#!/bin/bash

###
### Copyright 2019, 2025, Instana Inc.
###
### Licensed 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.
###

set -o pipefail

AGENT_DIR="/opt/instana/agent"
AGENT_DIR_ZOS="${PWD}/instana-agent"
AGENT_DIR_ZOS_OLD="${PWD}/instana-agent-old"
# AIX, Darwin, Linux, SunOS
OS=$(uname -s)
MACHINE=""
FAMILY="unknown"
INIT="sysv"

PKG_URI=packages.instana.io

AGENT_TYPE="dynamic"
OPEN_J9="false"
PROMPT=true
ENABLE_SERVICE=false
RESTART=false
LOCATION=
ENDPOINT=""
MODE="apm"
GIT_REPO=
GIT_BRANCH=
GIT_USERNAME=
GIT_PASSWORD=
INSTANA_AGENT_SYSTEMD_TYPE=simple

INSTANA_AGENT_KEY="$INSTANA_AGENT_KEY"
INSTANA_DOWNLOAD_KEY="$INSTANA_DOWNLOAD_KEY"
INSTANA_AGENT_HOST="$INSTANA_AGENT_HOST"
INSTANA_AGENT_PORT="${INSTANA_AGENT_PORT:-443}"

INSTANA_AWS_REGION_CONFIG=""

gpg_check=1

function exists {
  if which "$1" >/dev/null 2>&1; then
    return 0
  else
    return 1
  fi
}

download_command='none'

function download_to_stdout {
  case "${download_command}" in
  'curl')
    download_to_stdout_curl $@
    ;;
  'wget')
    download_to_stdout_wget $@
    ;;
  *)
    log_error "Unknown download command '${download_command}'"
    exit 1;
  esac
}

function download_to_stdout_curl {
  local request_method=""
  if [[ "$1" == "GET" || "$1" == "POST" || "$1" == "PUT" ]]; then
    request_method="-X ${1}"
    shift
  fi

  local url="$1"

  local header_parameter
  if [[ "$2" == "-H" ]]; then
    header_parameter="-H ${3}"
    shift 2
  fi
  # Auth is passed in curl format: <user>:<password>
  local authentication="$2"
  local authentication_parameters
  # Connection timeout, default 2 secs
  local connect_timeout="${3:-2}"

  if [ -n "${authentication}" ]; then
    authentication_parameters="-u ${authentication}"
  fi

  if curl -s --fail --connect-timeout "${connect_timeout}" ${request_method} ${header_parameter} ${authentication_parameters} "${url}"; then
    return 0
  else
    return $?
  fi
}

function download_to_stdout_wget {
  local request_method=""
  if [[ "$1" == "GET" || "$1" == "POST" || "$1" == "PUT" ]]; then
    request_method="--method=${1}"
    shift
  fi

  local url="$1"

  local header_parameter
  if [[ "$2" == "-H" ]]; then
    header_parameter="--header ${3}"
    shift 2
  fi
  # Auth is passed in curl format: <user>:<password>
  local authentication="$2"
  local authentication_parameters
  # Connection timeout, default 2 secs
  local connect_timeout="${3:-2}"

  if [ -n "${authentication}" ]; then
    local username;
    username=$(awk -F ':' '{ print $1}' <<< "${authentication}")

    local password
    password=$(awk -F ':' '{ print $2}' <<< "${authentication}")

    authentication_parameters="--auth-no-challenge --http-user=${username} --http-password=${password}"
  fi

  if wget --timeout="${connect_timeout}" ${request_method} ${header_parameter} -qO- ${authentication_parameters} "${url}"; then
    return 0
  else
    return $?
  fi
}

function log_error {
  local message=$1

  if [[ $TERM == *"color"* ]]; then
    echo -e "\e[31m$message\e[0m"
  else
    echo $message
  fi
}

function log_info {
  local message=$1

  if [[ $TERM == *"color"* ]]; then
    echo -e "\e[32m$message\e[0m"
  else
    echo $message
  fi
}

function log_warn {
  local message=$1

  if [[ $TERM == *"color"* ]]; then
    echo -e "\e[33m${message}\e[0m"
  else
    echo "${message}"
  fi
}

function receive_confirmation() {
  read -r -p "$1 [y/N] " response

  if [[ ! $response =~ ^([yY][eE][sS]|[yY])$ ]]; then
    return 1
  fi

  return 0
}

function check_zOS_prerequisites() {
 if command -v gzip > /dev/null && command -v pax > /dev/null; then
   log_info 'pax and gzip are available on the system'
 else
   log_error 'This script requires pax and gzip to be installed on this system. Aborting installation.'
   exit 1
 fi

