Updates default network readiness to use apimachinery wait.Exponentia…

…lBackoff

README.md

@@ -499,12 +499,11 @@ For example, if you use Flannel as a default network, the recommended method for
 
 In this manner, you may prevent pods from crash looping, and instead wait for that default network to be ready.
 
-Two options are available to configure this functionality:
+Only one option is necessary to configure this functionality:
 
-* `defaultnetworkfile`: The path to a file whose existance denotes that the default network is ready.
-* `defaultnetworkwaitseconds`: The number of seconds to wait for that file to become available. Defaults to 120 seconds.
+* `readinessindicatorfile`: The path to a file whose existance denotes that the default network is ready.
 
-*NOTE*: If `defaultnetworkfile` is unset, or is an empty string, this functionality will be disabled, and is disabled by default.
+*NOTE*: If `readinessindicatorfile` is unset, or is an empty string, this functionality will be disabled, and is disabled by default.
 
 ## Testing Multus CNI
 

multus/multus.go

@@ -24,7 +24,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"k8s.io/client-go/util/retry"
+	"time"
 
 	"github.com/containernetworking/cni/libcni"
 	"github.com/containernetworking/cni/pkg/invoke"
@@ -35,8 +35,16 @@ import (
 	k8s "github.com/intel/multus-cni/k8sclient"
 	"github.com/intel/multus-cni/types"
 	"github.com/vishvananda/netlink"
+	"k8s.io/apimachinery/pkg/util/wait"
 )
 
+var defaultReadinessBackoff = wait.Backoff{
+	Steps:    4,
+	Duration: 250 * time.Millisecond,
+	Factor:   4.0,
+	Jitter:   0.1,
+}
+
 func saveScratchNetConf(containerID, dataDir string, netconf []byte) error {
 	if err := os.MkdirAll(dataDir, 0700); err != nil {
 		return fmt.Errorf("failed to create the multus data directory(%q): %v", dataDir, err)
@@ -205,34 +213,6 @@ func delPlugins(exec invoke.Exec, argIfname string, delegates []*types.DelegateN
 	return nil
 }
 
-// Sits in a wait loop until a file indicating the readiness of the "default network"
-// is present (or until a user-defined timeout is reached)
-func waitForDefaultNetwork(indicatorFile string, waitSeconds int) error {
-	// If there's no file to wait for, then, this is essentially disabled.
-	if len(indicatorFile) > 0 {
-		attempts := 0
-		found := false
-		// Sleep in a loop until we find that file.
-		for attempts < waitSeconds {
-			attempts++
-			if _, err := os.Stat(indicatorFile); err == nil {
-				found = true
-				attempts = waitSeconds
-			} else {
-				time.Sleep(1 * time.Second)
-			}
-		}
-
-		if !found {
-			return fmt.Errorf("Multus: Timeout (%v seconds) finding default network file: %v", waitSeconds, indicatorFile)
-		}
-		return nil
-
-	}
-
-	return nil
-}
-
 func cmdAdd(args *skel.CmdArgs, exec invoke.Exec, kubeClient k8s.KubeClient) (cnitypes.Result, error) {
 	n, err := types.LoadNetConf(args.StdinData)
 	if err != nil {
@@ -244,9 +224,15 @@ func cmdAdd(args *skel.CmdArgs, exec invoke.Exec, kubeClient k8s.KubeClient) (cn
 		return nil, fmt.Errorf("Multus: Err in getting k8s args: %v", err)
 	}
 
-	if err = waitForDefaultNetwork(n.DefaultNetworkFile, n.DefaultNetworkWaitSeconds); err != nil {
-		return nil, err
-	}
+	wait.ExponentialBackoff(defaultReadinessBackoff, func() (bool, error) {
+		_, err := os.Stat(n.ReadinessIndicatorFile)
+		switch {
+		case err == nil:
+			return true, nil
+		default:
+			return false, nil
+		}
+	})
 
 	numK8sDelegates, kc, err := k8s.TryLoadK8sDelegates(k8sArgs, n, kubeClient)
 	if err != nil {

multus/multus_test.go

@@ -173,8 +173,7 @@ var _ = Describe("multus operations", func() {
 			StdinData: []byte(`{
     "name": "node-cni-network",
     "type": "multus",
-    "defaultnetworkfile": "/tmp/foo.multus.conf",
-    "defaultnetworkwaitseconds": 3,
+    "readinessindicatorfile": "/tmp/foo.multus.conf",
     "delegates": [{
         "name": "weave1",
         "cniVersion": "0.2.0",
@@ -320,51 +319,4 @@ var _ = Describe("multus operations", func() {
 		Expect(reflect.DeepEqual(r, expectedResult1)).To(BeTrue())
 	})
 
