Support TLS for galera

Ability to specify a certificate and a CA to be used for galera
cluster communication (GCOMM, SST).

Updates to the certificate used for galera automatically triggers
a rolling restart of the galera pods, without service disruption.

When the Galera CR is configured to use TLS, the mariadbdatabase
CR creates DB users that still allow connection to the DB without
using TLS. This is because Openstack clients currently cannot be
configured to connect via TLS or via plain TCP. This specific
part will be addressed in a subsequent commit.

api/bases/mariadb.openstack.org_galeras.yaml

@@ -91,6 +91,18 @@ spec:
               storageRequest:
                 description: Storage size allocated for the mariadb databases
                 type: string
+              tls:
+                description: TLS settings to use for MySQL and Galera replication
+                properties:
+                  caSecretName:
+                    description: Secret in the same namespace containing the CA cert
+                      (ca.crt) for client certificate validation
+                    type: string
+                  secretName:
+                    description: Secret in the same namespace containing the server
+                      private key (tls.key) and public cert (tls.crt) for TLS
+                    type: string
+                type: object
             required:
             - containerImage
             - replicas

api/v1beta1/galera_types.go

@@ -62,6 +62,16 @@ type GaleraSpec struct {
 	// +kubebuilder:validation:Enum=rsync;mariabackup
 	// Snapshot State Transfer method to use for full node synchronization
 	SST GaleraSST `json:"sst"`
+	// TLS settings to use for MySQL and Galera replication
+	TLS TLSSpec `json:"tls,omitempty"`
+}
+
+// TLSSpec defines the TLS options
+type TLSSpec struct {
+	// Secret in the same namespace containing the server private key (tls.key) and public cert (tls.crt) for TLS
+	SecretName string `json:"secretName,omitempty"`
+	// Secret in the same namespace containing the CA cert (ca.crt) for client certificate validation
+	CaSecretName string `json:"caSecretName,omitempty"`
 }
 
 // Supported SST type

config/crd/bases/mariadb.openstack.org_galeras.yaml

@@ -91,6 +91,18 @@ spec:
               storageRequest:
                 description: Storage size allocated for the mariadb databases
                 type: string
+              tls:
+                description: TLS settings to use for MySQL and Galera replication
+                properties:
+                  caSecretName:
+                    description: Secret in the same namespace containing the CA cert
+                      (ca.crt) for client certificate validation
+                    type: string
+                  secretName:
+                    description: Secret in the same namespace containing the server
+                      private key (tls.key) and public cert (tls.crt) for TLS
+                    type: string
+                type: object
             required:
             - containerImage
             - replicas

config/rbac/role.yaml

@@ -112,6 +112,18 @@ rules:
   - pods/exec
   verbs:
   - create
+- apiGroups:
+  - ""
+  resources:
+  - secrets
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - ""
   resources:

config/samples/cert-manager-galera-cert.yaml

@@ -0,0 +1,74 @@
+# the cluster-wide issuer, used to generate a root certificate
+apiVersion: cert-manager.io/v1
+kind: ClusterIssuer
+metadata:
+  name: selfsigned-issuer
+spec:
+  selfSigned: {}
+---
+# The root certificate. they cert/key/ca will be generated in the secret 'root-secret'
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: my-selfsigned-ca
+  namespace: openstack
+spec:
+  isCA: true
+  commonName: my-selfsigned-ca
+  secretName: root-secret
+  privateKey:
+    algorithm: ECDSA
+    size: 256
+  issuerRef:
+    name: selfsigned-issuer
+    kind: ClusterIssuer
+    group: cert-manager.io
+---
+# The CA issuer for galera, uses the certificate from `my-selfsigned-ca`
+apiVersion: cert-manager.io/v1
+kind: Issuer
+metadata:
+  name: my-ca-issuer
+  namespace: openstack
+spec:
+  ca:
+    secretName: root-secret
+---
+# The certificate used by all galera replicas for GCOMM and SST.
+# The replicas in the galera statefulset all share the same
+# certificate, so the latter requires wildcard in dnsNames for TLS
+# validation.
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: galera-cert
+spec:
+  secretName: galera-tls
+  secretTemplate:
+    labels:
+       mariadb-ref: openstack
+  duration: 6h
+  renewBefore: 1h
+  subject:
+    organizations:
+      - cluster.local
+  commonName: openstack-galera
+  isCA: false
+  privateKey:
+    algorithm: RSA
+    encoding: PKCS8
+    size: 2048
+  usages:
+    - server auth
+    - client auth
+  dnsNames:
+    - "openstack-galera"
+    - "*.openstack-galera"
+    - "*.openstack-galera.openstack"
+    - "*.openstack-galera.openstack.svc"
+    - "*.openstack-galera.openstack.svc.cluster"
+    - "*.openstack-galera.openstack.svc.cluster.local"
+  issuerRef:
+    name: my-ca-issuer
+    group: cert-manager.io
+    kind: Issuer

config/samples/mariadb_v1beta1_galera_tls.yaml

@@ -0,0 +1,12 @@
+apiVersion: mariadb.openstack.org/v1beta1
+kind: Galera
+metadata:
+  name: openstack
+spec:
+  secret: osp-secret
+  storageClass: local-storage
+  storageRequest: 500M
+  replicas: 3
+  tls:
+    secretName: galera-tls
+    caSecretName: galera-tls