Merge pull request #17 from 4ARMED/eks_refactor

Tweaks to support EKS cloud-config changes

Makefile

@@ -2,14 +2,14 @@ EXECUTABLE := "kubeletmein"
 GITVERSION := $(shell git describe --dirty --always --tags --long)
 PACKAGENAME := $(shell go list -m -f '{{.Path}}')
 
-build: clean test
+build: clean
 	go build -ldflags "-extldflags '-static' -X ${PACKAGENAME}/pkg/config.GitVersion=${GITVERSION}" -o ${EXECUTABLE} ./cmd/kubeletmein
 
 build-quick: clean
 	go build -ldflags "-extldflags '-static' -X ${PACKAGENAME}/pkg/config.GitVersion=${GITVERSION}" -o ${EXECUTABLE} ./cmd/kubeletmein
 
 build-linux:
-	GOOS=linux go build -ldflags "-extldflags '-static' -X ${PACKAGENAME}/pkg/config.GitVersion=${GITVERSION}" -o ${EXECUTABLE}-linux ./cmd/kubeletmein
+	GOOS=linux GOARCH=amd64 go build -ldflags "-extldflags '-static' -X ${PACKAGENAME}/pkg/config.GitVersion=${GITVERSION}" -o ${EXECUTABLE}-linux ./cmd/kubeletmein
 
 clean:
 	@rm -f ${EXECUTABLE}

cmd/kubeletmein/generate.go

@@ -71,6 +71,7 @@ func Generate(c *config.Config) *cobra.Command {
 	cmd.Flags().StringVarP(&c.MetadataFile, "metadata-file", "f", "", "Don't try to parse metadata, load from the specified filename instead")
 	cmd.Flags().StringVarP(&c.CertDir, "cert-dir", "d", "kubeletmein-pki", "Directory into which the new cert will be written")
 	cmd.Flags().StringVarP(&c.NodeName, "node-name", "n", "", "Node name to use for CSR. Default is to detect from metadata if needed")
+	cmd.Flags().StringVar(&c.Region, "region", "", "Region used in generation of kubeconfig")
 
 	return cmd
 }

pkg/config/config.go

@@ -29,4 +29,5 @@ type Config struct {
 	NodeName        string
 	KubeAPIServer   string
 	MetadataFile    string
+	Region          string
 }

pkg/eks/eks.go

@@ -29,6 +29,7 @@ import (
 // Generate creates the kubeconfig for EKS
 func Generate(c *config.Config) error {
 	var userData string
+	var region string
 	var err error
 
 	// get user-data
@@ -46,9 +47,16 @@ func Generate(c *config.Config) error {
 		}
 	}
 
+	if c.Region != "" {
+		region, err = getRegion()
+		if err != nil {
+			return err
+		}
+	}
+
 	// These parsers should return an api.Config{} struct
 	logger.Info("parsing user-data")
-	kubeConfigData, err := ParseUserData(userData)
+	kubeConfigData, err := ParseUserData(userData, region)
 	if err != nil {
 		return err
 	}
@@ -65,13 +73,17 @@ func Generate(c *config.Config) error {
 	return err
 }
 
+// TODO: refactor all of this to be better mockable.
+// At the moment we have these calls here which ignore the functions in
+// metadata.go completely.
 func getUserData() (string, error) {
 	md := ec2metadata.New(session.New())
 
-	userData, err := md.GetUserData()
-	if err != nil {
-		return "", err
-	}
+	return md.GetUserData()
+}
+
+func getRegion() (string, error) {
+	md := ec2metadata.New(session.New())
 
-	return userData, nil
+	return md.Region()
 }

pkg/eks/eks_test.go

@@ -8,6 +8,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var (
+	region string = "eu-west-1"
+)
+
 func TestGetUserDataCloudConfig(t *testing.T) {
 	// Shell script
 
@@ -24,7 +28,7 @@ func TestParseUserDataFromFile(t *testing.T) {
 		t.Errorf("err: %v", err)
 	}
 
-	kubeConfigData, err := ParseUserData(userData)
+	kubeConfigData, err := ParseUserData(userData, region)
 	if err != nil {
 		t.Errorf("err: %v", err)
 	}

pkg/eks/metadata.go

@@ -25,10 +25,12 @@ func NewEC2MetadataClient() (*EC2MetadataClient, error) {
 // This is all so we can mock it. There has to be a better way but
 // the AWS Go SDK seems...a bit rubbish.
 func (c *EC2MetadataClient) GetUserData() (string, error) {
-	userData, err := c.GetUserData()
-	if err != nil {
-		return "", err
-	}
+	return c.GetUserData()
+}
 
