Implement EKS support [#5]

I *think* this will work, but without access to an EKS cluster I can't
actually test it.

docs/parameter_reference.md

@@ -30,7 +30,9 @@ Installations are triggered when the `helm_command` setting is "upgrade." They c
 | chart                  | string         | yes      | The chart to use for this installation. |
 | release                | string         | yes      | The release name for helm to use. |
 | api_server             | string         | yes      | API endpoint for the Kubernetes cluster. |
-| kubernetes_token       | string         | yes      | Token for authenticating to Kubernetes. |
+| kubernetes_token       | string         | yes, unless using EKS | Token for authenticating to Kubernetes. |
+| eks_cluster            | string         |          | AWS EKS cluster ID. |
+| eks_role_arn           | string         |          | AWS IAM role ARN for EKS authentication. |
 | service_account        | string         |          | Service account for authenticating to Kubernetes. Default is `helm`. |
 | kubernetes_certificate | string         |          | Base64 encoded TLS certificate used by the Kubernetes cluster's certificate authority. |
 | chart_version          | string         |          | Specific chart version to install. |
@@ -52,7 +54,9 @@ Uninstallations are triggered when the `helm_command` setting is "uninstall" or
 |------------------------|----------|----------|---------|
 | release                | string   | yes      | The release name for helm to use. |
 | api_server             | string   | yes      | API endpoint for the Kubernetes cluster. |
-| kubernetes_token       | string   | yes      | Token for authenticating to Kubernetes. |
+| kubernetes_token       | string   | yes, unless using EKS | Token for authenticating to Kubernetes. |
+| eks_cluster            | string   |          | AWS EKS cluster ID. |
+| eks_role_arn           | string   |          | AWS IAM role ARN for EKS authentication. |
 | service_account        | string   |          | Service account for authenticating to Kubernetes. Default is `helm`. |
 | kubernetes_certificate | string   |          | Base64 encoded TLS certificate used by the Kubernetes cluster's certificate authority. |
 | dry_run                | boolean  |          | Pass `--dry-run` to `helm uninstall`. |

internal/helm/config.go

@@ -23,6 +23,8 @@ type Config struct {
 	ValuesFiles        []string `split_words:"true"`                 // Arguments to pass to --values in applicable helm commands
 	Namespace          string   ``                                   // Kubernetes namespace for all helm commands
 	KubeToken          string   `envconfig:"KUBERNETES_TOKEN"`       // Kubernetes authentication token to put in .kube/config
+	EKSCluster         string   `envconfig:"EKS_CLUSTER"`            // AWS EKS Cluster ID to put in .kube/config
+	EKSRoleARN         string   `envconfig:"EKS_ROLE_ARN"`           // AWS IAM role resource name to put in .kube/config
 	SkipTLSVerify      bool     `envconfig:"SKIP_TLS_VERIFY"`        // Put insecure-skip-tls-verify in .kube/config
 	Certificate        string   `envconfig:"KUBERNETES_CERTIFICATE"` // The Kubernetes cluster CA's self-signed certificate (must be base64-encoded)
 	APIServer          string   `envconfig:"API_SERVER"`             // The Kubernetes cluster's API endpoint

internal/helm/plan.go

@@ -142,6 +142,8 @@ func initKube(cfg Config) []Step {
 			APIServer:      cfg.APIServer,
 			ServiceAccount: cfg.ServiceAccount,
 			Token:          cfg.KubeToken,
+			EKSCluster:     cfg.EKSCluster,
+			EKSRoleARN:     cfg.EKSRoleARN,
 			TemplateFile:   kubeConfigTemplate,
 			ConfigFile:     kubeConfigFile,
 		},

internal/helm/plan_test.go

@@ -212,6 +212,8 @@ func (suite *PlanTestSuite) TestInitKube() {
 		Certificate:    "b2Ygd29rZW5lc3MK",
 		APIServer:      "123.456.78.9",
 		ServiceAccount: "helmet",
+		EKSCluster:     "eks_reader",
+		EKSRoleARN:     "arn:aws:iam::9631085:role/eksSpangleRole",
 	}
 
 	steps := initKube(cfg)
@@ -225,6 +227,8 @@ func (suite *PlanTestSuite) TestInitKube() {
 		APIServer:      "123.456.78.9",
 		ServiceAccount: "helmet",
 		Token:          "cXVlZXIgY2hhcmFjdGVyCg==",
+		EKSCluster:     "eks_reader",
+		EKSRoleARN:     "arn:aws:iam::9631085:role/eksSpangleRole",
 		TemplateFile:   kubeConfigTemplate,
 		ConfigFile:     kubeConfigFile,
 	}

internal/run/initkube.go

@@ -15,6 +15,8 @@ type InitKube struct {
 	APIServer      string
 	ServiceAccount string
 	Token          string
+	EKSCluster     string
+	EKSRoleARN     string
 	TemplateFile   string
 	ConfigFile     string
 
