string]internal.Config `mapstructure:"-"`
+}

receiver/hostmetricsreceiver/config_test.go

@@ -0,0 +1,35 @@
+// Copyright 2020, 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 hostmetricsreceiver
+
+import (
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/open-telemetry/opentelemetry-collector/config"
+)
+
+func TestLoadConfig(t *testing.T) {
+	factories, err := config.ExampleComponents()
+	require.NoError(t, err)
+
+	factory := NewFactory()
+	factories.Receivers[typeStr] = factory
+	_, err = config.LoadConfigFile(t, path.Join(".", "testdata", "config.yaml"), factories)
+
+	require.Error(t, err)
+}

receiver/hostmetricsreceiver/example_config.yaml

@@ -0,0 +1,21 @@
+extensions:
+  zpages:
+    endpoint: 0.0.0.0:55679
+
+receivers:
+  hostmetrics:
+    default_collection_interval: 10s
+    scrapers:
+
+exporters:
+  logging:
+  prometheus:
+    endpoint: 0.0.0.0:8889
+
+service:
+  pipelines:
+    metrics:
+      receivers: [hostmetrics]
+      exporters: [prometheus, logging]
+
+  extensions: [zpages]

receiver/hostmetricsreceiver/factory.go

@@ -0,0 +1,147 @@
+// Copyright 2020, 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 hostmetricsreceiver
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"runtime"
+	"time"
+
+	"github.com/spf13/viper"
+
+	"github.com/open-telemetry/opentelemetry-collector/component"
+	"github.com/open-telemetry/opentelemetry-collector/config/configerror"
+	"github.com/open-telemetry/opentelemetry-collector/config/configmodels"
+	"github.com/open-telemetry/opentelemetry-collector/consumer"
+	"github.com/open-telemetry/opentelemetry-collector/receiver/hostmetricsreceiver/internal"
+)
+
+// This file implements Factory for HostMetrics receiver.
+
+const (
+	// The value of "type" key in configuration.
+	typeStr     = "hostmetrics"
+	scrapersKey = "scrapers"
+)
+
+// Factory is the Factory for receiver.
+type Factory struct {
+	ScraperFactories map[string]internal.Factory
+}
+
+// NewFactory creates a new factory
+func NewFactory() *Factory {
+	return &Factory{
+		ScraperFactories: map[string]internal.Factory{},
+	}
+}
+
+// Type gets the type of the Receiver config created by this Factory.
+func (f *Factory) Type() string {
+	return typeStr
+}
+
+// CustomUnmarshaler returns custom unmarshaler for this config.
+func (f *Factory) CustomUnmarshaler() component.CustomUnmarshaler {
+	return func(componentViperSection *viper.Viper, intoCfg interface{}) error {
+
+		// load the non-dynamic config normally
+
+		err := componentViperSection.Unmarshal(intoCfg)
+		if err != nil {
+			return err
+		}
+
+		cfg, ok := intoCfg.(*Config)
+		if !ok {
+			return fmt.Errorf("config type not hostmetrics.Config")
+		}
+
+		// dynamically load the individual collector configs based on the key name
+
+		cfg.Scrapers = map[string]internal.Config{}
+
+		scrapersViperSection := componentViperSection.Sub(scrapersKey)
+		if scrapersViperSection == nil || len(scrapersViperSection.AllKeys()) == 0 {
+			return fmt.Errorf("must specify at least one scraper when using hostmetrics receiver")
+		}
+
+		for key := range componentViperSection.GetStringMap(scrapersKey) {
+			factory, ok := f.ScraperFactories[key]
+			if !ok {
+				return fmt.Errorf("invalid hostmetrics scraper key: %s", key)
+			}
+
+			collectorCfg := factory.CreateDefaultConfig()
+			collectorViperSection := scrapersViperSection.Sub(key)
+			if collectorViperSection != nil {
+				err := collectorViperSection.UnmarshalExact(collectorCfg)
+				if err != nil {
+					return fmt.Errorf("error reading settings for hostmetric scraper type %q: %v", key, err)
+				}
+			}
+
+			cfg.Scrapers[key] = collectorCfg
+		}
+
+		return nil
+	}
+}
+
+// CreateDefaultConfig creates the default configuration for receiver.
+func (f *Factory) CreateDefaultConfig() configmodels.Receiver {
+	return &Config{
+		ReceiverSettings: configmodels.ReceiverSettings{
+			TypeVal: typeStr,
+			NameVal: typeStr,
+		},
+		DefaultCollectionInterval: 10 * time.Second,
+	}
+}
+
+// CreateTraceReceiver creates a trace receiver based on provided config.
+func (f *Factory) CreateTraceReceiver(
+	ctx context.Context,
+	params component.ReceiverCreateParams,
+	cfg configmodels.Receiver,
+	consumer consumer.TraceConsumer,
+) (component.TraceReceiver, error) {
+	// Host Metrics does not support traces
+	return nil, configerror.ErrDataTypeIsNotSupported
+}
+
+// CreateMetricsReceiver creates a metrics receiver based on provided config.
+func (f *Factory) CreateMetricsReceiver(
+	ctx context.Context,
+	params component.ReceiverCreateParams,
+	cfg configmodels.Receiver,
+	consumer consumer.MetricsConsumer,
+) (component.MetricsReceiver, error) {
+
+	if runtime.GOOS != "windows" {
+		return nil, errors.New("hostmetrics receiver is currently only supported on windows")
+	}
+
+	config := cfg.(*Config)
+
+	hmr, err := NewHostMetricsReceiver(ctx, params.Logger, config, f.ScraperFactories, consumer)
+	if err != nil {
+		return nil, err
+	}
+
+	return hmr, nil
+}

receiver/hostmetricsreceiver/factory_test.go

@@ -0,0 +1,57 @@
+// Copyright 2020, 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 hostmetricsreceiver
+
+import (
+	"context"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap"
+
+	"github.com/open-telemetry/opentelemetry-collector/component"
+	"github.com/open-telemetry/opentelemetry-collector/config/configcheck"
+	"github.com/open-telemetry/opentelemetry-collector/config/configerror"
+)
+
+var creationParams = component.ReceiverCreateParams{Logger: zap.NewNop()}
+
+func TestCreateDefaultConfig(t *testing.T) {
+	factory := &Factory{}
+	cfg := factory.CreateDefaultConfig()
+	assert.NotNil(t, cfg, "failed to create default config")
+	assert.NoError(t, configcheck.ValidateConfig(cfg))
+}
+
+func TestCreateReceiver(t *testing.T) {
+	factory := &Factory{}
+	cfg := factory.CreateDefaultConfig()
+
+	tReceiver, err := factory.CreateTraceReceiver(context.Background(), creationParams, cfg, nil)
+
+	assert.Equal(t, err, configerror.ErrDataTypeIsNotSupported)
+	assert.Nil(t, tReceiver)
+
+	mReceiver, err := factory.CreateMetricsReceiver(context.Background(), creationParams, cfg, nil)
+
+	if runtime.GOOS != "windows" {
+		assert.NotNil(t, err)
+		assert.Nil(t, tReceiver)
+	} else {
+		assert.Nil(t, err)
+		assert.NotNil(t, mReceiver)
+	}
+}