refactor kafka exporter script and add ut

addons/kafka/scripts-ut-spec/kafka_exporter_setup_spec.sh

@@ -0,0 +1,81 @@
+# shellcheck shell=bash
+# shellcheck disable=SC2034
+
+# validate_shell_type_and_version defined in shellspec/spec_helper.sh used to validate the expected shell type and version this script needs to run.
+if ! validate_shell_type_and_version "bash" 4 &>/dev/null; then
+  echo "kafka_exporter_setup_spec.sh skip cases because dependency bash version 4 or higher is not installed."
+  exit 0
+fi
+
+Describe "Kafka Exporter Setup Script Tests"
+  # Load the scripts to be tested and dependencies
+  Include ../scripts/kafka-exporter-setup.sh
+
+  init() {
+    ut_mode="true"
+  }
+  BeforeAll "init"
+
+  un_setup() {
+    # Reset environment variables before each test
+    unset BROKER_POD_FQDN_LIST
+    unset COMBINE_POD_FQDN_LIST
+    unset TLS_ENABLED
+  }
+
+  Describe "generate_kafka_servers()"
+    It "returns an error if both BROKER_POD_FQDN_LIST and COMBINE_POD_FQDN_LIST are unset"
+      un_setup
+      When run generate_kafka_servers
+      The stderr should include "Error: BROKER_POD_FQDN_LIST and COMBINE_POD_FQDN_LIST environment variable is not set"
+      The status should be failure
+    End
+
+    It "generates server list from COMBINE_POD_FQDN_LIST"
+      un_setup
+      COMBINE_POD_FQDN_LIST="kafka-kafka-0.kafka-kafka-headless.default.svc.cluster.local,kafka-kafka-1.kafka-kafka-headless.default.svc.cluster.local"
+      When run generate_kafka_servers
+      The output should equal " --kafka.server=kafka-kafka-0.kafka-kafka-headless.default.svc.cluster.local:9094 --kafka.server=kafka-kafka-1.kafka-kafka-headless.default.svc.cluster.local:9094"
+      The status should be success
+    End
+
+    It "generates server list from BROKER_POD_FQDN_LIST if COMBINE_POD_FQDN_LIST is unset"
+      un_setup
+      BROKER_POD_FQDN_LIST="kafka-kafka-0.kafka-kafka-headless.default.svc.cluster.local,kafka-kafka-1.kafka-kafka-headless.default.svc.cluster.local"
+      When run generate_kafka_servers
+      The output should equal " --kafka.server=kafka-kafka-0.kafka-kafka-headless.default.svc.cluster.local:9094 --kafka.server=kafka-kafka-1.kafka-kafka-headless.default.svc.cluster.local:9094"
+      The status should be success
+    End
+  End
+
+  Describe "get_start_kafka_exporter_cmd()"
+    It "returns failure if generate_kafka_servers fails"
+      generate_kafka_servers() {
+        return 1
+      }
+      When run get_start_kafka_exporter_cmd
+      The stderr should include "failed to generate kafka servers. Exiting."
+      The status should be failure
+    End
+
+    It "returns the correct command with TLS enabled"
+      un_setup
+      COMBINE_POD_FQDN_LIST="combine1.example.com"
+      TLS_ENABLED="true"
+      When run get_start_kafka_exporter_cmd
+      The output should include "kafka_exporter --web.listen-address=:9308 --tls.enabled  --kafka.server=combine1.example.com:9094"
+      The stderr should include "TLS_ENABLED is set to true, start kafka_exporter with tls enabled."
+      The status should be success
+    End
+
+    It "returns the correct command with TLS disabled"
+      un_setup
+      BROKER_POD_FQDN_LIST="broker1.example.com"
+      TLS_ENABLED=""
+      When run get_start_kafka_exporter_cmd
+      The output should include "kafka_exporter --web.listen-address=:9308  --kafka.server=broker1.example.com:9094"
+      The stderr should include "TLS_ENABLED is not set, start kafka_exporter with tls disabled."
+      The status should be success
+    End
+  End
+End

