Fix empty flannel backend configuration expectation on an existing cluster

lib/defaults/defaults.go

@@ -1345,6 +1345,9 @@ var (
 
  // KubeControllerManagerPort specifies the default controller manager healthz port
  KubeControllerManagerPort = 10257
+
+ // FlannelBackend specifies the default flannel backend
+ FlannelBackend = "vxlan"
 )
 
 // HookSecurityContext returns default securityContext for hook pods

lib/ops/opsservice/configure.go

@@ -1444,9 +1444,9 @@ func (s *site) addClusterConfig(config clusterconfig.Interface, overrideArgs map
  if globalConfig.HighAvailability != nil && *globalConfig.HighAvailability {
  args = append(args, "--high-availability")
  }
- if globalConfig.FlannelBackend != "" {
+ if globalConfig.FlannelBackend != nil {
  args = append(args,
- fmt.Sprintf("--flannel-backend=%v", globalConfig.FlannelBackend))
+ fmt.Sprintf("--flannel-backend=%v", *globalConfig.FlannelBackend))
  }
  return args
 }

lib/ops/resources/gravity/collection.go

@@ -664,9 +664,7 @@ func (r configCollection) WriteText(w io.Writer) error {
  fmt.Fprintf(t, "%v\n", string(config.Config))
  }
  config := r.GetGlobalConfig()
- if len(config.FlannelBackend) != 0 {
- fmt.Fprintf(t, "Flannel Backend:\t%v\n", config.FlannelBackend)
- }
+ fmt.Fprintf(t, "Flannel Backend:\t%v\n", utils.FormatStringPtrWithDefault(config.FlannelBackend, defaults.FlannelBackend))
  if len(config.PodCIDR) != 0 {
  fmt.Fprintf(t, "Pod IP Range:\t%v\n", config.PodCIDR)
  }
@@ -685,7 +683,7 @@ func (r configCollection) WriteText(w io.Writer) error {
  if len(config.FeatureGates) != 0 {
  fmt.Fprintf(t, "Feature Gates:\t%v\n", formatFeatureGates(config.FeatureGates))
  }
- fmt.Fprintf(t, "High Availability:\t%v\n", formatBoolPtr(config.HighAvailability))
+ fmt.Fprintf(t, "High Availability:\t%v\n", utils.FormatBoolPtr(config.HighAvailability))
  displayCloudConfig := config.CloudProvider != "" || config.CloudConfig != ""
  if displayCloudConfig {
  common.PrintCustomTableHeader(t, []string{"Cloud"}, "-")
@@ -742,13 +740,6 @@ func formatFeatureGates(features map[string]bool) string {
  return strings.Join(result, ",")
 }
 
-func formatBoolPtr(ptr *bool) string {
- if ptr == nil {
- return "<unset>"
- }
- return fmt.Sprint(*ptr)
-}
-
 type operationsCollection struct {
  operations []storage.Operation
 }

lib/storage/clusterconfig/clusterconfig.go

@@ -140,8 +140,11 @@ func (r Resource) Merge(other Resource) Resource {
  }
  }
  // Changing cloud provider is not supported
- if other.Spec.Global.FlannelBackend != "" {
- r.Spec.Global.FlannelBackend = other.Spec.Global.FlannelBackend
+ if other.Spec.Global.FlannelBackend != nil {
+ if r.Spec.Global.FlannelBackend == nil {
+ r.Spec.Global.FlannelBackend = new(string)
+ }
+ *r.Spec.Global.FlannelBackend = *other.Spec.Global.FlannelBackend
  }
  if other.Spec.Global.PodCIDR != "" {
  r.Spec.Global.PodCIDR = other.Spec.Global.PodCIDR
@@ -279,7 +282,7 @@ func (r Global) IsEmpty() bool {
  r.ServiceNodePortRange == "" &&
  r.ProxyPortRange == "" &&
  r.HighAvailability == nil &&
- r.FlannelBackend == "" &&
+ r.FlannelBackend == nil &&
  len(r.FeatureGates) == 0
 }
 
@@ -313,8 +316,8 @@ type Global struct {
  FeatureGates map[string]bool `json:"featureGates,omitempty"`
  // HighAvailability enables high availability mode for Kubernetes.
  HighAvailability *bool `json:"highAvailability,omitempty"`
- // FlannelBackend specifies the backend to pair with flannel.
- FlannelBackend string `json:"flannelBackend,omitempty"`
+ // FlannelBackend optionally specifies the backend to pair with flannel.
+ FlannelBackend *string `json:"flannelBackend,omitempty"`
 }
 
