Loading & namespacing external plugins

cmd/telegraf/telegraf.go

@@ -16,6 +16,7 @@ import (
 	"github.com/influxdata/telegraf/agent"
 	"github.com/influxdata/telegraf/internal/config"
 	"github.com/influxdata/telegraf/logger"
+	"github.com/influxdata/telegraf/registry"
 	"github.com/influxdata/telegraf/registry/inputs"
 	"github.com/influxdata/telegraf/registry/outputs"
 
@@ -273,6 +274,15 @@ func loadExternalPlugins(rootDir string) error {
 			return nil
 		}
 
+		// name will be the path to the plugin file beginning at the root
+		// directory, minus the extension.
+		// ie, if the plugin file is /opt/telegraf-plugins/group1/foo.so, name
+		//     will be "group1/foo"
+		name := strings.TrimPrefix(strings.TrimPrefix(pth, rootDir), string(os.PathSeparator))
+		name = strings.TrimSuffix(name, filepath.Ext(pth))
+		registry.SetName("external" + string(os.PathSeparator) + name)
+		defer registry.SetName("")
+
 		// Load plugin.
 		_, err = plugin.Open(pth)
 		if err != nil {

doc.go

@@ -1 +0,0 @@
-package telegraf

internal/config/config.go

@@ -40,6 +40,14 @@ var (
 
 	// envVarRe is a regex to find environment variables in the config file
 	envVarRe = regexp.MustCompile(`\$\w+`)
+
+	// addQuoteRe is a regex for finding and adding quotes around / characters
+	// when they are used for distinguishing external plugins.
+	// ie, a ReplaceAll() with this pattern will be used to turn this:
+	//     [[inputs.external/test/example]]
+	//  to
+	//     [[inputs."external/test/example"]]
+	addQuoteRe = regexp.MustCompile(`(\[?\[?inputs|outputs|processors|aggregators)\.(external\/[^.\]]+)`)
 )
 
 // Config specifies the URL/user/password for the database that telegraf
@@ -701,6 +709,9 @@ func parseFile(fpath string) (*ast.Table, error) {
 		}
 	}
 
+	// add quotes around external plugin paths.
+	contents = addQuoteRe.ReplaceAll(contents, []byte(`$1."$2"`))
+
 	return toml.Parse(contents)
 }
 

registry/aggregators/registry.go

@@ -1,11 +1,20 @@
 package aggregators
 
-import "github.com/influxdata/telegraf"
+import (
+	"log"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/registry"
+)
 
 type Creator func() telegraf.Aggregator
 
 var Aggregators = map[string]Creator{}
 
 func Add(name string, creator Creator) {
+	if override := registry.GetName(); override != "" {
+		name = override
+	}
+	log.Println("D! Loading plugin: [[aggregators." + name + "]]")
 	Aggregators[name] = creator
 }

registry/doc.go

@@ -1 +0,0 @@
-package registry

registry/inputs/registry.go

@@ -1,11 +1,20 @@
 package inputs
 
-import "github.com/influxdata/telegraf"
+import (
+	"log"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/registry"
+)
 
 type Creator func() telegraf.Input
 
 var Inputs = map[string]Creator{}
 
 func Add(name string, creator Creator) {
+	if override := registry.GetName(); override != "" {
+		name = override
+	}
+	log.Println("D! Loading plugin: [[inputs." + name + "]]")
 	Inputs[name] = creator
 }

registry/name.go

@@ -0,0 +1,20 @@
+package registry
+
+import (
+	"sync"
+)
+
+var nameOverride string
+var mu sync.Mutex
+
+func SetName(s string) {
+	mu.Lock()
+	nameOverride = s
+	mu.Unlock()
+}
+
+func GetName() string {
+	mu.Lock()
+	defer mu.Unlock()
+	return nameOverride
+}

registry/outputs/registry.go

@@ -1,7 +1,10 @@
 package outputs
 
 import (
+	"log"
+
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/registry"
 )
 
 type Creator func() telegraf.Output
@@ -9,5 +12,9 @@ type Creator func() telegraf.Output
 var Outputs = map[string]Creator{}
 
 func Add(name string, creator Creator) {
+	if override := registry.GetName(); override != "" {
+		name = override
+	}
+	log.Println("D! Loading plugin: [[outputs." + name + "]]")
 	Outputs[name] = creator
 }

registry/processors/registry.go

@@ -1,11 +1,20 @@
 package processors
 
-import "github.com/influxdata/telegraf"
+import (
+	"log"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/registry"
+)
 
 type Creator func() telegraf.Processor
 
 var Processors = map[string]Creator{}
 
 func Add(name string, creator Creator) {
+	if override := registry.GetName(); override != "" {
+		name = override
+	}
+	log.Println("D! Loading plugin: [[processors." + name + "]]")
 	Processors[name] = creator
 }