1. docker
  2. Commit 79a4cbbec94ea72b7c7b44c775f59f02bff3f468
Browse code

builder-next: make stub executor generic

The current executor is only tested on Linux, so let's be honest about
that. Stubbing this correctly helps avoid incorrectly trying to call
into Linux-only code in e.g. libnetwork.

Signed-off-by: Bjorn Neergaard <bjorn.neergaard@docker.com>

Bjorn Neergaard authored on 2023/07/14 07:48:01
Showing 4 changed files
builder/builder-next/executor_linux.go
History View file @ 79a4cbb
1 1 
new file mode 100644
... ... 
@@ -0,0 +1,163 @@
0 
+package buildkit
1 
+
2 
+import (
3 
+	"context"
4 
+	"os"
5 
+	"path/filepath"
6 
+	"strconv"
7 
+	"sync"
8 
+
9 
+	"github.com/containerd/containerd/log"
10 
+	"github.com/docker/docker/daemon/config"
11 
+	"github.com/docker/docker/libnetwork"
12 
+	"github.com/docker/docker/pkg/idtools"
13 
+	"github.com/docker/docker/pkg/stringid"
14 
+	"github.com/moby/buildkit/executor"
15 
+	"github.com/moby/buildkit/executor/oci"
16 
+	"github.com/moby/buildkit/executor/runcexecutor"
17 
+	"github.com/moby/buildkit/identity"
18 
+	"github.com/moby/buildkit/solver/pb"
19 
+	"github.com/moby/buildkit/util/network"
20 
+	specs "github.com/opencontainers/runtime-spec/specs-go"
21 
+)
22 
+
23 
+const networkName = "bridge"
24 
+
25 
+func newExecutor(root, cgroupParent string, net *libnetwork.Controller, dnsConfig *oci.DNSConfig, rootless bool, idmap idtools.IdentityMapping, apparmorProfile string) (executor.Executor, error) {
26 
+	netRoot := filepath.Join(root, "net")
27 
+	networkProviders := map[pb.NetMode]network.Provider{
28 
+		pb.NetMode_UNSET: &bridgeProvider{Controller: net, Root: netRoot},
29 
+		pb.NetMode_HOST:  network.NewHostProvider(),
30 
+		pb.NetMode_NONE:  network.NewNoneProvider(),
31 
+	}
32 
+
33 
+	// make sure net state directory is cleared from previous state
34 
+	fis, err := os.ReadDir(netRoot)
35 
+	if err == nil {
36 
+		for _, fi := range fis {
37 
+			fp := filepath.Join(netRoot, fi.Name())
38 
+			if err := os.RemoveAll(fp); err != nil {
39 
+				log.G(context.TODO()).WithError(err).Errorf("failed to delete old network state: %v", fp)
40 
+			}
41 
+		}
42 
+	}
43 
+
44 
+	// Returning a non-nil but empty *IdentityMapping breaks BuildKit:
45 
+	// https://github.com/moby/moby/pull/39444
46 
+	pidmap := &idmap
47 
+	if idmap.Empty() {
48 
+		pidmap = nil
49 
+	}
50 
+
51 
+	return runcexecutor.New(runcexecutor.Opt{
52 
+		Root:                filepath.Join(root, "executor"),
53 
+		CommandCandidates:   []string{"runc"},
54 
+		DefaultCgroupParent: cgroupParent,
55 
+		Rootless:            rootless,
56 
+		NoPivot:             os.Getenv("DOCKER_RAMDISK") != "",
57 
+		IdentityMapping:     pidmap,
58 
+		DNS:                 dnsConfig,
59 
+		ApparmorProfile:     apparmorProfile,
60 
+	}, networkProviders)
61 
+}
62 
+
63 
+type bridgeProvider struct {
64 
+	*libnetwork.Controller
65 
+	Root string
66 
+}
67 
+
68 
+func (p *bridgeProvider) New(ctx context.Context, hostname string) (network.Namespace, error) {
69 
+	n, err := p.NetworkByName(networkName)
70 
+	if err != nil {
71 
+		return nil, err
72 
+	}
73 
+
74 
+	iface := &lnInterface{ready: make(chan struct{}), provider: p}
75 
+	iface.Once.Do(func() {
76 
+		go iface.init(p.Controller, n)
77 
+	})
78 
+
79 
+	return iface, nil
80 
+}
81 
+
82 
+func (p *bridgeProvider) Close() error {
83 
+	return nil
84 
+}
85 
+
86 
+type lnInterface struct {
87 
+	ep  *libnetwork.Endpoint
88 
+	sbx *libnetwork.Sandbox
89 
+	sync.Once
90 
+	err      error
91 
+	ready    chan struct{}
92 
+	provider *bridgeProvider
93 
+}
94 
+
95 
+func (iface *lnInterface) init(c *libnetwork.Controller, n *libnetwork.Network) {
