Configure Cassandra Sidecar (#308)

* Configure Cassandra Sidecar with proper directory structure and JVM flags

- Add sidecar configuration constants to Constants.kt
- Extract sidecar config resource during init for user customization
- Update packer provisioning to create /etc/cassandra-sidecar/ directory
- Create /mnt/cassandra/import staging directory with proper ownership
- Add JVM flag to systemd service: -Dsidecar.config=file:///etc/cassandra-sidecar/cassandra-sidecar.yaml
- Remove packer config file (config deployed via update-config command)
- Add cassandra-sidecar.yaml resource for local template

Configuration follows project pattern:
- Packer creates directory structure during AMI build
- Init extracts local template for user editing
- Users run update-config to deploy changes to remote nodes

Addresses #303

* Remove empty config directory provisioner from packer

The config directory is no longer needed since cassandra-sidecar.yaml
is now deployed via update-config command rather than baked into the AMI.

* Add update-config to end-to-end test

Test the update-config workflow which deploys configurations
including cassandra-sidecar.yaml to remote nodes.

* Add list command to end-to-end test

Verify that Cassandra versions are available before selecting one.

* Add restart command to end-to-end test

Verify that Cassandra and sidecar can be restarted successfully.

Author: rustyrazorblade

bin/end-to-end-test

@@ -8,12 +8,21 @@ echo "=== Building project ==="
 echo "=== Initializing cluster ==="
 bin/easy-cass-lab init -c 2 -i t3a.xlarge test --clean --up
 
+echo "=== Updating configuration ==="
+bin/easy-cass-lab update-config
+
+echo "=== Listing available Cassandra versions ==="
+bin/easy-cass-lab list
+
 echo "=== Setting Cassandra version to 5.0 ==="
 bin/easy-cass-lab use 5.0
 
 echo "=== Starting Cassandra ==="
 bin/easy-cass-lab start
 
+echo "=== Restarting Cassandra ==="
+bin/easy-cass-lab restart
+
 echo "=== Tearing down cluster ==="
 bin/easy-cass-lab down --yes
 

packer/cassandra/cassandra.pkr.hcl

@@ -72,13 +72,6 @@ build {
     destination = "environment"
   }
 
-  provisioner "file" {
-    source = "config"
-    destination = "config"
-  }
-
-
-
   provisioner "shell" {
     inline = ["sudo mv environment /etc/environment"]
   }
@@ -117,7 +110,11 @@ build {
   }
 
   provisioner "shell" {
-    inline = ["sudo mv config/cassandra-sidecar.yaml /usr/local/cassandra-sidecar/conf/sidecar.yaml"]
+    inline = [
+      "sudo mkdir -p /etc/cassandra-sidecar",
+      "sudo mkdir -p /mnt/cassandra/import",
+      "sudo chown ubuntu:ubuntu /mnt/cassandra/import"
+    ]
   }
 
   provisioner "shell" {

packer/cassandra/services/cassandra-sidecar.service

@@ -2,6 +2,7 @@
 Description=Apache Cassandra Sidecar
 
 [Service]
+Environment="JAVA_OPTS=-Dsidecar.config=file:///etc/cassandra-sidecar/cassandra-sidecar.yaml"
 ExecStart=/usr/local/cassandra-sidecar/bin/cassandra-sidecar
 User=cassandra
 

src/main/kotlin/com/rustyrazorblade/easycasslab/Constants.kt

@@ -95,13 +95,22 @@ object Constants {
         const val CASSANDRA_DOCKER_COMPOSE = "cassandra/docker-compose.yaml"
         const val CASSANDRA_OTEL_CONFIG = "cassandra/otel-cassandra-config.yaml"
         const val CASSANDRA_REMOTE_OTEL_CONFIG = "otel-cassandra-config.yaml"
+        const val CASSANDRA_SIDECAR_CONFIG = "cassandra/cassandra-sidecar.yaml"
+        const val CASSANDRA_REMOTE_SIDECAR_DIR = "/etc/cassandra-sidecar"
+        const val CASSANDRA_REMOTE_SIDECAR_CONFIG = "$CASSANDRA_REMOTE_SIDECAR_DIR/cassandra-sidecar.yaml"
 
         // Stress node configs
         const val STRESS_DOCKER_COMPOSE = "stress/docker-compose.yaml"
         const val STRESS_OTEL_CONFIG = "stress/otel-stress-config.yaml"
         const val STRESS_REMOTE_OTEL_CONFIG = "otel-stress-config.yaml"
     }
 
+    // Cassandra Sidecar configuration
+    object Sidecar {
+        const val STORAGE_DIR = "/mnt/cassandra/data"
+        const val STAGING_DIR = "/mnt/cassandra/import"
+    }
+
     // Remote file existence checks
     object RemoteChecks {
         const val FILE_EXISTS_SUFFIX = "&& echo 'exists' || echo 'not found'"

src/main/kotlin/com/rustyrazorblade/easycasslab/commands/Init.kt

@@ -311,6 +311,7 @@ class Init(
         File("cassandra").mkdirs()
         extractResourceFile("otel-cassandra-config.yaml", "cassandra/otel-cassandra-config.yaml")
         extractResourceFile("docker-compose-cassandra.yaml", "cassandra/docker-compose.yaml")
+        extractResourceFile("cassandra-sidecar.yaml", "cassandra/cassandra-sidecar.yaml")
 
         // Create stress directory and extract OTel configs for stress nodes
         outputHandler.handleMessage(