Remove log4j dependency and debug parameter (#238)

Fixes #162

README.md

@@ -125,8 +125,6 @@ The following configuration options are available:
 
 - `--volatile-group-instance-id`: Whether the group instance id is volatile, i.e., it will change on a Streams shutdown.
 
-- `--debug`: Configure logging to debug
-
 Additionally, the following commands are available:
 
 - `clean`: Reset the Kafka Streams application. Additionally, delete the consumer group and all output and intermediate
@@ -188,8 +186,6 @@ The following configuration options are available:
 
 - `--extra-output-topics`: Additional named output topics (`String=String>[,<String=String>...]`)
 
-- `--debug`: Configure logging to debug
-
 Additionally, the following commands are available:
 
 - `clean`: Delete all output topics associated with the Kafka Producer application.

charts/producer-app-cleanup-job/templates/job.yaml

@@ -72,10 +72,6 @@ spec:
             - name: "{{ .Values.configurationEnvPrefix }}_SCHEMA_REGISTRY_URL"
               value: {{ .Values.streams.schemaRegistryUrl | quote }}
             {{- end }}
-            {{- if hasKey .Values "debug" }}
-            - name: "{{ .Values.configurationEnvPrefix }}_DEBUG"
-              value: {{ .Values.debug | quote }}
-            {{- end }}
             {{- if hasKey .Values.streams "outputTopic" }}
             - name: "{{ .Values.configurationEnvPrefix }}_OUTPUT_TOPIC"
               value: {{ .Values.streams.outputTopic | quote }}

charts/producer-app-cleanup-job/values.yaml

@@ -29,8 +29,6 @@ streams:
 commandLine: {}
 #  MY_CLI_PARAM: "foo-bar"
 
-debug: false
-
 env: {}
 #  MY_ENV_VARIABLE: foo-bar
 

charts/producer-app/README.md

@@ -60,7 +60,6 @@ Alternatively, a YAML file that specifies the values for the parameters can be p
 |--------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|
 | `configurationEnvPrefix` | Prefix for environment variables to use that should be parsed as command line arguments.                                                                                                                                                                                                                                      | `APP`   |
 | `commandLine`            | Map of command line arguments passed to the producer app.                                                                                                                                                                                                                                                                     | `{}`    |
-| `debug`                  | Configure logging to debug                                                                                                                                                                                                                                                                                                    | `false` |
 | `env`                    | Custom environment variables                                                                                                                                                                                                                                                                                                  | `{}`    |
 | `secrets`                | Custom secret environment variables. Prefix with `configurationEnvPrefix` in order to pass secrets to command line or prefix with `KAFKA_` to pass secrets to Kafka Streams configuration. E.g., `APP_MY_PARAM` would be passed as `--my-param` and `KAFKA_MAX_POLL_TIMEOUT_MS` would be translated to `max.poll.timeout.ms`. | `{}`    |
 | `secretRefs`             | Inject existing secrets as environment variables. Map key is used as environment variable name. Value consists of secret `name` and `key`.                                                                                                                                                                                    | `{}`    |

charts/producer-app/templates/pod.yaml

@@ -56,10 +56,6 @@ spec:
       - name: "{{ .Values.configurationEnvPrefix }}_SCHEMA_REGISTRY_URL"
         value: {{ .Values.streams.schemaRegistryUrl | quote }}
         {{- end }}
-        {{- if hasKey .Values "debug" }}
-      - name: "{{ .Values.configurationEnvPrefix }}_DEBUG"
-        value: {{ .Values.debug | quote }}
-        {{- end }}
         {{- if hasKey .Values.streams "outputTopic" }}
       - name: "{{ .Values.configurationEnvPrefix }}_OUTPUT_TOPIC"
         value: {{ .Values.streams.outputTopic | quote }}

charts/producer-app/values.yaml

@@ -62,8 +62,6 @@ streams:
 commandLine: {}
 #  MY_CLI_PARAM: "foo-bar"
 
-debug: false
-
 env: {}
 #  MY_ENV_VARIABLE: foo-bar
 

charts/streams-app-cleanup-job/templates/job.yaml

@@ -76,10 +76,6 @@ spec:
             - name: "{{ .Values.configurationEnvPrefix }}_SCHEMA_REGISTRY_URL"
               value: {{ .Values.streams.schemaRegistryUrl | quote }}
             {{- end }}
-            {{- if hasKey .Values "debug" }}
-            - name: "{{ .Values.configurationEnvPrefix }}_DEBUG"
-              value: {{ .Values.debug | quote }}
-            {{- end }}
             {{- if and (hasKey .Values.streams "inputTopics") (.Values.streams.inputTopics) }}
             - name: "{{ .Values.configurationEnvPrefix }}_INPUT_TOPICS"
               value: {{ .Values.streams.inputTopics | join "," | quote }}

charts/streams-app-cleanup-job/values.yaml

@@ -41,8 +41,6 @@ streams:
 commandLine: {}
 #  MY_CLI_PARAM: "foo-bar"
 
