cc-metric-collector/sinks/stdoutSink.go

package sinks

import (
	"bytes"
	"encoding/json"
	"fmt"
	"os"
	"strings"

	//	"time"
	lp "github.com/ClusterCockpit/cc-energy-manager/pkg/cc-message"
	cclog "github.com/ClusterCockpit/cc-metric-collector/pkg/ccLogger"
	mp "github.com/ClusterCockpit/cc-metric-collector/pkg/messageProcessor"
)

type StdoutSink struct {
	sink   // meta_as_tags, name
	output *os.File
	config struct {
		defaultSinkConfig
		Output string `json:"output_file,omitempty"`
	}
}

func (s *StdoutSink) Write(m lp.CCMessage) error {
	msg, err := s.mp.ProcessMessage(m)
	if err == nil && msg != nil {
		fmt.Fprint(
			s.output,
			msg.ToLineProtocol(s.meta_as_tags),
		)
	}
	return nil
}

func (s *StdoutSink) Flush() error {
	s.output.Sync()
	return nil
}

func (s *StdoutSink) Close() {
	if s.output != os.Stdout && s.output != os.Stderr {
		s.output.Close()
	}
}

func NewStdoutSink(name string, config json.RawMessage) (Sink, error) {

	s := new(StdoutSink)
	s.name = fmt.Sprintf("StdoutSink(%s)", name)
	if len(config) > 0 {
		d := json.NewDecoder(bytes.NewReader(config))
		d.DisallowUnknownFields()
		if err := d.Decode(&s.config); err != nil {
			cclog.ComponentError(s.name, "Error reading config:", err.Error())
			return nil, err
		}
	}
	p, err := mp.NewMessageProcessor()
	if err != nil {
		return nil, fmt.Errorf("initialization of message processor failed: %v", err.Error())
	}
	s.mp = p

	s.output = os.Stdout
	if len(s.config.Output) > 0 {
		switch strings.ToLower(s.config.Output) {
		case "stdout":
			s.output = os.Stdout
		case "stderr":
			s.output = os.Stderr
		default:
			f, err := os.OpenFile(s.config.Output, os.O_CREATE|os.O_WRONLY, os.FileMode(0600))
			if err != nil {
				return nil, err
			}
			s.output = f
		}
	}

	// Add message processor configuration
	if len(s.config.MessageProcessor) > 0 {
		err = s.mp.FromConfigJSON(s.config.MessageProcessor)
		if err != nil {
			return nil, fmt.Errorf("failed parsing JSON for message processor: %v", err.Error())
		}
	}
	// Create lookup map to use meta infos as tags in the output metric
	// s.meta_as_tags = make(map[string]bool)
	// for _, k := range s.config.MetaAsTags {
	// 	s.meta_as_tags[k] = true
	// }
	for _, k := range s.config.MetaAsTags {
		s.mp.AddMoveMetaToTags("true", k, k)
	}

	return s, nil
}