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when building read-only volumes, still use overlayfs

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Signed-off-by: Avi Deitcher <avi@deitcher.net>
This commit is contained in:
Avi Deitcher
2024-08-22 18:15:48 +03:00
parent 370bf51cdf
commit b36cad081b
124 changed files with 164 additions and 168 deletions
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56
pkg/init/cmd/service/volumeinit.go
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@@ -6,6 +6,7 @@ import (
"fmt"
"os"
"path/filepath"
"strings"
log "github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
@@ -59,36 +60,35 @@ func volumeInitCmd(ctx context.Context) int {
}
lowerDir := filepath.Join(*path, vol.Name(), "lower")
mergedDir := filepath.Join(*path, vol.Name(), "merged")
// need a tmpfs to create the workdir and upper
tmpDir := filepath.Join(*path, vol.Name(), "tmp")
if err := unix.Mount("tmpfs", tmpDir, "tmpfs", unix.MS_RELATIME, ""); err != nil {
log.WithError(err).Errorf("Error creating tmpDir for volume %s", vol.Name())
return 1
}
workDir := filepath.Join(tmpDir, "work")
upperDir := filepath.Join(tmpDir, "upper")
if err := os.Mkdir(upperDir, 0755); err != nil {
log.WithError(err).Errorf("Error creating upper dir for volume %s", vol.Name())
return 1
}
if err := os.Mkdir(workDir, 0755); err != nil {
log.WithError(err).Errorf("Error creating work dir for volume %s", vol.Name())
return 1
}
// and let's mount the actual dir
mountOps := []string{fmt.Sprintf("lowerdir=%s", lowerDir), fmt.Sprintf("upperdir=%s", upperDir), fmt.Sprintf("workdir=%s", workDir)}
if !readWrite {
log.Infof("Volume %s is read-only, bind-mounting read-only", vol.Name())
if err := unix.Mount(lowerDir, mergedDir, "bind", unix.MS_RDONLY, ""); err != nil {
log.WithError(err).Errorf("Error bind-mounting volume %s", vol.Name())
return 1
}
log.Infof("Volume %s is read-only", vol.Name())
mountOps = append(mountOps, "ro")
} else {
log.Infof("Volume %s is read-write, overlay mounting", vol.Name())
// need a tmpfs to create the workdir and upper
tmpDir := filepath.Join(*path, vol.Name(), "tmp")
if err := unix.Mount("tmpfs", tmpDir, "tmpfs", unix.MS_RELATIME, ""); err != nil {
log.WithError(err).Errorf("Error creating tmpDir for volume %s", vol.Name())
return 1
}
workDir := filepath.Join(tmpDir, "work")
upperDir := filepath.Join(tmpDir, "upper")
if err := os.Mkdir(upperDir, 0755); err != nil {
log.WithError(err).Errorf("Error creating upper dir for volume %s", vol.Name())
return 1
}
if err := os.Mkdir(workDir, 0755); err != nil {
log.WithError(err).Errorf("Error creating work dir for volume %s", vol.Name())
return 1
}
// and let's mount the actual dir
data := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
if err := unix.Mount("overlay", mergedDir, "overlay", unix.MS_RELATIME, data); err != nil {
log.WithError(err).Errorf("Error overlay-mounting volume %s", vol.Name())
return 1
}
log.Infof("Volume %s is read-write", vol.Name())
}
data := strings.Join(mountOps, ",")
if err := unix.Mount("overlay", mergedDir, "overlay", unix.MS_RELATIME, data); err != nil {
log.WithError(err).Errorf("Error overlay-mounting volume %s", vol.Name())
return 1
}
}
return 0