}

function check_user_privilege() {
  if [ "$(id -u)" -eq 0 ]; then
    echo "You are root!"
  else
    echo "You are not root Aborting Agent Installation. Switch to the user which has root privilege and retry"
    exit 1
  fi
}
function check_prerequisites() {
  if exists curl; then
    download_command='curl'
  elif exists wget; then
    download_command='wget'
  else
    log_error 'This script requires either curl or wget to be installed on this system. Aborting installation.'
    exit 1
  fi

  if ! which gpg > /dev/null 2>&1; then
    log_warn 'The "gpg" program is not installed on this system: the verification of the Instana agent packages cannot be performed.'
    if [ $PROMPT = true ]; then
      if ! receive_confirmation 'Do you want to continue?'; then
        exit 1
      fi
    fi

    log_warn 'The verification of the Instana agent packages will be skipped.'
    gpg_check=0
  fi
}

function check_download_key() {
  # Retry the download-key check a few times with increasing timeout as this appeared to be unreliable at times
  # Timeout is identified by exit code 28 for curl, and 4 for wget.
  local retval
  local n=1
  while [ ${n} -le 5 ]
  do
    # Use an increasing timeout of "n*3" seconds
    download_to_stdout "https://${PKG_URI}/agent/generic/x86_64/repodata/repomd.xml" "_:${INSTANA_DOWNLOAD_KEY}" $((n * 3)) > /dev/null 2>&1
    retval=$?

    if [ ${retval} -ne 28 ] && [ ${retval} -ne 4 ]
    then
      break
    fi
    n=$((n + 1))
  done

  if [ ${retval} -eq 28 ] || [ ${retval} -eq 4 ]; then
    log_error "Verifying the Instana agent download key timed-out, please try again."
    exit 1
  elif [ ${retval} -ne 0 ]; then
    log_error "The Instana agent download key provided seems to be invalid, please check the agent key and try again."
    exit 1
  fi
}

function detect_family() {
  if which apt-get &> /dev/null; then
    FAMILY="apt"
    return 0
  fi

  if type dnf &>/dev/null
  then
    FAMILY="dnf"
    return 0
  fi

  if type yum &>/dev/null
  then
    FAMILY="yum"
    return 0
  fi

  if which zypper &> /dev/null; then
    FAMILY="zypper"
    return 0
  fi

  if [ "$OS" = "OS/390" ]; then
    FAMILY="zOS"
    return 0
  fi
}

function detect_init() {
  if ls -l /sbin/init | grep systemd &> /dev/null; then
    INIT="systemd"
    return 0
  fi

  if /sbin/init --version | grep upstart &> /dev/null; then
    INIT="upstart"
    return 0
  fi
}

function detect_machine() {
  if [ "$OS" = "AIX" ]; then
    MACHINE=$(uname -p)
  elif [ "$OS" = "Darwin" ]; then
    MACHINE=$(uname -m)
  elif [ "$OS" = "Linux" ]; then
    MACHINE=$(uname -m)
  elif [ "$OS" = "SunOS" ]; then
    MACHINE=$(uname -m)
  elif [ "$OS" = "OS/390" ]; then
    MACHINE=$(uname -s)
  else
    log_info "Could not detect machine for OS: $OS"
    MACHINE="unknown"
  fi
}

function get_endpoint() {
  if [ -n "${ENDPOINT}" ]; then
    local split=(${ENDPOINT//:/ })
    INSTANA_AGENT_HOST="${split[0]}"
    INSTANA_AGENT_PORT="${split[1]}"
  elif [[ "${LOCATION}" == "eu" ]]; then
    INSTANA_AGENT_HOST="saas-eu-west-1.instana.io"
  elif [[ "${LOCATION}" == "us" ]]; then
    INSTANA_AGENT_HOST="saas-us-west-2.instana.io"
  elif [[ "${LOCATION}" == "red" ]]; then
    INSTANA_AGENT_HOST="ingress-red-saas.instana.io"
  elif [[ "${LOCATION}" == "blue" ]]; then
    INSTANA_AGENT_HOST="ingress-blue-saas.instana.io"
  elif [[ "${LOCATION}" == "green" ]]; then
    INSTANA_AGENT_HOST="ingress-green-saas.instana.io"
  fi
}

function use_internal_packages () {
  if [ "${USE_INTERNAL_PACKAGES}" = 'true' ]; then
    local MVN_CFG_FILE='/opt/instana/agent/etc/org.ops4j.pax.url.mvn.cfg'
    log_info "Configuring internal repository usage in ${MVN_CFG_FILE} file"
    sed -i 's/features-public@id=features/features-internal@id=features/' "${MVN_CFG_FILE}"
  fi
}

function setup_agent() {
  local gpg_uri="https://${PKG_URI}/Instana.gpg"

  case "$FAMILY" in

  'apt')

    log_info "Setting up Instana APT repository"

    # For whatever reason debian uses rando arch names instead of what is reported by uname
    local arch="$MACHINE"

    case "${MACHINE}" in

    'x86_64')
      arch='amd64'
      ;;

    'aarch64')
      arch='arm64'
      ;;

