75 lines
1.6 KiB
Go
75 lines
1.6 KiB
Go
package snapshot
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import (
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"io/ioutil"
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"os"
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"sync"
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"github.com/containerd/containerd/mount"
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"github.com/pkg/errors"
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)
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type Mounter interface {
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Mount() (string, error)
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Unmount() error
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}
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// LocalMounter is a helper for mounting mountfactory to temporary path. In
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// addition it can mount binds without privileges
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func LocalMounter(mountable Mountable) Mounter {
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return &localMounter{mountable: mountable}
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}
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// LocalMounterWithMounts is a helper for mounting to temporary path. In
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// addition it can mount binds without privileges
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func LocalMounterWithMounts(mounts []mount.Mount) Mounter {
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return &localMounter{mounts: mounts}
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}
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type localMounter struct {
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mu sync.Mutex
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mounts []mount.Mount
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mountable Mountable
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target string
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release func() error
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}
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func (lm *localMounter) Mount() (string, error) {
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lm.mu.Lock()
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defer lm.mu.Unlock()
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if lm.mounts == nil {
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mounts, release, err := lm.mountable.Mount()
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if err != nil {
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return "", err
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}
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lm.mounts = mounts
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lm.release = release
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}
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if len(lm.mounts) == 1 && (lm.mounts[0].Type == "bind" || lm.mounts[0].Type == "rbind") {
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ro := false
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for _, opt := range lm.mounts[0].Options {
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if opt == "ro" {
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ro = true
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break
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}
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}
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if !ro {
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return lm.mounts[0].Source, nil
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}
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}
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dir, err := ioutil.TempDir("", "buildkit-mount")
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if err != nil {
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return "", errors.Wrap(err, "failed to create temp dir")
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}
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if err := mount.All(lm.mounts, dir); err != nil {
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os.RemoveAll(dir)
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return "", errors.Wrapf(err, "failed to mount %s: %+v", dir, lm.mounts)
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}
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lm.target = dir
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return dir, nil
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}
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