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snapshot: Add context to Snapshotter interface

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Signed-off-by: Samuel Karp <skarp@amazon.com>
This commit is contained in:
Samuel Karp 2017-02-24 15:23:23 -08:00
parent d377454659
commit 4382d553ea
6 changed files with 60 additions and 47 deletions
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10
rootfs/apply.go
View file

@ -30,6 +30,7 @@ type Mounter interface {
func ApplyLayer(snapshots snapshot.Snapshotter, mounter Mounter, rd io.Reader, parent digest.Digest) (digest.Digest, error) { func ApplyLayer(snapshots snapshot.Snapshotter, mounter Mounter, rd io.Reader, parent digest.Digest) (digest.Digest, error) {
digester := digest.Canonical.Digester() // used to calculate diffID. digester := digest.Canonical.Digester() // used to calculate diffID.
rd = io.TeeReader(rd, digester.Hash()) rd = io.TeeReader(rd, digester.Hash())
ctx := context.TODO()
// create a temporary directory to work from, needs to be on same // create a temporary directory to work from, needs to be on same
// filesystem. Probably better if this shared but we'll use a tempdir, for // filesystem. Probably better if this shared but we'll use a tempdir, for
@ -45,13 +46,13 @@ func ApplyLayer(snapshots snapshot.Snapshotter, mounter Mounter, rd io.Reader, p
// layerID (since we don't know the diffID until we are done!). // layerID (since we don't know the diffID until we are done!).
key := dir key := dir
mounts, err := snapshots.Prepare(key, parent.String()) mounts, err := snapshots.Prepare(ctx, key, parent.String())
if err != nil { if err != nil {
return "", err return "", err
} }
if err := mounter.Mount(mounts...); err != nil { if err := mounter.Mount(mounts...); err != nil {
if err := snapshots.Remove(key); err != nil { if err := snapshots.Remove(ctx, key); err != nil {
log.L.WithError(err).Error("snapshot rollback failed") log.L.WithError(err).Error("snapshot rollback failed")
} }
return "", err return "", err
@ -74,7 +75,7 @@ func ApplyLayer(snapshots snapshot.Snapshotter, mounter Mounter, rd io.Reader, p
chainID = identity.ChainID([]digest.Digest{parent, chainID}) chainID = identity.ChainID([]digest.Digest{parent, chainID})
} }
return diffID, snapshots.Commit(chainID.String(), key) return diffID, snapshots.Commit(ctx, chainID.String(), key)
} }
// Prepare the root filesystem from the set of layers. Snapshots are created // Prepare the root filesystem from the set of layers. Snapshots are created
@ -96,6 +97,7 @@ func Prepare(snapshots snapshot.Snapshotter, mounter Mounter, layers []ocispec.D
parent digest.Digest parent digest.Digest
chain []digest.Digest chain []digest.Digest
) )
ctx := context.TODO()
for _, layer := range layers { for _, layer := range layers {
// TODO: layer.Digest should not be string // TODO: layer.Digest should not be string
@ -110,7 +112,7 @@ func Prepare(snapshots snapshot.Snapshotter, mounter Mounter, layers []ocispec.D
chainLocal := append(chain, diffID) chainLocal := append(chain, diffID)
chainID := identity.ChainID(chainLocal) chainID := identity.ChainID(chainLocal)
if _, err := snapshots.Stat(chainID.String()); err == nil { if _, err := snapshots.Stat(ctx, chainID.String()); err == nil {
continue continue
} }
} }

