Fix redpanda default log_retention_ms=-1 using init loop

kafka/redpanda.kafka.values.yaml

@@ -27,8 +27,11 @@ config:
     default_topic_partitions: 1
     storage_min_free_bytes: 10485760
     group_topic_partitions: 1
-    # like Kafka brokers set up by Yolean/kubernetes-kafka: a topic deletes by age only when it says so
-    log_retention_ms: -1
+    # log_retention_ms is not set here. Like Kafka brokers set up by Yolean/kubernetes-kafka, a topic
+    # deletes by age only when it says so, but redpanda v24.2 imports a negative log_retention_ms
+    # from bootstrap.yaml as 18446744073709551615, rejects that, and falls back to 7 days after the
+    # first restart. Instead the rendered postStart.sh (templates/secrets.yaml) sets -1 at each
+    # broker start, while the cluster has the 7 day default.
 tuning:
   tune_aio_events: false
 tls:

kafka/redpanda/kafka/redpanda/templates/configmap.yaml

@@ -26,7 +26,6 @@ data:
     compacted_log_segment_size: 16777216
     group_topic_partitions: 1
     kafka_batch_max_bytes: 1048576
-    log_retention_ms: -1
     kafka_connection_rate_limit: 1000
     log_segment_size: 16777216
     log_segment_size_max: 33554432

kafka/redpanda/kafka/redpanda/templates/secrets.yaml

@@ -54,6 +54,21 @@ stringData:
       touch /tmp/postStartHookFinished
     }
 
+    # Added to the chart's script, and independent of common.sh, which /bin/sh (dash) does not
+    # source: topics without their own retention.ms keep their records. Redpanda's default
+    # log_retention_ms deletes by age after 7 days, and bootstrap.yaml can not carry -1 (see
+    # redpanda.kafka.values.yaml). Any value other than the 7 day default is left as it is.
+    retentionDefault () {
+      for _ in 1 2 3 4 5 6 7 8 9 10; do
+        if retention=$(rpk cluster config get log_retention_ms); then
+          [ "$retention" = "604800000" ] || return 0
+          rpk cluster config set log_retention_ms=-1 && return 0
+        fi
+        sleep 2
+      done
+    }
+
+    retentionDefault
     postStartHook
     true