-debug: false
-
 env: {}
 #  MY_ENV_VARIABLE: foo-bar
 #

charts/streams-app/README.md

@@ -71,7 +71,6 @@ Alternatively, a YAML file that specifies the values for the parameters can be p
 |--------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|
 | `configurationEnvPrefix` | Prefix for environment variables to use that should be parsed as command line arguments.                                                                                                                                                                                                                                      | `APP`   |
 | `commandLine`            | Map of command line arguments passed to the streams app.                                                                                                                                                                                                                                                                      | `{}`    |
-| `debug`                  | Configure logging to debug                                                                                                                                                                                                                                                                                                    | `false` |
 | `env`                    | Custom environment variables                                                                                                                                                                                                                                                                                                  | `{}`    |
 | `secrets`                | Custom secret environment variables. Prefix with `configurationEnvPrefix` in order to pass secrets to command line or prefix with `KAFKA_` to pass secrets to Kafka Streams configuration. E.g., `APP_MY_PARAM` would be passed as `--my-param` and `KAFKA_MAX_POLL_TIMEOUT_MS` would be translated to `max.poll.timeout.ms`. | `{}`    |
 | `secretRefs`             | Inject existing secrets as environment variables. Map key is used as environment variable name. Value consists of secret `name` and `key`.                                                                                                                                                                                    | `{}`    |

charts/streams-app/templates/deployment.yaml

@@ -123,10 +123,6 @@ spec:
             - name: "{{ .Values.configurationEnvPrefix }}_SCHEMA_REGISTRY_URL"
               value: {{ .Values.streams.schemaRegistryUrl | quote }}
           {{- end }}
-          {{- if hasKey .Values "debug" }}
-            - name: "{{ .Values.configurationEnvPrefix }}_DEBUG"
-              value: {{ .Values.debug | quote }}
-          {{- end }}
           {{- if and (hasKey .Values.streams "inputTopics") (.Values.streams.inputTopics) }}
             - name: "{{ .Values.configurationEnvPrefix }}_INPUT_TOPICS"
               value: {{ .Values.streams.inputTopics | join "," | quote }}

charts/streams-app/values.yaml

@@ -49,8 +49,6 @@ streams:
 commandLine: {}
 #  MY_CLI_PARAM: "foo-bar"
 
-debug: false
-
 env: {}
 #  MY_ENV_VARIABLE: foo-bar
 

streams-bootstrap-cli/build.gradle.kts

@@ -7,9 +7,6 @@ plugins {
 dependencies {
     api(project(":streams-bootstrap-core"))
     api(group = "info.picocli", name = "picocli", version = "4.7.5")
-    val log4jVersion: String by project
-    implementation(group = "org.apache.logging.log4j", name = "log4j-core", version = log4jVersion)
-    implementation(group = "org.apache.logging.log4j", name = "log4j-slf4j2-impl", version = log4jVersion)
 
     val junitVersion: String by project
     testRuntimeOnly(group = "org.junit.jupiter", name = "junit-jupiter-engine", version = junitVersion)
@@ -31,4 +28,6 @@ dependencies {
         name = "schema-registry-mock-junit5",
         version = fluentKafkaVersion
     )
+    val log4jVersion: String by project
+    testImplementation(group = "org.apache.logging.log4j", name = "log4j-slf4j2-impl", version = log4jVersion)
 }

streams-bootstrap-cli/src/main/java/com/bakdata/kafka/KafkaApplication.java

@@ -42,8 +42,6 @@
 import lombok.Setter;
 import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.logging.log4j.Level;
-import org.apache.logging.log4j.core.config.Configurator;
 import picocli.CommandLine;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.ParseResult;
@@ -56,7 +54,6 @@
  *     <li>{@link #outputTopic}</li>
  *     <li>{@link #extraOutputTopics}</li>
  *     <li>{@link #brokers}</li>
- *     <li>{@link #debug}</li>
  *     <li>{@link #schemaRegistryUrl}</li>
  *     <li>{@link #kafkaConfig}</li>
  * </ul>
@@ -92,8 +89,6 @@ public abstract class KafkaApplication<R extends Runner, CR extends CleanUpRunne
     private Map<String, String> extraOutputTopics = emptyMap();
     @CommandLine.Option(names = "--brokers", required = true, description = "Broker addresses to connect to")
     private String brokers;
-    @CommandLine.Option(names = "--debug", arity = "0..1", description = "Configure logging to debug")
-    private boolean debug;
     @CommandLine.Option(names = "--schema-registry-url", description = "URL of Schema Registry")
     private String schemaRegistryUrl;
     @CommandLine.Option(names = "--kafka-config", split = ",", description = "Additional Kafka properties")
@@ -299,20 +294,16 @@ public final CleanableApp<CR> createCleanableApp() {
     protected abstract CA createConfiguredApp(final A app, AppConfiguration<T> configuration);
 
     /**
-     * Configure application when running in debug mode. By default, Log4j2 log level is configured to debug for
-     * {@code com.bakdata} and the applications package.
+     * Called before starting the application, e.g., invoking {@link #run()}
      */
-    protected void configureDebug() {
-        Configurator.setLevel("com.bakdata", Level.DEBUG);
-        Configurator.setLevel(this.getClass().getPackageName(), Level.DEBUG);
+    protected void onApplicationStart() {
+        // do nothing by default
     }
 
     private void startApplication() {
         Runtime.getRuntime().addShutdownHook(new Thread(this::close));
+        this.onApplicationStart();
         log.info("Starting application");
-        if (this.debug) {
-            this.configureDebug();
-        }
         log.debug("Starting application: {}", this);
     }