17
snapshot/btrfs/btrfs.go
View file

@ -1,6 +1,7 @@
package btrfs package btrfs
import ( import (
"context"
"crypto/sha256" "crypto/sha256"
"fmt" "fmt"
"io/ioutil" "io/ioutil"
@ -48,7 +49,7 @@ func NewSnapshotter(device, root string) (*Snapshotter, error) {
// //
// Should be used for parent resolution, existence checks and to discern // Should be used for parent resolution, existence checks and to discern
// the kind of snapshot. // the kind of snapshot.
func (b *Snapshotter) Stat(key string) (snapshot.Info, error) { func (b *Snapshotter) Stat(ctx context.Context, key string) (snapshot.Info, error) {
// resolve the snapshot out of the index. // resolve the snapshot out of the index.
target, err := os.Readlink(filepath.Join(b.root, "index", hash(key))) target, err := os.Readlink(filepath.Join(b.root, "index", hash(key)))
if err != nil { if err != nil {
@ -119,11 +120,11 @@ func (b *Snapshotter) stat(target string) (snapshot.Info, error) {
} }
func (b *Snapshotter) Prepare(key, parent string) ([]containerd.Mount, error) { func (b *Snapshotter) Prepare(ctx context.Context, key, parent string) ([]containerd.Mount, error) {
return b.makeActive(key, parent, false) return b.makeActive(key, parent, false)
} }
func (b *Snapshotter) View(key, parent string) ([]containerd.Mount, error) { func (b *Snapshotter) View(ctx context.Context, key, parent string) ([]containerd.Mount, error) {
return b.makeActive(key, parent, true) return b.makeActive(key, parent, true)
} }
@ -198,7 +199,7 @@ func (b *Snapshotter) mounts(dir string) ([]containerd.Mount, error) {
}, nil }, nil
} }
func (b *Snapshotter) Commit(name, key string) error { func (b *Snapshotter) Commit(ctx context.Context, name, key string) error {
var ( var (
active = filepath.Join(b.root, "active") active = filepath.Join(b.root, "active")
snapshots = filepath.Join(b.root, "snapshots") snapshots = filepath.Join(b.root, "snapshots")
@ -283,19 +284,19 @@ func (b *Snapshotter) Commit(name, key string) error {
// called on an read-write or readonly transaction. // called on an read-write or readonly transaction.
// //
// This can be used to recover mounts after calling View or Prepare. // This can be used to recover mounts after calling View or Prepare.
func (b *Snapshotter) Mounts(key string) ([]containerd.Mount, error) { func (b *Snapshotter) Mounts(ctx context.Context, key string) ([]containerd.Mount, error) {
dir := filepath.Join(b.root, "active", hash(key)) dir := filepath.Join(b.root, "active", hash(key))
return b.mounts(dir) return b.mounts(dir)
} }
// Remove abandons the transaction identified by key. All resources // Remove abandons the transaction identified by key. All resources
// associated with the key will be removed. // associated with the key will be removed.
func (b *Snapshotter) Remove(key string) error { func (b *Snapshotter) Remove(ctx context.Context, key string) error {
panic("not implemented") panic("not implemented")
} }
// Walk the committed snapshots. // Walk the committed snapshots.
func (b *Snapshotter) Walk(fn func(snapshot.Info) error) error { func (b *Snapshotter) Walk(ctx context.Context, fn func(context.Context, snapshot.Info) error) error {
// TODO(stevvooe): Copy-pasted almost verbatim from overlay. Really need to // TODO(stevvooe): Copy-pasted almost verbatim from overlay. Really need to
// unify the metadata for snapshot implementations. // unify the metadata for snapshot implementations.
root := filepath.Join(b.root, "index") root := filepath.Join(b.root, "index")
@ -325,7 +326,7 @@ func (b *Snapshotter) Walk(fn func(snapshot.Info) error) error {
return err return err
} }
if err := fn(si); err != nil { if err := fn(ctx, si); err != nil {
return err return err
} }

