#!/bin/bash

#By installing the Amazon Inspector Agent, you agree that your use is 
# subject to the terms of your existing AWS Customer Agreement or other 
# agreement with Amazon Web Services, Inc. or its affiliates governing your 
# use of AWS services. You may not install and use the 
# Amazon Inspector Agent unless you have an account in good standing with AWS.

# Copyright 2016 Amazon Web Services, Inc. or its affiliates. All Rights Reserved.
# Licensed under the terms of your existing AWS Customer Agreement 
# <https://aws.amazon.com/agreement/> or other agreement with Amazon Web Services, Inc. 
# or its affiliates governing your use of AWS services.
#
# Inspector Agent installer script to get the proper package installed.
# Version: 1.1.1921.0

# For debugging, uncomment this line:

#set -eux

###GET_INSTALL_FUNCTIONS###
#!/bin/bash

#functions
function in_array() { 
    local haystack=${1}[@]
    local needle=${2}
    for i in ${!haystack}; do
        if [[ ${i} == ${needle} ]]; then 
            return 0
        fi
    done
    return 1
}

function exit_run_once {
    local pidfile=${1}
    local exitcode=${2}

    rm -f $pidfile
    exit $exitcode
}
  
function init_run_once {
    local pidfile=${1}
    local pid_creation_code=1
    if [[ -f $pidfile ]]; then
        local pid=$(cat $pidfile)
        ps -p $pid > /dev/null 2>&1
        if [[ $? -eq 0 ]]; then
            echo "AWS Agent is already installing or updating with pid ${pid}. Exiting..."
            exit 0
        else # assume stale pidfile
            echo $$ > $pidfile
            pid_creation_code=$?
        fi
    else # There a theoretical race condition right here, but our cron does not spawn twice within a fractional second or even a minute, ever.
        echo $$ > $pidfile
        pid_creation_code=$?
    fi

    if [[ $pid_creation_code -ne 0 ]]; then
        echo "Could not create PID file: $pidfile."
        exit 1
    fi
}

#This function expects at least 2 arguments:
#  $1 - must be 'report_only' or 'report_and_exit', 
#      if this argument equals to 'report_only' then this function will only report status
#      if this argument equals to 'report_and_exit' then it will it report status and exit
#      otherwise scrip will exit with error code 129
#  $2 - status code
#  $3 - (optional) args
function report_status_and_exit_if_requested() {

    local action="nil"
    
    if [[ $# -le 1 ]]; then
        echo "no arguments has been passed... When expected at least two"
        exit 129
    fi
    
    if [[ $1 != "report_only" && $1 != "report_and_exit" ]]; then
       echo "invalid first argument (action): '${1}', when expecting 'report_only' or 'report_and_exit'"
       exit 129
    fi

    action=$1
    
    local result_param="nil"
    local result="nil"

    if [[ $# > 2 ]]; then
        result_param=$3
    fi
    result=$2

    #if inventory url is defined then start publishing
    if [[ ! -z ${AGENT_METRICS_URL} ]]; then
        ${DOWNLOAD_CMD} ${HEADER_ARG} "${AGENT_METRICS_URL}&x-op=${OP}&x-result=${result}&x-result-param=${result_param}"
        res=$?
        if [[ $res -ne 0 ]]; then
            echo "Download command failed with exist status code: ${res}"
        fi
    else
        echo "AWS Agent Inventory URL is not yet defined."
    fi
    
    if [[ "${action}" = "report_and_exit" ]]; then
        echo "Script exited with status code ${result} ${result_param}"
        if [[ "${result}" = "SUCCESS" ]]; then 
            exit 0
        else 
            exit 1
        fi
    fi
    echo "Script reports status code ${result} ${result_param}"
}

function report_status() {
    report_status_and_exit_if_requested "report_only" "$@"
}

function handle_status() {
    report_status_and_exit_if_requested "report_and_exit" "$@"
}

function download_and_verify_sig() {

    local download_url=$1
    local download_file_name=$2
    local is_it_km=$3

    if [[ -z "${PUBKEY_FILE}" || -z "${SECURE_TMP_DIR}" || ! -d "${SECURE_TMP_DIR}" ]]; then
        handle_status "SANITY_CHECK_FAILURE" "SECURE_TMP_DIR"
    fi

    echo "PUBKEY_FILE: ${SECURE_TMP_DIR}/${PUBKEY_FILE}"
    if [[ -z "${SECURE_TMP_DIR}/${PUBKEY_FILE}" || ! -s "${SECURE_TMP_DIR}/${PUBKEY_FILE}" ]]; then
        handle_status "SANITY_CHECK_FAILURE" "PUBKEY_FILE"
    fi

