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96 lines
2.8 KiB
Go
96 lines
2.8 KiB
Go
package main
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import (
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"context"
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"flag"
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"fmt"
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"os"
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"path/filepath"
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"strings"
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log "github.com/sirupsen/logrus"
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"golang.org/x/sys/unix"
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)
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func volumeInitCmd(ctx context.Context) int {
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invoked := filepath.Base(os.Args[0])
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flags := flag.NewFlagSet("volume", flag.ExitOnError)
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flags.Usage = func() {
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fmt.Printf("USAGE: %s volume\n\n", invoked)
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fmt.Printf("Options:\n")
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flags.PrintDefaults()
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}
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path := flags.String("path", defaultVolumesPath, "Path to volume configs")
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// Set up volumes
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vols, err := os.ReadDir(*path)
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// just skip if there is an error, eg no such path
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if err != nil {
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return 1
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}
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// go through each volume, ensure that the volPath/merged exists as a directory,
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// and is one of:
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// - read-only: i.e. no tmp exists, merged bindmounted to lower
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// - read-write: i.e. tmp exists, overlayfs lower/upper/merged
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for _, vol := range vols {
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subs, err := os.ReadDir(filepath.Join(*path, vol.Name()))
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if err != nil {
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log.WithError(err).Errorf("Error reading volume %s", vol.Name())
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return 1
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}
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var hasLower, hasMerged, readWrite bool
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for _, sub := range subs {
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switch sub.Name() {
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case "lower":
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hasLower = true
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case "tmp":
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readWrite = true
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case "merged":
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hasMerged = true
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}
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}
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if !hasMerged {
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log.Errorf("Volume %s does not have a merged directory", vol.Name())
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return 1
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}
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if !hasLower {
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log.Errorf("Volume %s does not have a lower directory", vol.Name())
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return 1
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}
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lowerDir := filepath.Join(*path, vol.Name(), "lower")
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mergedDir := filepath.Join(*path, vol.Name(), "merged")
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// need a tmpfs to create the workdir and upper
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tmpDir := filepath.Join(*path, vol.Name(), "tmp")
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if err := unix.Mount("tmpfs", tmpDir, "tmpfs", unix.MS_RELATIME, ""); err != nil {
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log.WithError(err).Errorf("Error creating tmpDir for volume %s", vol.Name())
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return 1
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}
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workDir := filepath.Join(tmpDir, "work")
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upperDir := filepath.Join(tmpDir, "upper")
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if err := os.Mkdir(upperDir, 0755); err != nil {
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log.WithError(err).Errorf("Error creating upper dir for volume %s", vol.Name())
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return 1
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}
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if err := os.Mkdir(workDir, 0755); err != nil {
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log.WithError(err).Errorf("Error creating work dir for volume %s", vol.Name())
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return 1
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}
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// and let's mount the actual dir
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mountOps := []string{fmt.Sprintf("lowerdir=%s", lowerDir), fmt.Sprintf("upperdir=%s", upperDir), fmt.Sprintf("workdir=%s", workDir)}
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if !readWrite {
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log.Infof("Volume %s is read-only", vol.Name())
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mountOps = append(mountOps, "ro")
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} else {
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log.Infof("Volume %s is read-write", vol.Name())
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}
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data := strings.Join(mountOps, ",")
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if err := unix.Mount("overlay", mergedDir, "overlay", unix.MS_RELATIME, data); err != nil {
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log.WithError(err).Errorf("Error overlay-mounting volume %s", vol.Name())
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return 1
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}
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}
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return 0
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}
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