Port networking to CNI

Replaced netns utility with CNI plugins to create a bridge network
and allow communication between containers with firewall plugin.

Overwrite the CNI config in case it exists. Allow updating the config
on new versions.

Signed-off-by: Carlos de Paula <me@carlosedp.com>

vendor/github.com/containernetworking/cni/pkg/invoke/args.go

@@ -0,0 +1,128 @@
+// Copyright 2015 CNI 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 invoke
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+type CNIArgs interface {
+	// For use with os/exec; i.e., return nil to inherit the
+	// environment from this process
+	// For use in delegation; inherit the environment from this
+	// process and allow overrides
+	AsEnv() []string
+}
+
+type inherited struct{}
+
+var inheritArgsFromEnv inherited
+
+func (_ *inherited) AsEnv() []string {
+	return nil
+}
+
+func ArgsFromEnv() CNIArgs {
+	return &inheritArgsFromEnv
+}
+
+type Args struct {
+	Command       string
+	ContainerID   string
+	NetNS         string
+	PluginArgs    [][2]string
+	PluginArgsStr string
+	IfName        string
+	Path          string
+}
+
+// Args implements the CNIArgs interface
+var _ CNIArgs = &Args{}
+
+func (args *Args) AsEnv() []string {
+	env := os.Environ()
+	pluginArgsStr := args.PluginArgsStr
+	if pluginArgsStr == "" {
+		pluginArgsStr = stringify(args.PluginArgs)
+	}
+
+	// Duplicated values which come first will be overrided, so we must put the
+	// custom values in the end to avoid being overrided by the process environments.
+	env = append(env,
+		"CNI_COMMAND="+args.Command,
+		"CNI_CONTAINERID="+args.ContainerID,
+		"CNI_NETNS="+args.NetNS,
+		"CNI_ARGS="+pluginArgsStr,
+		"CNI_IFNAME="+args.IfName,
+		"CNI_PATH="+args.Path,
+	)
+	return dedupEnv(env)
+}
+
+// taken from rkt/networking/net_plugin.go
+func stringify(pluginArgs [][2]string) string {
+	entries := make([]string, len(pluginArgs))
+
+	for i, kv := range pluginArgs {
+		entries[i] = strings.Join(kv[:], "=")
+	}
+
+	return strings.Join(entries, ";")
+}
+
+// DelegateArgs implements the CNIArgs interface
+// used for delegation to inherit from environments
+// and allow some overrides like CNI_COMMAND
+var _ CNIArgs = &DelegateArgs{}
+
+type DelegateArgs struct {
+	Command string
+}
+
+func (d *DelegateArgs) AsEnv() []string {
+	env := os.Environ()
+
+	// The custom values should come in the end to override the existing
+	// process environment of the same key.
+	env = append(env,
+		"CNI_COMMAND="+d.Command,
+	)
+	return dedupEnv(env)
+}
+
+// dedupEnv returns a copy of env with any duplicates removed, in favor of later values.
+// Items not of the normal environment "key=value" form are preserved unchanged.
+func dedupEnv(env []string) []string {
+	out := make([]string, 0, len(env))
+	envMap := map[string]string{}
+
+	for _, kv := range env {
+		// find the first "=" in environment, if not, just keep it
+		eq := strings.Index(kv, "=")
+		if eq < 0 {
+			out = append(out, kv)
+			continue
+		}
+		envMap[kv[:eq]] = kv[eq+1:]
+	}
+
+	for k, v := range envMap {
+		out = append(out, fmt.Sprintf("%s=%s", k, v))
+	}
+
+	return out
+}

