Support for nerdctl build on Windows

cmd/nerdctl/builder.go

@@ -24,7 +24,6 @@ import (
 
 	"github.com/containerd/log"
 	"github.com/containerd/nerdctl/v2/pkg/buildkitutil"
-	"github.com/containerd/nerdctl/v2/pkg/defaults"
 	"github.com/spf13/cobra"
 )
 
@@ -56,7 +55,7 @@ func newBuilderPruneCommand() *cobra.Command {
 		SilenceErrors: true,
 	}
 
-	AddStringFlag(buildPruneCommand, "buildkit-host", nil, defaults.BuildKitHost(), "BUILDKIT_HOST", "BuildKit address")
+	AddStringFlag(buildPruneCommand, "buildkit-host", nil, "", "BUILDKIT_HOST", "BuildKit address")
 	return buildPruneCommand
 }
 

cmd/nerdctl/builder_build.go

@@ -27,7 +27,6 @@ import (
 	"github.com/containerd/nerdctl/v2/pkg/buildkitutil"
 	"github.com/containerd/nerdctl/v2/pkg/clientutil"
 	"github.com/containerd/nerdctl/v2/pkg/cmd/builder"
-	"github.com/containerd/nerdctl/v2/pkg/defaults"
 	"github.com/containerd/nerdctl/v2/pkg/strutil"
 
 	"github.com/spf13/cobra"
@@ -43,7 +42,7 @@ If Dockerfile is not present and -f is not specified, it will look for Container
 		SilenceUsage:  true,
 		SilenceErrors: true,
 	}
-	AddStringFlag(buildCommand, "buildkit-host", nil, defaults.BuildKitHost(), "BUILDKIT_HOST", "BuildKit address")
+	AddStringFlag(buildCommand, "buildkit-host", nil, "", "BUILDKIT_HOST", "BuildKit address")
 	buildCommand.Flags().StringArrayP("tag", "t", nil, "Name and optionally a tag in the 'name:tag' format")
 	buildCommand.Flags().StringP("file", "f", "", "Name of the Dockerfile")
 	buildCommand.Flags().String("target", "", "Set the target build stage to build")

cmd/nerdctl/container_top_unix_test.go

@@ -1,4 +1,4 @@
-//go:build linux || darwin || freebsd || netbsd || openbsd
+//go:build unix
 
 /*
    Copyright The containerd Authors.

cmd/nerdctl/main_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

cmd/nerdctl/network_create_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/buildkitutil/buildkitutil.go

@@ -34,6 +34,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strings"
 
 	"github.com/containerd/log"
 	"github.com/containerd/nerdctl/v2/pkg/rootlessutil"
@@ -56,28 +57,14 @@ func BuildctlBaseArgs(buildkitHost string) []string {
 }
 
 func GetBuildkitHost(namespace string) (string, error) {
-	if namespace == "" {
-		return "", fmt.Errorf("namespace must be specified")
-	}
-	// Try candidate locations of the current containerd namespace.
-	run := "/run/"
-	if rootlessutil.IsRootless() {
-		var err error
-		run, err = rootlessutil.XDGRuntimeDir()
-		if err != nil {
-			log.L.Warn(err)
-			run = fmt.Sprintf("/run/user/%d", rootlessutil.ParentEUID())
-		}
-	}
-	var hostRel []string
-	if namespace != "default" {
-		hostRel = append(hostRel, fmt.Sprintf("buildkit-%s/buildkitd.sock", namespace))
+	paths, err := getBuildkitHostCandidates(namespace)
+	if err != nil {
+		return "", err
 	}
-	hostRel = append(hostRel, "buildkit-default/buildkitd.sock", "buildkit/buildkitd.sock")
+
 	var errs []error //nolint:prealloc
-	for _, p := range hostRel {
-		log.L.Debugf("Choosing the buildkit host %q, candidates=%v (in %q)", p, hostRel, run)
-		buildkitHost := "unix://" + filepath.Join(run, p)
+	for _, buildkitHost := range paths {
+		log.L.Debugf("Choosing the buildkit host %q, candidates=%v", buildkitHost, paths)
 		_, err := pingBKDaemon(buildkitHost)
 		if err == nil {
 			log.L.Debugf("Chosen buildkit host %q", buildkitHost)
@@ -87,7 +74,7 @@ func GetBuildkitHost(namespace string) (string, error) {
 	}
 	allErr := errors.Join(errs...)
 	log.L.WithError(allErr).Error(getHint())
-	return "", fmt.Errorf("no buildkit host is available, tried %d candidates: %w", len(hostRel), allErr)
+	return "", fmt.Errorf("no buildkit host is available, tried %d candidates: %w", len(paths), allErr)
 }
 