@@ -30,6 +32,8 @@ type kubeValues struct {
 	Namespace      string
 	ServiceAccount string
 	Token          string
+	EKSCluster     string
+	EKSRoleARN     string
 }
 
 // Execute generates a kubernetes config file from drone-helm3's template.
@@ -48,9 +52,12 @@ func (i *InitKube) Prepare(cfg Config) error {
 	if i.APIServer == "" {
 		return errors.New("an API Server is needed to deploy")
 	}
-	if i.Token == "" {
+	if i.Token == "" && i.EKSCluster == "" {
 		return errors.New("token is needed to deploy")
 	}
+	if i.Token != "" && i.EKSCluster != "" {
+		return errors.New("token cannot be used simultaneously with eksCluster")
+	}
 
 	if i.ServiceAccount == "" {
 		i.ServiceAccount = "helm"
@@ -70,6 +77,8 @@ func (i *InitKube) Prepare(cfg Config) error {
 		APIServer:      i.APIServer,
 		ServiceAccount: i.ServiceAccount,
 		Token:          i.Token,
+		EKSCluster:     i.EKSCluster,
+		EKSRoleARN:     i.EKSRoleARN,
 		Namespace:      cfg.Namespace,
 	}
 

internal/run/initkube_test.go

@@ -2,7 +2,6 @@ package run
 
 import (
 	"github.com/stretchr/testify/suite"
-	yaml "gopkg.in/yaml.v2"
 	"io/ioutil"
 	"os"
 	"testing"
@@ -58,59 +57,6 @@ namespace: Cisco
 	suite.Equal(want, string(conf))
 }
 
-func (suite *InitKubeTestSuite) TestExecuteGeneratesConfig() {
-	configFile, err := tempfile("kubeconfig********.yml", "")
-	defer os.Remove(configFile.Name())
-	suite.Require().NoError(err)
-
-	cfg := Config{
-		Namespace: "marshmallow",
-	}
-	init := InitKube{
-		ConfigFile:     configFile.Name(),
-		TemplateFile:   "../../assets/kubeconfig.tpl", // the actual kubeconfig template
-		APIServer:      "https://kube.cluster/peanut",
-		ServiceAccount: "chef",
-		Token:          "eWVhaCB3ZSB0b2tpbic=",
-		Certificate:    "d293LCB5b3UgYXJlIHNvIGNvb2wgZm9yIHNtb2tpbmcgd2VlZCDwn5mE",
-	}
-	suite.Require().NoError(init.Prepare(cfg))
-	suite.Require().NoError(init.Execute(cfg))
-
-	contents, err := ioutil.ReadFile(configFile.Name())
-	suite.Require().NoError(err)
-
-	// each setting should be reflected in the generated file
-	expectations := []string{
-		"namespace: marshmallow",
-		"server: https://kube.cluster/peanut",
-		"user: chef",
-		"name: chef",
-		"token: eWVhaCB3ZSB0b2tpbic",
-		"certificate-authority-data: d293LCB5b3UgYXJlIHNvIGNvb2wgZm9yIHNtb2tpbmcgd2VlZCDwn5mE",
-	}
-	for _, expected := range expectations {
-		suite.Contains(string(contents), expected)
-	}
-
-	// the generated config should be valid yaml, with no repeated keys
-	conf := map[string]interface{}{}
-	suite.NoError(yaml.UnmarshalStrict(contents, &conf))
-
-	// test the other branch of the certificate/SkipTLSVerify conditional
-	init.SkipTLSVerify = true
-	init.Certificate = ""
-
-	suite.Require().NoError(init.Prepare(cfg))
-	suite.Require().NoError(init.Execute(cfg))
-	contents, err = ioutil.ReadFile(configFile.Name())
-	suite.Require().NoError(err)
-	suite.Contains(string(contents), "insecure-skip-tls-verify: true")
-
-	conf = map[string]interface{}{}
-	suite.NoError(yaml.UnmarshalStrict(contents, &conf))
-}
-
 func (suite *InitKubeTestSuite) TestPrepareParseError() {
 	templateFile, err := tempfile("kubeconfig********.yml.tpl", `{{ NonexistentFunction }}`)
 	defer os.Remove(templateFile.Name())
@@ -187,6 +133,33 @@ func (suite *InitKubeTestSuite) TestPrepareRequiredConfig() {
 	suite.Error(init.Prepare(cfg), "Token should be required.")
 }
 