10
snapshot/btrfs/btrfs_test.go
View file

@ -1,6 +1,7 @@
package btrfs package btrfs
import ( import (
"context"
"io/ioutil" "io/ioutil"
"os" "os"
"os/exec" "os/exec"
@ -34,6 +35,7 @@ func TestBtrfs(t *testing.T) {
func TestBtrfsMounts(t *testing.T) { func TestBtrfsMounts(t *testing.T) {
testutil.RequiresRoot(t) testutil.RequiresRoot(t)
ctx := context.TODO()
// create temporary directory for mount point // create temporary directory for mount point
mountPoint, err := ioutil.TempDir("", "containerd-btrfs-test") mountPoint, err := ioutil.TempDir("", "containerd-btrfs-test")
@ -56,7 +58,7 @@ func TestBtrfsMounts(t *testing.T) {
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
mounts, err := b.Prepare(target, "") mounts, err := b.Prepare(ctx, target, "")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -92,12 +94,12 @@ func TestBtrfsMounts(t *testing.T) {
t.Fatal(err) t.Fatal(err)
} }
if err := b.Commit(filepath.Join(root, "snapshots/committed"), filepath.Join(root, "test")); err != nil { if err := b.Commit(ctx, filepath.Join(root, "snapshots/committed"), filepath.Join(root, "test")); err != nil {
t.Fatal(err) t.Fatal(err)
} }
target = filepath.Join(root, "test2") target = filepath.Join(root, "test2")
mounts, err = b.Prepare(target, filepath.Join(root, "snapshots/committed")) mounts, err = b.Prepare(ctx, target, filepath.Join(root, "snapshots/committed"))
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -116,7 +118,7 @@ func TestBtrfsMounts(t *testing.T) {
t.Fatal(err) t.Fatal(err)
} }
if err := b.Commit(filepath.Join(root, "snapshots/committed2"), target); err != nil { if err := b.Commit(ctx, filepath.Join(root, "snapshots/committed2"), target); err != nil {
t.Fatal(err) t.Fatal(err)
} }
} }

17
snapshot/overlay/overlay.go
View file

@ -1,6 +1,7 @@
package overlay package overlay
import ( import (
"context"
"fmt" "fmt"
"io/ioutil" "io/ioutil"
"os" "os"
@ -43,7 +44,7 @@ func NewSnapshotter(root string) (*Snapshotter, error) {
// //
// Should be used for parent resolution, existence checks and to discern // Should be used for parent resolution, existence checks and to discern
// the kind of snapshot. // the kind of snapshot.
func (o *Snapshotter) Stat(key string) (snapshot.Info, error) { func (o *Snapshotter) Stat(ctx context.Context, key string) (snapshot.Info, error) {
path, err := o.links.get(filepath.Join(o.root, "index", hash(key))) path, err := o.links.get(filepath.Join(o.root, "index", hash(key)))
if err != nil { if err != nil {
if !os.IsNotExist(err) { if !os.IsNotExist(err) {
@ -100,7 +101,7 @@ func (o *Snapshotter) stat(path string) (snapshot.Info, error) {
}, nil }, nil
} }
func (o *Snapshotter) Prepare(key, parent string) ([]containerd.Mount, error) { func (o *Snapshotter) Prepare(ctx context.Context, key, parent string) ([]containerd.Mount, error) {
active, err := o.newActiveDir(key) active, err := o.newActiveDir(key)
if err != nil { if err != nil {
return nil, err return nil, err
@ -113,7 +114,7 @@ func (o *Snapshotter) Prepare(key, parent string) ([]containerd.Mount, error) {
return active.mounts(o.links) return active.mounts(o.links)
} }
func (o *Snapshotter) View(key, parent string) ([]containerd.Mount, error) { func (o *Snapshotter) View(ctx context.Context, key, parent string) ([]containerd.Mount, error) {
panic("not implemented") panic("not implemented")
} }
@ -121,24 +122,24 @@ func (o *Snapshotter) View(key, parent string) ([]containerd.Mount, error) {
// called on an read-write or readonly transaction. // called on an read-write or readonly transaction.
// //
// This can be used to recover mounts after calling View or Prepare. // This can be used to recover mounts after calling View or Prepare.
func (o *Snapshotter) Mounts(key string) ([]containerd.Mount, error) { func (o *Snapshotter) Mounts(ctx context.Context, key string) ([]containerd.Mount, error) {
active := o.getActive(key) active := o.getActive(key)
return active.mounts(o.links) return active.mounts(o.links)
} }
func (o *Snapshotter) Commit(name, key string) error { func (o *Snapshotter) Commit(ctx context.Context, name, key string) error {
active := o.getActive(key) active := o.getActive(key)
return active.commit(name, o.links) return active.commit(name, o.links)
} }
// Remove abandons the transaction identified by key. All resources // Remove abandons the transaction identified by key. All resources
// associated with the key will be removed. // associated with the key will be removed.
func (o *Snapshotter) Remove(key string) error { func (o *Snapshotter) Remove(ctx context.Context, key string) error {
panic("not implemented") panic("not implemented")
} }
// Walk the committed snapshots. // Walk the committed snapshots.
func (o *Snapshotter) Walk(fn func(snapshot.Info) error) error { func (o *Snapshotter) Walk(ctx context.Context, fn func(context.Context, snapshot.Info) error) error {
root := filepath.Join(o.root, "index") root := filepath.Join(o.root, "index")
return filepath.Walk(root, func(path string, fi os.FileInfo, err error) error { return filepath.Walk(root, func(path string, fi os.FileInfo, err error) error {
if err != nil { if err != nil {
@ -166,7 +167,7 @@ func (o *Snapshotter) Walk(fn func(snapshot.Info) error) error {
return err return err
} }
if err := fn(si); err != nil { if err := fn(ctx, si); err != nil {
return err return err
} }

