[feature] Add a request ID and include it in logs (#1476)

This adds a lightweight form of tracing to GTS. Each incoming request is
assigned a Request ID which we then pass on and log in all our log
lines. Any function that gets called downstream from an HTTP handler
should now emit a requestID=value pair whenever it logs something.

Co-authored-by: kim <grufwub@gmail.com>

internal/api/client/media/mediacreate_test.go

@@ -100,7 +100,7 @@ func (suite *MediaCreateTestSuite) SetupSuite() {
 
 func (suite *MediaCreateTestSuite) TearDownSuite() {
 	if err := suite.db.Stop(context.Background()); err != nil {
-		log.Panicf("error closing db connection: %s", err)
+		log.Panicf(nil, "error closing db connection: %s", err)
 	}
 }
 

internal/api/client/media/mediaupdate_test.go

@@ -98,7 +98,7 @@ func (suite *MediaUpdateTestSuite) SetupSuite() {
 
 func (suite *MediaUpdateTestSuite) TearDownSuite() {
 	if err := suite.db.Stop(context.Background()); err != nil {
-		log.Panicf("error closing db connection: %s", err)
+		log.Panicf(nil, "error closing db connection: %s", err)
 	}
 }
 

internal/api/client/streaming/stream.go

@@ -166,11 +166,12 @@ func (m *Module) StreamGETHandler(c *gin.Context) {
 		return
 	}
 
-	l := log.WithFields(kv.Fields{
-		{"account", account.Username},
-		{"streamID", stream.ID},
-		{"streamType", streamType},
-	}...)
+	l := log.WithContext(c.Request.Context()).
+		WithFields(kv.Fields{
+			{"account", account.Username},
+			{"streamID", stream.ID},
+			{"streamType", streamType},
+		}...)
 
 	// Upgrade the incoming HTTP request, which hijacks the underlying
 	// connection and reuses it for the websocket (non-http) protocol.

internal/api/fileserver/fileserver_test.go

@@ -99,7 +99,7 @@ func (suite *FileserverTestSuite) SetupTest() {
 
 func (suite *FileserverTestSuite) TearDownSuite() {
 	if err := suite.db.Stop(context.Background()); err != nil {
-		log.Panicf("error closing db connection: %s", err)
+		log.Panicf(nil, "error closing db connection: %s", err)
 	}
 }
 

internal/api/fileserver/servefile.go

@@ -77,7 +77,10 @@ func (m *Module) ServeFile(c *gin.Context) {
 		return
 	}
 
-	content, errWithCode := m.processor.FileGet(c.Request.Context(), authed, &apimodel.GetContentRequestForm{
+	// Acquire context from gin request.
+	ctx := c.Request.Context()
+
+	content, errWithCode := m.processor.FileGet(ctx, authed, &apimodel.GetContentRequestForm{
 		AccountID: accountID,
 		MediaType: mediaType,
 		MediaSize: mediaSize,
@@ -101,7 +104,7 @@ func (m *Module) ServeFile(c *gin.Context) {
 	defer func() {
 		// Close content when we're done, catch errors.
 		if err := content.Content.Close(); err != nil {
-			log.Errorf("ServeFile: error closing readcloser: %s", err)
+			log.Errorf(ctx, "ServeFile: error closing readcloser: %s", err)
 		}
 	}()
 
@@ -130,15 +133,21 @@ func (m *Module) ServeFile(c *gin.Context) {
 		return
 	}
 
-	// Set known content-type and serve this file range.
+	// Set known content-type and serve range.
 	c.Header("Content-Type", format)
-	serveFileRange(c.Writer, content.Content, rng, content.ContentLength)
+	serveFileRange(
+		c.Writer,
+		c.Request,
+		content.Content,
+		rng,
+		content.ContentLength,
+	)
 }
 
