Update cni and go-cni to the v0.7.1 release

Closes #1236

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

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

@@ -15,6 +15,7 @@
 package invoke
 
 import (
+	"fmt"
 	"os"
 	"strings"
 )
@@ -22,6 +23,8 @@ import (
 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
 }
 
@@ -57,17 +60,17 @@ func (args *Args) AsEnv() []string {
 		pluginArgsStr = stringify(args.PluginArgs)
 	}
 
-	// Ensure that the custom values are first, so any value present in
-	// the process environment won't override them.
-	env = append([]string{
-		"CNI_COMMAND=" + args.Command,
-		"CNI_CONTAINERID=" + args.ContainerID,
-		"CNI_NETNS=" + args.NetNS,
-		"CNI_ARGS=" + pluginArgsStr,
-		"CNI_IFNAME=" + args.IfName,
-		"CNI_PATH=" + args.Path,
-	}, env...)
-	return env
+	// 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
@@ -80,3 +83,46 @@ func stringify(pluginArgs [][2]string) string {
 
 	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

@@ -15,39 +15,66 @@
 package invoke
 
 import (
-	"fmt"
+	"context"
 	"os"
 	"path/filepath"
 
 	"github.com/containernetworking/cni/pkg/types"
 )
 
-func DelegateAdd(delegatePlugin string, netconf []byte) (types.Result, error) {
-	if os.Getenv("CNI_COMMAND") != "ADD" {
-		return nil, fmt.Errorf("CNI_COMMAND is not ADD")
+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
+	}
 
-	pluginPath, err := FindInPath(delegatePlugin, paths)
+	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
 	}
 
-	return ExecPluginWithResult(pluginPath, netconf, ArgsFromEnv())
+	// DelegateAdd will override the original "CNI_COMMAND" env from process with ADD
+	return ExecPluginWithResult(ctx, pluginPath, netconf, delegateArgs("ADD"), realExec)
 }
 
-func DelegateDel(delegatePlugin string, netconf []byte) error {
-	if os.Getenv("CNI_COMMAND") != "DEL" {
-		return fmt.Errorf("CNI_COMMAND is not DEL")
-	}
-
-	paths := filepath.SplitList(os.Getenv("CNI_PATH"))
-
-	pluginPath, err := FindInPath(delegatePlugin, paths)
+// 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
 	}
 
-	return ExecPluginWithoutResult(pluginPath, netconf, ArgsFromEnv())
+	// 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

@@ -15,6 +15,7 @@
 package invoke
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -22,34 +23,62 @@ import (
 	"github.com/containernetworking/cni/pkg/version"
 )
 
-func ExecPluginWithResult(pluginPath string, netconf []byte, args CNIArgs) (types.Result, error) {
-	return defaultPluginExec.WithResult(pluginPath, netconf, args)
+// 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)
 }
 
-func ExecPluginWithoutResult(pluginPath string, netconf []byte, args CNIArgs) error {
-	return defaultPluginExec.WithoutResult(pluginPath, netconf, args)
-}
+// 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 GetVersionInfo(pluginPath string) (version.PluginInfo, error) {
-	return defaultPluginExec.GetVersionInfo(pluginPath)
-}
-
-var defaultPluginExec = &PluginExec{
-	RawExec:        &RawExec{Stderr: os.Stderr},
-	VersionDecoder: &version.PluginDecoder{},
-}
-
-type PluginExec struct {
-	RawExec interface {
-		ExecPlugin(pluginPath string, stdinData []byte, environ []string) ([]byte, error)
+func ExecPluginWithResult(ctx context.Context, pluginPath string, netconf []byte, args CNIArgs, exec Exec) (types.Result, error) {
+	if exec == nil {
+		exec = defaultExec
 	}
-	VersionDecoder interface {
-		Decode(jsonBytes []byte) (version.PluginInfo, error)
-	}
-}
 
-func (e *PluginExec) WithResult(pluginPath string, netconf []byte, args CNIArgs) (types.Result, error) {
-	stdoutBytes, err := e.RawExec.ExecPlugin(pluginPath, netconf, args.AsEnv())
+	stdoutBytes, err := exec.ExecPlugin(ctx, pluginPath, netconf, args.AsEnv())
 	if err != nil {
 		return nil, err
 	}
@@ -64,8 +93,11 @@ func (e *PluginExec) WithResult(pluginPath string, netconf []byte, args CNIArgs)
 	return version.NewResult(confVersion, stdoutBytes)
 }
 
