feat: Add support for whitelisting topic prefixes (#74)

Closes devshawn#90

Author: joschi

docs/specification.md

@@ -23,6 +23,11 @@ The desired state file consists of:
 - **topics** [Optional]: 
     - **defaults** [Optional]: Specify topic defaults so you don't need to specify them for every topic in the state file. Currently, only replication is supported. 
     - **blacklist** [Optional]: Add a prefixed topic blacklist for ignoring specific topics when using `kafka-gitops`. This allows topics to be ignored from being deleted if they are not defined in the desired state file.
+    - **whitelist** [Optional]: Add a prefixed topic whitelist for exclusively handling specific topics when using `kafka-gitops`. This allows topics to be exclusively handled and topics not on the list are being ignored, even if they are not defined in the desired state file.
+
+?> `topics.blacklist` and `topics.whitelist` are _not mutually exclusive_ can be used together to whitelist specific topic prefixes and blacklist individual "sub-topics".
+
+?> The blacklist takes precedence over the whitelist, so if a topic name is matched by both, it will be ignored and not deleted if it was not defined in the desired state file.
 
 **Example**:
 ```yaml
@@ -35,6 +40,10 @@ settings:
     blacklist:
       prefixed:
         - _confluent
+        - my-topics-excluded
+    whitelist:
+      prefixed:
+        - my-topics
 ```
 
 ## Topics

src/main/java/com/devshawn/kafka/gitops/StateManager.java

@@ -18,7 +18,7 @@
 import com.devshawn.kafka.gitops.domain.state.settings.Settings;
 import com.devshawn.kafka.gitops.domain.state.settings.SettingsCCloud;
 import com.devshawn.kafka.gitops.domain.state.settings.SettingsTopics;
-import com.devshawn.kafka.gitops.domain.state.settings.SettingsTopicsBlacklist;
+import com.devshawn.kafka.gitops.domain.state.settings.SettingsTopicsList;
 import com.devshawn.kafka.gitops.exception.ConfluentCloudException;
 import com.devshawn.kafka.gitops.exception.InvalidAclDefinitionException;
 import com.devshawn.kafka.gitops.exception.MissingConfigurationException;
@@ -39,6 +39,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -153,7 +154,8 @@ private void createServiceAccount(String name, List<ServiceAccount> serviceAccou
     private DesiredState getDesiredState() {
         DesiredStateFile desiredStateFile = getAndValidateStateFile();
         DesiredState.Builder desiredState = new DesiredState.Builder()
-                .addAllPrefixedTopicsToIgnore(getPrefixedTopicsToIgnore(desiredStateFile));
+                .addAllPrefixedTopicsToIgnore(getPrefixedTopicsToIgnore(desiredStateFile))
+                .addAllPrefixedTopicsToAccept(getPrefixedTopicsToAccept(desiredStateFile));
 
         generateTopicsState(desiredState, desiredStateFile);
 
@@ -297,7 +299,7 @@ private List<String> getPrefixedTopicsToIgnore(DesiredStateFile desiredStateFile
         desiredStateFile.getSettings()
                 .flatMap(Settings::getTopics)
                 .flatMap(SettingsTopics::getBlacklist)
-                .map(SettingsTopicsBlacklist::getPrefixed)
+                .map(SettingsTopicsList::getPrefixed)
                 .ifPresent(topics::addAll);
 
         desiredStateFile.getServices().forEach((name, service) -> {
@@ -308,6 +310,16 @@ private List<String> getPrefixedTopicsToIgnore(DesiredStateFile desiredStateFile
         return topics;
     }
 
+    private List<String> getPrefixedTopicsToAccept(DesiredStateFile desiredStateFile) {
+        return desiredStateFile.getSettings()
+                .flatMap(Settings::getTopics)
+                .flatMap(SettingsTopics::getWhitelist)
+                .map(SettingsTopicsList::getPrefixed)
+                .stream()
+                .flatMap(Collection::stream)
+                .toList();
+    }
+
     private GetAclOptions buildGetAclOptions(String serviceName) {
         return new GetAclOptions.Builder().setServiceName(serviceName).setDescribeAclEnabled(describeAclEnabled).build();
     }

src/main/java/com/devshawn/kafka/gitops/domain/state/DesiredState.java

@@ -16,6 +16,8 @@ public interface DesiredState {
 
     List<String> getPrefixedTopicsToIgnore();
 
+    List<String> getPrefixedTopicsToAccept();
+
     class Builder extends DesiredState_Builder {
     }
 }

src/main/java/com/devshawn/kafka/gitops/domain/state/settings/SettingsTopics.java

@@ -11,7 +11,9 @@ public interface SettingsTopics {
 
     Optional<SettingsTopicsDefaults> getDefaults();
 
-    Optional<SettingsTopicsBlacklist> getBlacklist();
+    Optional<SettingsTopicsList> getBlacklist();
+
+    Optional<SettingsTopicsList> getWhitelist();
 
     class Builder extends SettingsTopics_Builder {
     }

src/main/java/com/devshawn/kafka/gitops/domain/state/settings/SettingsTopicsBlacklist.java renamed to src/main/java/com/devshawn/kafka/gitops/domain/state/settings/SettingsTopicsList.java

@@ -6,11 +6,11 @@
 import java.util.List;
 