23
snapshot/overlay/overlay_test.go
View file

@ -1,6 +1,7 @@
package overlay package overlay
import ( import (
"context"
"io/ioutil" "io/ioutil"
"os" "os"
"path/filepath" "path/filepath"
@ -25,6 +26,7 @@ func TestOverlay(t *testing.T) {
} }
func TestOverlayMounts(t *testing.T) { func TestOverlayMounts(t *testing.T) {
ctx := context.TODO()
root, err := ioutil.TempDir("", "overlay") root, err := ioutil.TempDir("", "overlay")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
@ -35,7 +37,7 @@ func TestOverlayMounts(t *testing.T) {
t.Error(err) t.Error(err)
return return
} }
mounts, err := o.Prepare("/tmp/test", "") mounts, err := o.Prepare(ctx, "/tmp/test", "")
if err != nil { if err != nil {
t.Error(err) t.Error(err)
return return
@ -60,6 +62,7 @@ func TestOverlayMounts(t *testing.T) {
} }
func TestOverlayCommit(t *testing.T) { func TestOverlayCommit(t *testing.T) {
ctx := context.TODO()
root, err := ioutil.TempDir("", "overlay") root, err := ioutil.TempDir("", "overlay")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
@ -71,7 +74,7 @@ func TestOverlayCommit(t *testing.T) {
return return
} }
key := "/tmp/test" key := "/tmp/test"
mounts, err := o.Prepare(key, "") mounts, err := o.Prepare(ctx, key, "")
if err != nil { if err != nil {
t.Error(err) t.Error(err)
return return
@ -81,13 +84,14 @@ func TestOverlayCommit(t *testing.T) {
t.Error(err) t.Error(err)
return return
} }
if err := o.Commit("base", key); err != nil { if err := o.Commit(ctx, "base", key); err != nil {
t.Error(err) t.Error(err)
return return
} }
} }
func TestOverlayOverlayMount(t *testing.T) { func TestOverlayOverlayMount(t *testing.T) {
ctx := context.TODO()
root, err := ioutil.TempDir("", "overlay") root, err := ioutil.TempDir("", "overlay")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
@ -99,16 +103,16 @@ func TestOverlayOverlayMount(t *testing.T) {
return return
} }
key := "/tmp/test" key := "/tmp/test"
mounts, err := o.Prepare(key, "") mounts, err := o.Prepare(ctx, key, "")
if err != nil { if err != nil {
t.Error(err) t.Error(err)
return return
} }
if err := o.Commit("base", key); err != nil { if err := o.Commit(ctx, "base", key); err != nil {
t.Error(err) t.Error(err)
return return
} }
if mounts, err = o.Prepare("/tmp/layer2", "base"); err != nil { if mounts, err = o.Prepare(ctx, "/tmp/layer2", "base"); err != nil {
t.Error(err) t.Error(err)
return return
} }
@ -142,6 +146,7 @@ func TestOverlayOverlayMount(t *testing.T) {
func TestOverlayOverlayRead(t *testing.T) { func TestOverlayOverlayRead(t *testing.T) {
testutil.RequiresRoot(t) testutil.RequiresRoot(t)
ctx := context.TODO()
root, err := ioutil.TempDir("", "overlay") root, err := ioutil.TempDir("", "overlay")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
@ -153,7 +158,7 @@ func TestOverlayOverlayRead(t *testing.T) {
return return
} }
key := "/tmp/test" key := "/tmp/test"
mounts, err := o.Prepare(key, "") mounts, err := o.Prepare(ctx, key, "")
if err != nil { if err != nil {
t.Error(err) t.Error(err)
return return
@ -163,11 +168,11 @@ func TestOverlayOverlayRead(t *testing.T) {
t.Error(err) t.Error(err)
return return
} }
if err := o.Commit("base", key); err != nil { if err := o.Commit(ctx, "base", key); err != nil {
t.Error(err) t.Error(err)
return return
} }
if mounts, err = o.Prepare("/tmp/layer2", "base"); err != nil { if mounts, err = o.Prepare(ctx, "/tmp/layer2", "base"); err != nil {
t.Error(err) t.Error(err)
return return
} }