+func (suite *InitKubeTestSuite) TestPrepareEKSConfig() {
+	templateFile, err := tempfile("kubeconfig********.yml.tpl", "hurgity burgity")
+	defer os.Remove(templateFile.Name())
+	suite.Require().Nil(err)
+
+	configFile, err := tempfile("kubeconfig********.yml", "")
+	defer os.Remove(configFile.Name())
+	suite.Require().Nil(err)
+
+	init := InitKube{
+		TemplateFile: templateFile.Name(),
+		ConfigFile:   configFile.Name(),
+		APIServer:    "eks.aws.amazonaws.com",
+		EKSCluster:   "it-is-an-eks-parrot",
+		EKSRoleARN:   "arn:aws:iam::19691207:role/mrPraline",
+	}
+
+	cfg := Config{}
+
+	suite.NoError(init.Prepare(cfg))
+	suite.Equal(init.values.EKSCluster, "it-is-an-eks-parrot")
+	suite.Equal(init.values.EKSRoleARN, "arn:aws:iam::19691207:role/mrPraline")
+
+	init.Token = "cGluaW5nIGZvciB0aGUgZmrDtnJkcw=="
+	suite.EqualError(init.Prepare(cfg), "token cannot be used simultaneously with eksCluster")
+}
+
 func (suite *InitKubeTestSuite) TestPrepareDefaultsServiceAccount() {
 	templateFile, err := tempfile("kubeconfig********.yml.tpl", "hurgity burgity")
 	defer os.Remove(templateFile.Name())

internal/run/kubeconfig_test.go

@@ -0,0 +1,109 @@
+package run
+
+import (
+	"github.com/stretchr/testify/suite"
+	yaml "gopkg.in/yaml.v2"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+type KubeconfigTestSuite struct {
+	suite.Suite
+	configFile *os.File
+	initKube   InitKube
+}
+
+func (suite *KubeconfigTestSuite) BeforeTest(_, _ string) {
+	file, err := ioutil.TempFile("", "kubeconfig********.yml")
+	suite.Require().NoError(err)
+	file.Close()
+	suite.configFile = file
+
+	// set up an InitKube with the bare minimum configuration
+	suite.initKube = InitKube{
+		ConfigFile:   file.Name(),
+		TemplateFile: "../../assets/kubeconfig.tpl", // the actual kubeconfig template
+		APIServer:    "a",
+		Token:        "b",
+	}
+}
+
+func (suite *KubeconfigTestSuite) AfterTest(_, _ string) {
+	if suite.configFile != nil {
+		os.Remove(suite.configFile.Name())
+	}
+}
+
+func TestKubeconfigTestSuite(t *testing.T) {
+	suite.Run(t, new(KubeconfigTestSuite))
+}
+
+func (suite *KubeconfigTestSuite) TestSetsNamespace() {
+	cfg := Config{
+		Namespace: "marshmallow",
+	}
+	contents := suite.generateKubeconfig(cfg)
+	suite.Contains(contents, "namespace: marshmallow")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsAPIServer() {
+	suite.initKube.APIServer = "https://kube.cluster/peanut"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "server: https://kube.cluster/peanut")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsServiceAccount() {
+	suite.initKube.ServiceAccount = "chef"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "user: chef")
+	suite.Contains(contents, "name: chef")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsToken() {
+	suite.initKube.Token = "eWVhaCB3ZSB0b2tpbic"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "token: eWVhaCB3ZSB0b2tpbic")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsCertificate() {
+	suite.initKube.Certificate = "d293LCB5b3UgYXJlIHNvIGNvb2wgZm9yIHNtb2tpbmcgd2VlZCDwn5mE"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "certificate-authority-data: d293LCB5b3UgYXJlIHNvIGNvb2wgZm9yIHNtb2tpbmcgd2VlZCDwn5mE")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsSkipTLSVerify() {
+	suite.initKube.SkipTLSVerify = true
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "insecure-skip-tls-verify: true")
+}
+
+func (suite *KubeconfigTestSuite) TestSetsEKSCluster() {
+	suite.initKube.Token = ""
+	suite.initKube.EKSCluster = "it-is-an-eks-parrot"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, "command: aws-iam-authenticator")
+	suite.Contains(contents, `- "it-is-an-eks-parrot"`)
+}
+
+func (suite *KubeconfigTestSuite) TestSetsEKSRoleARN() {
+	suite.initKube.Token = ""
+	suite.initKube.EKSCluster = "it-is-an-eks-parrot"
+	suite.initKube.EKSRoleARN = "arn:aws:iam::19691207:role/mrPraline"
+	contents := suite.generateKubeconfig(Config{})
+	suite.Contains(contents, `- "-r"`)
+	suite.Contains(contents, `- "arn:aws:iam::19691207:role/mrPraline"`)
+}
+
+func (suite *KubeconfigTestSuite) generateKubeconfig(cfg Config) string {
+	suite.Require().NoError(suite.initKube.Prepare(cfg))
+	suite.Require().NoError(suite.initKube.Execute(cfg))
+
+	contents, err := ioutil.ReadFile(suite.configFile.Name())
+	suite.Require().NoError(err)
+
+	conf := map[string]interface{}{}
+	suite.NoError(yaml.UnmarshalStrict(contents, &conf))
+
+	return string(contents)
+}