-	It("times out waiting for default networks", func() {
-		args := &skel.CmdArgs{
-			ContainerID: "123456789",
-			Netns:       testNS.Path(),
-			IfName:      "eth0",
-			StdinData: []byte(`{
-    "name": "defaultnetwork",
-    "type": "multus",
-    "defaultnetworkfile": "/tmp/foo.multus.conf",
-    "defaultnetworkwaitseconds": 1,
-    "delegates": [{
-        "name": "weave1",
-        "cniVersion": "0.2.0",
-        "type": "weave-net"
-    }]
-}`),
-		}
-
-		// Always remove the defaultnetworkfile
-		configPath := "/tmp/foo.multus.conf"
-		if _, errStat := os.Stat(configPath); errStat == nil {
-			errRemove := os.Remove(configPath)
-			Expect(errRemove).NotTo(HaveOccurred())
-		}
-
-		fExec := &fakeExec{}
-		expectedResult1 := &types020.Result{
-			CNIVersion: "0.2.0",
-			IP4: &types020.IPConfig{
-				IP: *testhelpers.EnsureCIDR("1.1.1.2/24"),
-			},
-		}
-		expectedConf1 := `{
-    "name": "weave1",
-    "cniVersion": "0.2.0",
-    "type": "weave-net"
-}`
-		fExec.addPlugin(nil, "eth0", expectedConf1, expectedResult1, nil)
-
-		os.Setenv("CNI_COMMAND", "ADD")
-		os.Setenv("CNI_IFNAME", "eth0")
-		_, err := cmdAdd(args, fExec, nil)
-
-		Expect(err).To(HaveOccurred())
-		Expect(err).To(MatchError("Multus: Timeout (1 seconds) finding default network file: /tmp/foo.multus.conf"))
-
-	})
 })

types/conf.go

@@ -28,11 +28,10 @@ import (
 )
 
 const (
-	defaultCNIDir  = "/var/lib/cni/multus"
-	defaultConfDir = "/etc/cni/multus/net.d"
-	defaultBinDir  = "/opt/cni/bin"
-	defaultDefaultNetworkFile = ""
-	defaultDefaultNetworkWaitSeconds = 120
+	defaultCNIDir             = "/var/lib/cni/multus"
+	defaultConfDir            = "/etc/cni/multus/net.d"
+	defaultBinDir             = "/opt/cni/bin"
+	defaultReadinessIndicatorFile = ""
 )
 
 func LoadDelegateNetConfList(bytes []byte, delegateConf *DelegateNetConf) error {
@@ -181,12 +180,8 @@ func LoadNetConf(bytes []byte) (*NetConf, error) {
 		netconf.BinDir = defaultBinDir
 	}
 
-	if netconf.DefaultNetworkFile == "" {
-		netconf.DefaultNetworkFile = defaultDefaultNetworkFile
-	}
-
-	if netconf.DefaultNetworkWaitSeconds < 1 {
-		netconf.DefaultNetworkWaitSeconds = defaultDefaultNetworkWaitSeconds
+	if netconf.ReadinessIndicatorFile == "" {
+		netconf.ReadinessIndicatorFile = defaultReadinessIndicatorFile
 	}
 
 	for idx, rawConf := range netconf.RawDelegates {

types/conf_test.go

@@ -82,8 +82,8 @@ var _ = Describe("config operations", func() {
 		Expect(err).To(HaveOccurred())
 	})
 
-  It("has defaults set for network readiness", func() {
-    conf := `{
+	It("has defaults set for network readiness", func() {
+		conf := `{
     "name": "defaultnetwork",
     "type": "multus",
     "kubeconfig": "/etc/kubernetes/kubelet.conf",
@@ -94,18 +94,16 @@ var _ = Describe("config operations", func() {
       "isDefaultGateway": true
     }]
 }`
-    netConf, err := LoadNetConf([]byte(conf))
-    Expect(err).NotTo(HaveOccurred())
-    Expect(netConf.DefaultNetworkFile).To(Equal(""))
-    Expect(netConf.DefaultNetworkWaitSeconds).To(Equal(120))
-  })
+		netConf, err := LoadNetConf([]byte(conf))
+		Expect(err).NotTo(HaveOccurred())
+		Expect(netConf.ReadinessIndicatorFile).To(Equal(""))
+	})
 
-  It("honors overrides for network readiness", func() {
-    conf := `{
+	It("honors overrides for network readiness", func() {
+		conf := `{
     "name": "defaultnetwork",
     "type": "multus",
-    "defaultnetworkfile": "/etc/cni/net.d/foo",
-    "defaultnetworkwaitseconds": 30,
+    "readinessindicatorfile": "/etc/cni/net.d/foo",
     "kubeconfig": "/etc/kubernetes/kubelet.conf",
     "delegates": [{
       "cniVersion": "0.3.0",
@@ -114,11 +112,9 @@ var _ = Describe("config operations", func() {
       "isDefaultGateway": true
     }]
 }`
-    netConf, err := LoadNetConf([]byte(conf))
-    Expect(err).NotTo(HaveOccurred())
-    Expect(netConf.DefaultNetworkFile).To(Equal("/etc/cni/net.d/foo"))
-    Expect(netConf.DefaultNetworkWaitSeconds).To(Equal(30))
-  })
-
+		netConf, err := LoadNetConf([]byte(conf))
+		Expect(err).NotTo(HaveOccurred())
+		Expect(netConf.ReadinessIndicatorFile).To(Equal("/etc/cni/net.d/foo"))
+	})
 
 })

types/types.go

@@ -43,8 +43,7 @@ type NetConf struct {
 	LogFile      string                   `json:"logFile"`
 	LogLevel     string                   `json:"logLevel"`
 	// Default network readiness options
-	DefaultNetworkFile        string      `json:defaultnetworkfile`
-	DefaultNetworkWaitSeconds int         `json:defaultnetworkwaitseconds`
+	ReadinessIndicatorFile string `json:readinessindicatorfile`
 }
 
 type NetworkStatus struct {