chore(inputs.gnmi): Test plugin and subscription options (#13384)

plugins/inputs/gnmi/gnmi.go

@@ -3,7 +3,6 @@ package gnmi
 
 import (
 	"context"
-	"crypto/tls"
 	_ "embed"
 	"fmt"
 	"path"
@@ -58,13 +57,12 @@ type GNMI struct {
 	MaxMsgSize          config.Size       `toml:"max_msg_size"`
 	Trace               bool              `toml:"dump_responses"`
 	CanonicalFieldNames bool              `toml:"canonical_field_names"`
-	EnableTLS           bool              `toml:"enable_tls"`
+	EnableTLS           bool              `toml:"enable_tls" deprecated:"1.27.0;use 'tls_enable' instead"`
 	Log                 telegraf.Logger   `toml:"-"`
 	internaltls.ClientConfig
 
 	// Internal state
 	internalAliases map[string]string
-	acc             telegraf.Accumulator
 	cancel          context.CancelFunc
 	wg              sync.WaitGroup
 }
@@ -100,17 +98,35 @@ func (*GNMI) SampleConfig() string {
 	return sampleConfig
 }
 
-// Start the http listener service
-func (c *GNMI) Start(acc telegraf.Accumulator) error {
-	var err error
-	var ctx context.Context
-	var tlscfg *tls.Config
-	var request *gnmiLib.SubscribeRequest
-	c.acc = acc
-	ctx, c.cancel = context.WithCancel(context.Background())
+func (c *GNMI) Init() error {
+	// Check options
+	if time.Duration(c.Redial) <= 0 {
+		return fmt.Errorf("redial duration must be positive")
+	}
 
+	// Check vendor_specific options configured by user
+	if err := choice.CheckSlice(c.VendorSpecific, supportedExtensions); err != nil {
+		return fmt.Errorf("unsupported vendor_specific option: %w", err)
+	}
+
+	// Use the new TLS option for enabling
+	// Honor deprecated option
+	enable := (c.ClientConfig.Enable != nil && *c.ClientConfig.Enable) || c.EnableTLS
+	c.ClientConfig.Enable = &enable
+
+	// Split the subscriptions into "normal" and "tag" subscription
+	// and prepare them.
 	for i := len(c.Subscriptions) - 1; i >= 0; i-- {
 		subscription := c.Subscriptions[i]
+
+		// Check the subscription
+		if subscription.Name == "" {
+			return fmt.Errorf("empty 'name' found for subscription %d", i+1)
+		}
+		if subscription.Path == "" {
+			return fmt.Errorf("empty 'path' found for subscription %d", i+1)
+		}
+
 		// Support and convert legacy TagOnly subscriptions
 		if subscription.TagOnly {
 			tagSub := TagSubscription{
@@ -122,12 +138,12 @@ func (c *GNMI) Start(acc telegraf.Accumulator) error {
 			c.Subscriptions = append(c.Subscriptions[:i], c.Subscriptions[i+1:]...)
 			continue
 		}
-		if err = subscription.buildFullPath(c); err != nil {
+		if err := subscription.buildFullPath(c); err != nil {
 			return err
 		}
 	}
 	for idx := range c.TagSubscriptions {
-		if err = c.TagSubscriptions[idx].buildFullPath(c); err != nil {
+		if err := c.TagSubscriptions[idx].buildFullPath(c); err != nil {
 			return err
 		}
 		if c.TagSubscriptions[idx].TagOnly != c.TagSubscriptions[0].TagOnly {
@@ -151,27 +167,8 @@ func (c *GNMI) Start(acc telegraf.Accumulator) error {
 		}
 	}
 