    #get the awsagent inventory file
    ${DOWNLOAD_CMD} ${O_ARG} "${SECURE_TMP_DIR}/${download_file_name}" "${download_url}"
    res=$?
    if [[ $res -ne 0 ]]; then
        echo "Download command failed with exist status code: ${res}"
        if [[ "${is_it_km}" == "true" ]]; then
            return
        fi 
        echo "Failed to download the ${download_file_name} from ${download_url}"
        if [[ "${is_it_km}" == "true" ]]; then
           report_status "FILE_DOWNLOAD_ERROR" "${download_file_name}"
           return
        else
           handle_status "FILE_DOWNLOAD_ERROR" "${download_file_name}" 
        fi
    fi

    #get the awsagent inventory signature
    ${DOWNLOAD_CMD} ${O_ARG} "${SECURE_TMP_DIR}/${download_file_name}.sig" "${download_url}.sig"
    res=$?
    if [[ $res -ne 0 ]]; then
        echo "Download command failed with exist status code: ${res}"
        echo "Failed to download the ${download_file_name} signature from ${download_url}.sig"
        handle_status "FILE_DOWNLOAD_ERROR" "${download_file_name}.sig"
    fi

    gpg_results=$( gpg -q --no-default-keyring --keyring "${SECURE_TMP_DIR}/${PUBKEY_FILE}" --verify "${SECURE_TMP_DIR}/${download_file_name}.sig" "${SECURE_TMP_DIR}/${download_file_name}" 2>&1 )
    if [[ $? -eq 0 ]]; then
        echo "Validated ${download_file_name} signature with: $(echo "${gpg_results}" | grep -i fingerprint)"
    else
        echo "Error validating signature of ${download_file_name}, terminating.  Please contact AWS Support."
        echo ${gpg_results}
        handle_status "SIGNATURE_MISMATCH" "${download_file_name}"
    fi
}

function get_signature_timestamp() {
    local download_file_name=$1

    SIGNATURE_TIMESTAMP="$(gpg --list-packets "${SECURE_TMP_DIR}/${download_file_name}.sig" 2>/dev/null | egrep 'version .* created' | head -n 1 | sed -e 's/.* created \([0-9]\{10\}\), .*/\1/')"
}

function verify_signature_timestamp() {
    local previous_timestamp=$1
    local signature_timestamp=$2

    # SANITY CHECKS
    # date --date='@1470000000' ==> Sun Jul 31 21:20:00 UTC 2016
    # date --date='@2000000000' ==> Wed May 18 03:33:20 UTC 2033
    if [[ -z "${previous_timestamp}" || -z "${signature_timestamp}" ]]; then
        echo "Missing timestamp."
        return 2
    fi
    if [[ "${previous_timestamp}" -lt 1470000000 || "${previous_timestamp}" -gt 2000000000 ]]; then
        echo "Invalid previous timestamp."
        return 3
    fi
    if [[ "${signature_timestamp}" -lt 1470000000 || "${signature_timestamp}" -gt 2000000000 ]]; then
        echo "Invalid signature timestamp."
        return 4
    fi

    # We have two valid timestamps -- the new one should excede the old
    if [[ "${signature_timestamp}" -ge "${previous_timestamp}" ]]; then
        return 0
    else
        return 1
    fi
}

function package_install() {
    local package_path=$1 
    local new_version=$2
    local existing_version=$3
    local package_type=$4
    local rv=0

    echo "package_install:package_path:     ${package_path}"
    echo "package_install:new_version:      ${new_version}"
    echo "package_install:existing_version: ${existing_version}"
    echo "package_type                    : ${package_type}"
    
    if [[ -z ${package_path} || -z ${new_version} || -z ${existing_version} ]]; then
        handle_status "SANITY_CHECK_FAILURE" "PACKAGE_INSTALLATION"
    fi

    local package_name=$(basename ${package_path})

