SetLogger and panic stacktrace. (#210)

* Initialize opencensus for GKE

* update readme

* Generalize initialization of sd exporter

* fix sdExporterOptions

* do not initilize SD exporters and error reporting unless we are in the cloud or set proper environment variables

* Update doc

* address comments

* remove redundant if

* SetLogger to context. Log panic with a stacktrace.

* Func comment

* fix typo

* fix typo

server/kit/kitserver.go

@@ -8,6 +8,7 @@ import (
 	"net"
 	"net/http"
 	"net/http/pprof"
+	"runtime/debug"
 	"strings"
 
 	"cloud.google.com/go/errorreporting"
@@ -154,7 +155,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				err = e
 			}
 
-			s.logger.Log("error", err, "message", "the server encountered a panic")
+			s.logger.Log("error", err, "message", "the server encountered a panic", "stacktrace", string(debug.Stack()))
 
 			w.WriteHeader(http.StatusInternalServerError)
 			_, werr := w.Write([]byte(http.StatusText(http.StatusInternalServerError)))
@@ -191,7 +192,7 @@ func (s *Server) register(svc Service) {
 		}),
 		// inject the server logger into every request context
 		httptransport.ServerBefore(func(ctx context.Context, _ *http.Request) context.Context {
-			return context.WithValue(ctx, logKey, AddLogKeyVals(ctx, s.logger))
+			return SetLogger(ctx, AddLogKeyVals(ctx, s.logger))
 		}),
 	}
 	opts = append(opts, svc.HTTPOptions()...)

server/kit/log.go

@@ -37,6 +37,11 @@ func NewLogger(ctx context.Context, logID string) (log.Logger, func() error, err
 	return lg, cl, err
 }
 
+// SetLogger sets log.Logger to the context and returns new context with logger.
+func SetLogger(ctx context.Context, logger log.Logger) context.Context {
+	return context.WithValue(ctx, logKey, logger)
+}
+
 // Logger will return a kit/log.Logger that has been injected into the context by the kit
 // server. This logger has had request headers and metadata added as key values.
 // This function will only work within the scope of a request initiated by the server.