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  • Committer: Nicholas Skaggs
  • Date: 2016-10-24 20:56:05 UTC
  • Revision ID: nicholas.skaggs@canonical.com-20161024205605-z8lta0uvuhtxwzwl
Initi with beta15

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src/github.com/juju/juju/worker/uniter/runner/logger.go
 
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// Copyright 2012-2014 Canonical Ltd.
 
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// Licensed under the AGPLv3, see LICENCE file for details.
 
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package runner
 
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import (
 
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        "bufio"
 
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        "io"
 
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        "sync"
 
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        "time"
 
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        "github.com/juju/loggo"
 
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)
 
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type hookLogger struct {
 
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        r       io.ReadCloser
 
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        done    chan struct{}
 
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        mu      sync.Mutex
 
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        stopped bool
 
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        logger  loggo.Logger
 
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}
 
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func (l *hookLogger) run() {
 
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        defer close(l.done)
 
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        defer l.r.Close()
 
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        br := bufio.NewReaderSize(l.r, 4096)
 
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        for {
 
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                line, _, err := br.ReadLine()
 
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                if err != nil {
 
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                        if err != io.EOF {
 
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                                logger.Errorf("cannot read hook output: %v", err)
 
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                        }
 
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                        break
 
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                }
 
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                l.mu.Lock()
 
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                if l.stopped {
 
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                        l.mu.Unlock()
 
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                        return
 
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                }
 
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                l.logger.Infof("%s", line)
 
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                l.mu.Unlock()
 
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        }
 
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}
 
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func (l *hookLogger) stop() {
 
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        // We can see the process exit before the logger has processed
 
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        // all its output, so allow a moment for the data buffered
 
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        // in the pipe to be processed. We don't wait indefinitely though,
 
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        // because the hook may have started a background process
 
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        // that keeps the pipe open.
 
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        select {
 
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        case <-l.done:
 
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        case <-time.After(100 * time.Millisecond):
 
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        }
 
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        // We can't close the pipe asynchronously, so just
 
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        // stifle output instead.
 
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        l.mu.Lock()
 
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        l.stopped = true
 
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        l.mu.Unlock()
 
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}