96 
+	defer close(iface.ready)
97 
+	id := identity.NewID()
98 
+
99 
+	ep, err := n.CreateEndpoint(id, libnetwork.CreateOptionDisableResolution())
100 
+	if err != nil {
101 
+		iface.err = err
102 
+		return
103 
+	}
104 
+
105 
+	sbx, err := c.NewSandbox(id, libnetwork.OptionUseExternalKey(), libnetwork.OptionHostsPath(filepath.Join(iface.provider.Root, id, "hosts")),
106 
+		libnetwork.OptionResolvConfPath(filepath.Join(iface.provider.Root, id, "resolv.conf")))
107 
+	if err != nil {
108 
+		iface.err = err
109 
+		return
110 
+	}
111 
+
112 
+	if err := ep.Join(sbx); err != nil {
113 
+		iface.err = err
114 
+		return
115 
+	}
116 
+
117 
+	iface.sbx = sbx
118 
+	iface.ep = ep
119 
+}
120 
+
121 
+func (iface *lnInterface) Set(s *specs.Spec) error {
122 
+	<-iface.ready
123 
+	if iface.err != nil {
124 
+		log.G(context.TODO()).WithError(iface.err).Error("failed to set networking spec")
125 
+		return iface.err
126 
+	}
127 
+	shortNetCtlrID := stringid.TruncateID(iface.provider.Controller.ID())
128 
+	// attach netns to bridge within the container namespace, using reexec in a prestart hook
129 
+	s.Hooks = &specs.Hooks{
130 
+		Prestart: []specs.Hook{{
131 
+			Path: filepath.Join("/proc", strconv.Itoa(os.Getpid()), "exe"),
132 
+			Args: []string{"libnetwork-setkey", "-exec-root=" + iface.provider.Config().ExecRoot, iface.sbx.ContainerID(), shortNetCtlrID},
133 
+		}},
134 
+	}
135 
+	return nil
136 
+}
137 
+
138 
+func (iface *lnInterface) Close() error {
139 
+	<-iface.ready
140 
+	if iface.sbx != nil {
141 
+		go func() {
142 
+			if err := iface.sbx.Delete(); err != nil {
143 
+				log.G(context.TODO()).WithError(err).Errorf("failed to delete builder network sandbox")
144 
+			}
145 
+			if err := os.RemoveAll(filepath.Join(iface.provider.Root, iface.sbx.ContainerID())); err != nil {
146 
+				log.G(context.TODO()).WithError(err).Errorf("failed to delete builder sandbox directory")
147 
+			}
148 
+		}()
149 
+	}
150 
+	return iface.err
151 
+}
152 
+
153 
+func getDNSConfig(cfg config.DNSConfig) *oci.DNSConfig {
154 
+	if cfg.DNS != nil || cfg.DNSSearch != nil || cfg.DNSOptions != nil {
155 
+		return &oci.DNSConfig{
156 
+			Nameservers:   cfg.DNS,
157 
+			SearchDomains: cfg.DNSSearch,
158 
+			Options:       cfg.DNSOptions,
159 
+		}
160 
+	}
161 
+	return nil
162 
+}
builder/builder-next/executor_nolinux.go
History View file @ 79a4cbb
0 163 
new file mode 100644
... ... 
@@ -0,0 +1,33 @@
0 
+//go:build !linux
1 
+
2 
+package buildkit
3 
+
4 
+import (
5 
+	"context"
6 
+	"errors"
7 
+	"runtime"
8 
+
9 
+	"github.com/docker/docker/daemon/config"
10 
+	"github.com/docker/docker/libnetwork"
11 
+	"github.com/docker/docker/pkg/idtools"
12 
+	"github.com/moby/buildkit/executor"
13 
+	"github.com/moby/buildkit/executor/oci"
14 
+)
15 
+
16 
+func newExecutor(_, _ string, _ *libnetwork.Controller, _ *oci.DNSConfig, _ bool, _ idtools.IdentityMapping, _ string) (executor.Executor, error) {
17 
+	return &stubExecutor{}, nil
18 
+}
19 
+
20 
+type stubExecutor struct{}
21 
+
22 
+func (w *stubExecutor) Run(ctx context.Context, id string, root executor.Mount, mounts []executor.Mount, process executor.ProcessInfo, started chan<- struct{}) (err error) {
23 
+	return errors.New("buildkit executor not implemented for "+runtime.GOOS)
24 
+}
25 
+
26 
+func (w *stubExecutor) Exec(ctx context.Context, id string, process executor.ProcessInfo) error {
27 
+	return errors.New("buildkit executor not implemented for "+runtime.GOOS)
28 
+}
29 
+
30 
+func getDNSConfig(config.DNSConfig) *oci.DNSConfig {
31 
+	return nil
32 
+}
builder/builder-next/executor_unix.go
History View file @ 79a4cbb
0 33 
deleted file mode 100644
... ... 