-func (e *PluginExec) WithoutResult(pluginPath string, netconf []byte, args CNIArgs) error {
-	_, err := e.RawExec.ExecPlugin(pluginPath, netconf, args.AsEnv())
+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
 }
 
@@ -73,7 +105,10 @@ func (e *PluginExec) WithoutResult(pluginPath string, netconf []byte, args CNIAr
 // 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 (e *PluginExec) GetVersionInfo(pluginPath string) (version.PluginInfo, error) {
+func GetVersionInfo(ctx context.Context, pluginPath string, exec Exec) (version.PluginInfo, error) {
+	if exec == nil {
+		exec = defaultExec
+	}
 	args := &Args{
 		Command: "VERSION",
 
@@ -83,7 +118,7 @@ func (e *PluginExec) GetVersionInfo(pluginPath string) (version.PluginInfo, erro
 		Path:   "dummy",
 	}
 	stdin := []byte(fmt.Sprintf(`{"cniVersion":%q}`, version.Current()))
-	stdoutBytes, err := e.RawExec.ExecPlugin(pluginPath, stdin, args.AsEnv())
+	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
@@ -91,5 +126,19 @@ func (e *PluginExec) GetVersionInfo(pluginPath string) (version.PluginInfo, erro
 		return nil, err
 	}
 
-	return e.VersionDecoder.Decode(stdoutBytes)
+	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/os_unix.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build darwin dragonfly freebsd linux netbsd opensbd solaris
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package invoke
 

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

@@ -16,6 +16,7 @@ package invoke
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -28,17 +29,13 @@ type RawExec struct {
 	Stderr io.Writer
 }
 
-func (e *RawExec) ExecPlugin(pluginPath string, stdinData []byte, environ []string) ([]byte, error) {
+func (e *RawExec) ExecPlugin(ctx context.Context, pluginPath string, stdinData []byte, environ []string) ([]byte, error) {
 	stdout := &bytes.Buffer{}
-
-	c := exec.Cmd{
-		Env:    environ,
-		Path:   pluginPath,
-		Args:   []string{pluginPath},
-		Stdin:  bytes.NewBuffer(stdinData),
-		Stdout: stdout,
-		Stderr: e.Stderr,
-	}
+	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())
 	}
@@ -49,7 +46,9 @@ func (e *RawExec) ExecPlugin(pluginPath string, stdinData []byte, environ []stri
 func pluginErr(err error, output []byte) error {
 	if _, ok := err.(*exec.ExitError); ok {
 		emsg := types.Error{}
-		if perr := json.Unmarshal(output, &emsg); perr != nil {
+		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
@@ -57,3 +56,7 @@ func pluginErr(err error, output []byte) error {
 
 	return err
 }
+
+func (e *RawExec) FindInPath(plugin string, paths []string) (string, error) {
+	return FindInPath(plugin, paths)
+}

vendor/github.com/containernetworking/cni/pkg/types/020/types.go

@@ -17,6 +17,7 @@ package types020
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net"
 	"os"
 
@@ -73,11 +74,15 @@ func (r *Result) GetAsVersion(version string) (types.Result, error) {
 }
 
 func (r *Result) Print() error {
+	return r.PrintTo(os.Stdout)
+}
+
+func (r *Result) PrintTo(writer io.Writer) error {
 	data, err := json.MarshalIndent(r, "", "    ")
 	if err != nil {
 		return err
 	}
-	_, err = os.Stdout.Write(data)
+	_, err = writer.Write(data)
 	return err
 }
 

vendor/github.com/containernetworking/cni/pkg/types/current/types.go

@@ -17,6 +17,7 @@ package current
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net"
 	"os"
 
@@ -24,9 +25,9 @@ import (
 	"github.com/containernetworking/cni/pkg/types/020"
 )
 
-const ImplementedSpecVersion string = "0.3.1"
+const ImplementedSpecVersion string = "0.4.0"
 