 // serveFileRange serves the range of a file from a given source reader, without the
 // need for implementation of io.Seeker. Instead we read the first 'start' many bytes
 // into a discard reader. Code is adapted from https://codeberg.org/gruf/simplehttp.
-func serveFileRange(rw http.ResponseWriter, src io.Reader, rng string, size int64) {
+func serveFileRange(rw http.ResponseWriter, r *http.Request, src io.Reader, rng string, size int64) {
 	var i int
 
 	if i = strings.IndexByte(rng, '='); i < 0 {
@@ -219,7 +228,7 @@ func serveFileRange(rw http.ResponseWriter, src io.Reader, rng string, size int6
 
 	// Dump the first 'start' many bytes into the void...
 	if _, err := fastcopy.CopyN(io.Discard, src, start); err != nil {
-		log.Errorf("error reading from source: %v", err)
+		log.Errorf(r.Context(), "error reading from source: %v", err)
 		return
 	}
 
@@ -239,7 +248,7 @@ func serveFileRange(rw http.ResponseWriter, src io.Reader, rng string, size int6
 
 	// Read the "seeked" source reader into destination writer.
 	if _, err := fastcopy.Copy(rw, src); err != nil {
-		log.Errorf("error reading from source: %v", err)
+		log.Errorf(r.Context(), "error reading from source: %v", err)
 		return
 	}
 }

internal/api/util/errorhandling.go

@@ -27,6 +27,7 @@ import (
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/middleware"
 )
 
 // TODO: add more templated html pages here for different error types
@@ -43,16 +44,20 @@ import (
 func NotFoundHandler(c *gin.Context, instanceGet func(ctx context.Context) (*apimodel.InstanceV1, gtserror.WithCode), accept string) {
 	switch accept {
 	case string(TextHTML):
-		instance, err := instanceGet(c.Request.Context())
+		ctx := c.Request.Context()
+		instance, err := instanceGet(ctx)
 		if err != nil {
 			panic(err)
 		}
 
 		c.HTML(http.StatusNotFound, "404.tmpl", gin.H{
-			"instance": instance,
+			"instance":  instance,
+			"requestID": middleware.RequestID(ctx),
 		})
 	default:
-		c.JSON(http.StatusNotFound, gin.H{"error": http.StatusText(http.StatusNotFound)})
+		c.JSON(http.StatusNotFound, gin.H{
+			"error": http.StatusText(http.StatusNotFound),
+		})
 	}
 }
 
@@ -62,15 +67,17 @@ func NotFoundHandler(c *gin.Context, instanceGet func(ctx context.Context) (*api
 func genericErrorHandler(c *gin.Context, instanceGet func(ctx context.Context) (*apimodel.InstanceV1, gtserror.WithCode), accept string, errWithCode gtserror.WithCode) {
 	switch accept {
 	case string(TextHTML):
-		instance, err := instanceGet(c.Request.Context())
+		ctx := c.Request.Context()
+		instance, err := instanceGet(ctx)
 		if err != nil {
 			panic(err)
 		}
 
 		c.HTML(errWithCode.Code(), "error.tmpl", gin.H{
-			"instance": instance,
-			"code":     errWithCode.Code(),
-			"error":    errWithCode.Safe(),
+			"instance":  instance,
+			"code":      errWithCode.Code(),
+			"error":     errWithCode.Safe(),
+			"requestID": middleware.RequestID(ctx),
 		})
 	default:
 		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
@@ -108,11 +115,12 @@ func ErrorHandler(c *gin.Context, errWithCode gtserror.WithCode, instanceGet fun
 // to pass any detailed errors (that might contain sensitive information) into the
 // errWithCode.Error() field, since the client will see this. Use your noggin!
 func OAuthErrorHandler(c *gin.Context, errWithCode gtserror.WithCode) {
-	l := log.WithFields(kv.Fields{
-		{"path", c.Request.URL.Path},
-		{"error", errWithCode.Error()},
-		{"help", errWithCode.Safe()},
-	}...)
+	l := log.WithContext(c.Request.Context()).
+		WithFields(kv.Fields{
+			{"path", c.Request.URL.Path},
+			{"error", errWithCode.Error()},
+			{"help", errWithCode.Safe()},
+		}...)
 
 	statusCode := errWithCode.Code()