 func GetWorkerLabels(buildkitHost string) (labels map[string]string, _ error) {
@@ -143,9 +130,21 @@ func PingBKDaemon(buildkitHost string) error {
 	return nil
 }
 
+// contains open-codes slices.Contains (without generics) from Go 1.21.
+// TODO: Replace once Go 1.21 is the minimum supported compiler.
+func contains(haystack []string, needle string) bool {
+	for i := range haystack {
+		if needle == haystack[i] {
+			return true
+		}
+	}
+	return false
+}
+
 func pingBKDaemon(buildkitHost string) (output string, _ error) {
-	if runtime.GOOS != "linux" && runtime.GOOS != "freebsd" {
-		return "", errors.New("only linux and freebsd are supported")
+	supportedOses := []string{"linux", "freebsd", "windows"}
+	if !contains(supportedOses, runtime.GOOS) {
+		return "", fmt.Errorf("only %s are supported", strings.Join(supportedOses, ", "))
 	}
 	buildctlBinary, err := BuildctlBinary()
 	if err != nil {

pkg/buildkitutil/buildkitutil_freebsd.go

@@ -0,0 +1,22 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package buildkitutil
+
+func getRuntimeVariableDataDir() string {
+	// Per hier(7) dated July 6, 2023.
+	return "/var/run"
+}

pkg/buildkitutil/buildkitutil_linux.go

@@ -0,0 +1,39 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package buildkitutil
+
+import (
+	"fmt"
+
+	"github.com/containerd/log"
+	"github.com/containerd/nerdctl/v2/pkg/rootlessutil"
+)
+
+func getRuntimeVariableDataDir() string {
+	// Per Linux Foundation "Filesystem Hierarchy Standard" version 3.0 section 3.15.
+	// Under version 2.3, this was "/var/run".
+	run := "/run"
+	if rootlessutil.IsRootless() {
+		var err error
+		run, err = rootlessutil.XDGRuntimeDir()
+		if err != nil {
+			log.L.Warn(err)
+			run = fmt.Sprintf("/run/user/%d", rootlessutil.ParentEUID())
+		}
+	}
+	return run
+}

pkg/buildkitutil/buildkitutil_unix.go

@@ -0,0 +1,39 @@
+//go:build unix
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package buildkitutil
+
+import (
+	"fmt"
+	"path/filepath"
+)
+
+func getBuildkitHostCandidates(namespace string) ([]string, error) {
+	if namespace == "" {
+		return []string{}, fmt.Errorf("namespace must be specified")
+	}
+	// Try candidate locations of the current containerd namespace.
+	run := getRuntimeVariableDataDir()
+	var candidates []string
+	if namespace != "default" {
+		candidates = append(candidates, "unix://"+filepath.Join(run, fmt.Sprintf("buildkit-%s/buildkitd.sock", namespace)))
+	}
+	candidates = append(candidates, "unix://"+filepath.Join(run, "buildkit-default/buildkitd.sock"), "unix://"+filepath.Join(run, "buildkit/buildkitd.sock"))
+
+	return candidates, nil
+}

pkg/buildkitutil/buildkitutil_windows.go

@@ -0,0 +1,21 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package buildkitutil
+
+func getBuildkitHostCandidates(namespace string) ([]string, error) {
+	return []string{"npipe:////./pipe/buildkitd"}, nil
+}

pkg/cioutil/container_io_unix.go

@@ -1,4 +1,4 @@
-//go:build !windows
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/cioutil/container_io_windows.go