-var SupportedVersions = []string{"0.3.0", ImplementedSpecVersion}
+var SupportedVersions = []string{"0.3.0", "0.3.1", ImplementedSpecVersion}
 
 func NewResult(data []byte) (types.Result, error) {
 	result := &Result{}
@@ -75,13 +76,9 @@ func convertFrom020(result types.Result) (*Result, error) {
 			Gateway: oldResult.IP4.Gateway,
 		})
 		for _, route := range oldResult.IP4.Routes {
-			gw := route.GW
-			if gw == nil {
-				gw = oldResult.IP4.Gateway
-			}
 			newResult.Routes = append(newResult.Routes, &types.Route{
 				Dst: route.Dst,
-				GW:  gw,
+				GW:  route.GW,
 			})
 		}
 	}
@@ -93,21 +90,13 @@ func convertFrom020(result types.Result) (*Result, error) {
 			Gateway: oldResult.IP6.Gateway,
 		})
 		for _, route := range oldResult.IP6.Routes {
-			gw := route.GW
-			if gw == nil {
-				gw = oldResult.IP6.Gateway
-			}
 			newResult.Routes = append(newResult.Routes, &types.Route{
 				Dst: route.Dst,
-				GW:  gw,
+				GW:  route.GW,
 			})
 		}
 	}
 
-	if len(newResult.IPs) == 0 {
-		return nil, fmt.Errorf("cannot convert: no valid IP addresses")
-	}
-
 	return newResult, nil
 }
 
@@ -196,7 +185,7 @@ func (r *Result) Version() string {
 
 func (r *Result) GetAsVersion(version string) (types.Result, error) {
 	switch version {
-	case "0.3.0", ImplementedSpecVersion:
+	case "0.3.0", "0.3.1", ImplementedSpecVersion:
 		r.CNIVersion = version
 		return r, nil
 	case types020.SupportedVersions[0], types020.SupportedVersions[1], types020.SupportedVersions[2]:
@@ -206,11 +195,15 @@ func (r *Result) GetAsVersion(version string) (types.Result, error) {
 }
 
 func (r *Result) Print() error {
+	return r.PrintTo(os.Stdout)
+}
+
+func (r *Result) PrintTo(writer io.Writer) error {
 	data, err := json.MarshalIndent(r, "", "    ")
 	if err != nil {
 		return err
 	}
-	_, err = os.Stdout.Write(data)
+	_, err = writer.Write(data)
 	return err
 }
 

vendor/github.com/containernetworking/cni/pkg/types/types.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"os"
 )
@@ -63,25 +64,31 @@ type NetConf struct {
 	Name         string          `json:"name,omitempty"`
 	Type         string          `json:"type,omitempty"`
 	Capabilities map[string]bool `json:"capabilities,omitempty"`
-	IPAM         struct {
-		Type string `json:"type,omitempty"`
-	} `json:"ipam,omitempty"`
-	DNS DNS `json:"dns"`
+	IPAM         IPAM            `json:"ipam,omitempty"`
+	DNS          DNS             `json:"dns"`
+
+	RawPrevResult map[string]interface{} `json:"prevResult,omitempty"`
+	PrevResult    Result                 `json:"-"`
+}
+
+type IPAM struct {
+	Type string `json:"type,omitempty"`
 }
 
 // NetConfList describes an ordered list of networks.
 type NetConfList struct {
 	CNIVersion string `json:"cniVersion,omitempty"`
 
-	Name    string     `json:"name,omitempty"`
-	Plugins []*NetConf `json:"plugins,omitempty"`
+	Name         string     `json:"name,omitempty"`
+	DisableCheck bool       `json:"disableCheck,omitempty"`
+	Plugins      []*NetConf `json:"plugins,omitempty"`
 }
 
 type ResultFactoryFunc func([]byte) (Result, error)
 
 // Result is an interface that provides the result of plugin execution
 type Result interface {
-	// The highest CNI specification result verison the result supports
+	// The highest CNI specification result version the result supports
 	// without having to convert
 	Version() string
 
@@ -92,6 +99,9 @@ type Result interface {
 	// Prints the result in JSON format to stdout
 	Print() error
 
+	// Prints the result in JSON format to provided writer
+	PrintTo(writer io.Writer) error
+
 	// Returns a JSON string representation of the result
 	String() string
 }
@@ -167,7 +177,7 @@ func (r *Route) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-func (r *Route) MarshalJSON() ([]byte, error) {
+func (r Route) MarshalJSON() ([]byte, error) {
 	rt := route{
 		Dst: IPNet(r.Dst),
 		GW:  r.GW,

vendor/github.com/containernetworking/cni/pkg/version/plugin.go

@@ -18,6 +18,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"strconv"
+	"strings"
 )
 