vendor/github.com/containernetworking/cni/pkg/invoke/delegate.go

@@ -0,0 +1,80 @@
+// Copyright 2016 CNI 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 invoke
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+
+	"github.com/containernetworking/cni/pkg/types"
+)
+
+func delegateCommon(delegatePlugin string, exec Exec) (string, Exec, error) {
+	if exec == nil {
+		exec = defaultExec
+	}
+
+	paths := filepath.SplitList(os.Getenv("CNI_PATH"))
+	pluginPath, err := exec.FindInPath(delegatePlugin, paths)
+	if err != nil {
+		return "", nil, err
+	}
+
+	return pluginPath, exec, nil
+}
+
+// DelegateAdd calls the given delegate plugin with the CNI ADD action and
+// JSON configuration
+func DelegateAdd(ctx context.Context, delegatePlugin string, netconf []byte, exec Exec) (types.Result, error) {
+	pluginPath, realExec, err := delegateCommon(delegatePlugin, exec)
+	if err != nil {
+		return nil, err
+	}
+
+	// DelegateAdd will override the original "CNI_COMMAND" env from process with ADD
+	return ExecPluginWithResult(ctx, pluginPath, netconf, delegateArgs("ADD"), realExec)
+}
+
+// DelegateCheck calls the given delegate plugin with the CNI CHECK action and
+// JSON configuration
+func DelegateCheck(ctx context.Context, delegatePlugin string, netconf []byte, exec Exec) error {
+	pluginPath, realExec, err := delegateCommon(delegatePlugin, exec)
+	if err != nil {
+		return err
+	}
+
+	// DelegateCheck will override the original CNI_COMMAND env from process with CHECK
+	return ExecPluginWithoutResult(ctx, pluginPath, netconf, delegateArgs("CHECK"), realExec)
+}
+
+// DelegateDel calls the given delegate plugin with the CNI DEL action and
+// JSON configuration
+func DelegateDel(ctx context.Context, delegatePlugin string, netconf []byte, exec Exec) error {
+	pluginPath, realExec, err := delegateCommon(delegatePlugin, exec)
+	if err != nil {
+		return err
+	}
+
+	// DelegateDel will override the original CNI_COMMAND env from process with DEL
+	return ExecPluginWithoutResult(ctx, pluginPath, netconf, delegateArgs("DEL"), realExec)
+}
+
+// return CNIArgs used by delegation
+func delegateArgs(action string) *DelegateArgs {
+	return &DelegateArgs{
+		Command: action,
+	}
+}

vendor/github.com/containernetworking/cni/pkg/invoke/exec.go

@@ -0,0 +1,144 @@
+// Copyright 2015 CNI 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 invoke
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/containernetworking/cni/pkg/types"
+	"github.com/containernetworking/cni/pkg/version"
+)
+
+// Exec is an interface encapsulates all operations that deal with finding
+// and executing a CNI plugin. Tests may provide a fake implementation
+// to avoid writing fake plugins to temporary directories during the test.
+type Exec interface {
+	ExecPlugin(ctx context.Context, pluginPath string, stdinData []byte, environ []string) ([]byte, error)
+	FindInPath(plugin string, paths []string) (string, error)
+	Decode(jsonBytes []byte) (version.PluginInfo, error)
+}
+
+// For example, a testcase could pass an instance of the following fakeExec
+// object to ExecPluginWithResult() to verify the incoming stdin and environment
+// and provide a tailored response:
+//
+//import (
+//	"encoding/json"
+//	"path"
+//	"strings"
+//)
+//
+//type fakeExec struct {
+//	version.PluginDecoder
+//}
+//
+//func (f *fakeExec) ExecPlugin(pluginPath string, stdinData []byte, environ []string) ([]byte, error) {
+//	net := &types.NetConf{}
+//	err := json.Unmarshal(stdinData, net)
+//	if err != nil {
+//		return nil, fmt.Errorf("failed to unmarshal configuration: %v", err)
+//	}
+//	pluginName := path.Base(pluginPath)
+//	if pluginName != net.Type {
+//		return nil, fmt.Errorf("plugin name %q did not match config type %q", pluginName, net.Type)
+//	}
+//	for _, e := range environ {
+//		// Check environment for forced failure request
+//		parts := strings.Split(e, "=")
+//		if len(parts) > 0 && parts[0] == "FAIL" {
+//			return nil, fmt.Errorf("failed to execute plugin %s", pluginName)
+//		}
+//	}
+//	return []byte("{\"CNIVersion\":\"0.4.0\"}"), nil
+//}
+//
+//func (f *fakeExec) FindInPath(plugin string, paths []string) (string, error) {
+//	if len(paths) > 0 {
+//		return path.Join(paths[0], plugin), nil
+//	}
+//	return "", fmt.Errorf("failed to find plugin %s in paths %v", plugin, paths)
+//}
+
+func ExecPluginWithResult(ctx context.Context, pluginPath string, netconf []byte, args CNIArgs, exec Exec) (types.Result, error) {
+	if exec == nil {
+		exec = defaultExec
+	}
+
+	stdoutBytes, err := exec.ExecPlugin(ctx, pluginPath, netconf, args.AsEnv())
+	if err != nil {
+		return nil, err
+	}
+
+	// Plugin must return result in same version as specified in netconf
+	versionDecoder := &version.ConfigDecoder{}
+	confVersion, err := versionDecoder.Decode(netconf)
+	if err != nil {
+		return nil, err
+	}
+
+	return version.NewResult(confVersion, stdoutBytes)
+}
+
+func ExecPluginWithoutResult(ctx context.Context, pluginPath string, netconf []byte, args CNIArgs, exec Exec) error {
+	if exec == nil {
+		exec = defaultExec
+	}
+	_, err := exec.ExecPlugin(ctx, pluginPath, netconf, args.AsEnv())
+	return err
+}
+
+// GetVersionInfo returns the version information available about the plugin.
+// For recent-enough plugins, it uses the information returned by the VERSION
+// command.  For older plugins which do not recognize that command, it reports
+// version 0.1.0
+func GetVersionInfo(ctx context.Context, pluginPath string, exec Exec) (version.PluginInfo, error) {
+	if exec == nil {
+		exec = defaultExec
+	}
+	args := &Args{
+		Command: "VERSION",
+
+		// set fake values required by plugins built against an older version of skel
+		NetNS:  "dummy",
+		IfName: "dummy",
+		Path:   "dummy",
+	}
+	stdin := []byte(fmt.Sprintf(`{"cniVersion":%q}`, version.Current()))
+	stdoutBytes, err := exec.ExecPlugin(ctx, pluginPath, stdin, args.AsEnv())
+	if err != nil {
+		if err.Error() == "unknown CNI_COMMAND: VERSION" {
+			return version.PluginSupports("0.1.0"), nil
+		}
+		return nil, err
+	}
+
+	return exec.Decode(stdoutBytes)
+}
+
+// DefaultExec is an object that implements the Exec interface which looks
+// for and executes plugins from disk.
+type DefaultExec struct {
+	*RawExec
+	version.PluginDecoder
+}
+
+// DefaultExec implements the Exec interface
+var _ Exec = &DefaultExec{}
+
+var defaultExec = &DefaultExec{
+	RawExec: &RawExec{Stderr: os.Stderr},
+}