@@ -1,165 +0,0 @@
1 
-//go:build !windows
2 
-
3 
-package buildkit
4 
-
5 
-import (
6 
-	"context"
7 
-	"os"
8 
-	"path/filepath"
9 
-	"strconv"
10 
-	"sync"
11 
-
12 
-	"github.com/containerd/containerd/log"
13 
-	"github.com/docker/docker/daemon/config"
14 
-	"github.com/docker/docker/libnetwork"
15 
-	"github.com/docker/docker/pkg/idtools"
16 
-	"github.com/docker/docker/pkg/stringid"
17 
-	"github.com/moby/buildkit/executor"
18 
-	"github.com/moby/buildkit/executor/oci"
19 
-	"github.com/moby/buildkit/executor/runcexecutor"
20 
-	"github.com/moby/buildkit/identity"
21 
-	"github.com/moby/buildkit/solver/pb"
22 
-	"github.com/moby/buildkit/util/network"
23 
-	specs "github.com/opencontainers/runtime-spec/specs-go"
24 
-)
25 
-
26 
-const networkName = "bridge"
27 
-
28 
-func newExecutor(root, cgroupParent string, net *libnetwork.Controller, dnsConfig *oci.DNSConfig, rootless bool, idmap idtools.IdentityMapping, apparmorProfile string) (executor.Executor, error) {
29 
-	netRoot := filepath.Join(root, "net")
30 
-	networkProviders := map[pb.NetMode]network.Provider{
31 
-		pb.NetMode_UNSET: &bridgeProvider{Controller: net, Root: netRoot},
32 
-		pb.NetMode_HOST:  network.NewHostProvider(),
33 
-		pb.NetMode_NONE:  network.NewNoneProvider(),
34 
-	}
35 
-
36 
-	// make sure net state directory is cleared from previous state
37 
-	fis, err := os.ReadDir(netRoot)
38 
-	if err == nil {
39 
-		for _, fi := range fis {
40 
-			fp := filepath.Join(netRoot, fi.Name())
41 
-			if err := os.RemoveAll(fp); err != nil {
42 
-				log.G(context.TODO()).WithError(err).Errorf("failed to delete old network state: %v", fp)
43 
-			}
44 
-		}
45 
-	}
46 
-
47 
-	// Returning a non-nil but empty *IdentityMapping breaks BuildKit:
48 
-	// https://github.com/moby/moby/pull/39444
49 
-	pidmap := &idmap
50 
-	if idmap.Empty() {
51 
-		pidmap = nil
52 
-	}
53 
-
54 
-	return runcexecutor.New(runcexecutor.Opt{
55 
-		Root:                filepath.Join(root, "executor"),
56 
-		CommandCandidates:   []string{"runc"},
57 
-		DefaultCgroupParent: cgroupParent,
58 
-		Rootless:            rootless,
59 
-		NoPivot:             os.Getenv("DOCKER_RAMDISK") != "",
60 
-		IdentityMapping:     pidmap,
61 
-		DNS:                 dnsConfig,
62 
-		ApparmorProfile:     apparmorProfile,
63 
-	}, networkProviders)
64 
-}
65 
-
66 
-type bridgeProvider struct {
67 
-	*libnetwork.Controller
68 
-	Root string
69 
-}
70 
-
71 
-func (p *bridgeProvider) New(ctx context.Context, hostname string) (network.Namespace, error) {
72 
-	n, err := p.NetworkByName(networkName)
73 
-	if err != nil {
74 
-		return nil, err
75 
-	}
76 
-
77 
-	iface := &lnInterface{ready: make(chan struct{}), provider: p}
78 
-	iface.Once.Do(func() {
79 
-		go iface.init(p.Controller, n)
80 
-	})
81 
-
82 
-	return iface, nil
83 
-}
84 
-
85 
-func (p *bridgeProvider) Close() error {
86 
-	return nil
87 
-}
88 
-
89 
-type lnInterface struct {
90 
-	ep  *libnetwork.Endpoint
91 
-	sbx *libnetwork.Sandbox
92 
-	sync.Once
93 
-	err      error
94 
-	ready    chan struct{}
95 
-	provider *bridgeProvider
96 
-}
97 
-
98 
-func (iface *lnInterface) init(c *libnetwork.Controller, n *libnetwork.Network) {
99 
-	defer close(iface.ready)
100 
-	id := identity.NewID()
101 
-
102 
-	ep, err := n.CreateEndpoint(id, libnetwork.CreateOptionDisableResolution())
103 
-	if err != nil {
