Merge pull request #66 from tonistiigi/mounts-slice

worker: change mounts map to slice

client/llb/state.go

@@ -3,6 +3,7 @@ package llb
 import (
 	_ "crypto/sha256"
 
+	"github.com/moby/buildkit/solver/pb"
 	digest "github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 )
@@ -48,7 +49,7 @@ func (s *State) Run(opts ...RunOption) *ExecState {
 		meta:   meta,
 		mounts: []*mount{},
 		root: &mount{
-			dest:      "/",
+			dest:      pb.RootMount,
 			source:    s.source,
 			parent:    s.mount,
 			hasOutput: true,

control/control_standalone_test.go

@@ -111,20 +111,16 @@ func TestControl(t *testing.T) {
 		Cwd:  "/",
 	}
 
-	m := make(map[string]cache.Mountable)
-	m["/"] = snap
-
 	stderr := bytes.NewBuffer(nil)
 
-	err = w.Exec(ctx, meta, m, nil, &nopCloser{stderr})
+	err = w.Exec(ctx, meta, snap, nil, nil, &nopCloser{stderr})
 	assert.Error(t, err) // Read-only root
 	assert.Contains(t, stderr.String(), "Read-only file system")
 
 	root, err := cm.New(ctx, snap)
 	assert.NoError(t, err)
 
-	m["/"] = root
-	err = w.Exec(ctx, meta, m, nil, nil)
+	err = w.Exec(ctx, meta, root, nil, nil, nil)
 	assert.NoError(t, err)
 
 	rf, err := root.Freeze()

solver/exec.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"io"
 	"os"
+	"sort"
 
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/client"
@@ -45,9 +46,9 @@ func (e *execOp) CacheKey(ctx context.Context, inputs []string) (string, error)
 }
 
 func (e *execOp) Run(ctx context.Context, inputs []Reference) ([]Reference, error) {
-	mounts := make(map[string]cache.Mountable)
-
+	var mounts []worker.Mount
 	var outputs []cache.MutableRef
+	var root cache.Mountable
 
 	defer func() {
 		for _, o := range outputs {
@@ -84,9 +85,17 @@ func (e *execOp) Run(ctx context.Context, inputs []Reference) ([]Reference, erro
 			outputs = append(outputs, active)
 			mountable = active
 		}
-		mounts[m.Dest] = mountable
+		if m.Dest == pb.RootMount {
+			root = mountable
+		} else {
+			mounts = append(mounts, worker.Mount{Src: mountable, Dest: m.Dest})
+		}
 	}
 
+	sort.Slice(mounts, func(i, j int) bool {
+		return mounts[i].Dest < mounts[j].Dest
+	})
+
 	meta := worker.Meta{
 		Args: e.op.Meta.Args,
 		Env:  e.op.Meta.Env,
@@ -98,7 +107,7 @@ func (e *execOp) Run(ctx context.Context, inputs []Reference) ([]Reference, erro
 	stderr := newStreamWriter(ctx, 2)
 	defer stderr.Close()
 
-	if err := e.w.Exec(ctx, meta, mounts, stdout, stderr); err != nil {
+	if err := e.w.Exec(ctx, meta, root, mounts, stdout, stderr); err != nil {
 		return nil, errors.Wrapf(err, "worker failed running %v", meta.Args)
 	}
 

solver/pb/const.go

@@ -0,0 +1,3 @@
+package pb
+
+const RootMount = "/"

worker/oci/spec_unix.go

@@ -4,7 +4,6 @@ import (
 	"context"
 
 	"github.com/containerd/containerd"
-	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/worker"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
@@ -12,7 +11,7 @@ import (
 
 // Ideally we don't have to import whole containerd just for the default spec
 
-func GenerateSpec(ctx context.Context, meta worker.Meta, mounts map[string]cache.Mountable) (*specs.Spec, error) {
+func GenerateSpec(ctx context.Context, meta worker.Meta, mounts []worker.Mount) (*specs.Spec, error) {
 	s, err := containerd.GenerateSpec(containerd.WithHostNamespace(specs.NetworkNamespace))
 	if err != nil {
 		return nil, err
@@ -22,17 +21,14 @@ func GenerateSpec(ctx context.Context, meta worker.Meta, mounts map[string]cache
 	s.Process.Cwd = meta.Cwd
 	// TODO: User
 
-	for dest, m := range mounts {
-		if dest == "/" {
-			continue
-		}
-		mounts, err := m.Mount(ctx)
+	for _, m := range mounts {
+		mounts, err := m.Src.Mount(ctx)
 		if err != nil {
-			return nil, errors.Wrapf(err, "failed to mount to %s", dest)
+			return nil, errors.Wrapf(err, "failed to mount %s", m.Dest)
 		}
 		for _, mount := range mounts {
 			s.Mounts = append(s.Mounts, specs.Mount{
-				Destination: dest,
+				Destination: m.Dest,
 				Type:        mount.Type,
 				Source:      mount.Source,
 				Options:     mount.Options,

worker/runcworker/worker.go

@@ -54,12 +54,7 @@ func New(root string) (worker.Worker, error) {
 	return w, nil
 }
 
-func (w *runcworker) Exec(ctx context.Context, meta worker.Meta, mounts map[string]cache.Mountable, stdout, stderr io.WriteCloser) error {
-	root, ok := mounts["/"]
-	if !ok {
-		return errors.Errorf("no root mount")
-	}
-
+func (w *runcworker) Exec(ctx context.Context, meta worker.Meta, root cache.Mountable, mounts []worker.Mount, stdout, stderr io.WriteCloser) error {
 	rootMount, err := root.Mount(ctx)
 	if err != nil {
 		return err

worker/worker.go

@@ -16,7 +16,13 @@ type Meta struct {
 	// DisableNetworking bool
 }
 
+type Mount struct {
+	Src      cache.Mountable
+	Dest     string
+	ReadOnly bool
+}
+
 type Worker interface {
 	// TODO: add stdout/err
-	Exec(ctx context.Context, meta Meta, mounts map[string]cache.Mountable, stdout, stderr io.WriteCloser) error
+	Exec(ctx context.Context, meta Meta, rootfs cache.Mountable, mounts []Mount, stdout, stderr io.WriteCloser) error
 }