@@ -1,5 +1,3 @@
-//go:build windows
-
 /*
    Copyright The containerd Authors.
 

pkg/cmd/container/top_unix.go

@@ -1,4 +1,4 @@
-//go:build linux || darwin || freebsd || netbsd || openbsd
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/cmd/login/login_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/consoleutil/consoleutil_unix.go

@@ -1,4 +1,4 @@
-//go:build !windows
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/containerutil/container_network_manager_other.go

@@ -1,4 +1,4 @@
-//go:build darwin || freebsd || netbsd || openbsd
+//go:build !(linux || windows)
 
 /*
    Copyright The containerd Authors.

pkg/defaults/defaults_freebsd.go

@@ -43,10 +43,6 @@ func CNIRuntimeDir() string {
 	return "/run/cni"
 }
 
-func BuildKitHost() string {
-	return "unix:///run/buildkit/buildkitd.sock"
-}
-
 func CgroupManager() string {
 	return ""
 }

pkg/defaults/defaults_linux.go

@@ -99,18 +99,6 @@ func CNIRuntimeDir() string {
 	return fmt.Sprintf("%s/cni", xdr)
 }
 
-func BuildKitHost() string {
-	if !rootlessutil.IsRootless() {
-		return "unix:///run/buildkit/buildkitd.sock"
-	}
-	xdr, err := rootlessutil.XDGRuntimeDir()
-	if err != nil {
-		log.L.Warn(err)
-		xdr = fmt.Sprintf("/run/user/%d", rootlessutil.ParentEUID())
-	}
-	return fmt.Sprintf("unix://%s/buildkit/buildkitd.sock", xdr)
-}
-
 func NerdctlTOML() string {
 	if !rootlessutil.IsRootless() {
 		return "/etc/nerdctl/nerdctl.toml"

pkg/defaults/defaults_windows.go

@@ -17,7 +17,6 @@
 package defaults
 
 import (
-	"fmt"
 	"os"
 	"path/filepath"
 )
@@ -44,10 +43,6 @@ func CNIRuntimeDir() string {
 	return ""
 }
 
-func BuildKitHost() string {
-	return fmt.Sprint("\\\\.\\pipe\\buildkit")
-}
-
 func IsSystemdAvailable() bool {
 	return false
 }

pkg/infoutil/infoutil_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/infoutil/infoutil_unix_test.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/ipcutil/ipcutil_linux.go

@@ -1,5 +1,3 @@
-//go:build linux
-
 /*
    Copyright The containerd Authors.
 

pkg/ipcutil/ipcutil_unix.go → pkg/ipcutil/ipcutil_other.go

@@ -1,4 +1,4 @@
-//go:build freebsd
+//go:build !(linux || windows)
 
 /*
    Copyright The containerd Authors.

pkg/lockutil/lockutil_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/mountutil/mountutil_other.go → pkg/mountutil/mountutil_unix.go

@@ -1,4 +1,4 @@
-//go:build !windows
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/mountutil/mountutil_windows.go

@@ -1,5 +1,3 @@
-//go:build windows
-
 /*
    Copyright The containerd Authors.
 

pkg/netutil/cni_plugin_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.

pkg/netutil/netutil_linux_test.go

@@ -1,5 +1,3 @@
-//go:build linux
-
 /*
    Copyright The containerd Authors.
 

pkg/netutil/netutil_unix.go

@@ -1,4 +1,4 @@
-//go:build freebsd || linux
+//go:build unix
 
 /*
    Copyright The containerd Authors.