 @FreeBuilder
-@JsonDeserialize(builder = SettingsTopicsBlacklist.Builder.class)
-public interface SettingsTopicsBlacklist {
+@JsonDeserialize(builder = SettingsTopicsList.Builder.class)
+public interface SettingsTopicsList {
 
     List<String> getPrefixed();
 
-    class Builder extends SettingsTopicsBlacklist_Builder {
+    class Builder extends SettingsTopicsList_Builder {
     }
 }

src/main/java/com/devshawn/kafka/gitops/manager/PlanManager.java

@@ -66,22 +66,28 @@ public void planTopics(DesiredState desiredState, DesiredPlan.Builder desiredPla
             desiredPlan.addTopicPlans(topicPlan.build());
         });
 
-        topics.forEach(currentTopic -> {
-            boolean shouldIgnore = desiredState.getPrefixedTopicsToIgnore().stream().anyMatch(it -> currentTopic.name().startsWith(it));
-            if (shouldIgnore) {
-                LOG.info("[PLAN] Ignoring topic {} due to prefix", currentTopic.name());
-                return;
+        for (TopicListing currentTopic : topics) {
+            boolean acceptTopic = desiredState.getPrefixedTopicsToAccept().stream().anyMatch(it -> currentTopic.name().startsWith(it));
+            if (!desiredState.getPrefixedTopicsToAccept().isEmpty() && !acceptTopic) {
+                LOG.info("[PLAN] Ignoring topic {} due to missing prefix (whitelist)", currentTopic.name());
+                continue;
             }
 
-            if (!managerConfig.isDeleteDisabled() && desiredState.getTopics().getOrDefault(currentTopic.name(), null) == null) {
+            boolean ignoreTopic = desiredState.getPrefixedTopicsToIgnore().stream().anyMatch(it -> currentTopic.name().startsWith(it));
+            if (ignoreTopic) {
+                LOG.info("[PLAN] Ignoring topic {} due to prefix (blacklist)", currentTopic.name());
+                continue;
+            }
+
+            if (!managerConfig.isDeleteDisabled() && !desiredState.getTopics().containsKey(currentTopic.name())) {
                 TopicPlan topicPlan = new TopicPlan.Builder()
                         .setName(currentTopic.name())
                         .setAction(PlanAction.REMOVE)
                         .build();
 
                 desiredPlan.addTopicPlans(topicPlan);
             }
-        });
+        }
     }
 
     private void planTopicConfigurations(String topicName, TopicDetails topicDetails, List<ConfigEntry> configs, TopicPlan.Builder topicPlan) {

src/test/groovy/com/devshawn/kafka/gitops/PlanCommandIntegrationSpec.groovy

@@ -158,6 +158,8 @@ class PlanCommandIntegrationSpec extends Specification {
         "seed-topic-modification-no-delete" | true
         "seed-acl-exists"                   | true
         "seed-blacklist-topics"             | false
+        "seed-blacklist-whitelist-topics"   | false
+        "seed-whitelist-topics"             | false
     }
 
     void 'test include unchanged flag - #planName #includeUnchanged'() {

src/test/resources/plans/seed-blacklist-whitelist-topics-plan.json

@@ -0,0 +1,35 @@
+{
+    "topicPlans": [
+        {
+            "name": "new-topic",
+            "action": "ADD",
+            "topicDetails": {
+                "partitions": 6,
+                "replication": 1,
+                "configs": {}
+            },
+            "topicConfigPlans": []
+        },
+        {
+            "name": "topic-with-configs-1",
+            "action": "REMOVE",
+            "topicDetails": null,
+            "topicConfigPlans": []
+        }
+    ],
+    "aclPlans": [
+        {
+            "name": "Unnamed ACL",
+            "aclDetails": {
+                "name": "test-topic",
+                "type": "TOPIC",
+                "pattern": "LITERAL",
+                "principal": "User:test",
+                "host": "*",
+                "operation": "READ",
+                "permission": "ALLOW"
+            },
+            "action": "REMOVE"
+        }
+    ]
+}

src/test/resources/plans/seed-blacklist-whitelist-topics.yaml

@@ -0,0 +1,14 @@
+settings:
+  topics:
+    blacklist:
+      prefixed:
+        - test
+        - topic-with-configs-2
+    whitelist:
+      prefixed:
+        - topic-with
+
+topics:
+  new-topic:
+    partitions: 6
+    replication: 1

src/test/resources/plans/seed-whitelist-topics-plan.json

@@ -0,0 +1,35 @@
+{
+  "topicPlans": [
+    {
+      "name": "test-new-topic",
+      "action": "ADD",
+      "topicDetails": {
+        "partitions": 6,
+        "replication": 1,
+        "configs": {}
+      },
+      "topicConfigPlans": []
+    },
+    {
+      "name": "test-topic",
+      "action": "REMOVE",
+      "topicDetails": null,
+      "topicConfigPlans": []
+    }
+  ],
+  "aclPlans": [
+    {
+      "name": "Unnamed ACL",
+      "aclDetails": {
+        "name": "test-topic",
+        "type": "TOPIC",
+        "pattern": "LITERAL",
+        "principal": "User:test",
+        "host": "*",
+        "operation": "READ",
+        "permission": "ALLOW"
+      },
+      "action": "REMOVE"
+    }
+  ]
+}