An outline plan

pkg/controllers/cassandra/nodepool/resource.go

@@ -196,6 +196,8 @@ func StatefulSetForCluster(
 									Name:  "HEAP_NEWSIZE",
 									Value: "100M",
 								},
+								// XXX: Remove all these environment variables
+								// They won't be necessary.
 								// Deliberately set to a single space to force Cassandra to do a host name lookup.
 								// See https://github.com/apache/cassandra/blob/cassandra-3.11.2/conf/cassandra.yaml#L592
 								{

pkg/pilot/cassandra/v3/pilot.go

@@ -43,6 +43,7 @@ func NewPilot(opts *PilotOptions) (*Pilot, error) {
 		nodeTool:            opts.nodeTool,
 	}
 
+	// XXX Remove all this
 	// hack to test the seedprovider, this should use whatever pattern is decided upon here:
 	//   https://github.com/jetstack/navigator/issues/251
 	cfgPath := "/etc/cassandra/cassandra.yaml"
@@ -71,10 +72,13 @@ func (p *Pilot) WaitForCacheSync(stopCh <-chan struct{}) error {
 }
 
 func (p *Pilot) Hooks() *hook.Hooks {
+	// XXX: Add a hook here to merge our blob of essential configuration with
+	// the default configuration file found in the Docker image.
 	return &hook.Hooks{}
 }
 
 func (p *Pilot) CmdFunc(pilot *v1alpha1.Pilot) (*exec.Cmd, error) {
+	// XXX: Change this to Command("cassandra", "-f")
 	cmd := exec.Command("/docker-entrypoint.sh")
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
@@ -129,3 +133,14 @@ func (p *Pilot) LivenessCheck() error {
 	_, err := p.nodeTool.Status()
 	return err
 }
+
+// XXX: Add a WriteConfig method which takes
+func (p *Pilot) WriteConfig() error {
+	// Look for cassandra.yaml in directory given by $CASSANDRA_CONFIG environment variable.
+	// Unmarshall it as an unstructured map of strings.
+	// Remove keys
+	// Set SeedProvider key
+	// Write back out (backing up the original)
+	// NB: Comments will be lost.
+	// Write the properties file. (backing up the original (if present))
+}