kafka documentation updates

I never got kafka-ui to actually work, but I'm 99.9% sure that the
BOOTSTRAPSERVERS env var was incorrect.

README.md

@@ -45,6 +45,7 @@ Of course, if you haven't already done so, you should check out [Tidepool](https
   - [Working With Yarn For NodeJS Services](#working-with-yarn-for-nodejs-services)
 - [Misc](#misc)
   - [Tracing Internal Services](#tracing-internal-services)
+  - [Kafka CLI Usage](#kafka-cli-usage)
   - [Troubleshooting](#troubleshooting)
   - [Known Issues](#known-issues)
 
@@ -945,6 +946,32 @@ The good news is that we anticipate upgrading the Gloo version in the near futur
 
 Stay Tuned :)
 
+
+## Kafka CLI Usage
+
+A few notes for how to access/use the Kafka CLI. Accurate as of 2023-12-15 at least. :)
+
+The Kafka CLI (which is just a bunch a bash scripts) is accessible via the kafka pod:
+
+    $ kubectl exec -it kafka-kafka-0 -- bash
+    $ ls bin/kafka-* # to see all the various CLI commands
+
+However, a lot of the commands require authentication credentials, and those more or less have to come from a file. The kafka pod is lacking in editors, so here's one way to get around that:
+
+    $ cat - > /tmp/kafka.config <<EOF
+	KafkaClient {
+        security.protocol=SASL_PLAINTEXT
+        sasl.mechanism=SCRAM-SHA-512
+        sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required username="kafka" password="<password from kafka secret>";
+    };
+    EOF
+	$ bin/kafka-topics.sh --command-config=/tmp/kafka.config --list --bootstrap-server localhost:9092
+
+And remember that the password found in the kafka secret will be base64 encoded, so reverse that before you insert it in the file above.
+
+    $ kubectl get -o json secret kafka | jq -r '.data.password | @base64d'
+
+
 ## Troubleshooting
 
 | Issue                                                           | Things to try                                                                                                                                                                                                                                                                                                                           |

tools/kafka-ui/kafka-ui-configMap.yaml

@@ -1,5 +1,5 @@
 # Add config map:
-# create configmap kafka-ui-helm-values --from-file tools/kafka-ui/kafka-ui-configMap.yaml
+# kubectl create configmap kafka-ui-helm-values --from-file tools/kafka-ui/kafka-ui-configMap.yaml
 
 # Provision kafka-ui with:
 # helm repo add kafka-ui https://provectus.github.io/kafka-ui-charts
@@ -11,7 +11,7 @@ metadata:
   name: kafka-ui-helm-values
 data:
   KAFKA_CLUSTERS_0_NAME: "kafka-kafka"
-  KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS: "kafka-kafka-bootstrap:9092"
+  KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS: "kafka-kafka-0:9092"
   KAFKA_CLUSTERS_0_PROPERTIES_SASL_MECHANISM: "SCRAM-SHA-512"
   KAFKA_CLUSTERS_0_PROPERTIES_SECURITY_PROTOCOL: "SASL_PLAINTEXT"
   KAFKA_CLUSTERS_0_PROPERTIES_SASL_JAAS_CONFIG: "org.apache.kafka.common.security.scram.ScramLoginModule required username='kafka' password='**GET_FROM_KAFKA_SECRET**';"