feat: Add route_controller to linode CCM (#199)

* add back changes reverted in PR #195

* get instanceConfig only when running within VPC

* add and fix unittests

* use lock when reading/writing vpc id

* updated route-controller using /v4/vpcs/ips api

* fix tests

* switch to new api returning ips for specific vpc

* when running with vpc set, only cache instances which are part of VPC

* address review comments

* update linodego to v1.33.0

* address review comment, make variable required if routecontroller is enabled

---------

Co-authored-by: Rahul Sharma <[email protected]>

Author: rahulait

README.md

@@ -126,6 +126,17 @@ Users can create CloudFirewall instances, supply their own rules and attach them
 **Note**<br/>
 If the user supplies a firewall-id, and later switches to using an ACL, the CCM will take over the CloudFirewall Instance. To avoid this, delete the service, and re-create it so the original CloudFirewall is left undisturbed.
 
+#### Routes
+When running k8s clusters within VPC, node specific podCIDRs need to be allowed on the VPC interface. Linode CCM comes with route-controller functionality which can be enabled for automatically adding/deleting routes on VPC interfaces. When installing CCM with helm, make sure to specify routeController settings.
+
+##### Example usage in values.yaml
+```yaml
+routeController:
+  vpcName: <name of VPC>
+  clusterCIDR: 10.0.0.0/8
+  configureCloudRoutes: true
+```
+
 ### Nodes
 Kubernetes Nodes can be configured with the following annotations.
 

cloud/linode/client/client.go

@@ -16,6 +16,11 @@ type Client interface {
 	ListInstances(context.Context, *linodego.ListOptions) ([]linodego.Instance, error)
 	GetInstanceIPAddresses(context.Context, int) (*linodego.InstanceIPAddressResponse, error)
 
+	UpdateInstanceConfigInterface(context.Context, int, int, int, linodego.InstanceConfigInterfaceUpdateOptions) (*linodego.InstanceConfigInterface, error)
+
+	ListVPCs(context.Context, *linodego.ListOptions) ([]linodego.VPC, error)
+	ListVPCIPAddresses(context.Context, int, *linodego.ListOptions) ([]linodego.VPCIP, error)
+
 	CreateNodeBalancer(context.Context, linodego.NodeBalancerCreateOptions) (*linodego.NodeBalancer, error)
 	GetNodeBalancer(context.Context, int) (*linodego.NodeBalancer, error)
 	UpdateNodeBalancer(context.Context, int, linodego.NodeBalancerUpdateOptions) (*linodego.NodeBalancer, error)

cloud/linode/client/mocks/mock_client.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sync"
 
 	"github.com/linode/linodego"
 	"github.com/spf13/pflag"
@@ -25,14 +26,46 @@ const (
 // We expect it to be initialized with flags external to this package, likely in
 // main.go
 var Options struct {
-	KubeconfigFlag *pflag.Flag
-	LinodeGoDebug  bool
+	KubeconfigFlag        *pflag.Flag
+	LinodeGoDebug         bool
+	EnableRouteController bool
+	VPCName               string
 }
 
+// vpcDetails is set when VPCName options flag is set.
+// We use it to list instances running within the VPC if set
+type vpcDetails struct {
+	mu   sync.RWMutex
+	id   int
+	name string
+}
+
+func (v *vpcDetails) setDetails(client client.Client, name string) error {
+	v.mu.Lock()
+	defer v.mu.Unlock()
+
+	id, err := getVPCID(client, Options.VPCName)
+	if err != nil {
+		return fmt.Errorf("failed finding VPC ID: %w", err)
+	}
+	v.id = id
+	v.name = name
+	return nil
+}
+
+func (v *vpcDetails) getID() int {
+	v.mu.Lock()
+	defer v.mu.Unlock()
+	return v.id
+}
+
+var vpcInfo vpcDetails = vpcDetails{id: 0, name: ""}
+
 type linodeCloud struct {
 	client        client.Client
 	instances     cloudprovider.InstancesV2
 	loadbalancers cloudprovider.LoadBalancer
+	routes        cloudprovider.Routes
 }
 
 func init() {
@@ -67,12 +100,26 @@ func newCloud() (cloudprovider.Interface, error) {
 		linodeClient.SetDebug(true)
 	}
 
-	// Return struct that satisfies cloudprovider.Interface
-	return &linodeCloud{
+	if Options.VPCName != "" {
+		err := vpcInfo.setDetails(linodeClient, Options.VPCName)
+		if err != nil {
+			return nil, fmt.Errorf("failed finding VPC ID: %w", err)
+		}
+	}
+
+	routes, err := newRoutes(linodeClient)
+	if err != nil {
+		return nil, fmt.Errorf("routes client was not created successfully: %w", err)
+	}
+
+	// create struct that satisfies cloudprovider.Interface
+	lcloud := &linodeCloud{
 		client:        linodeClient,
 		instances:     newInstances(linodeClient),
 		loadbalancers: newLoadbalancers(linodeClient, region),
-	}, nil
+		routes:        routes,
+	}
+	return lcloud, nil
 }
 
 func (c *linodeCloud) Initialize(clientBuilder cloudprovider.ControllerClientBuilder, stopCh <-chan struct{}) {
@@ -109,6 +156,9 @@ func (c *linodeCloud) Clusters() (cloudprovider.Clusters, bool) {
 }
 
 func (c *linodeCloud) Routes() (cloudprovider.Routes, bool) {
+	if Options.EnableRouteController {
+		return c.routes, true
+	}
 	return nil, false
 }
 

cloud/linode/cloud.go

@@ -0,0 +1,30 @@
+package linode
+
+import (
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewCloudRouteControllerDisabled(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	t.Setenv("LINODE_API_TOKEN", "dummyapitoken")
+	t.Setenv("LINODE_REGION", "us-east")
+
+	t.Run("should not fail if vpc is empty and routecontroller is disabled", func(t *testing.T) {
+		Options.VPCName = ""
+		Options.EnableRouteController = false
+		_, err := newCloud()
+		assert.NoError(t, err)
+	})
+
+	t.Run("fail if vpcname is empty and routecontroller is enabled", func(t *testing.T) {
+		Options.VPCName = ""
+		Options.EnableRouteController = true
+		_, err := newCloud()
+		assert.Error(t, err)
+	})
+}