expand tests and docs (#2721)

Signed-off-by: Mark McCormick <mark.mccormick@chainguard.dev>

images/cassandra/README.md

@@ -26,4 +26,50 @@ docker pull cgr.dev/chainguard/cassandra:latest
 <!--getting:end-->
 
 <!--body:start-->
+
+## Deploying
+Deploy a new instance of Cassandra using this image:
+
+```bash
+docker run -d \
+  --name cassandra \
+  -e CASSANDRA_START_RPC=true \
+  -p 9042:9042 cgr.dev/chainguard/cassandra:latest
+```
+
+You can use `nodetool status` command to check if Cassandra is running properly.
+Note, it'll take a couple of minutes for Cassandra to become fully operational:
+
+```bash
+docker exec -it cassandra nodetool status
+
+Datacenter: datacenter1
+=======================
+Status=Up/Down
+|/ State=Normal/Leaving/Joining/Moving
+--  Address    Load        Tokens  Owns (effective)  Host ID                               Rack
+UN  127.0.0.1  104.38 KiB  16      100.0%            0e75f72d-d273-4fac-807e-2b230583458c  rack1
+```
+
+`cqlsh` is available on the image:
+
+```bash
+docker exec -i cassandra cqlsh -e "
+CREATE KEYSPACE testkeyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};
+USE testkeyspace;
+CREATE TABLE users (user_id UUID PRIMARY KEY, name text);
+INSERT INTO users (user_id, name) VALUES (uuid(), 'Chainguard');
+SELECT * FROM users;
+"
+
+ user_id                              | name
+--------------------------------------+------------
+ 3f13c6b4-4a22-4de7-a1f6-a3ac6e887ddb | Chainguard
+ 67e3be15-07f9-4dd6-b9b9-c00037d705ac | Chainguard
+
+(2 rows)
+```
+
+For more information, refer to the [Cassandra documentation](https://cassandra.apache.org/_/quickstart.html).
+
 <!--body:end-->

images/cassandra/tests/main.tf

@@ -1,6 +1,8 @@
 terraform {
   required_providers {
-    oci = { source = "chainguard-dev/oci" }
+    oci       = { source = "chainguard-dev/oci" }
+    imagetest = { source = "chainguard-dev/imagetest" }
+
     kubernetes = {
       source  = "hashicorp/kubernetes"
       version = "~> 2.28.1"
@@ -197,3 +199,32 @@ resource "kubernetes_stateful_set" "cassandra" {
     service_name = kubernetes_service.cassandra.metadata[0].name
   }
 }
+
+data "imagetest_inventory" "this" {}
+
+resource "imagetest_harness_docker" "docker" {
+  name      = "cassandra"
+  inventory = data.imagetest_inventory.this
+
+  mounts = [{
+    source      = path.module
+    destination = "/tests"
+  }]
+
+  envs = {
+    IMAGE_NAME : var.digest
+  }
+}
+
+resource "imagetest_feature" "basic" {
+  harness     = imagetest_harness_docker.docker
+  name        = "Basic"
+  description = "Run Cassandra functionality tests."
+
+  steps = [
+    {
+      name = "Cassandra tests"
+      cmd  = "/tests/run-tests.sh"
+    }
+  ]
+}

images/cassandra/tests/run-tests.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+
+set -o errexit -o nounset -o pipefail -x
+
+# Start a Cassandra container
+CASSANDRA_CONTAINER=$(docker run -d -e CASSANDRA_START_RPC=true $IMAGE_NAME)
+
+# Wait for Cassandra to start
+MAX_RETRIES=10
+RETRY_INTERVAL=10
+
+for ((i=0; i<MAX_RETRIES; i++)); do
+  if docker exec "$CASSANDRA_CONTAINER" nodetool status; then
+    echo "Cassandra is running"
+    break
+  else
+    echo "Waiting for Cassandra to start..."
+    sleep $RETRY_INTERVAL
+  fi
+
+  if [[ $i -eq $((MAX_RETRIES-1)) ]]; then
+    echo "Error: Cassandra did not start within the expected time"
+    docker logs "$CASSANDRA_CONTAINER"
+    docker stop "$CASSANDRA_CONTAINER"
+    docker rm "$CASSANDRA_CONTAINER"
+    exit 1
+  fi
+done
+
+# Create a keyspace and table, insert data, and query it
+docker exec -i "$CASSANDRA_CONTAINER" cqlsh <<EOF
+CREATE KEYSPACE testkeyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};
+USE testkeyspace;
+CREATE TABLE users (user_id UUID PRIMARY KEY, name text);
+INSERT INTO users (user_id, name) VALUES (uuid(), 'Chainguard');
+SELECT * FROM users;
+EOF
+sleep 5
+
+# Check if the data was inserted and queried correctly
+RESULT=$(docker exec "$CASSANDRA_CONTAINER" cqlsh -e "USE testkeyspace; SELECT * FROM users;")
+if [[ "$RESULT" != *"Chainguard"* ]]; then
+  echo "Error: Data insertion/query failed"
+  docker logs "$CASSANDRA_CONTAINER"
+  docker stop "$CASSANDRA_CONTAINER"
+  docker rm "$CASSANDRA_CONTAINER"
+  exit 1
+fi
+
+# Clean up
+docker stop "$CASSANDRA_CONTAINER"
+docker rm "$CASSANDRA_CONTAINER"
+
+echo "Cassandra functionality test passed!"