-	return userData, nil
+// Region wraps the the AWS EC2 Region call
+// This is all so we can mock it. There has to be a better way but
+// the AWS Go SDK seems...a bit rubbish.
+func (c *EC2MetadataClient) Region() (string, error) {
+	return c.Region()
 }

pkg/eks/userdata.go

@@ -30,7 +30,7 @@ type CloudConfig struct {
 
 // ParseUserData takes a string input metadata, works out its type
 // and returns a *clientcmdapi.Config ready for marshalling to disk.
-func ParseUserData(userData string) (*clientcmdapi.Config, error) {
+func ParseUserData(userData, region string) (*clientcmdapi.Config, error) {
 
 	var kubeConfigData *clientcmdapi.Config
 
@@ -55,7 +55,7 @@ func ParseUserData(userData string) (*clientcmdapi.Config, error) {
 	match := re.MatchString(userData)
 	if match {
 		logger.Debug("assuming gzipped cloud-config")
-		kubeConfigData, err = ParseCloudConfig([]byte(userData))
+		kubeConfigData, err = ParseCloudConfig([]byte(userData), region)
 		if err != nil {
 			return nil, err
 		}
@@ -74,7 +74,7 @@ func ParseUserData(userData string) (*clientcmdapi.Config, error) {
 // As a kubelet kubeconfig file is provided we basically pull this out as-is
 // from cloud-config but merge in our CA data as `certificate-authority-data`
 // to save us having to write out a cert file.
-func ParseCloudConfig(cloudConfig []byte) (*clientcmdapi.Config, error) {
+func ParseCloudConfig(cloudConfig []byte, region string) (*clientcmdapi.Config, error) {
 
 	var cloudConfigData []byte
 	k := &clientcmdapi.Config{}
@@ -111,6 +111,63 @@ func ParseCloudConfig(cloudConfig []byte) (*clientcmdapi.Config, error) {
 				return nil, err
 			}
 		}
+		if v.Path == "/etc/eksctl/kubelet.env" {
+
+			kubeletEnvContent := v.Content
+
+			re := regexp.MustCompile(`CLUSTER_NAME=(.*)`)
+			fetchedValue := re.FindStringSubmatch(kubeletEnvContent)
+
+			if len(fetchedValue) == 0 {
+				// different format of cloud-config
+				continue
+			}
+
+			clusterName := fetchedValue[1]
+
+			re = regexp.MustCompile(`API_SERVER_URL=(.*)`)
+			fetchedValue = re.FindStringSubmatch(kubeletEnvContent)
+			k8sMaster := fetchedValue[1]
+
+			re = regexp.MustCompile(`B64_CLUSTER_CA=(.*)`)
+			fetchedValue = re.FindStringSubmatch(kubeletEnvContent)
+			base64DecodedCAData := fetchedValue[1]
+
+			k = &clientcmdapi.Config{
+				// Define a cluster stanza
+				Clusters: map[string]*clientcmdapi.Cluster{
+					clusterName: {
+						Server:                   k8sMaster,
+						CertificateAuthorityData: []byte(base64DecodedCAData),
+					},
+				},
+				// Define auth based on the kubelet client cert retrieved
+				AuthInfos: map[string]*clientcmdapi.AuthInfo{
+					"kubelet": {
+						Exec: &clientcmdapi.ExecConfig{
+							APIVersion: "client.authentication.k8s.io/v1alpha1",
+							Command:    "aws",
+							Args: []string{
+								"eks",
+								"get-token",
+								"--cluster-name",
+								clusterName,
+								"--region",
+								region,
+							},
+						},
+					},
+				},
+				// Define a context and set as current
+				Contexts: map[string]*clientcmdapi.Context{
+					"kubeletmein": {
+						Cluster:  clusterName,
+						AuthInfo: "kubelet",
+					},
+				},
+				CurrentContext: "kubeletmein",
+			}
+		}
 	}
 
 	if caData != "" {

pkg/eks/userdata_test.go

@@ -15,7 +15,7 @@ func TestParseCloudConfigGzip(t *testing.T) {
 		t.Errorf("err: %v", err)
 	}
 
-	kubeConfig, err := ParseCloudConfig(cloudConfigData)
+	kubeConfig, err := ParseCloudConfig(cloudConfigData, region)
 	if err != nil {
 		t.Errorf("err: %v", err)
 	}
@@ -24,6 +24,22 @@ func TestParseCloudConfigGzip(t *testing.T) {
 	assert.Contains(t, kubeConfig.Clusters, "test3.eu-west-1.eksctl.io")
 }
 
+func TestParseCloudConfigGzip2(t *testing.T) {
+
+	cloudConfigData, err := common.FetchMetadataFromFile(filepath.Join("testdata", "cloud-config-two.txt.gz"))
+	if err != nil {
+		t.Errorf("err: %v", err)
+	}
+
+	kubeConfig, err := ParseCloudConfig(cloudConfigData, region)
+	if err != nil {
+		t.Errorf("err: %v", err)
+	}
+
+	// if you change the testdata, make sure the cluster name matches here
+	assert.Contains(t, kubeConfig.Clusters, "test3")
+}
+
 func TestParseCloudConfigNoGzip(t *testing.T) {
 
 	cloudConfigData, err := common.FetchMetadataFromFile(filepath.Join("testdata", "cloud-config.txt.gz"))
@@ -37,7 +53,7 @@ func TestParseCloudConfigNoGzip(t *testing.T) {
 		t.Errorf("err: %v", err)
 	}
 
-	kubeConfig, err := ParseCloudConfig(gzipCloudCloudConfigData)
+	kubeConfig, err := ParseCloudConfig(gzipCloudCloudConfigData, region)
 	if err != nil {
 		t.Errorf("err: %v", err)
 	}