30
snapshot/snapshotter.go
View file

@ -1,6 +1,7 @@
package snapshot package snapshot
import ( import (
"context"
"io/ioutil" "io/ioutil"
"os" "os"
"path/filepath" "path/filepath"
@ -148,14 +149,14 @@ type Snapshotter interface {
// //
// Should be used for parent resolution, existence checks and to discern // Should be used for parent resolution, existence checks and to discern
// the kind of snapshot. // the kind of snapshot.
Stat(key string) (Info, error) Stat(ctx context.Context, key string) (Info, error)
// Mounts returns the mounts for the active snapshot transaction identified // Mounts returns the mounts for the active snapshot transaction identified
// by key. Can be called on an read-write or readonly transaction. This is // by key. Can be called on an read-write or readonly transaction. This is
// available only for active snapshots. // available only for active snapshots.
// //
// This can be used to recover mounts after calling View or Prepare. // This can be used to recover mounts after calling View or Prepare.
Mounts(key string) ([]containerd.Mount, error) Mounts(ctx context.Context, key string) ([]containerd.Mount, error)
// Prepare creates an active snapshot identified by key descending from the // Prepare creates an active snapshot identified by key descending from the
// provided parent. The returned mounts can be used to mount the snapshot // provided parent. The returned mounts can be used to mount the snapshot
@ -171,7 +172,7 @@ type Snapshotter interface {
// one is done with the transaction, Remove should be called on the key. // one is done with the transaction, Remove should be called on the key.
// //
// Multiple calls to Prepare or View with the same key should fail. // Multiple calls to Prepare or View with the same key should fail.
Prepare(key, parent string) ([]containerd.Mount, error) Prepare(ctx context.Context, key, parent string) ([]containerd.Mount, error)
// View behaves identically to Prepare except the result may not be // View behaves identically to Prepare except the result may not be
// committed back to the snapshot snapshotter. View returns a readonly view on // committed back to the snapshot snapshotter. View returns a readonly view on
@ -186,7 +187,7 @@ type Snapshotter interface {
// Commit may not be called on the provided key and will return an error. // Commit may not be called on the provided key and will return an error.
// To collect the resources associated with key, Remove must be called with // To collect the resources associated with key, Remove must be called with
// key as the argument. // key as the argument.
View(key, parent string) ([]containerd.Mount, error) View(ctx context.Context, key, parent string) ([]containerd.Mount, error)
// Commit captures the changes between key and its parent into a snapshot // Commit captures the changes between key and its parent into a snapshot
// identified by name. The name can then be used with the snapshotter's other // identified by name. The name can then be used with the snapshotter's other
@ -198,7 +199,7 @@ type Snapshotter interface {
// Commit may be called multiple times on the same key. Snapshots created // Commit may be called multiple times on the same key. Snapshots created
// in this manner will all reference the parent used to start the // in this manner will all reference the parent used to start the
// transaction. // transaction.
Commit(name, key string) error Commit(ctx context.Context, name, key string) error