    'ppc64le')
      arch='ppc64el'
      ;;

    esac

    local INSTANA_AUTH_CONF_FILE='/etc/apt/auth.conf.d/instana-packages.conf'
    if [ -d "$(dirname "${INSTANA_AUTH_CONF_FILE}")" ]; then
      # We should use /etc/apt/auth.conf.d rather than hard-coding the credentials in the `apt url`.
      if ! echo "machine ${PKG_URI}
login _
password ${INSTANA_DOWNLOAD_KEY}
" > "${INSTANA_AUTH_CONF_FILE}"; then
        log_error "Cannot create the ${INSTANA_AUTH_CONF_FILE} file to configure authentication for the ${PKG_URI} repository"
        exit 1
      fi

      log_info "Authentication for the ${PKG_URI} repository has been added to apt via the ${INSTANA_AUTH_CONF_FILE} file"

      local apt_uri="deb [arch=${arch}] https://${PKG_URI}/agent/deb generic main"
    else
      local apt_uri="deb [arch=${arch}] https://_:${INSTANA_DOWNLOAD_KEY}@${PKG_URI}/agent/deb generic main"
    fi

    if ! echo "$apt_uri" > /etc/apt/sources.list.d/instana-agent.list; then
      log_error "Instana APT repository setup failed"
      exit 1
    fi

    if [ "${gpg_check}" -eq 1 ]; then
      log_info "Importing Instana GPG key"
      # Retry the gpg key download a few times as the network connection appear to be unreliable in certain environments
      # Timeout is identified by exit code 28 for curl, and 4 for wget.
      local retval
      local n=1
      while [ ${n} -le 5 ]
      do
        download_to_stdout "$gpg_uri" > Instana.gpg
        retval=$?

        if [ ${retval} -ne 28 ] && [ ${retval} -ne 4 ]
        then
          break
        fi
        n=$((n + 1))
      done

      if [ ${retval} -eq 28 ] || [ ${retval} -eq 4 ]; then
        log_error "Downloading the Instana GPG key timed-out, please try again."
        exit 1
      elif [ ${retval} -ne 0 ]; then
        log_error "Downloading the Instana GPG key failed, please try again."
        exit 1
      fi

      if ! apt-key add Instana.gpg > /dev/null; then
        log_error "Instana GPG key import failed"
        rm -f Instana.gpg
        exit 1
      fi
      rm -f Instana.gpg
    else
      AUTHENTICATION_PARAM='--allow-unauthenticated -o Acquire::AllowInsecureRepositories=true'
    fi

    log_info "Updating apt metadata"

    if ! apt-get ${AUTHENTICATION_PARAM} update -o Dir::Etc::sourcelist="sources.list.d/instana-agent.list" -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0" > /dev/null; then
      log_error "APT repository metadata update failed"
      exit 1
    fi

    log_info "Installing Instana agent"

    # retry download 5 times, add connection timeouts for downloads
    if ! apt-get ${AUTHENTICATION_PARAM} -o Acquire::Retries=5 -o Acquire::http::Timeout=60 -o Acquire::ftp::Timeout=60 -o DPkg::lock::Timeout=120 install -y instana-agent-${AGENT_TYPE} > /dev/null; then
      log_error "Instana agent package install failed"
      exit 1
    fi

    use_internal_packages
    ;;

  'dnf')

    log_info "Setting up Instana RPM repository"

    local yum_repo
    read -r -d '' yum_repo <<EOF
[instana-agent]
name=Instana
baseurl=https://_:${INSTANA_DOWNLOAD_KEY}@${PKG_URI}/agent/rpm/generic/$MACHINE
enabled=1
gpgcheck=${gpg_check}
repo_gpgcheck=${gpg_check}
gpgkey=${gpg_uri}
sslverify=1
EOF

    if ! echo "$yum_repo" > /etc/yum.repos.d/Instana-Agent.repo; then
      log_error "Instana YUM repository setup failed"
      exit 1
    fi

    log_info "Updating YUM metadata"
    if ! dnf makecache -y > /dev/null 2>&1; then
      log_error "YUM repository metadata update failed"
      exit 1
    fi

    log_info "Installing Instana agent"

    if ! dnf install -y instana-agent-$AGENT_TYPE > /dev/null; then
      log_error "Instana agent package install failed"
      exit 1
    fi

    use_internal_packages
    ;;

  'yum')

    log_info "Setting up Instana YUM repository"

    local yum_repo
    read -r -d '' yum_repo <<EOF
[instana-agent]
name=Instana
baseurl=https://_:${INSTANA_DOWNLOAD_KEY}@${PKG_URI}/agent/rpm/generic/$MACHINE
enabled=1
gpgcheck=${gpg_check}
repo_gpgcheck=${gpg_check}
gpgkey=${gpg_uri}
sslverify=1
EOF

    if ! echo "$yum_repo" > /etc/yum.repos.d/Instana-Agent.repo; then
      log_error "Instana YUM repository setup failed"
      exit 1
    fi

    log_info "Updating YUM metadata"
    if ! yum makecache -y fast > /dev/null 2>&1; then
      log_error "YUM repository metadata update failed"
      exit 1
    fi

    log_info "Installing Instana agent"

    if ! yum install -y instana-agent-$AGENT_TYPE > /dev/null; then
      log_error "Instana agent package install failed"
      exit 1
    fi

    use_internal_packages
    ;;