 // specSchemaTemplate is JSON schema for the cluster configuration resource

lib/storage/clusterconfig/clusterconfig_test.go

@@ -24,6 +24,7 @@ import (
  "github.com/gravitational/gravity/lib/constants"
  "github.com/gravitational/gravity/lib/defaults"
  "github.com/gravitational/gravity/lib/storage"
+ "github.com/gravitational/gravity/lib/utils"
 
  teleservices "github.com/gravitational/teleport/lib/services"
  "github.com/gravitational/trace"
@@ -187,7 +188,7 @@ spec:
  },
  PodSubnetSize: "26",
  HighAvailability: newBoolPtr(true),
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  },
  },
  },
@@ -246,7 +247,7 @@ func (*S) TestMergesClusterConfiguration(c *C) {
  "feature2": false,
  },
  HighAvailability: newBoolPtr(true),
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  },
  },
  },
@@ -266,7 +267,7 @@ func (*S) TestMergesClusterConfiguration(c *C) {
  "feature2": false,
  },
  HighAvailability: newBoolPtr(true),
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  },
  },
  },
@@ -294,7 +295,7 @@ address: 10.0.0.1
  "feature1": true,
  "feature2": false,
  },
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  },
  },
  },
@@ -341,7 +342,7 @@ address: 10.0.0.1
  "feature1": true,
  "feature3": true,
  },
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  },
  },
  },

lib/update/clusterconfig/plan.go

@@ -197,7 +197,7 @@ func shouldUpdateNodes(clusterConfig clusterconfig.Interface, numWorkerNodes int
  config := clusterConfig.GetGlobalConfig()
  hasComponentUpdate := len(config.FeatureGates) != 0
  hasCIDRUpdate := len(config.PodCIDR) != 0 || len(config.ServiceCIDR) != 0 || config.PodSubnetSize != ""
- hasFlannelUpdate := config.FlannelBackend != ""
+ hasFlannelUpdate := config.FlannelBackend != nil
  return !clusterConfig.GetKubeletConfig().IsEmpty() || hasComponentUpdate || hasCIDRUpdate || hasFlannelUpdate
 }
 

lib/utils/units.go

@@ -146,13 +146,38 @@ func BoolPtr(v bool) *bool {
  return &v
 }
 
+// FormatBoolPtr formats the bool pointer value for output
+func FormatBoolPtr(v *bool) string {
+ if v == nil {
+ return "<unset>"
+ }
+ return fmt.Sprint(*v)
+}
+
 // DurationPtr returns a pointer to the provided duration value
 func DurationPtr(v time.Duration) *teleservices.Duration {
  d := teleservices.NewDuration(v)
  return &d
 }
 
+// StringValue returns the string value in v or an empty string if it's nil
+func StringValue(v *string) string {
+ if v != nil {
+ return *v
+ }
+ return ""
+}
+
 // StringPtr returns a pointer to the provided string
 func StringPtr(s string) *string {
  return &s
 }
+
+// FormatStringPtrWithDefault formats the string pointer value for output.
+// If the pointer value is nil, the specified default is used
+func FormatStringPtrWithDefault(v *string, def string) string {
+ if v == nil {
+ return def
+ }
+ return *v
+}

lib/validate/clusterconfig.go

@@ -89,8 +89,13 @@ func ClusterConfiguration(existing, update clusterconfig.Interface) error {
  return trace.Wrap(err)
  }
 
- if !isSupportedBackend(newGlobalConfig.FlannelBackend) {
- return trace.BadParameter("unsupported flannel backend was specified: %v", newGlobalConfig.FlannelBackend)
+ if newGlobalConfig.FlannelBackend != nil {
+ if *newGlobalConfig.FlannelBackend == "" {
+ return trace.BadParameter("flannel backend cannot be reset")
+ }
+ if !isSupportedBackend(*newGlobalConfig.FlannelBackend) {
+ return trace.BadParameter("unsupported flannel backend was specified: %v", *newGlobalConfig.FlannelBackend)
+ }
  }
 
  return nil

tool/gravity/cli/config_test.go

@@ -23,6 +23,7 @@ import (
  "github.com/gravitational/gravity/lib/ops/resources"
  "github.com/gravitational/gravity/lib/storage"
  "github.com/gravitational/gravity/lib/storage/clusterconfig"
+ "github.com/gravitational/gravity/lib/utils"
 
  "gopkg.in/check.v1"
 )
@@ -77,7 +78,7 @@ spec:
  ServiceCIDR: "100.200.0.0/16",
  PodCIDR: "100.96.0.0/16",
  PodSubnetSize: "26",
- FlannelBackend: "vxlan",
+ FlannelBackend: utils.StringPtr("vxlan"),
  CloudConfig: `[global]
 node-tags=example-cluster
 multizone="true"