feat: return partial reports without failure (#45)

go.mod

@@ -15,6 +15,11 @@ require (
 	sigs.k8s.io/controller-runtime v0.12.3
 )
 
+require (
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+)
+
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/emicklei/go-restful/v3 v3.8.0 // indirect
@@ -27,6 +32,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/gnostic v0.6.9 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
+	github.com/hashicorp/go-multierror v1.1.1
 	github.com/imdario/mergo v0.3.13 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect

go.sum

@@ -197,6 +197,10 @@ github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB7
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7/go.mod h1:FecbI9+v66THATjSRHfNgh1IVFe/9kFxbXtjV0ctIMA=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
+github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
+github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=

pkg/forwarders/rawchannelforwarder.go

@@ -0,0 +1,25 @@
+package forwarders
+
+import (
+	"github.com/kong/kubernetes-telemetry/pkg/types"
+)
+
+type rawChannelForwarder struct {
+	ch chan types.Report
+}
+
+// NewRawChannelForwarder creates new rawChannelForwarder.
+func NewRawChannelForwarder(ch chan types.Report) *rawChannelForwarder {
+	return &rawChannelForwarder{
+		ch: ch,
+	}
+}
+
+func (f *rawChannelForwarder) Name() string {
+	return "LogForwarder"
+}
+
+func (f *rawChannelForwarder) Forward(r types.Report) error {
+	f.ch <- r
+	return nil
+}

pkg/forwarders/tlsforwarder.go

@@ -7,7 +7,8 @@ import (
 	"time"
 
 	"github.com/go-logr/logr"
-	"github.com/sirupsen/logrus"
+
+	"github.com/kong/kubernetes-telemetry/pkg/log"
 )
 
 const (
@@ -20,32 +21,14 @@ var tlsConf = tls.Config{
 	MaxVersion: tls.VersionTLS13,
 }
 
-// TODO: Address logging levels and library to be used.
-// See: https://github.com/Kong/kubernetes-ingress-controller/issues/1893
-const (
-	logrusrDiff = 4
-
-	// InfoLevel is the converted logging level from logrus to go-logr for
-	// information level logging. Note that the logrusr middleware technically
-	// flattens all levels prior to this level into this level as well.
-	InfoLevel = int(logrus.InfoLevel) - logrusrDiff
-
-	// DebugLevel is the converted logging level from logrus to go-logr for
-	// debug level logging.
-	DebugLevel = int(logrus.DebugLevel) - logrusrDiff
-
-	// WarnLevel is the converted logrus level to go-logr for warnings.
-	WarnLevel = int(logrus.WarnLevel) - logrusrDiff
-)
-
 type tlsForwarder struct {
-	log  logr.Logger
-	conn *tls.Conn
+	logger logr.Logger
+	conn   *tls.Conn
 }
 
 // NewTLSForwarder creates a TLS forwarder which forwards received serialized reports
 // to a TLS endpoint specified by the provided address.
-func NewTLSForwarder(address string, log logr.Logger) *tlsForwarder {
+func NewTLSForwarder(address string, logger logr.Logger) *tlsForwarder {
 	conn, err := tls.DialWithDialer(
 		&net.Dialer{
 			Timeout: defaultTimeout,
@@ -55,13 +38,13 @@ func NewTLSForwarder(address string, log logr.Logger) *tlsForwarder {
 		&tlsConf,
 	)
 	if err != nil {
-		log.V(DebugLevel).Info("failed to connect to reporting server", "error", err)
+		logger.V(log.DebugLevel).Info("failed to connect to reporting server", "error", err)
 		return nil
 	}
 
 	return &tlsForwarder{
-		log:  log,
-		conn: conn,
+		logger: logger,
+		conn:   conn,
 	}
 }
 