 // PluginInfo reports information about CNI versioning
@@ -79,3 +81,64 @@ func (*PluginDecoder) Decode(jsonBytes []byte) (PluginInfo, error) {
 	}
 	return &info, nil
 }
+
+// ParseVersion parses a version string like "3.0.1" or "0.4.5" into major,
+// minor, and micro numbers or returns an error
+func ParseVersion(version string) (int, int, int, error) {
+	var major, minor, micro int
+	if version == "" {
+		return -1, -1, -1, fmt.Errorf("invalid version %q: the version is empty", version)
+	}
+
+	parts := strings.Split(version, ".")
+	if len(parts) >= 4 {
+		return -1, -1, -1, fmt.Errorf("invalid version %q: too many parts", version)
+	}
+
+	major, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return -1, -1, -1, fmt.Errorf("failed to convert major version part %q: %v", parts[0], err)
+	}
+
+	if len(parts) >= 2 {
+		minor, err = strconv.Atoi(parts[1])
+		if err != nil {
+			return -1, -1, -1, fmt.Errorf("failed to convert minor version part %q: %v", parts[1], err)
+		}
+	}
+
+	if len(parts) >= 3 {
+		micro, err = strconv.Atoi(parts[2])
+		if err != nil {
+			return -1, -1, -1, fmt.Errorf("failed to convert micro version part %q: %v", parts[2], err)
+		}
+	}
+
+	return major, minor, micro, nil
+}
+
+// GreaterThanOrEqualTo takes two string versions, parses them into major/minor/micro
+// numbers, and compares them to determine whether the first version is greater
+// than or equal to the second
+func GreaterThanOrEqualTo(version, otherVersion string) (bool, error) {
+	firstMajor, firstMinor, firstMicro, err := ParseVersion(version)
+	if err != nil {
+		return false, err
+	}
+
+	secondMajor, secondMinor, secondMicro, err := ParseVersion(otherVersion)
+	if err != nil {
+		return false, err
+	}
+
+	if firstMajor > secondMajor {
+		return true, nil
+	} else if firstMajor == secondMajor {
+		if firstMinor > secondMinor {
+			return true, nil
+		} else if firstMinor == secondMinor && firstMicro >= secondMicro {
+			return true, nil
+		}
+	}
+	return false, nil
+}

vendor/github.com/containernetworking/cni/pkg/version/version.go

@@ -15,6 +15,7 @@
 package version
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/containernetworking/cni/pkg/types"
@@ -24,7 +25,7 @@ import (
 
 // Current reports the version of the CNI spec implemented by this library
 func Current() string {
-	return "0.3.1"
+	return "0.4.0"
 }
 
 // Legacy PluginInfo describes a plugin that is backwards compatible with the
@@ -35,7 +36,7 @@ func Current() string {
 // Any future CNI spec versions which meet this definition should be added to
 // this list.
 var Legacy = PluginSupports("0.1.0", "0.2.0")
-var All = PluginSupports("0.1.0", "0.2.0", "0.3.0", "0.3.1")
+var All = PluginSupports("0.1.0", "0.2.0", "0.3.0", "0.3.1", "0.4.0")
 
 var resultFactories = []struct {
 	supportedVersions []string
@@ -59,3 +60,24 @@ func NewResult(version string, resultBytes []byte) (types.Result, error) {
 
 	return nil, fmt.Errorf("unsupported CNI result version %q", version)
 }
+
+// ParsePrevResult parses a prevResult in a NetConf structure and sets
+// the NetConf's PrevResult member to the parsed Result object.
+func ParsePrevResult(conf *types.NetConf) error {
+	if conf.RawPrevResult == nil {
+		return nil
+	}
+
+	resultBytes, err := json.Marshal(conf.RawPrevResult)
+	if err != nil {
+		return fmt.Errorf("could not serialize prevResult: %v", err)
+	}
+
+	conf.RawPrevResult = nil
+	conf.PrevResult, err = NewResult(conf.CNIVersion, resultBytes)
+	if err != nil {
+		return fmt.Errorf("could not parse prevResult: %v", err)
+	}
+
+	return nil
+}