104 
-		iface.err = err
105 
-		return
106 
-	}
107 
-
108 
-	sbx, err := c.NewSandbox(id, libnetwork.OptionUseExternalKey(), libnetwork.OptionHostsPath(filepath.Join(iface.provider.Root, id, "hosts")),
109 
-		libnetwork.OptionResolvConfPath(filepath.Join(iface.provider.Root, id, "resolv.conf")))
110 
-	if err != nil {
111 
-		iface.err = err
112 
-		return
113 
-	}
114 
-
115 
-	if err := ep.Join(sbx); err != nil {
116 
-		iface.err = err
117 
-		return
118 
-	}
119 
-
120 
-	iface.sbx = sbx
121 
-	iface.ep = ep
122 
-}
123 
-
124 
-func (iface *lnInterface) Set(s *specs.Spec) error {
125 
-	<-iface.ready
126 
-	if iface.err != nil {
127 
-		log.G(context.TODO()).WithError(iface.err).Error("failed to set networking spec")
128 
-		return iface.err
129 
-	}
130 
-	shortNetCtlrID := stringid.TruncateID(iface.provider.Controller.ID())
131 
-	// attach netns to bridge within the container namespace, using reexec in a prestart hook
132 
-	s.Hooks = &specs.Hooks{
133 
-		Prestart: []specs.Hook{{
134 
-			Path: filepath.Join("/proc", strconv.Itoa(os.Getpid()), "exe"),
135 
-			Args: []string{"libnetwork-setkey", "-exec-root=" + iface.provider.Config().ExecRoot, iface.sbx.ContainerID(), shortNetCtlrID},
136 
-		}},
137 
-	}
138 
-	return nil
139 
-}
140 
-
141 
-func (iface *lnInterface) Close() error {
142 
-	<-iface.ready
143 
-	if iface.sbx != nil {
144 
-		go func() {
145 
-			if err := iface.sbx.Delete(); err != nil {
146 
-				log.G(context.TODO()).WithError(err).Errorf("failed to delete builder network sandbox")
147 
-			}
148 
-			if err := os.RemoveAll(filepath.Join(iface.provider.Root, iface.sbx.ContainerID())); err != nil {
149 
-				log.G(context.TODO()).WithError(err).Errorf("failed to delete builder sandbox directory")
150 
-			}
151 
-		}()
152 
-	}
153 
-	return iface.err
154 
-}
155 
-
156 
-func getDNSConfig(cfg config.DNSConfig) *oci.DNSConfig {
157 
-	if cfg.DNS != nil || cfg.DNSSearch != nil || cfg.DNSOptions != nil {
158 
-		return &oci.DNSConfig{
159 
-			Nameservers:   cfg.DNS,
160 
-			SearchDomains: cfg.DNSSearch,
161 
-			Options:       cfg.DNSOptions,
162 
-		}
163 
-	}
164 
-	return nil
165 
-}
builder/builder-next/executor_windows.go
History View file @ 79a4cbb
166 1 
deleted file mode 100644
... ... 
@@ -1,30 +0,0 @@
1 
-package buildkit
2 
-
3 
-import (
4 
-	"context"
5 
-	"errors"
6 
-
7 
-	"github.com/docker/docker/daemon/config"
8 
-	"github.com/docker/docker/libnetwork"
9 
-	"github.com/docker/docker/pkg/idtools"
10 
-	"github.com/moby/buildkit/executor"
11 
-	"github.com/moby/buildkit/executor/oci"
12 
-)
13 
-
14 
-func newExecutor(_, _ string, _ *libnetwork.Controller, _ *oci.DNSConfig, _ bool, _ idtools.IdentityMapping, _ string) (executor.Executor, error) {
15 
-	return &winExecutor{}, nil
16 
-}
17 
-
18 
-type winExecutor struct{}
19 
-
20 
-func (w *winExecutor) Run(ctx context.Context, id string, root executor.Mount, mounts []executor.Mount, process executor.ProcessInfo, started chan<- struct{}) (err error) {
21 
-	return errors.New("buildkit executor not implemented for windows")
22 
-}
23 
-
24 
-func (w *winExecutor) Exec(ctx context.Context, id string, process executor.ProcessInfo) error {
25 
-	return errors.New("buildkit executor not implemented for windows")
26 
-}
27 
-
28 
-func getDNSConfig(config.DNSConfig) *oci.DNSConfig {
29 
-	return nil
30 
-}