pkg/log/logp.go

@@ -0,0 +1,21 @@
+package log
+
+import "github.com/sirupsen/logrus"
+
+// TODO: Address logging levels and library to be used.
+// See: https://github.com/Kong/kubernetes-ingress-controller/issues/1893
+const (
+	logrusrDiff = 4
+
+	// InfoLevel is the converted logging level from logrus to go-logr for
+	// information level logging. Note that the logrusr middleware technically
+	// flattens all levels prior to this level into this level as well.
+	InfoLevel = int(logrus.InfoLevel) - logrusrDiff
+
+	// DebugLevel is the converted logging level from logrus to go-logr for
+	// debug level logging.
+	DebugLevel = int(logrus.DebugLevel) - logrusrDiff
+
+	// WarnLevel is the converted logrus level to go-logr for warnings.
+	WarnLevel = int(logrus.WarnLevel) - logrusrDiff
+)

pkg/telemetry/consumer.go

@@ -25,9 +25,10 @@ type Forwarder interface {
 // serialize the data and then forward it using the provided forwarder.
 func NewConsumer(s Serializer, f Forwarder) *consumer {
 	var (
-		ch     = make(chan types.Report)
-		done   = make(chan struct{})
-		logger = defaultLogger() // TODO: allow configuration
+		ch   = make(chan types.Report)
+		done = make(chan struct{})
+		// TODO: allow configuration: https://github.com/Kong/kubernetes-telemetry/issues/46
+		logger = defaultLogger()
 	)
 
 	go func() {
@@ -56,12 +57,70 @@ func NewConsumer(s Serializer, f Forwarder) *consumer {
 	}
 }
 
+// Intake returns a channel on which this consumer will wait for data to consume it.
 func (c *consumer) Intake() chan<- types.Report {
 	return c.ch
 }
 
+// Close closes the consumer.
 func (c *consumer) Close() {
 	c.once.Do(func() {
 		close(c.done)
 	})
 }
+
+type rawConsumer struct {
+	logger logr.Logger
+	once   sync.Once
+	ch     chan types.Report
+	done   chan struct{}
+}
+
+// RawForwarder is used to forward raw, unserialized telemetry reports to configured
+// destination(s).
+type RawForwarder interface {
+	Name() string
+	Forward(types.Report) error
+}
+
+// NewRawConsumer creates a new rawconsumer that will use the provided raw forwarder
+// to forward received reports.
+func NewRawConsumer(f RawForwarder) *rawConsumer {
+	var (
+		ch   = make(chan types.Report)
+		done = make(chan struct{})
+		// TODO: allow configuration: https://github.com/Kong/kubernetes-telemetry/issues/46
+		logger = defaultLogger()
+	)
+
+	go func() {
+		for {
+			select {
+			case <-done:
+				return
+			case r := <-ch:
+				if err := f.Forward(r); err != nil {
+					logger.Error(err, "failed to forward report using raw forwarder: %s", f.Name())
+				}
+			}
+		}
+	}()
+
+	return &rawConsumer{
+		logger: logger,
+		ch:     ch,
+		done:   done,
+	}
+}
+
+// Intake returns a channel on which this consumer will wait for data to consume it.
+func (c *rawConsumer) Intake() chan<- types.Report {
+	return c.ch
+}
+
+// Close closes rawconsumer.
+func (c *rawConsumer) Close() {
+	c.once.Do(func() {
+		close(c.done)
+	})
+}

pkg/telemetry/manager.go

@@ -8,10 +8,10 @@ import (
 	"time"
 
 	"github.com/go-logr/logr"
-	"github.com/pkg/errors"
+	"github.com/hashicorp/go-multierror"
 	"github.com/puzpuzpuz/xsync"
 
-	"github.com/kong/kubernetes-telemetry/pkg/provider"
+	"github.com/kong/kubernetes-telemetry/pkg/log"
 	"github.com/kong/kubernetes-telemetry/pkg/types"
 )
 