    #calculate version strings
    local new_version_str=$(printf "%06d%06d%06d%06d" $(echo ${new_version} | sed 's/\./ /g'))
    local existing_version_str=$(printf "%06d%06d%06d%06d" $(echo ${existing_version} | sed 's/\./ /g'))

    if [[ "${package_name}" =~ \.deb$ ]] && which apt-get 2>/dev/null; then
        echo "Installing with dpkg..."
        apt-get update 
        dpkg --force-overwrite -i "${package_path}"
        apt-get --fix-broken -y install --no-remove
        rv="$?"
    elif [[ "${package_name}" =~ \.rpm$ ]] && which yum 2>/dev/null; then
        echo "Installing with yum..."
        if [[ ${new_version_str} == ${existing_version_str} ]]; then
            echo "yum reinstall -y ${package_path}"
            yum reinstall -y "${package_path}"
        elif [[ ${new_version_str} > ${existing_version_str} ]]; then
            echo "yum install -y ${package_path}"
            yum install -y "${package_path}"
        elif [[ ${new_version_str} < ${existing_version_str} ]]; then
             echo "yum downgrade -y ${package_path}"
             yum downgrade -y "${package_path}"
        else
             handle_status "SANITY_CHECK_FAILURE" "PACKAGE_VERSION_RPM"
        fi
        
        rv="$?"
    else
        echo "No supported package managers are installed."
        handle_status "MISSING_PACKAGE_MANAGER" "${DIST_TYPE}_${package_name}"
    fi

    if [[ ${rv} -ne 0 ]]; then
        if [[ "${package_type}" == "agent" ]]; then
            handle_status "PACKAGE_INSTALLATION_ERROR" "Agent__rv_${rv}__${package_name}__${new_version}__${existing_version}__${package_path}"
        else
            report_status "PACKAGE_INSTALLATION_ERROR" "KM__rv_${rv}__${package_name}__${new_version}__${existing_version}__${package_path}"
        fi
    fi
}

function verify_hash_package() {
    local checked_package=$1
    local expected_package_hash=$2

    if [[ ! -s ${checked_package} || -z ${expected_package_hash} ]]; then
        handle_status "SANITY_CHECK_FAILURE" "HASH_VERIFICATION_ERROR"
    fi

    # Check the hash of the package downloaded vs. the hash of the package in the index
    local actual_package_hash=$( sha256sum ${checked_package} | cut -f1 -d' ')
    if [[ "${actual_package_hash}" != "${expected_package_hash}" ]]; then
        echo "Package sha256 hash does not match expected package hash from package inventory."
        handle_status "HASH_MISMATCH" "${checked_package}"
    else
        echo "Validated agent package sha256 hash matches expected value."
    fi
}


function download_and_install_agent_package() {
    local agent_package_name=$1 
    local agent_package_url=$2
    local expected_agent_package_hash=$3
    local new_agent_version="${NEW_AGENT_VERSION}"
    local existing_agent_version="${EXISTING_AGENT_VERSION}"
    
    
    if [[ -z "${new_agent_version}" || -z "${existing_agent_version}" || -z "${expected_agent_package_hash}" ]]; then
        handle_status "SANITY_CHECK_FAILURE" "INSTALL_AGENT_PACKAGE"
    fi

    if [[ -z "${agent_package_url}" || -z "${agent_package_name}" || -z "${expected_agent_package_hash}" ]]; then
        echo "Agent package URL: ${agent_package_url} or Agent Package Hash: ${expected_agent_package_hash} or Agent package name : ${agent_package_name} is invalid."
        handle_status "PARSE_ERROR" "AGENT_INSTALL_PACKAGE_${UNIQ_OS_ID}"
    fi
 
