client: take a context.Context to New().

This allows two things:

- The caller to set a shorter timeout than previously hardcoded 30s. In
  `buildctl` reduce the timeout to 5s. Since the existing timeout has gone
  callers will need to arrange to pass one themselves.
- The caller can arrange for the context to be cancelled for other reasons, use
  this in `buildctl` to plumb through the Ctrl-C handling, meaning that
  `buildctl` now exits almost immediately on Ctrl-C instead of after several
  seconds.

Signed-off-by: Ian Campbell <ijc@docker.com>

client/client.go

@@ -5,7 +5,6 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"io/ioutil"
-	"time"
 
 	"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
 	controlapi "github.com/moby/buildkit/api/services/control"
@@ -23,7 +22,7 @@ type Client struct {
 type ClientOpt interface{}
 
 // New returns a new buildkit client. Address can be empty for the system-default address.
-func New(address string, opts ...ClientOpt) (*Client, error) {
+func New(ctx context.Context, address string, opts ...ClientOpt) (*Client, error) {
 	gopts := []grpc.DialOption{
 		grpc.WithDialer(dialer),
 		grpc.FailOnNonTempDialError(true),
@@ -54,9 +53,6 @@ func New(address string, opts ...ClientOpt) (*Client, error) {
 		address = appdefaults.Address
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-	defer cancel()
-
 	conn, err := grpc.DialContext(ctx, address, gopts...)
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to dial %q . make sure buildkitd is running", address)

client/client_test.go

@@ -59,7 +59,7 @@ func TestClientIntegration(t *testing.T) {
 func testTmpfsMounts(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 	requiresLinux(t)
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -76,7 +76,7 @@ func testTmpfsMounts(t *testing.T, sb integration.Sandbox) {
 func testLocalSymlinkEscape(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 	requiresLinux(t)
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -134,7 +134,7 @@ func testLocalSymlinkEscape(t *testing.T, sb integration.Sandbox) {
 func testRelativeWorkDir(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 	requiresLinux(t)
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -164,7 +164,7 @@ func testRelativeWorkDir(t *testing.T, sb integration.Sandbox) {
 
 func testCallDiskUsage(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 	_, err = c.DiskUsage(context.TODO())
@@ -174,7 +174,7 @@ func testCallDiskUsage(t *testing.T, sb integration.Sandbox) {
 func testBuildMultiMount(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 	requiresLinux(t)
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -196,7 +196,7 @@ func testBuildMultiMount(t *testing.T, sb integration.Sandbox) {
 func testBuildHTTPSource(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -284,7 +284,7 @@ func testBuildHTTPSource(t *testing.T, sb integration.Sandbox) {
 func testResolveAndHosts(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -324,7 +324,7 @@ func testResolveAndHosts(t *testing.T, sb integration.Sandbox) {
 func testUser(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -377,7 +377,7 @@ func testUser(t *testing.T, sb integration.Sandbox) {
 func testOCIExporter(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -476,7 +476,7 @@ func testOCIExporter(t *testing.T, sb integration.Sandbox) {
 func testBuildPushAndValidate(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -673,7 +673,7 @@ func testBasicCacheImportExport(t *testing.T, sb integration.Sandbox) {
 	}
 	require.NoError(t, err)
 
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -738,7 +738,7 @@ func testBasicCacheImportExport(t *testing.T, sb integration.Sandbox) {
 func testCachedMounts(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -801,7 +801,7 @@ func testCachedMounts(t *testing.T, sb integration.Sandbox) {
 func testDuplicateWhiteouts(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -869,7 +869,7 @@ func testDuplicateWhiteouts(t *testing.T, sb integration.Sandbox) {
 func testWhiteoutParentDir(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -931,7 +931,7 @@ func testWhiteoutParentDir(t *testing.T, sb integration.Sandbox) {
 // #296
 func testSchema1Image(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -949,7 +949,7 @@ func testSchema1Image(t *testing.T, sb integration.Sandbox) {
 // #319
 func testMountWithNoSource(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -979,7 +979,7 @@ func testMountWithNoSource(t *testing.T, sb integration.Sandbox) {
 // #324
 func testReadonlyRootFS(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1008,7 +1008,7 @@ func testReadonlyRootFS(t *testing.T, sb integration.Sandbox) {
 func testProxyEnv(t *testing.T, sb integration.Sandbox) {
 	t.Parallel()
 
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1208,7 +1208,7 @@ loop0:
 func testInvalidExporter(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	t.Parallel()
-	c, err := New(sb.Address())
+	c, err := New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 

cmd/buildctl/debug/workers.go

@@ -28,7 +28,7 @@ var WorkersCommand = cli.Command{
 }
 
 func resolveClient(c *cli.Context) (*client.Client, error) {
-	return client.New(c.GlobalString("addr"), client.WithBlock())
+	return client.New(commandContext(c), c.GlobalString("addr"), client.WithBlock())
 }
 
 func listWorkers(clicontext *cli.Context) error {

cmd/buildctl/main.go

@@ -1,9 +1,11 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"net/url"
 	"os"
+	"time"
 