// Remove the committed or active snapshot by the provided key. // Remove the committed or active snapshot by the provided key.
// //
@ -206,11 +207,11 @@ type Snapshotter interface {
// //
// If the snapshot is a parent of another snapshot, its children must be // If the snapshot is a parent of another snapshot, its children must be
// removed before proceeding. // removed before proceeding.
Remove(key string) error Remove(ctx context.Context, key string) error
// Walk the committed snapshots. For each snapshot in the snapshotter, the // Walk the committed snapshots. For each snapshot in the snapshotter, the
// function will be called. // function will be called.
Walk(fn func(Info) error) error Walk(ctx context.Context, fn func(context.Context, Info) error) error
} }
// SnapshotterSuite runs a test suite on the snapshotter given a factory function. // SnapshotterSuite runs a test suite on the snapshotter given a factory function.
@ -255,12 +256,13 @@ func makeTest(t *testing.T, name string, snapshotterFn func(root string) (Snapsh
// checkSnapshotterBasic tests the basic workflow of a snapshot snapshotter. // checkSnapshotterBasic tests the basic workflow of a snapshot snapshotter.
func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) { func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) {
ctx := context.TODO()
preparing := filepath.Join(work, "preparing") preparing := filepath.Join(work, "preparing")
if err := os.MkdirAll(preparing, 0777); err != nil { if err := os.MkdirAll(preparing, 0777); err != nil {
t.Fatal(err) t.Fatal(err)
} }
mounts, err := snapshotter.Prepare(preparing, "") mounts, err := snapshotter.Prepare(ctx, preparing, "")
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -283,11 +285,11 @@ func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) {
} }
committed := filepath.Join(work, "committed") committed := filepath.Join(work, "committed")
if err := snapshotter.Commit(committed, preparing); err != nil { if err := snapshotter.Commit(ctx, committed, preparing); err != nil {
t.Fatal(err) t.Fatal(err)
} }
si, err := snapshotter.Stat(committed) si, err := snapshotter.Stat(ctx, committed)
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -299,7 +301,7 @@ func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) {
t.Fatal(err) t.Fatal(err)
} }
mounts, err = snapshotter.Prepare(next, committed) mounts, err = snapshotter.Prepare(ctx, next, committed)
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -322,11 +324,11 @@ func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) {
} }
nextCommitted := filepath.Join(work, "committed-next") nextCommitted := filepath.Join(work, "committed-next")
if err := snapshotter.Commit(nextCommitted, next); err != nil { if err := snapshotter.Commit(ctx, nextCommitted, next); err != nil {
t.Fatal(err) t.Fatal(err)
} }
si2, err := snapshotter.Stat(nextCommitted) si2, err := snapshotter.Stat(ctx, nextCommitted)
if err != nil { if err != nil {
t.Fatal(err) t.Fatal(err)
} }
@ -338,7 +340,7 @@ func checkSnapshotterBasic(t *testing.T, snapshotter Snapshotter, work string) {
si2.Name: si2, si2.Name: si2,
} }
walked := map[string]Info{} // walk is not ordered walked := map[string]Info{} // walk is not ordered
assert.NoError(t, snapshotter.Walk(func(si Info) error { assert.NoError(t, snapshotter.Walk(ctx, func(ctx context.Context, si Info) error {
walked[si.Name] = si walked[si.Name] = si
return nil return nil
})) }))