@@ -165,7 +165,14 @@ func (m *manager) workflowsLoop() {
 		case <-ticker.C:
 			report, err := m.Execute(context.Background())
 			if err != nil {
-				m.logger.Error(err, "error executing workflows")
+				m.logger.V(log.DebugLevel).
+					WithValues("error", err.Error()).
+					Info("error executing workflows")
+			}
+
+			// Continue the execution even if we get an error but account for possibility
+			// of getting nil reports, in which case move on to the next iteration (tick).
+			if report == nil {
 				continue
 			}
 
@@ -179,28 +186,27 @@ func (m *manager) workflowsLoop() {
 }
 
 // Execute executes all configures workflows and returns an aggregated report
-// from all the underying providers.
+// from all the underlying providers.
 func (m *manager) Execute(ctx context.Context) (types.Report, error) {
 	var (
-		err    error
+		mErr   error
 		report = types.Report{}
 	)
 
 	m.workflows.Range(func(name string, v Workflow) bool {
-		var r provider.Report
-		r, err = v.Execute(ctx)
+		r, err := v.Execute(ctx)
 		if err != nil {
-			err = errors.Wrapf(err, "error executing workflow %s", name)
-			// TODO: return true and don't abort when encountering an error.
-			// Better to report partial report than nothing. In order to do so
-			// use an error agreggator like https://github.com/hashicorp/go-multierror.
-			return false
+			mErr = multierror.Append(mErr, err)
+		}
+
+		// Add the report regardless if it's partial only omitting empty (nil) reports.
+		if r != nil {
+			report[v.Name()] = r
 		}
 
-		report[v.Name()] = r
 		return true
 	})
-	return report, err
+	return report, mErr
 }
 
 // consumerLoop loops over all configured consumers and sends the gathered telemetry

pkg/telemetry/manager_test.go

@@ -1,12 +1,15 @@
 package telemetry
 
 import (
+	"errors"
 	"fmt"
 	"runtime"
 	"testing"
 	"time"
 
+	"github.com/bombsimon/logrusr/v3"
 	"github.com/go-logr/logr"
+	"github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/require"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -238,3 +241,63 @@ func TestManagerWithCatalogWorkflows(t *testing.T) {
 		}, report)
 	})
 }
+
+func TestManagerWithMultilpleWorkflowsOneReturningError(t *testing.T) {
+	logrusLog := logrus.New()
+	logrusLog.Level = logrus.DebugLevel
+	log := logrusr.New(logrusLog)
+	m, err := NewManager(
+		OptManagerLogger(log),
+		OptManagerPeriod(time.Millisecond),
+	)
+	require.NoError(t, err)
+
+	{
+		w := NewWorkflow("basic")
+		{
+			p, err := provider.NewFixedValueProvider("constant1", provider.Report{
+				"constant1": "value1",
+			})
+			require.NoError(t, err)
+			w.AddProvider(p)
+		}
+
+		m.AddWorkflow(w)
+	}
+	{
+		w := NewWorkflow("basic_with_error")
+		{
+			p, err := provider.NewFunctorProvider("error_provider", func() (provider.Report, error) {
+				return nil, errors.New("I am an error")
+			})
+			require.NoError(t, err)
+			w.AddProvider(p)
+		}
+		{
+
+			p, err := provider.NewFixedValueProvider("constant2", provider.Report{
+				"constant2": "value2",
+			})
+			require.NoError(t, err)
+			w.AddProvider(p)
+		}
+
+		m.AddWorkflow(w)
+	}
+
+	ch := make(chan types.Report)
+	consumer := NewRawConsumer(forwarders.NewRawChannelForwarder(ch))
+	require.NoError(t, m.AddConsumer(consumer))
+	require.NoError(t, m.Start())
+
+	report := <-ch
+	m.Stop()
+	require.EqualValues(t, types.Report{
+		"basic": provider.Report{
+			"constant1": "value1",
+		},
+		"basic_with_error": provider.Report{
+			"constant2": "value2",
+		},
+	}, report)
+}