open-consul/command/agent/rpc_log_stream.go

69 lines
1.4 KiB
Go

package agent
import (
"github.com/hashicorp/logutils"
"log"
)
type streamClient interface {
Send(*responseHeader, interface{}) error
}
// logStream is used to stream logs to a client over RPC
type logStream struct {
client streamClient
filter *logutils.LevelFilter
logCh chan string
logger *log.Logger
seq uint64
}
func newLogStream(client streamClient, filter *logutils.LevelFilter,
seq uint64, logger *log.Logger) *logStream {
ls := &logStream{
client: client,
filter: filter,
logCh: make(chan string, 512),
logger: logger,
seq: seq,
}
go ls.stream()
return ls
}
func (ls *logStream) HandleLog(l string) {
// Check the log level
if !ls.filter.Check([]byte(l)) {
return
}
// Do a non-blocking send
select {
case ls.logCh <- l:
default:
// We can't log synchronously, since we are already being invoked
// from the logWriter, and a log will need to invoke Write() which
// already holds the lock. We must therefor do the log async, so
// as to not deadlock
go ls.logger.Printf("[WARN] Dropping logs to %v", ls.client)
}
}
func (ls *logStream) Stop() {
close(ls.logCh)
}
func (ls *logStream) stream() {
header := responseHeader{Seq: ls.seq, Error: ""}
rec := logRecord{Log: ""}
for line := range ls.logCh {
rec.Log = line
if err := ls.client.Send(&header, &rec); err != nil {
ls.logger.Printf("[ERR] Failed to stream log to %v: %v",
ls.client, err)
return
}
}
}