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43d6eb7173
This type felt really redundant; `pidfile.New()` takes the path of the file to create as an argument, so this is already known. The only thing the PIDFile type provided was a `Remove()` method, which was just calling `os.Remove()` on the path of the file. Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
42 lines
1.1 KiB
Go
42 lines
1.1 KiB
Go
// Package pidfile provides structure and helper functions to create and remove
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// PID file. A PID file is usually a file used to store the process ID of a
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// running process.
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package pidfile // import "github.com/docker/docker/pkg/pidfile"
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import (
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"bytes"
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"fmt"
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"os"
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"path/filepath"
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"strconv"
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"github.com/docker/docker/pkg/system"
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)
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func checkPIDFileAlreadyExists(path string) error {
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pidByte, err := os.ReadFile(path)
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if err != nil {
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if os.IsNotExist(err) {
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return nil
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}
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return err
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}
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pid, err := strconv.Atoi(string(bytes.TrimSpace(pidByte)))
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if err == nil && processExists(pid) {
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return fmt.Errorf("pid file found, ensure docker is not running or delete %s", path)
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}
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return nil
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}
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// Write writes a "PID file" at the specified path. It returns an error if the
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// file exists and contains a valid PID of a running process, or when failing
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// to write the file.
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func Write(path string) error {
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if err := checkPIDFileAlreadyExists(path); err != nil {
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return err
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}
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if err := system.MkdirAll(filepath.Dir(path), 0o755); err != nil {
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return err
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}
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return os.WriteFile(path, []byte(strconv.Itoa(os.Getpid())), 0o644)
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}
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