fix: plugin logging

cmd/exporter/main.go

@@ -74,7 +74,7 @@ func main() {
 	setLogLevel(lvl, config.AppConfig().LogLevel)
 
 	// Load exporter plugins
-	logger.Info("loading plugins")
+	logger.Info("loading exporters", "dir", config.AppConfig().Plugins.ExporterDir)
 	pluginsystem := &plugin.ExportPluginSystem{
 		Dir: config.AppConfig().Plugins.ExporterDir,
 	}
@@ -84,9 +84,11 @@ func main() {
 		logger.Error("failed to load exporter plugin system", "error", err)
 		os.Exit(1)
 	}
+	logger.Info("finished loading exporters", "output",
+		fmt.Sprintf("%d loaded", len(pluginsystem.Plugins)))
 
 	// Load source plugins
-	logger.Info("loading sources")
+	logger.Info("loading sources", "dir", config.AppConfig().Plugins.SourceDir)
 	sourcePluginSystem := &plugin.SourcePluginSystem{
 		Dir: config.AppConfig().Plugins.SourceDir,
 	}
@@ -96,6 +98,8 @@ func main() {
 		logger.Error("failed to load exporter plugin system", "error", err)
 		os.Exit(1)
 	}
+	logger.Info("finished loading sources", "output",
+		fmt.Sprintf("%d loaded", len(sourcePluginSystem.Plugins)))
 
 	// Init the application bus
 	b := bus.New()

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/go-yaml/yaml v2.1.0+incompatible
 	github.com/google/go-cmp v0.6.0
 	github.com/gorilla/mux v1.8.1
+	github.com/hashicorp/go-hclog v1.5.0
 	github.com/hashicorp/go-plugin v1.6.0
 	github.com/prometheus/client_golang v1.17.0
 	github.com/prometheus/common v0.45.0
@@ -68,7 +69,6 @@ require (
 	github.com/google/s2a-go v0.1.7 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.2 // indirect
 	github.com/googleapis/gax-go/v2 v2.12.0 // indirect
-	github.com/hashicorp/go-hclog v1.5.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect

pkg/plugin/exporter.go

@@ -8,6 +8,7 @@ import (
 	"os/exec"
 	"path/filepath"
 
+	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-plugin"
 	"google.golang.org/grpc"
 
@@ -133,6 +134,12 @@ func (e *ExportPluginSystem) Load(ctx context.Context) error {
 			},
 			AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
 			Cmd:              exec.Command(pluginPath),
+			Logger: hclog.New(&hclog.LoggerOptions{
+				Name:       "exporter",
+				Output:     os.Stdout,
+				Level:      hclog.Debug,
+				JSONFormat: true,
+			}),
 		})
 
 		// Start the plugin process.

pkg/plugin/source.go

@@ -8,6 +8,7 @@ import (
 	"os/exec"
 	"path/filepath"
 
+	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-plugin"
 	"google.golang.org/grpc"
 
@@ -162,6 +163,12 @@ func (s *SourcePluginSystem) Load(ctx context.Context) error {
 			},
 			AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
 			Cmd:              exec.Command(pluginPath),
+			Logger: hclog.New(&hclog.LoggerOptions{
+				Name:       "source",
+				Output:     os.Stdout,
+				Level:      hclog.Debug,
+				JSONFormat: true,
+			}),
 		})
 
 		// Start the plugin process.