Merge pull request #4 from projectsyn/initial-implementation

Initial implementation

Author: simu

.codeclimate.yml

@@ -10,6 +10,25 @@ plugins:
     enabled: true
   fixme:
     enabled: true
+
+checks:
+  argument-count:
+    enabled: true
+    config:
+      threshold: 6
+  method-lines:
+    enabled: true
+    config:
+      threshold: 50
+  return-statements:
+    enabled: true
+    config:
+      threshold: 10
+  similar-code:
+    enabled: true
+  identical-code:
+    enabled: true
+
 exclude_patterns:
 - 'config/'
 - 'db/'

Makefile

@@ -23,7 +23,11 @@ build: build-bin build-docker ## All-in-one build
 .PHONY: build-bin
 build-bin: export CGO_ENABLED = 0
 build-bin: fmt vet ## Build binary
-	@go build -o $(BIN_FILENAME) ./...
+	@go build -o $(BIN_FILENAME)
+
+.PHONY: run
+run:
+	go run . -zap-devel -zap-log-level info
 
 .PHONY: build-docker
 build-docker: build-bin ## Build docker image

PROJECT

@@ -0,0 +1,13 @@
+domain: syn.tools
+layout:
+- go.kubebuilder.io/v3
+projectName: k8s-service-ca-controller
+repo: github.com/projectsyn/k8s-service-ca-controller
+resources:
+- controller: true
+  kind: Service
+  version: v1
+- controller: true
+  kind: ConfigMap
+  version: v1
+version: "3"