  'zypper')

    log_info "Setting up Instana zypper repository"

    local zypp_repo
    read -r -d '' zypp_repo <<EOF
[instana-agent]
name=Instana
baseurl=https://_:${INSTANA_DOWNLOAD_KEY}@${PKG_URI}/agent/rpm/generic/$MACHINE/
enabled=1
gpgcheck=${gpg_check}
repo_gpgcheck=${gpg_check}
gpgkey=${gpg_uri}
sslverify=1
EOF

    if ! echo "$zypp_repo" > /etc/zypp/repos.d/Instana-Agent.repo; then
      log_error "Instana zypper repository setup failed"
      exit 1
    fi

    if [ "${gpg_check}" -eq 1 ]; then
      log_info "Importing Instana GPG key"
      if ! rpm --import "$gpg_uri"; then
        log_error "Instana GPG key import failed"
        exit 1
      fi
    fi

    log_info "Updating zypper metadata"
    if ! zypper -n refresh Instana > /dev/null 2>&1; then
      log_error "zypper repository metadata update failed"
      exit 1
    fi

    log_info "Installing Instana agent"

    if ! zypper -n install instana-agent-$AGENT_TYPE > /dev/null; then
      log_error "Instana agent package install failed"
      exit 1
    fi

    use_internal_packages
    ;;
  'zOS')
    log_info "Cheking on Prereq. for Installing Instana agent"
    check_user_privilege
    check_zOS_prerequisites
    check_zOS_server_update_prerequisites
    check_existing_instana_agent
    check_existing_instana_agent_process
    log_info "Installing Instana agent"
    EXPECTED_FILE="org.apache.felix.framework-*.jar"
    DIR="$AGENT_DIR_ZOS/system/org/apache/felix/org.apache.felix.framework/"
    if [ $AGENT_TYPE = "dynamic" ]; then
      curl -g -u _:${INSTANA_DOWNLOAD_KEY} "https://artifact-public.instana.io/artifactory/rel-generic-instana-virtual/com/instana/agent-assembly/[RELEASE]/agent-assembly-[RELEASE]-linux-s390x.tar.gz" -o agent-assembly-linux-dynamic-s390x.tar.gz
      gzip -d agent-assembly-linux-dynamic-s390x.tar.gz
      pax -r -f agent-assembly-linux-dynamic-s390x.tar
    fi
    if [ $AGENT_TYPE = "static" ]; then
      curl -g -u _:${INSTANA_DOWNLOAD_KEY} "https://artifact-public.instana.io/artifactory/rel-generic-instana-virtual/com/instana/agent-assembly-offline/[RELEASE]/agent-assembly-offline-[RELEASE]-linux-s390x.tar.gz" -o agent-assembly-linux-static-s390x.tar.gz
      gzip -d agent-assembly-linux-static-s390x.tar.gz
      pax -r -f agent-assembly-linux-static-s390x.tar
    fi
    if ls "$DIR"/*/org.apache.felix.framework-*.jar 2>/dev/null | grep -q .; then
        echo "The required file is available for further installation process of instana-agent i.e. $EXPECTED_FILE"
    else
        echo "The required file NOT found: i.e. $EXPECTED_FILE, Issue during download/Untar of build aborting further installation"
        exit 1
    fi


    #Will have Remaining logic to handle and convert code page tagging and all...
    export _BPXK_AUTOCVT=ON
    echo 'INFO: Auto Character Conversion (export _BPXK_AUTOCVT=ON) is enabled for this session. For convenience it is recommended to set this in your User Profile, so you don’t need to export it each time you log in'
    echo 'Enabling codepage Setting'
    chtag -R -tc 819 ${AGENT_DIR_ZOS}/bin
    chtag -R -tc 819 ${AGENT_DIR_ZOS}/etc
    echo 'Codepage Setting for required folder of Instana-Agent has been enabled'
    configure_server_details
    set_java_home_and_start_agent

    ;;

    *)
      log_error 'Unsupported package manager. The supported packages managers are: apt, dnf, yum, zypper'
      exit 1;

  esac

}

function check_existing_instana_agent_process() {
  # Check if the process is running
  process_command="/bin/sh ${AGENT_DIR_ZOS}/bin/karaf server"
  echo $process_command
  pid=$(ps -ef | grep "$process_command" | grep -v grep | awk '{print $2}')
  if [ -n	"$pid" ]; then
      echo "Process is running with PID: $pid"
      echo "Stopping running agent process and cleaning the directory"
      if [ $PROMPT = true ]; then
        if ! receive_confirmation 'Do you want to continue to stop the running process?'; then
          exit 1
        fi
        echo "Stopping current running agent"
        kill -9 ${pid}
        rm -rf ${AGENT_DIR_ZOS}
      fi
  else
      echo "Process is not running."
  fi

 }
function check_existing_instana_agent() {
  # Check if the instana-agent path exists in the current directory

  if [ -d "${AGENT_DIR_ZOS}" ]; then
      echo "Instana agent path is available in the current directory."
      mkdir ${AGENT_DIR_ZOS_OLD}
      echo ls
      cp "${AGENT_DIR_ZOS}/etc/mvn-settings.xml" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/org.ops4j.pax.url.mvn.cfg" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.bootstrap.AgentBootstrap.cfg" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.config.UpdateManager.cfg" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/instana/configuration.yaml" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.config.Agent.cfg" "${AGENT_DIR_ZOS_OLD}"
      cp "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg" "${AGENT_DIR_ZOS_OLD}"
  else
      echo "Instana agent path is NOT available in the current directory."
  fi
}

function check_zOS_server_update_prerequisites() {
  if command -v sed > /dev/null; then
    log_info 'sed are available on the system'
  else
    log_error 'This script requires sed to be installed on this system. Aborting installation.'
    exit 1
  fi