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/util/appdefaults"
@@ -57,6 +59,11 @@ func main() {
 			Usage: "client key",
 			Value: "",
 		},
+		cli.IntFlag{
+			Name:  "timeout",
+			Usage: "timeout backend connection after value seconds",
+			Value: 5,
+		},
 	}
 
 	app.Commands = []cli.Command{
@@ -106,12 +113,19 @@ func resolveClient(c *cli.Context) (*client.Client, error) {
 
 	opts := []client.ClientOpt{client.WithBlock()}
 
-	if span := opentracing.SpanFromContext(commandContext(c)); span != nil {
+	ctx := commandContext(c)
+
+	if span := opentracing.SpanFromContext(ctx); span != nil {
 		opts = append(opts, client.WithTracer(span.Tracer()))
 	}
 
 	if caCert != "" || cert != "" || key != "" {
 		opts = append(opts, client.WithCredentials(serverName, caCert, cert, key))
 	}
-	return client.New(c.GlobalString("addr"), opts...)
+
+	timeout := time.Duration(c.GlobalInt("timeout"))
+	ctx, cancel := context.WithTimeout(ctx, timeout*time.Second)
+	defer cancel()
+
+	return client.New(ctx, c.GlobalString("addr"), opts...)
 }

examples/build-using-dockerfile/main.go

@@ -66,10 +66,12 @@ By default, the built image is loaded to Docker.
 }
 
 func action(clicontext *cli.Context) error {
+	ctx := appcontext.Context()
+
 	if tag := clicontext.String("tag"); tag == "" {
 		return errors.New("tag is not specified")
 	}
-	c, err := client.New(clicontext.String("buildkit-addr"), client.WithBlock())
+	c, err := client.New(ctx, clicontext.String("buildkit-addr"), client.WithBlock())
 	if err != nil {
 		return err
 	}
@@ -79,7 +81,7 @@ func action(clicontext *cli.Context) error {
 		return err
 	}
 	ch := make(chan *client.SolveStatus)
-	eg, ctx := errgroup.WithContext(appcontext.Context())
+	eg, ctx := errgroup.WithContext(ctx)
 	eg.Go(func() error {
 		_, err := c.Solve(ctx, nil, *solveOpt, ch)
 		return err

frontend/dockerfile/dockerfile_test.go

@@ -93,7 +93,7 @@ COPY sub/l* alllinks/
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -138,7 +138,7 @@ COPY --from=0 /foo /foo
 	require.NoError(t, err)
 	defer os.RemoveAll(destDir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -182,7 +182,7 @@ CMD ["test"]
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -272,7 +272,7 @@ LABEL foo=bar
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -384,7 +384,7 @@ FROM busybox:${tag}
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -872,7 +872,7 @@ EXPOSE 5000
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -958,7 +958,7 @@ Dockerfile
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1017,12 +1017,13 @@ COPY . .
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	c, err := client.New(ctx, sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
-	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
-	defer cancel()
 	_, err = c.Solve(ctx, nil, client.SolveOpt{
 		Frontend: "dockerfile.v0",
 		LocalDirs: map[string]string{
@@ -1133,7 +1134,7 @@ USER nobody
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1229,7 +1230,7 @@ COPY --from=base /out /
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1281,7 +1282,7 @@ COPY files dest
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1326,7 +1327,7 @@ COPY $FOO baz
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1378,7 +1379,7 @@ COPY sub/dir1 subdest6
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1486,7 +1487,7 @@ COPY --from=build foo bar2
 	require.NoError(t, err)
 	defer os.RemoveAll(destDir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1572,7 +1573,7 @@ COPY foo bar
 	require.NoError(t, err)
 	defer os.RemoveAll(destDir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1606,7 +1607,7 @@ COPY --from=busybox /etc/passwd test
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1683,7 +1684,7 @@ COPY --from=stage1 baz bax
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1723,7 +1724,7 @@ LABEL foo=bar
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1811,7 +1812,7 @@ COPY --from=base unique /
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1892,7 +1893,7 @@ RUN echo bar > bar
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -1978,7 +1979,7 @@ RUN echo bar > bar
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -2054,7 +2055,7 @@ COPY --from=s1 unique2 /
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()
 
@@ -2140,7 +2141,7 @@ COPY --from=build /out /
 	require.NoError(t, err)
 	defer os.RemoveAll(dir)
 
-	c, err := client.New(sb.Address())
+	c, err := client.New(context.TODO(), sb.Address())
 	require.NoError(t, err)
 	defer c.Close()