docker/resources/common-scripts/configure

#!/usr/bin/env bash
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

ensure() {
  if [[ -z "${!1}" ]]; then
    echo "$1 environment variable not set"
    exit 1
  fi
}

path() {
  if [[ $2 == "writable" ]]; then
    if [[ ! -w "$1" ]]; then
      echo "$1 file not writable"
      exit 1
    fi
  elif [[ $2 == "existence" ]]; then
    if [[ ! -e "$1" ]]; then
      echo "$1 file does not exist"
      exit 1
    fi
  fi
}

# unset KAFKA_ADVERTISED_LISTENERS from ENV in KRaft mode when running as controller only
if [[ -n "${KAFKA_PROCESS_ROLES-}" ]]
then
  echo "Running in KRaft mode..."
  ensure CLUSTER_ID
  if [[ $KAFKA_PROCESS_ROLES == "controller" ]]
  then
    if [[ -n "${KAFKA_ADVERTISED_LISTENERS-}" ]]
    then
      echo "KAFKA_ADVERTISED_LISTENERS is not supported on a KRaft controller."
      exit 1
    else
      # Unset in case env variable is set with empty value
      unset KAFKA_ADVERTISED_LISTENERS
    fi
  fi 
fi

# By default, LISTENERS is derived from ADVERTISED_LISTENERS by replacing
# hosts with 0.0.0.0. This is good default as it ensures that the broker
# process listens on all ports.
if [[ -z "${KAFKA_LISTENERS-}" ]] && ( [[ -z "${KAFKA_PROCESS_ROLES-}" ]] || [[ $KAFKA_PROCESS_ROLES != "controller" ]] ) && [[ -n "${KAFKA_ADVERTISED_LISTENERS-}" ]]
then
  export KAFKA_LISTENERS
  KAFKA_LISTENERS=$(echo "$KAFKA_ADVERTISED_LISTENERS" | sed -e 's|://[^:]*:|://0.0.0.0:|g')
fi

path /opt/kafka/config/ writable

# Set if ADVERTISED_LISTENERS has SSL:// or SASL_SSL:// endpoints.
if [[ -n "${KAFKA_ADVERTISED_LISTENERS-}" ]] && [[ $KAFKA_ADVERTISED_LISTENERS == *"SSL://"* ]]
then
  echo "SSL is enabled."

  ensure KAFKA_SSL_KEYSTORE_FILENAME
  export KAFKA_SSL_KEYSTORE_LOCATION="/etc/kafka/secrets/$KAFKA_SSL_KEYSTORE_FILENAME"
  path "$KAFKA_SSL_KEYSTORE_LOCATION" existence

  ensure KAFKA_SSL_KEY_CREDENTIALS
  KAFKA_SSL_KEY_CREDENTIALS_LOCATION="/etc/kafka/secrets/$KAFKA_SSL_KEY_CREDENTIALS"
  path "$KAFKA_SSL_KEY_CREDENTIALS_LOCATION" existence
  export KAFKA_SSL_KEY_PASSWORD
  KAFKA_SSL_KEY_PASSWORD=$(cat "$KAFKA_SSL_KEY_CREDENTIALS_LOCATION")

  ensure KAFKA_SSL_KEYSTORE_CREDENTIALS
  KAFKA_SSL_KEYSTORE_CREDENTIALS_LOCATION="/etc/kafka/secrets/$KAFKA_SSL_KEYSTORE_CREDENTIALS"
  path "$KAFKA_SSL_KEYSTORE_CREDENTIALS_LOCATION" existence
  export KAFKA_SSL_KEYSTORE_PASSWORD
  KAFKA_SSL_KEYSTORE_PASSWORD=$(cat "$KAFKA_SSL_KEYSTORE_CREDENTIALS_LOCATION")

  if [[ -n "${KAFKA_SSL_CLIENT_AUTH-}" ]] && ( [[ $KAFKA_SSL_CLIENT_AUTH == *"required"* ]] || [[ $KAFKA_SSL_CLIENT_AUTH == *"requested"* ]] )
  then
      ensure KAFKA_SSL_TRUSTSTORE_FILENAME
      export KAFKA_SSL_TRUSTSTORE_LOCATION="/etc/kafka/secrets/$KAFKA_SSL_TRUSTSTORE_FILENAME"
      path "$KAFKA_SSL_TRUSTSTORE_LOCATION" existence

      ensure KAFKA_SSL_TRUSTSTORE_CREDENTIALS
      KAFKA_SSL_TRUSTSTORE_CREDENTIALS_LOCATION="/etc/kafka/secrets/$KAFKA_SSL_TRUSTSTORE_CREDENTIALS"
      path "$KAFKA_SSL_TRUSTSTORE_CREDENTIALS_LOCATION" existence
      export KAFKA_SSL_TRUSTSTORE_PASSWORD
      KAFKA_SSL_TRUSTSTORE_PASSWORD=$(cat "$KAFKA_SSL_TRUSTSTORE_CREDENTIALS_LOCATION")
  fi
fi

# Set if KAFKA_ADVERTISED_LISTENERS has SASL_PLAINTEXT:// or SASL_SSL:// endpoints.
if [[ -n "${KAFKA_ADVERTISED_LISTENERS-}" ]] && [[ $KAFKA_ADVERTISED_LISTENERS =~ .*SASL_.*://.* ]]
then
  echo "SASL" is enabled.

  ensure KAFKA_OPTS

  if [[ ! $KAFKA_OPTS == *"java.security.auth.login.config"*  ]]
  then
    echo "KAFKA_OPTS should contain 'java.security.auth.login.config' property."
  fi
fi

if [[ -n "${KAFKA_JMX_OPTS-}" ]]
then
  if [[ ! $KAFKA_JMX_OPTS == *"com.sun.management.jmxremote.rmi.port"*  ]]
  then
    echo "KAFKA_OPTS should contain 'com.sun.management.jmxremote.rmi.port' property. It is required for accessing the JMX metrics externally."
  fi
fi