}

function set_java_home_and_start_agent(){
  echo " To Start the Agent we need JAVA_HOME path, checking with installed java on the system"

  java_version=$(java -version 2>&1 | head -n 1 |	sed -E 's/.*"([^"]+)".*/\1/')
  # Check if the Java command succeeded
  if [ $?	-ne 0 ]; then
      echo "Java is not installed	or not in the PATH."
      echo "Please provide the path to the JAVA_HOME directory, ensuring it is located before the	'bin' directory; for example: /usr/lpp/java/11.0"
      read -p "Enter JAVA_HOME: "	JAVA_HOME
      echo "Entered JAVA_HOME is:	$JAVA_HOME"
  else
      echo "Java version detected: $java_version"
  fi

  # Extract the major version number
  if echo "$java_version" | grep -q "^1\."; then
      # For version like 1.8.x (Java 8), extract the second part of the version
      major_version=$(echo $java_version | cut -d. -f2)
  else
      # For versions like 9.x.x, 11.x.x, etc., the major version starts from the first number
      major_version=$(echo $java_version | cut -d. -f1)
  fi

  # Check if the version is exactly Java 11
  if [ "$major_version" -eq 11 ]; then
      echo "Java version $java_version is installed and is a supported version."
  else
      echo "Java version $java_version is installed, but it is not a supported version. Supported version is JAVA 11."
      log_warn 'Please provide the path to the JAVA_HOME directory with a supported version, ensuring it is located before the "bin" directory; for example : /usr/lpp/java/11.0'
      read JAVA_HOME
      echo "Enterd JAVA_HOME is :  $JAVA_HOME"

  fi

  echo 'Setting JAVA_HOME for Instana-Agent'
  FILE="${AGENT_DIR_ZOS}/bin/setenv"

  sed '/# unset JAVA_HOME/ {
    s/# unset JAVA_HOME/unset JAVA_HOME/;
  }' "$FILE" > "$FILE.tmp"
  echo "export JAVA_HOME=$JAVA_HOME" >> "$FILE.tmp"
  mv "$FILE.tmp" "$FILE"
  echo 'Updated JAVA_HOME for Instana-Agent'

  echo 'Ready to start the agent, will start the agent'
  if test -d "${AGENT_DIR_ZOS_OLD}"; then
      test -f "${AGENT_DIR_ZOS_OLD}/mvn-settings.xml" && cp "${AGENT_DIR_ZOS_OLD}/mvn-settings.xml" "${AGENT_DIR_ZOS}/etc/"
      test -f "${AGENT_DIR_ZOS_OLD}/org.ops4j.pax.url.mvn.cfg" && cp "${AGENT_DIR_ZOS_OLD}/org.ops4j.pax.url.mvn.cfg" "${AGENT_DIR_ZOS}/etc/"
      test -f "${AGENT_DIR_ZOS_OLD}/com.instana.agent.bootstrap.AgentBootstrap.cfg" && cp "${AGENT_DIR_ZOS_OLD}/com.instana.agent.bootstrap.AgentBootstrap.cfg" "${AGENT_DIR_ZOS}/etc/instana/"
      test -f "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.config.UpdateManager.cfg" && cp "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.config.UpdateManager.cfg" "${AGENT_DIR_ZOS}/etc/instana/"
      test -f "${AGENT_DIR_ZOS_OLD}/configuration.yaml" && cp "${AGENT_DIR_ZOS_OLD}/configuration.yaml" "${AGENT_DIR_ZOS}/etc/instana/"
      test -f "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.config.Agent.cfg" && cp "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.config.Agent.cfg" "${AGENT_DIR_ZOS}/etc/instana"
      test -f "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.sender.Backend.cfg" && cp "${AGENT_DIR_ZOS_OLD}/com.instana.agent.main.sender.Backend.cfg" "${AGENT_DIR_ZOS}/etc/instana"
      chtag -R -tc 819 ${AGENT_DIR_ZOS}/etc
      rm -rf ${AGENT_DIR_ZOS_OLD}/
  else
      echo "No configuration files are copied from the previously installed agent"
  fi


  ./instana-agent/bin/start
  echo 'Now, you can check logs at instana-agent/data/log/agent.log '

}

function configure_server_details() {

    sed "s/host=\${env:INSTANA_HOST}/host=${INSTANA_AGENT_HOST}/" ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg > ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp && mv ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp instana-agent/etc/instana/com.instana.agent.main.sender.Backend.cfg
    sed "s/port=\${env:INSTANA_PORT}/port=${INSTANA_AGENT_PORT}/" ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg > ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp && mv ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp instana-agent/etc/instana/com.instana.agent.main.sender.Backend.cfg
    sed "s/key=\${env:INSTANA_KEY}/key=${INSTANA_AGENT_KEY}/" ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg > ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp && mv ${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.sender.Backend.cfg.tmp instana-agent/etc/instana/com.instana.agent.main.sender.Backend.cfg

    sed -e "s|<password>_</password>|<password>${INSTANA_DOWNLOAD_KEY}</password>|g" ${AGENT_DIR_ZOS}/etc/mvn-settings.xml > ${AGENT_DIR_ZOS}/etc/mvn-settings.xml.tmp && mv instana-agent/etc/mvn-settings.xml.tmp ${AGENT_DIR_ZOS}/etc/mvn-settings.xml