-	// Validate configuration
-	if request, err = c.newSubscribeRequest(); err != nil {
-		return err
-	} else if time.Duration(c.Redial).Nanoseconds() <= 0 {
-		return fmt.Errorf("redial duration must be positive")
-	}
-
-	// Parse TLS config
-	if c.EnableTLS {
-		if tlscfg, err = c.ClientConfig.TLSConfig(); err != nil {
-			return err
-		}
-	}
-
-	if len(c.Username) > 0 {
-		ctx = metadata.AppendToOutgoingContext(ctx, "username", c.Username, "password", c.Password)
-	}
-
 	// Invert explicit alias list and prefill subscription names
 	c.internalAliases = make(map[string]string, len(c.Subscriptions)+len(c.Aliases)+len(c.TagSubscriptions))
-
 	for _, s := range c.Subscriptions {
 		if err := s.buildAlias(c.internalAliases); err != nil {
 			return err
@@ -182,12 +179,34 @@ func (c *GNMI) Start(acc telegraf.Accumulator) error {
 			return err
 		}
 	}
-
 	for alias, encodingPath := range c.Aliases {
 		c.internalAliases[encodingPath] = alias
 	}
 	c.Log.Debugf("Internal alias mapping: %+v", c.internalAliases)
 
+	return nil
+}
+
+func (c *GNMI) Start(acc telegraf.Accumulator) error {
+	// Validate configuration
+	request, err := c.newSubscribeRequest()
+	if err != nil {
+		return err
+	}
+
+	// Generate TLS config if enabled
+	tlscfg, err := c.ClientConfig.TLSConfig()
+	if err != nil {
+		return err
+	}
+
+	// Prepare the context, optionally with credentials
+	var ctx context.Context
+	ctx, c.cancel = context.WithCancel(context.Background())
+	if len(c.Username) > 0 {
+		ctx = metadata.AppendToOutgoingContext(ctx, "username", c.Username, "password", c.Password)
+	}
+
 	// Create a goroutine for each device, dial and subscribe
 	c.wg.Add(len(c.Addresses))
 	for _, addr := range c.Addresses {
@@ -321,14 +340,6 @@ func init() {
 	inputs.Add("cisco_telemetry_gnmi", New)
 }
 
-func (c *GNMI) Init() error {
-	// Check vendor_specific options configured by user
-	if err := choice.CheckSlice(c.VendorSpecific, supportedExtensions); err != nil {
-		return fmt.Errorf("unsupported vendor_specific option: %w", err)
-	}
-	return nil
-}
-
 func (s *Subscription) buildFullPath(c *GNMI) error {
 	var err error
 	if s.fullPath, err = xpath.ToGNMIPath(s.Path); err != nil {

plugins/inputs/gnmi/gnmi_test.go

@@ -89,8 +89,8 @@ func TestWaitError(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err = plugin.Start(&acc)
-	require.NoError(t, err)
+	require.NoError(t, plugin.Init())
+	require.NoError(t, plugin.Start(&acc))
 
 	var wg sync.WaitGroup
 	wg.Add(1)
@@ -148,8 +148,8 @@ func TestUsernamePassword(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err = plugin.Start(&acc)
-	require.NoError(t, err)
+	require.NoError(t, plugin.Init())
+	require.NoError(t, plugin.Start(&acc))
 
 	var wg sync.WaitGroup
 	wg.Add(1)
@@ -1005,8 +1005,8 @@ func TestNotification(t *testing.T) {
 			gnmiLib.RegisterGNMIServer(grpcServer, tt.server)
 
 			var acc testutil.Accumulator
-			err = tt.plugin.Start(&acc)
-			require.NoError(t, err)
+			require.NoError(t, tt.plugin.Init())
+			require.NoError(t, tt.plugin.Start(&acc))
 
 			var wg sync.WaitGroup
 			wg.Add(1)
@@ -1069,8 +1069,8 @@ func TestRedial(t *testing.T) {
 	}()
 
 	var acc testutil.Accumulator
-	err = plugin.Start(&acc)
-	require.NoError(t, err)
+	require.NoError(t, plugin.Init())
+	require.NoError(t, plugin.Start(&acc))
 
 	acc.Wait(2)
 	grpcServer.Stop()
@@ -1205,6 +1205,7 @@ func TestCases(t *testing.T) {
 			}()
 
 			var acc testutil.Accumulator
+			require.NoError(t, plugin.Init())
 			require.NoError(t, plugin.Start(&acc))
 
 			require.Eventually(t,