first commit

logging/context.go

@@ -0,0 +1,66 @@
+package logging
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/rs/xid"
+)
+
+type key int
+
+const (
+	// RequestIDKey is the context key that should store the request identifier.
+	RequestIDKey key = iota
+	// UserIDKey is the context key that should store the user identifier.
+	UserIDKey
+)
+
+// NewRequestID creates a new request id using github.com/rs/xid.
+func NewRequestID() string {
+	return xid.New().String()
+}
+
+// RequestID returns a new middleware that gets the given header and sets it
+// in the context so it can be written in the logger. If the header does not
+// exists or it's the empty string, it uses github.com/rs/xid to create a new
+// one.
+func RequestID(headerName string) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, req *http.Request) {
+			requestID := req.Header.Get(headerName)
+			if requestID == "" {
+				requestID = NewRequestID()
+				req.Header.Set(headerName, requestID)
+			}
+
+			ctx := WithRequestID(req.Context(), requestID)
+			next.ServeHTTP(w, req.WithContext(ctx))
+		}
+		return http.HandlerFunc(fn)
+	}
+}
+
+// WithRequestID returns a new context with the given requestID added to the
+// context.
+func WithRequestID(ctx context.Context, requestID string) context.Context {
+	return context.WithValue(ctx, RequestIDKey, requestID)
+}
+
+// GetRequestID returns the request id from the context if it exists.
+func GetRequestID(ctx context.Context) (string, bool) {
+	v, ok := ctx.Value(RequestIDKey).(string)
+	return v, ok
+}
+
+// WithUserID decodes the token, extracts the user from the payload and stores
+// it in the context.
+func WithUserID(ctx context.Context, userID string) context.Context {
+	return context.WithValue(ctx, UserIDKey, userID)
+}
+
+// GetUserID returns the request id from the context if it exists.
+func GetUserID(ctx context.Context) (string, bool) {
+	v, ok := ctx.Value(UserIDKey).(string)
+	return v, ok
+}