Support fullnameOverride

In the Helm chart there is an undocumented value that allows users to
override the prefix we usually apply to the resources. The default
prefix is <helm release name>-consul. This change adds a flag to the
server-acl-init command (the only command that is affected by the
prefix) called -resource-prefix. If set, we will use the correct prefix,
both for finding resources that we expect to be created by the helm
chart, e.g. Consul servers, and for creating our own resources, e.g.
Kubernetes secrets.

subcommand/server-acl-init/command.go

@@ -28,6 +28,7 @@ type Command struct {
 	flags                        *flag.FlagSet
 	k8s                          *k8sflags.K8SFlags
 	flagReleaseName              string
+	flagResourcePrefix           string
 	flagReplicas                 int
 	flagNamespace                string
 	flagAllowDNS                 bool
@@ -53,7 +54,9 @@ type Command struct {
 func (c *Command) init() {
 	c.flags = flag.NewFlagSet("", flag.ContinueOnError)
 	c.flags.StringVar(&c.flagReleaseName, "release-name", "",
-		"Name of Consul Helm release")
+		"Name of Consul Helm release.")
+	c.flags.StringVar(&c.flagResourcePrefix, "resource-prefix", "",
+		"Prefix to use for Kubernetes resources. If not set, will default to ${release-name}-consul.")
 	c.flags.IntVar(&c.flagReplicas, "expected-replicas", 1,
 		"Number of expected Consul server replicas")
 	c.flags.StringVar(&c.flagNamespace, "k8s-namespace", "",
@@ -115,6 +118,10 @@ func (c *Command) Run(args []string) int {
 		c.UI.Error(fmt.Sprintf("%q is not a valid timeout: %s", c.flagTimeout, err))
 		return 1
 	}
+	if c.flagReleaseName == "" {
+		c.UI.Error("-release-name must be set")
+		return 1
+	}
 	var cancel context.CancelFunc
 	c.cmdTimeout, cancel = context.WithTimeout(context.Background(), timeout)
 	// The context will only ever be intentionally ended by the timeout.
@@ -140,7 +147,7 @@ func (c *Command) Run(args []string) int {
 	}
 
 	// Wait if there's a rollout of servers.
-	ssName := c.flagReleaseName + "-consul-server"
+	ssName := c.withPrefix("server")
 	err = c.untilSucceeds(fmt.Sprintf("waiting for rollout of statefulset %s", ssName), func() error {
 		ss, err := c.clientset.AppsV1().StatefulSets(c.flagNamespace).Get(ssName, metav1.GetOptions{})
 		if err != nil {
@@ -158,7 +165,7 @@ func (c *Command) Run(args []string) int {
 	}
 
 	// Check if we've already been bootstrapped.
-	bootTokenSecretName := fmt.Sprintf("%s-consul-bootstrap-acl-token", c.flagReleaseName)
+	bootTokenSecretName := c.withPrefix("bootstrap-acl-token")
 	bootstrapToken, err := c.getBootstrapToken(logger, bootTokenSecretName)
 	if err != nil {
 		logger.Error(fmt.Sprintf("Unexpected error looking for preexisting bootstrap Secret: %s", err))
@@ -496,7 +503,7 @@ func (c *Command) setServerTokens(logger hclog.Logger, consulClient *api.Client,
 // policy and then writes the token to a Kubernetes secret.
 func (c *Command) createACL(name, rules string, consulClient *api.Client, logger hclog.Logger) error {
 	// Check if the secret already exists, if so, we assume the ACL has already been created.
-	secretName := fmt.Sprintf("%s-consul-%s-acl-token", c.flagReleaseName, name)
+	secretName := c.withPrefix(name + "-acl-token")
 	_, err := c.clientset.CoreV1().Secrets(c.flagNamespace).Get(secretName, metav1.GetOptions{})
 	if err == nil {
 		logger.Info(fmt.Sprintf("Secret %q already exists", secretName))
@@ -598,7 +605,7 @@ func (c *Command) configureDNSPolicies(logger hclog.Logger, consulClient *api.Cl
 func (c *Command) configureConnectInject(logger hclog.Logger, consulClient *api.Client) error {
 	// First, check if there's already an acl binding rule. If so, then this
 	// work is already done.
-	authMethodName := fmt.Sprintf("%s-consul-k8s-auth-method", c.flagReleaseName)
+	authMethodName := c.withPrefix("k8s-auth-method")
 	var existingRules []*api.ACLBindingRule
 	err := c.untilSucceeds(fmt.Sprintf("listing binding rules for auth method %s", authMethodName),
 		func() error {
@@ -627,7 +634,7 @@ func (c *Command) configureConnectInject(logger hclog.Logger, consulClient *api.
 
 	// Get the Secret name for the auth method ServiceAccount.
 	var authMethodServiceAccount *apiv1.ServiceAccount
-	saName := fmt.Sprintf("%s-consul-connect-injector-authmethod-svc-account", c.flagReleaseName)
+	saName := c.withPrefix("connect-injector-authmethod-svc-account")
 	err = c.untilSucceeds(fmt.Sprintf("getting %s ServiceAccount", saName),
 		func() error {
 			var err error
@@ -714,6 +721,15 @@ func (c *Command) untilSucceeds(opName string, op func() error, logger hclog.Log
 	return nil
 }
 
+// withPrefix returns the name of resource with the correct prefix based
+// on the -release-name or -resource-prefix flags.
+func (c *Command) withPrefix(resource string) string {
+	if c.flagResourcePrefix != "" {
+		return fmt.Sprintf("%s-%s", c.flagResourcePrefix, resource)
+	}
+	return fmt.Sprintf("%s-consul-%s", c.flagReleaseName, resource)
+}
+
 // isNoLeaderErr returns true if err is due to trying to call the
 // bootstrap ACLs API when there is no leader elected.
 func isNoLeaderErr(err error) bool {