    # Download the package for the proper version.
    ${DOWNLOAD_CMD} ${O_ARG} ${SECURE_TMP_DIR}/${agent_package_name} ${agent_package_url}
    res=$?
    if [[ ! -s ${SECURE_TMP_DIR}/${agent_package_name} ]]; then
        echo "Download command failed with exist status code: ${res}"
        echo "Failed to download package from the path ${agent_package_url}."  
        handle_status "FILE_DOWNLOAD_ERROR" "${agent_package_name}"
    fi

    # Check the hash of the package downloaded vs. the hash of the package in the index
    verify_hash_package "${SECURE_TMP_DIR}/${agent_package_name}" "${expected_agent_package_hash}"

    package_install "${SECURE_TMP_DIR}/${agent_package_name}" "${new_agent_version}" "${existing_agent_version}" "agent"
}

function lowercase(){
    echo "$1" | sed "y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"
}

function uppercase(){
    echo "$1" | sed "y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/"
}


function get_os_version() {
    local os_dist_type=$1
    local os_release_info=$2

    if [[ -z "${os_dist_type}" || -z "${os_release_info}" ]]; then
        handle_status "SANITY_CHECK_FAILURE" "GET_OS_VERSION"
    fi

    if [ "${os_dist_type}" = "CentOS" -o "${os_dist_type}" = "RedHat" -o "${os_dist_type}" = "amzn" ]; then
        DIST=`echo "${os_release_info}" | sed s/\ release.*//`
        REV=`echo "${os_release_info}" | sed s/.*release\ // | sed s/\ .*//`
    elif [ "${os_dist_type}" = "SuSe" ] ; then
        REV=`echo "${os_release_info}" | tr "\n" ' ' | sed s/.*=\ //`
    elif [ "${os_dist_type}" = "Mandrake" ] ; then
        REV=`echo "${os_release_info}" | sed s/.*release\ // | sed s/\ .*//`
    elif [ "${os_dist_type}" = "debian" ] ; then
        DIST=`echo "${os_release_info}" | grep '^DISTRIB_ID' | awk -F=  '{ print $2 }'`
        REV=`echo "${os_release_info}" | grep '^DISTRIB_RELEASE' | awk -F=  '{ print $2 }'`
    fi

    echo "${DIST}.${REV}"
}

function get_os_info () {
    OS=`lowercase \`uname\``
    KERNEL=`uname -r`
    MACH=`uname -m`
    KERNEL_GROUP=$(echo $KERNEL | cut -f1-2 -d'.')

    if [ "${OS}" = "linux" ] ; then
      # Figure out which OS we are running on
      local os_release_info=""

      if [ -f /etc/centos-release ]; then
          DIST_TYPE='CentOS'
          os_release_info=`cat /etc/centos-release`
      elif [ -f /etc/redhat-release ]; then
          DIST_TYPE='RedHat'
          os_release_info=`cat /etc/redhat-release`
      elif [ -f /etc/system-release ]; then
          if grep "Amazon Linux AMI" /etc/system-release; then
            DIST_TYPE='amzn'
          fi
          os_release_info=`cat /etc/system-release`
      elif [ -f /etc/SuSE-release ] ; then
          DIST_TYPE='SuSe'
          os_release_info=`cat /etc/SuSE-release`
      elif [ -f /etc/mandrake-release ] ; then
          DIST_TYPE='Mandrake'
          os_release_info=`cat /etc/mandrake-release`
      elif [ -f /etc/debian_version ] ; then
          DIST_TYPE='debian'
          os_release_info=`cat /etc/lsb-release`
      fi

      if [[ -z "${DIST_TYPE}" || -z "${os_release_info}" ]]; then
          if [ -f /etc/os-release ]; then
            source /etc/os-release
            DIST_TYPE=$ID
            DIST=$NAME
            REV=$VERSION_ID
          elif [ -f /usr/lib/os-release ]; then
            source /usr/lib/os-release
            DIST_TYPE=$ID
            DIST=$NAME
            REV=$VERSION_ID
          fi
      else
          get_os_version "${DIST_TYPE}" "${os_release_info}"
          if [[ "${DIST_TYPE}" = "RedHat" || "${DIST_TYPE}" = "debian" ]]  && [[ -f /etc/os-release ]]; then
            source /etc/os-release
            DIST_TYPE=$ID
          fi
      fi