    echo "Updated server details successfully"
    return 0

}
function configure_mode() {
  if [ "${MODE}" = 'apm' ]; then
    if [ "$FAMILY" = "zOS" ]; then
      echo "mode = APM" >> "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.config.Agent.cfg"
      echo "Updated Mode successfully for zOS"
      return 0
    else
      /bin/cp "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg.template" "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"
      echo "mode = APM" >> "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"

      return 0
    fi
  fi

  if [ "${MODE}" = 'aws' ]; then
    log_info 'Configuring AWS mode'
    # Get region from metadata endpoint

    export INSTANA_AWS_TOKEN=$(download_to_stdout PUT http://169.254.169.254/latest/api/token -H X-aws-ec2-metadata-token-ttl-seconds:21600)

    if [ -n "${INSTANA_AWS_REGION_CONFIG}" ]; then
      log_info "Using the AWS region ${INSTANA_AWS_REGION_CONFIG} configured via the 'INSTANA_AWS_REGION_CONFIG' environment variable"
      export INSTANA_AWS_REGION_CONFIG
    elif [ -z ${INSTANA_AWS_TOKEN+x} ]; then
      if ! INSTANA_AWS_REGION_CONFIG=$(download_to_stdout http://169.254.169.254/latest/dynamic/instance-identity/document | awk -F\" '/region/ {print $4}'); then
        log_error "Error querying AWS metadata. It seems this virtual machine is not running on EC2. Please set the 'INSTANA_AWS_REGION_CONFIG' environment variable manually."
        exit 1
      fi
    elif ! INSTANA_AWS_REGION_CONFIG=$(download_to_stdout http://169.254.169.254/latest/dynamic/instance-identity/document -H "X-aws-ec2-metadata-token:${INSTANA_AWS_TOKEN}" | awk -F\" '/region/ {print $4}'); then
      log_error "Error querying AWS metadata via token. It seems this virtual machine is not running on EC2. Please set the 'INSTANA_AWS_REGION_CONFIG' environment variable manually."
      exit 1
    fi

    ROLES_FOUND=false

    if [ -z ${INSTANA_AWS_TOKEN+x} ]; then
      if download_to_stdout http://169.254.169.254/latest/meta-data/iam/security-credentials/ > /dev/null 2>&1; then
        ROLES_FOUND=true
      fi
    elif download_to_stdout http://169.254.169.254/latest/meta-data/iam/security-credentials/ -H "X-aws-ec2-metadata-token:${INSTANA_AWS_TOKEN}" > /dev/null 2>&1; then
      ROLES_FOUND=true
    fi

    if [ "$ROLES_FOUND" = "false" ]; then
      if [ -z "$AWS_ACCESS_KEY_ID" ] || [ -z "$AWS_SECRET_ACCESS_KEY" ]; then
        log_error "AWS_ACCESS_KEY_ID and/or AWS_SECRET_ACCESS_KEY not exported, and no IAM instance role detected to allow AWS API access."
        exit 1
      fi
    fi

    /bin/cp "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg.template" "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"
    echo "mode = INFRASTRUCTURE" >> "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"

    return 0
  fi

  if [ "$MODE" = "infra" ]; then
   if [ "$FAMILY" = "zOS" ]; then
      echo "mode = INFRASTRUCTURE" >> "${AGENT_DIR_ZOS}/etc/instana/com.instana.agent.main.config.Agent.cfg"
      echo "Updated Mode successfully for zOS"
      return 0
    else
      /bin/cp "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg.template" "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"
      echo "mode = INFRASTRUCTURE" >> "${AGENT_DIR}/etc/instana/com.instana.agent.main.config.Agent.cfg"

      return 0
    fi
  fi
}

function delete_git_repo() {
  rm -rf "${AGENT_DIR}/etc/.git"
}

function check_preexisting_git_repository() {
  if [ -n "${GIT_REPO}" ] && [ -d "${AGENT_DIR}/etc/.git" ]; then
    log_warn "The Git options have been specified, but there is already a Git repository in '${AGENT_DIR}/etc/.git'. To continue, we need to remove the current Git repository."

    if [ $PROMPT = true ]; then
      if receive_confirmation 'Do you want to continue?'; then
        delete_git_repo
      fi
    else
      delete_git_repo
    fi
  fi
}

function configure_env() {
  local env_content=""
  local env_path=""

  if [ "$INIT" = "systemd" ]; then
    env_path=/opt/instana/agent/etc/systemd.env
  else
    if [ "$FAMILY" = "zypper" ] || [ "$FAMILY" = "yum" ]; then
      env_path=/etc/sysconfig/instana-agent
    fi

    if [ "$FAMILY" = "apt" ]; then
      env_path=/etc/default/instana-agent
    fi
  fi