addons/kafka/scripts/kafka-exporter-setup.sh

@@ -0,0 +1,76 @@
+#!/bin/bash
+
+# shellcheck disable=SC2034
+ut_mode="false"
+test || __() {
+  # when running in non-unit test mode, set the options "set -ex".
+  set -ex;
+}
+
+generate_kafka_servers() {
+  local servers=""
+
+  if [[ -z "$BROKER_POD_FQDN_LIST" ]] && [[ -z "$COMBINE_POD_FQDN_LIST" ]]; then
+    echo "Error: BROKER_POD_FQDN_LIST and COMBINE_POD_FQDN_LIST environment variable is not set, Please check and try again." >&2
+    return 1
+  fi
+
+  ## try to use COMBINE_POD_FQDN_LIST first
+  if [[ -n "$COMBINE_POD_FQDN_LIST" ]]; then
+    IFS=',' read -r -a combine_pod_fqdn_list <<< "$COMBINE_POD_FQDN_LIST"
+    for pod_fqdn in "${combine_pod_fqdn_list[@]}"; do
+      servers="${servers} --kafka.server=${pod_fqdn}:9094"
+    done
+    echo "$servers"
+    return 0
+  fi
+
+  # if COMBINE_POD_FQDN_LIST is not set, use BROKER_POD_FQDN_LIST
+  IFS=',' read -r -a broker_pod_fqdn_list <<< "$BROKER_POD_FQDN_LIST"
+  for pod_fqdn in "${broker_pod_fqdn_list[@]}"; do
+    servers="${servers} --kafka.server=${pod_fqdn}:9094"
+  done
+  echo "$servers"
+  return 0
+}
+
+get_start_kafka_exporter_cmd() {
+  local servers
+  local status
+  servers=$(generate_kafka_servers)
+  status=$?
+  if [[ $status -ne 0 ]]; then
+    echo "failed to generate kafka servers. Exiting." >&2
+    return 1
+  fi
+
+  if [[ -n "$TLS_ENABLED" ]]; then
+    echo "TLS_ENABLED is set to true, start kafka_exporter with tls enabled." >&2
+    echo "kafka_exporter --web.listen-address=:9308 --tls.enabled ${servers}"
+  else
+    echo "TLS_ENABLED is not set, start kafka_exporter with tls disabled." >&2
+    echo "kafka_exporter --web.listen-address=:9308 ${servers}"
+  fi
+  return 0
+}
+
+start_kafka_exporter() {
+  local cmd
+  cmd=$(get_start_kafka_exporter_cmd)
+  status=$?
+  if [[ $status -ne 0 ]]; then
+    ehco "failed to get start kafka_exporter command. Exiting." >&2
+    exit 1
+  fi
+  $cmd
+}
+
+# This is magic for shellspec ut framework.
+# Sometime, functions are defined in a single shell script.
+# You will want to test it. but you do not want to run the script.
+# When included from shellspec, __SOURCED__ variable defined and script
+# end here. The script path is assigned to the __SOURCED__ variable.
+${__SOURCED__:+false} : || return 0
+
+# main
+start_kafka_exporter

addons/kafka/templates/cmpd-exporter.yaml

@@ -21,6 +21,21 @@ spec:
   serviceKind: kafka-exporter
   serviceVersion: {{ .Values.defaultServiceVersion.exporter }}
   updateStrategy: BestEffortParallel
+  vars:
+    ## when server mode is kafka-broker
+    - name: BROKER_POD_FQDN_LIST
+      valueFrom:
+        componentVarRef:
+          compDef: {{ include "kafka-broker.cmpdRegexpPattern" . }}
+          optional: true
+          podFQDNs: Required
+    ## when server mode is kafka-combine
+    - name: COMBINE_POD_FQDN_LIST
+      valueFrom:
+        componentVarRef:
+          compDef: {{ include "kafka-combine.cmpdRegexpPattern" . }}
+          optional: true
+          podFQDNs: Required
   scripts:
   - name: kafka-scripts-tpl
     templateRef: {{ include "kafka.serverScriptsTplName" . }}

addons/kafka/templates/scripts-template.yaml

@@ -12,9 +12,9 @@ metadata:
   {{- end }}
 data:
   kafka-server-setup.sh: |-
-    {{- .Files.Get "scripts/kafka-server-setup.tpl" | nindent 4 }}
+    {{- .Files.Get "scripts/kafka-server-setup.sh" | nindent 4 }}
   kafka-exporter-setup.sh: |-
-    {{- .Files.Get "scripts/kafka-exporter-setup.tpl" | nindent 4 }}
+    {{- .Files.Get "scripts/kafka-exporter-setup.shsh" | nindent 4 }}
   kafka-env.sh: |-
     {{- .Files.Get "scripts/kafka-env.sh" | nindent 4 }}
 ---