libcni: implement disableGC

This allows administrators to disable GC behavior.

Signed-off-by: Casey Callendrello <[email protected]>

Author: squeed

libcni/api.go

@@ -76,6 +76,7 @@ type NetworkConfigList struct {
 	Name         string
 	CNIVersion   string
 	DisableCheck bool
+	DisableGC    bool
 	Plugins      []*NetworkConfig
 	Bytes        []byte
 }
@@ -764,6 +765,11 @@ func (c *CNIConfig) GetVersionInfo(ctx context.Context, pluginType string) (vers
 // - dump the list of cached attachments, and issue deletes as necessary
 // - issue a GC to the underlying plugins (if the version is high enough)
 func (c *CNIConfig) GCNetworkList(ctx context.Context, list *NetworkConfigList, args *GCArgs) error {
+	// If DisableGC is set, then don't bother GCing at all.
+	if list.DisableGC {
+		return nil
+	}
+
 	// First, get the list of cached attachments
 	cachedAttachments, err := c.GetCachedAttachments("")
 	if err != nil {

libcni/api_test.go

@@ -1511,8 +1511,19 @@ var _ = Describe("Invoking plugins", func() {
 				_, err := cniConfig.AddNetworkList(ctx, netConfigList, runtimeConfig)
 				Expect(err).NotTo(HaveOccurred())
 
+				By("Issuing a GC with disableGC=true")
+				netConfigList.DisableGC = true
+				gcargs := &libcni.GCArgs{}
+				err = cniConfig.GCNetworkList(ctx, netConfigList, gcargs)
+				Expect(err).NotTo(HaveOccurred())
+
+				commands, err := noop_debug.ReadCommandLog(plugins[0].commandFilePath)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(commands).To(HaveLen(1)) // ADD
+
 				By("Issuing a GC with valid networks")
-				gcargs := &libcni.GCArgs{
+				netConfigList.DisableGC = false
+				gcargs = &libcni.GCArgs{
 					ValidAttachments: []types.GCAttachment{{
 						ContainerID: runtimeConfig.ContainerID,
 						IfName:      runtimeConfig.IfName,
@@ -1526,7 +1537,7 @@ var _ = Describe("Invoking plugins", func() {
 				err = cniConfig.GCNetworkList(ctx, netConfigList, gcargs)
 				Expect(err).NotTo(HaveOccurred())
 
-				commands, err := noop_debug.ReadCommandLog(plugins[0].commandFilePath)
+				commands, err = noop_debug.ReadCommandLog(plugins[0].commandFilePath)
 				Expect(err).NotTo(HaveOccurred())
 				Expect(commands).To(HaveLen(4))
 

libcni/conf.go

@@ -130,28 +130,43 @@ func ConfListFromBytes(bytes []byte) (*NetworkConfigList, error) {
 		}
 	}
 
-	disableCheck := false
-	if rawDisableCheck, ok := rawList["disableCheck"]; ok {
-		disableCheck, ok = rawDisableCheck.(bool)
+	readBool := func(key string) (bool, error) {
+		rawVal, ok := rawList[key]
 		if !ok {
-			disableCheckStr, ok := rawDisableCheck.(string)
-			if !ok {
-				return nil, fmt.Errorf("error parsing configuration list: invalid disableCheck type %T", rawDisableCheck)
-			}
-			switch {
-			case strings.ToLower(disableCheckStr) == "false":
-				disableCheck = false
-			case strings.ToLower(disableCheckStr) == "true":
-				disableCheck = true
-			default:
-				return nil, fmt.Errorf("error parsing configuration list: invalid disableCheck value %q", disableCheckStr)
-			}
+			return false, nil
+		}
+		if b, ok := rawVal.(bool); ok {
+			return b, nil
+		}
+
+		s, ok := rawVal.(string)
+		if !ok {
+			return false, fmt.Errorf("error parsing configuration list: invalid type %T for %s", rawVal, key)
+		}
+		s = strings.ToLower(s)
+		switch s {
+		case "false":
+			return false, nil
+		case "true":
+			return true, nil
 		}
+		return false, fmt.Errorf("error parsing configuration list: invalid value %q for %s", s, key)
+	}
+
+	disableCheck, err := readBool("disableCheck")
+	if err != nil {
+		return nil, err
+	}
+
+	disableGC, err := readBool("disableGC")
+	if err != nil {
+		return nil, err
 	}
 
 	list := &NetworkConfigList{
 		Name:         name,
 		DisableCheck: disableCheck,
+		DisableGC:    disableGC,
 		CNIVersion:   cniVersion,
 		Bytes:        bytes,
 	}

libcni/conf_test.go

@@ -386,7 +386,7 @@ var _ = Describe("Loading configuration from disk", func() {
 				Expect(os.WriteFile(filepath.Join(configDir, "50-whatever.conflist"), configList, 0o600)).To(Succeed())
 
 				_, err := libcni.LoadConfList(configDir, "some-list")
-				Expect(err).To(MatchError(fmt.Sprintf("error parsing configuration list: invalid disableCheck value \"%s\"", badValue)))
+				Expect(err).To(MatchError(`error parsing configuration list: invalid value "adsfasdfasf" for disableCheck`))
 			})
 		})
 	})