CNS writes Cilium Conflist (#1901)

* implement cilium conflist generator

* add cilium conflist for generator test

* update generator-windows

* cleaning up generator constants

Author: camrynl

cns/cniconflist/generator.go

@@ -7,10 +7,15 @@ import (
 )
 
 const (
-	cniVersion     = "0.3.0"         //nolint:unused,deadcode,varcheck // used in linux
-	cniName        = "azure"         //nolint:unused,deadcode,varcheck // used in linux
-	cniType        = "azure-vnet"    //nolint:unused,deadcode,varcheck // used in linux
-	nodeLocalDNSIP = "169.254.20.10" //nolint:unused,deadcode,varcheck // used in linux
+	ciliumcniVersion  = "0.3.1"                   //nolint:unused,deadcode,varcheck // used in linux
+	ciliumcniName     = "cilium"                  //nolint:unused,deadcode,varcheck // used in linux
+	ciliumcniType     = "cilium-cni"              //nolint:unused,deadcode,varcheck // used in linux
+	ciliumLogFile     = "/var/log/cilium-cni.log" //nolint:unused,deadcode,varcheck // used in linux
+	ciliumIPAM        = "azure-ipam"              //nolint:unused,deadcode,varcheck // used in linux
+	overlaycniVersion = "0.3.0"                   //nolint:unused,deadcode,varcheck // used in linux
+	overlaycniName    = "azure"                   //nolint:unused,deadcode,varcheck // used in linux
+	overlaycniType    = "azure-vnet"              //nolint:unused,deadcode,varcheck // used in linux
+	nodeLocalDNSIP    = "169.254.20.10"           //nolint:unused,deadcode,varcheck // used in linux
 )
 
 // cniConflist represents the containernetworking/cni/pkg/types.NetConfList
@@ -21,15 +26,45 @@ type cniConflist struct { //nolint:unused,deadcode // used in linux
 	Plugins      []any  `json:"plugins,omitempty"`
 }
 
+// NetConf describes a network. It represents the Cilium specific containernetworking/cni/pkg/types.NetConf
+type NetConf struct {
+	CNIVersion   string          `json:"cniVersion,omitempty"`
+	Name         string          `json:"name,omitempty"`
+	Type         string          `json:"type,omitempty"`
+	Capabilities map[string]bool `json:"capabilities,omitempty"`
+	IPAM         IPAM            `json:"ipam,omitempty"`
+	EnableDebug  bool            `json:"enable-debug"`
+	LogFile      string          `json:"log-file"`
+
+	RawPrevResult map[string]interface{} `json:"prevResult,omitempty"`
+}
+
+type IPAM struct {
+	Type string `json:"type,omitempty"`
+}
+
 // V4OverlayGenerator generates the Azure CNI conflist for the ipv4 Overlay scenario
 type V4OverlayGenerator struct {
 	Writer io.WriteCloser
 }
 
+// CiliumGenerator generates the Azure CNI conflist for the Cilium scenario
+type CiliumGenerator struct {
+	Writer io.WriteCloser
+}
+
 func (v *V4OverlayGenerator) Close() error {
 	if err := v.Writer.Close(); err != nil {
 		return errors.Wrap(err, "error closing generator")
 	}
 
 	return nil
 }
+
+func (v *CiliumGenerator) Close() error {
+	if err := v.Writer.Close(); err != nil {
+		return errors.Wrap(err, "error closing generator")
+	}
+
+	return nil
+}

cns/cniconflist/generator_linux.go

@@ -26,11 +26,11 @@ var portmapConfig any = struct {
 // Generate writes the CNI conflist to the Generator's output stream
 func (v *V4OverlayGenerator) Generate() error {
 	conflist := cniConflist{
-		CNIVersion: cniVersion,
-		Name:       cniName,
+		CNIVersion: overlaycniVersion,
+		Name:       overlaycniName,
 		Plugins: []any{
 			cni.NetworkConfig{
-				Type:              cniType,
+				Type:              overlaycniType,
 				Mode:              cninet.OpModeTransparent,
 				ExecutionMode:     string(util.V4Swift),
 				IPsToRouteViaHost: []string{nodeLocalDNSIP},
@@ -51,3 +51,29 @@ func (v *V4OverlayGenerator) Generate() error {
 
 	return nil
 }
+
+// Generate writes the CNI conflist to the Generator's output stream
+func (v *CiliumGenerator) Generate() error {
+	conflist := cniConflist{
+		CNIVersion: ciliumcniVersion,
+		Name:       ciliumcniName,
+		Plugins: []any{
+			NetConf{
+				Type:        ciliumcniType,
+				LogFile:     ciliumLogFile,
+				EnableDebug: true,
+				IPAM: IPAM{
+					Type: ciliumIPAM,
+				},
+			},
+		},
+	}
+
+	enc := json.NewEncoder(v.Writer)
+	enc.SetIndent("", "\t")
+	if err := enc.Encode(conflist); err != nil {
+		return errors.Wrap(err, "error encoding conflist to json")
+	}
+
+	return nil
+}

cns/cniconflist/generator_linux_test.go

@@ -32,6 +32,21 @@ func TestGenerateV4OverlayConflist(t *testing.T) {
 	assert.Equal(t, removeNewLines(fixtureBytes), removeNewLines(buffer.Bytes()))
 }
 
+func TestGenerateCiliumConflist(t *testing.T) {
+	fixture := "testdata/fixtures/cilium.conflist"
+
+	buffer := new(bytes.Buffer)
+	g := cniconflist.CiliumGenerator{Writer: &bufferWriteCloser{buffer}}
+	err := g.Generate()
+	assert.NoError(t, err)
+
+	fixtureBytes, err := os.ReadFile(fixture)
+	assert.NoError(t, err)
+
+	// remove newlines and carriage returns in case these UTs are running on Windows
+	assert.Equal(t, removeNewLines(fixtureBytes), removeNewLines(buffer.Bytes()))
+}
+
 // removeNewLines will remove the newlines and carriage returns from the byte slice
 func removeNewLines(b []byte) []byte {
 	var bb []byte //nolint:prealloc // can't prealloc since we don't know how many bytes will get removed

cns/cniconflist/generator_windows.go

@@ -9,3 +9,7 @@ var errNotImplemented = errors.New("cni conflist generator not implemented on Wi
 func (v *V4OverlayGenerator) Generate() error {
 	return errNotImplemented
 }
+
+func (v *CiliumGenerator) Generate() error {
+	return errNotImplemented
+}

cns/cniconflist/testdata/fixtures/cilium.conflist

@@ -0,0 +1,14 @@
+{
+	"cniVersion": "0.3.1",
+	"name": "cilium",
+	"plugins": [
+		{
+			"type": "cilium-cni",
+			"ipam": {
+				"type": "azure-ipam"
+			},
+			"enable-debug": true,
+			"log-file": "/var/log/cilium-cni.log"
+		}
+	]
+}

cns/service/main.go

@@ -87,6 +87,7 @@ type cniConflistScenario string
 
 const (
 	scenarioV4Overlay cniConflistScenario = "v4overlay"
+	scenarioCilium    cniConflistScenario = "cilium"
 )
 
 var (
@@ -535,6 +536,8 @@ func main() {
 		switch scenario := cniConflistScenario(scenarioString); scenario {
 		case scenarioV4Overlay:
 			conflistGenerator = &cniconflist.V4OverlayGenerator{Writer: writer}
+		case scenarioCilium:
+			conflistGenerator = &cniconflist.CiliumGenerator{Writer: writer}
 		default:
 			logger.Errorf("unable to generate cni conflist for unknown scenario: %s", scenario)
 			os.Exit(1)