  [[ -n "$INSTANA_AWS_REGION_CONFIG" ]] && env_content+="$(get_env_line INSTANA_AWS_REGION_CONFIG $INSTANA_AWS_REGION_CONFIG)\n"
  [[ -n "$AWS_ACCESS_KEY_ID" ]] && env_content+="$(get_env_line AWS_ACCESS_KEY_ID $AWS_ACCESS_KEY_ID)\n"
  [[ -n "$AWS_SECRET_ACCESS_KEY" ]] && env_content+="$(get_env_line AWS_SECRET_ACCESS_KEY "$AWS_SECRET_ACCESS_KEY")\n"
  [[ -n "$GIT_REPO" && -n "$GIT_BRANCH" ]] && env_content+="$(get_env_line INSTANA_GIT_REMOTE_REPOSITORY "$GIT_REPO")\n$(get_env_line INSTANA_GIT_REMOTE_BRANCH "$GIT_BRANCH")\n"

  if [ -n "$GIT_USERNAME" ]; then
    env_content+="$(get_env_line INSTANA_GIT_REMOTE_USERNAME "$GIT_USERNAME")\n"
    if [ -n "$GIT_PASSWORD" ]; then
      env_content+="$(get_env_line INSTANA_GIT_REMOTE_PASSWORD "$GIT_PASSWORD")\n"
    else
      env_content+="$(get_env_line INSTANA_GIT_REMOTE_PASSWORD "")\n"
    fi
  fi

  if [ $MACHINE != "OS/390" ]; then
    printf "$env_content" > "$env_path"
  fi
}

function get_env_line() {
  local key=$1
  local val=$2

  if [ "$INIT" = "systemd" ]; then
    echo "${key}=${val}"
  else
    echo "export ${key}=${val}"
  fi
}

function update_custom_systemd_unit_file () {
  # file does not exists -> new installation indicator
  if [ "$INIT" = "systemd" ] && [ ! -e /lib/systemd/system/instana-agent.service ]; then
    mkdir -p /etc/systemd/system/instana-agent.service.d/
    local systemd_custom_start_conf
    read -r -d '' systemd_custom_start_conf <<EOF
[Service]
Type=$INSTANA_AGENT_SYSTEMD_TYPE
EOF

    if ! echo "$systemd_custom_start_conf" > /etc/systemd/system/instana-agent.service.d/agent-custom-start.conf; then
      log_warn "Failed to create '/etc/systemd/system/instana-agent.service.d/agent-custom-start.conf'"
    fi

  fi
}

function disable_autostart_on_systemd() {
  if [ "$INIT" != "systemd" ]; then
    INSTANA_AGENT_AUTOSTART=true
    return 0
  fi

  INSTANA_AGENT_AUTOSTART=false
  export INSTANA_AGENT_AUTOSTART
}


function start_agent() {
  if systemctl is-active instana-agent > /dev/null 2>&1; then
    log_info "Instana agent service is active and agent is reinstalled. Service will be restarted"
    RESTART=true
  fi

  if [ $ENABLE_SERVICE = false ] && [ $RESTART = false ] && [ $INSTANA_AGENT_AUTOSTART = true ]; then
    return 0
  fi

  if [ "$INIT" = "systemd" ]; then

    if grep -iq 'SUSE' /etc/*release 2>/dev/null; then
      # remove SysV file on SUSE linux before enabling the service
      if [ -f /etc/init.d/instana-agent ]; then
        rm -f /etc/init.d/instana-agent
      fi
    fi

    if [ $ENABLE_SERVICE = true ]; then
      if ! systemctl daemon-reload > /dev/null 2>&1; then
        log_error "systemctl daemon reload failed"
        exit 1
      fi
      if ! systemctl reset-failed > /dev/null 2>&1; then
        log_error "systemctl reset-failed failed"
        exit 1
      fi
      if ! systemctl enable instana-agent > /dev/null 2>&1; then
        log_error "Instana agent service enable on boot failed"
        exit 1
      fi
      log_info "Instana agent enabled on boot"
    fi

    log_info "Starting instana-agent"
    if ! systemctl restart instana-agent > /dev/null 2>&1; then
      log_error "Instana agent service start failed"
      exit 1
    fi
    log_info "Instana agent service started up"
  else
    log_warn "Instana agent automatic enable/startup by this script is only supported for systemd"
    log_warn "Utilize your distribution's init system methods to enable/start the agent"
  fi
}

while getopts "syjinl:e:t:m:a:d:i:g:b:u:p:" opt; do
  case $opt in
    a)
      INSTANA_AGENT_KEY=$OPTARG
      ;;
    b)
      GIT_BRANCH=$OPTARG
      ;;
    l)
      LOCATION=$OPTARG
      ;;
    d)
      INSTANA_DOWNLOAD_KEY=$OPTARG
      ;;
    e)
      ENDPOINT=$OPTARG
      ;;
    g)
      GIT_REPO=$OPTARG
      ;;
    m)
      MODE=$OPTARG
      ;;
    n)
      INSTANA_AGENT_SYSTEMD_TYPE=notify
      ;;
    p)
      GIT_PASSWORD=$OPTARG
      ;;
    u)
      GIT_USERNAME=$OPTARG
      ;;
    s)
      ENABLE_SERVICE=true
      ;;
    i)
      USE_INTERNAL_PACKAGES=true
      ;;
    j)
      OPEN_J9="true"
      ;;
    t)
      AGENT_TYPE=$OPTARG
      # full and minimal are deprecated
      # remove this when the packages are removed
      if [ "$AGENT_TYPE" = "full" ]; then
        AGENT_TYPE=dynamic
      fi