      if [ -f /etc/UnitedLinux-release ] ; then
          DIST="${DIST}[`cat /etc/UnitedLinux-release | tr "\n" ' ' | sed s/VERSION.*//`]"
      fi
    fi

    if [ "${OS}" == "darwin" ]; then
        OS=mac
    fi

    DIST_TYPE=`lowercase $DIST_TYPE`
    UNIQ_OS_ID="${DIST_TYPE}-${KERNEL}-${MACH}"
    UNIQ_PLATFORM_ID="${DIST_TYPE}-${KERNEL_GROUP}."
    OS_FULL_REVISION=$(echo "${REV}" | cut -f1-2 -d'.')
    OS_MAIN_REVISION=$(echo "${REV}" | cut -f1 -d'.')

    echo "${DIST_TYPE}.${OS_FULL_REVISION}.${OS_MAIN_REVISION}"

    if [[ -z "${DIST}" || -z "${DIST_TYPE}" ]]; then
        echo "Unsupported distribution: ${DIST} and distribution type: ${DIST_TYPE}"
        exit 1
    fi
}
function callUname () {
    local args=("$@")
    echo "$(uname ${args})"
}

function uninstall_km() {
    local kmods_dir=$1 
    if [ "${DIST_TYPE}" = "ubuntu" ] || [ "${DIST_TYPE}" = "debian" ]; then
        apt-get purge -qq -y "awsagentkernel*"
    else 
        yum remove -q -y 'AwsAgentKernel*'
    fi
    rm -rf ${kmods_dir}
}

function get_installed_km_version() {
    if [ "${DIST_TYPE}" = "ubuntu" ] || [ "${DIST_TYPE}" = "debian" ]; then
        EXISTING_KM_VERSION=$(dpkg-query -W -f='${VERSION}' "awsagentkernelmodule-${KERNEL_VERSION_WO_ARCH}" | cut -f1 -d'-')
        rv=${PIPESTATUS[0]}
    else
        EXISTING_KM_VERSION=$(rpm -qa "AwsAgentKernelModule__${DIST_TYPE}__${KERNEL_VERSION_WO_ARCH}" --queryformat '%{VERSION}')
        rv=$?
    fi
    
    if [[ -z "${EXISTING_KM_VERSION}" ]]; then
        echo "cannot find installed KM VERSION... assumed '0.0.0.0' "
        EXISTING_KM_VERSION="0.0.0.0"
    fi
    
    echo "get_installed_km_version: EXISTING_KM_VERSION:${EXISTING_KM_VERSION} exit status:${rv}"
}

function executeEnvironmentCleanup() {
    echo "Installation script completed successfully."
}

function getAgentStatus() {
    local agent_status=$( ${AGENT_EXEC} status )
    echo "Agent status completed with code:$?"
    echo "${agent_status}"
}

function usage() {
    executing_script=$(basename "${BASH_SOURCE[0]}")
    echo "Usage sudo ${executing_script}< options > "
    echo "Options:"
    echo "-u [ true | false ] Automatically update Aws Agent when versions become available. Applicable only during first installation."
}

# customer may have somehow disabled agent.
# an update shouldn't override that decision
function check_awsagent_condition() {
    if [[ $(basename "${BASH_SOURCE[0]}" ) = "update" ]]; then # otherwise this is a fresh install
        if [[ ! -f /var/run/awsagent.pid ]]; then
            echo "/var/run/awsagent.pid not found. Updater only runs when agent is expected to be running."
            handle_status "SUCCESS" "AGENT_NOT_RUNNING_NO_UPDATE"
        fi
    fi
}