vendor/github.com/containernetworking/cni/pkg/invoke/find.go

@@ -0,0 +1,43 @@
+// Copyright 2015 CNI 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 invoke
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// FindInPath returns the full path of the plugin by searching in the provided path
+func FindInPath(plugin string, paths []string) (string, error) {
+	if plugin == "" {
+		return "", fmt.Errorf("no plugin name provided")
+	}
+
+	if len(paths) == 0 {
+		return "", fmt.Errorf("no paths provided")
+	}
+
+	for _, path := range paths {
+		for _, fe := range ExecutableFileExtensions {
+			fullpath := filepath.Join(path, plugin) + fe
+			if fi, err := os.Stat(fullpath); err == nil && fi.Mode().IsRegular() {
+				return fullpath, nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("failed to find plugin %q in path %s", plugin, paths)
+}

vendor/github.com/containernetworking/cni/pkg/invoke/os_unix.go

@@ -0,0 +1,20 @@
+// Copyright 2016 CNI 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.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package invoke
+
+// Valid file extensions for plugin executables.
+var ExecutableFileExtensions = []string{""}

vendor/github.com/containernetworking/cni/pkg/invoke/os_windows.go

@@ -0,0 +1,18 @@
+// Copyright 2016 CNI 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 invoke
+
+// Valid file extensions for plugin executables.
+var ExecutableFileExtensions = []string{".exe", ""}

vendor/github.com/containernetworking/cni/pkg/invoke/raw_exec.go

@@ -0,0 +1,62 @@
+// Copyright 2016 CNI 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 invoke
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os/exec"
+
+	"github.com/containernetworking/cni/pkg/types"
+)
+
+type RawExec struct {
+	Stderr io.Writer
+}
+
+func (e *RawExec) ExecPlugin(ctx context.Context, pluginPath string, stdinData []byte, environ []string) ([]byte, error) {
+	stdout := &bytes.Buffer{}
+	c := exec.CommandContext(ctx, pluginPath)
+	c.Env = environ
+	c.Stdin = bytes.NewBuffer(stdinData)
+	c.Stdout = stdout
+	c.Stderr = e.Stderr
+	if err := c.Run(); err != nil {
+		return nil, pluginErr(err, stdout.Bytes())
+	}
+
+	return stdout.Bytes(), nil
+}
+
+func pluginErr(err error, output []byte) error {
+	if _, ok := err.(*exec.ExitError); ok {
+		emsg := types.Error{}
+		if len(output) == 0 {
+			emsg.Msg = "netplugin failed with no error message"
+		} else if perr := json.Unmarshal(output, &emsg); perr != nil {
+			emsg.Msg = fmt.Sprintf("netplugin failed but error parsing its diagnostic message %q: %v", string(output), perr)
+		}
+		return &emsg
+	}
+
+	return err
+}
+
+func (e *RawExec) FindInPath(plugin string, paths []string) (string, error) {
+	return FindInPath(plugin, paths)
+}