certs/ca.go

@@ -0,0 +1,194 @@
+package certs
+
+import (
+	"context"
+	"fmt"
+	"unicode/utf8"
+
+	cmapi "github.com/cert-manager/cert-manager/pkg/apis/certmanager/v1"
+	cmmeta "github.com/cert-manager/cert-manager/pkg/apis/meta/v1"
+	"github.com/go-logr/logr"
+	corev1 "k8s.io/api/core/v1"
+	extv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+const (
+	SelfSignedIssuerName = "service-ca-self-signed"
+	CACertName           = "service-ca-certificate"
+	CAName               = "service-ca"
+	CASecretName         = "service-ca-root"
+	ServiceIssuerName    = "service-ca-issuer"
+)
+
+// ensureCA ensures that the Service CA is completely setup on the cluster
+func ensureCA(ctx context.Context, c client.Client, l logr.Logger, caNamespace string) error {
+	log := l.WithValues("caNamespace", caNamespace)
+
+	err := ensureSelfSignedIssuer(ctx, c, log, caNamespace)
+	if err != nil {
+		return err
+	}
+
+	err = ensureCACertificate(ctx, c, log, caNamespace)
+	if err != nil {
+		return err
+	}
+
+	err = ensureServiceCAIssuer(ctx, c, log, caNamespace)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// ensureSelfSignedIssuer creates a self-signed issuer in `caNamespace` if it
+// doesn't exist
+func ensureSelfSignedIssuer(ctx context.Context, c client.Client, l logr.Logger, caNamespace string) error {
+	iss := cmapi.Issuer{}
+	err := c.Get(ctx, client.ObjectKey{
+		Name:      SelfSignedIssuerName,
+		Namespace: caNamespace,
+	}, &iss)
+	if err != nil && !errors.IsNotFound(err) {
+		l.Error(err, "while fetching self-signed issuer")
+		return err
+	}
+	if errors.IsNotFound(err) {
+		l.Info("Self-signed issuer doesn't exist, creating...")
+		iss.Name = SelfSignedIssuerName
+		iss.Namespace = caNamespace
+		iss.Spec.SelfSigned = &cmapi.SelfSignedIssuer{}
+		if err := c.Create(ctx, &iss); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ensureCACertificate creates the Service CA certificate if it doesn't exist
+func ensureCACertificate(ctx context.Context, c client.Client, l logr.Logger, caNamespace string) error {
+	// Create CA cert if not exists (in caNamespace)
+	caCert := cmapi.Certificate{}
+	err := c.Get(ctx, client.ObjectKey{
+		Name:      CACertName,
+		Namespace: caNamespace,
+	}, &caCert)
+	if err != nil && !errors.IsNotFound(err) {
+		l.Error(err, "while fetching service CA certificate")
+		return err
+	}
+	if errors.IsNotFound(err) {
+		l.Info("Service CA certificate doesn't exist, creating...")
+		caCert = newCACertificate(caNamespace)
+		if err := c.Create(ctx, &caCert); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ensureServiceCAIssuer creates the ClusterIssuer for the Service CA if it
+// doesn't exist
+func ensureServiceCAIssuer(ctx context.Context, c client.Client, l logr.Logger, caNamespace string) error {
+	// Create Service CA clusterissuer, if not exists
+	serviceIssuer := cmapi.ClusterIssuer{}
+	err := c.Get(ctx, client.ObjectKey{Name: ServiceIssuerName}, &serviceIssuer)
+	if err != nil && !errors.IsNotFound(err) {
+		l.Error(err, "while fetching service CA cluster issuer")
+		return err
+	}
+	if errors.IsNotFound(err) {
+		l.Info("Service CA cluster issuer doesn't exist, creating...")
+		serviceIssuer.Name = ServiceIssuerName
+		serviceIssuer.Spec.CA = &cmapi.CAIssuer{
+			SecretName: CASecretName,
+		}
+		if err := c.Create(ctx, &serviceIssuer); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// newCACertificate returns a new Service CA certificate resource
+func newCACertificate(caNamespace string) cmapi.Certificate {
+	return cmapi.Certificate{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      CACertName,
+			Namespace: caNamespace,
+		},
+		Spec: cmapi.CertificateSpec{
+			IsCA:       true,
+			CommonName: CAName,
+			SecretName: CASecretName,
+			// TODO: make the private key config configurable?
+			PrivateKey: &cmapi.CertificatePrivateKey{
+				Algorithm: cmapi.ECDSAKeyAlgorithm,
+				Size:      521,
+			},
+			IssuerRef: cmmeta.ObjectReference{
+				Name:  SelfSignedIssuerName,
+				Kind:  "Issuer",
+				Group: "cert-manager.io",
+			},
+		},
+	}
+}
+
+// GetServiceCA returns the Service CA certificate as a string
+// Intended to be called in the reconcile loop. Returns an error if the CA
+// certificate isn't ready yet.
+func GetServiceCA(ctx context.Context, c client.Client, l logr.Logger, caNamespace string) (string, error) {
+	log := l.WithValues("caNamespace", caNamespace)
+	caCert := cmapi.Certificate{}
+	if err := initializeServiceCA(ctx, log, c, caNamespace); err != nil {
+		return "", err
+	}
+	err := c.Get(ctx, client.ObjectKey{
+		Name:      CACertName,
+		Namespace: caNamespace,
+	}, &caCert)
+	if err != nil {
+		log.Error(err, "fetching CA certificate")
+		return "", err
+	}
+
+	if !isCertReady(&caCert) {
+		log.Info("CA certificate not yet ready")
+		return "", fmt.Errorf("CA certificate not yet ready")
+	}
+
+	secret := corev1.Secret{}
+	if err := c.Get(ctx, client.ObjectKey{
+		Name:      caCert.Spec.SecretName,
+		Namespace: caNamespace,
+	}, &secret); err != nil {
+		log.Error(err, "Fetching CA secret")
+		return "", err
+	}
+	caBytes, ok := secret.Data["tls.crt"]
+	if !ok {
+		return "", fmt.Errorf("key `tls.crt` missing in CA secret")
+	}
+
+	if !utf8.Valid(caBytes) {
+		return "", fmt.Errorf("`tls.crt` in secret is not valid UTF-8")
+	}
+
+	return string(caBytes), nil
+}
+
+// initializeServiceCA checks that cert-manager CRDs exist and ensures that the service CA is setup
+func initializeServiceCA(ctx context.Context, l logr.Logger, c client.Client, caNamespace string) error {
+	cmcrd := extv1.CustomResourceDefinition{}
+	if err := c.Get(ctx, client.ObjectKey{Name: "certificates.cert-manager.io"}, &cmcrd); err != nil {
+		return err
+	}
+
+	// Ensure that service CA exists
+	return ensureCA(ctx, c, l, caNamespace)
+}