go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/tsmon/monitor/debug.go (about)

     1  // Copyright 2015 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package monitor
    16  
    17  import (
    18  	"context"
    19  	"os"
    20  
    21  	"github.com/golang/protobuf/proto"
    22  
    23  	"go.chromium.org/luci/common/clock"
    24  	"go.chromium.org/luci/common/logging"
    25  	pb "go.chromium.org/luci/common/tsmon/ts_mon_proto"
    26  	"go.chromium.org/luci/common/tsmon/types"
    27  )
    28  
    29  type debugMonitor struct {
    30  	path string
    31  }
    32  
    33  // NewDebugMonitor returns a Monitor that outputs metrics to a log, and
    34  // optionally a file on disk.
    35  func NewDebugMonitor(path string) Monitor {
    36  	return &debugMonitor{
    37  		path: path,
    38  	}
    39  }
    40  
    41  func (m *debugMonitor) ChunkSize() int {
    42  	return 0
    43  }
    44  
    45  func (m *debugMonitor) Send(ctx context.Context, cells []types.Cell) error {
    46  	str := proto.MarshalTextString(&pb.MetricsPayload{
    47  		MetricsCollection: SerializeCells(cells, clock.Now(ctx)),
    48  	})
    49  
    50  	logging.Infof(ctx, "Sending ts_mon metrics:\n%s", str)
    51  
    52  	if m.path != "" {
    53  		file, err := os.OpenFile(m.path, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0664)
    54  		if err != nil {
    55  			logging.Errorf(ctx, "Failed to open file %s: %s", m.path, err)
    56  			return err
    57  		}
    58  
    59  		defer func() {
    60  			if err := file.Close(); err != nil {
    61  				logging.Errorf(ctx, "Failed to close file %s: %s", m.path, err)
    62  			}
    63  		}()
    64  
    65  		if _, err = file.WriteString(str); err != nil {
    66  			logging.Errorf(ctx, "Failed to write to the file %s: %s", m.path, err)
    67  			return err
    68  		}
    69  	}
    70  
    71  	return nil
    72  }
    73  
    74  func (m *debugMonitor) Close() error {
    75  	return nil
    76  }