      if [ "$AGENT_TYPE" = "minimal" ]; then
        AGENT_TYPE=dynamic
      fi
      ;;
    y)
      PROMPT=false
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
  esac
done

if [ "$(id -u)" != "0" ]; then
  log_error "This script must be executed as a user with root privileges"
  exit 1
fi

if [ "$OS" = "Darwin" ]; then
  log_error "Agent install script does not support macOS. Please download the macOS package from the 'Installing Instana Agents' wizard."
  exit 1
fi

if [ "$OS" = "AIX" ]; then
  log_error "Agent install script does not support AIX. Please download the AIX package from the 'Installing Instana Agents' wizard."
  exit 1
fi

if [ "$OS" = "SunOS" ]; then
  log_error "Agent install script does not support Solaris. Please download the Solaris package from the 'Installing Instana Agents' wizard."
  exit 1
fi

detect_machine

if [ $MACHINE != "x86_64" ] && [ $MACHINE != "aarch64" ] && [ $MACHINE != "s390x" ] && [ $MACHINE != "ppc64le" ] && [ $MACHINE != "OS/390" ]; then
  log_error "Systems architecture: $MACHINE not supported"
  exit 1
fi

if [ ! "$INSTANA_AGENT_KEY" ]; then
  echo "-a INSTANA_AGENT_KEY required!"
  exit 1
fi

if [ ! "$INSTANA_DOWNLOAD_KEY" ]; then
  INSTANA_DOWNLOAD_KEY="$INSTANA_AGENT_KEY"
fi

if [ $AGENT_TYPE != "static" ] && [ $AGENT_TYPE != "dynamic" ]; then
  log_error "Invalid agent type specified $AGENT_TYPE"
  exit 1
fi

if [ "$ENDPOINT" != "" ]; then
  if ! echo "$ENDPOINT" | grep ":" &>/dev/null; then
    log_error "Agent endpoint must be in the format of <host>:<port>"
    exit 1
  fi
fi

if [ -n "${LOCATION}" ]; then
  log_warn "The -l parameter is deprecated and will not be updated to cover new SaaS regions going forward. Use -e instead."
  if [ "${LOCATION}" != "eu" ] && [ "${LOCATION}" != "us" ] && [ "${LOCATION}" != "red" ] && [ "${LOCATION}" != "blue" ] && [ "${LOCATION}" != "green" ]; then
    log_error "Invalid location '${LOCATION}' specified. Please select 'blue', 'red' or 'green'."
    exit 1
  fi
fi

if [ "$MODE" != "apm" ] && [ "$MODE" != "aws" ] && [ "$MODE" != "infra" ]; then
  log_error "Invalid mode specified. Supported modes: apm | aws | infra."
  exit 1
fi

if [ $OPEN_J9 = "false" ]; then
  if [ $MACHINE = "s390x" ] || [ $MACHINE = "ppc64le" ]; then
    log_info "For the '${MACHINE}' architecture only OpenJ9 JDK is available. Enforcing OpenJ9 agent runtime."
    OPEN_J9="true"
  fi
fi

if [ $OPEN_J9 = "true" ]; then
  AGENT_TYPE="${AGENT_TYPE}-j9"
fi

if [ ! "$INSTANA_DOWNLOAD_KEY" ]; then
  INSTANA_DOWNLOAD_KEY="$INSTANA_AGENT_KEY"
fi

if [ -n "${GIT_REPO}" ]; then
  if [ -z "${GIT_BRANCH}" ]; then
    log_error "The '-g' option for the Git repository has been specified without the '-b' option to specify the remote branch."
    exit 1
  fi
else
  if [ -n "${GIT_BRANCH}" ]; then
    log_error "The '-b' option for the remote branch has been specified without the '-g' option to specify the Git repository."
    exit 1
  fi

  if [ -n "${GIT_USERNAME}" ]; then
    log_error "The '-u' option for the username to authenticate with has been specified without the '-g' option to specify the Git repository."
    exit 1
  fi

  if [ -n "${GIT_PASSWORD}" ]; then
    log_error "The '-p' option for the password to authenticate with has been specified without the '-g' option to specify the Git repository."
    exit 1
  fi
fi

if [ -n "${GIT_PASSWORD}" ]; then
  if [ -z "${GIT_USERNAME}" ]; then
    log_error "The '-p' option for the password to authenticate with has been specified without the '-u' option to specify the username."
    exit 1
  fi
fi

detect_family

detect_init

echo "Setting up the ${AGENT_TYPE} Instana agent for $OS"

if [ $PROMPT = false ]; then
  response=y
else
  if ! receive_confirmation "Are you sure?"; then
    exit 1
  fi
fi

check_prerequisites

export INSTANA_AGENT_KEY
export INSTANA_DOWNLOAD_KEY
export INSTANA_AGENT_HOST
export INSTANA_AGENT_PORT

check_download_key

get_endpoint

disable_autostart_on_systemd

update_custom_systemd_unit_file

if ! setup_agent; then
  exit 1
fi

configure_mode

check_preexisting_git_repository

configure_env

if ! start_agent; then
  exit 1
fi