#
#Search AgentManifest file or version file 
# - Search agent manifest file by              ${DIST_TYPE}.${OS_FULL_REVISION}
# - If not found then search agent manifest by ${DIST_TYPE}.${OS_MAIN_REVISION}
# - If not found then search agent version by  ${UNIQ_PLATFORM_ID}
#Load row_value and parsing out following global variables:
#  - AGENT_PACKAGE_URL
#  - EXPECTED_AGENT_PACKAGE_HASH
#  - NEW_AGENT_VERSION
function searchAgentManifest() {
    #first check the full version...
    local os_search_key="${DIST_TYPE}-${OS_FULL_REVISION} "
    if [ $MACH == "aarch64" ]; then
        os_search_key="${DIST_TYPE}-${OS_FULL_REVISION}-${MACH} "
    fi
    local path_to_agent_manifest=$1
    local path_to_agent_version=$2
    local row_value=$( grep -m 1 -i "${os_search_key}" "${path_to_agent_manifest}" )
    AGENT_PACKAGE_URL=$( echo "${row_value}" | cut -f3 -d' ' )
    EXPECTED_AGENT_PACKAGE_HASH=$( echo "${row_value}" | cut -f2 -d' ')
    NEW_AGENT_VERSION=$( echo "${row_value}" | cut -f7 -d'/' )
    if [[ -z "${row_value}" ]]; then
        # there is no entry for full version... searching for MainVersion:
        os_search_key="${DIST_TYPE}-${OS_MAIN_REVISION} "
        if [ $MACH == "aarch64" ]; then
            os_search_key="${DIST_TYPE}-${OS_MAIN_REVISION}-${MACH} "
        fi
        row_value=$( grep -m 1 -i "${os_search_key}" "${path_to_agent_manifest}" )
        AGENT_PACKAGE_URL=$( echo "${row_value}" | cut -f3 -d' ' )
        EXPECTED_AGENT_PACKAGE_HASH=$( echo "${row_value}" | cut -f2 -d' ' )
        NEW_AGENT_VERSION=$( echo "${row_value}" | cut -f7 -d'/' )
        if [[ -z "${row_value}" ]]; then
            echo "using legacy VERSION file"
            row_value=$( grep -m 1 -i "${UNIQ_PLATFORM_ID}" "${path_to_agent_version}" )            
            AGENT_PACKAGE_URL=$( echo "${row_value}" | cut -f4 -d' ' )
            EXPECTED_AGENT_PACKAGE_HASH=$( echo "${row_value}" | cut -f3 -d' ' )
            NEW_AGENT_VERSION=$( echo "${row_value}" | cut -f7 -d'/' )
            if [[ -z "${row_value}" ]]; then
                echo "Failed to find an inspector agent package for this OS:${UNIQ_PLATFORM_ID}."
                handle_status "MISSING_AGENT_PLATFORM" "$os_search_key"
            fi
        fi
    fi
}

if [[ $(whoami) != "root" ]]; then
    echo "Script is run as $(whoami). Please run as root"
    exit 1
fi

PIDFILE="/var/run/awsagent_install_or_update.PID"
init_run_once $PIDFILE

#Create a Secure temp directory where we get all files and then use them.
SECURE_TMP_DIR=$(mktemp -d /tmp/awsagent.XXXXXXXX)
if [[ ! -d "$SECURE_TMP_DIR" ]]; then
  echo "Script cannot create temporary directory"
  exit 1
fi

# Perform Cleanup upon exit
trap "EXIT_CODE=$?; rm -rf ${SECURE_TMP_DIR}; exit_run_once $PIDFILE $EXIT_CODE" EXIT

#define constants
declare -a SUPPORTED_REGIONS=("us-east-1" "us-west-1" "us-west-2" "ap-northeast-1" "eu-west-1" "eu-west-2" "ap-northeast-2" "ap-southeast-2" "ap-south-1" "eu-central-1" "eu-north-1" "us-east-2" "us-gov-west-1" "us-gov-east-1")
ROOTDIRECTORY="$(cd "$(dirname "${BASH_SOURCE[0]}" )" && pwd )"
AGENT_INVENTORY_FILE="AWS_AGENT_INVENTORY"
AGENT_MANIFEST_FILE="AGENT_MANIFEST"
AGENT_VERSION_FILE="VERSION"
AGENT_CFG_KEY="agent.cfg" 
PUBKEY_FILE="inspector.gpg"
CRON_UPDATE_AGENT=true
OP=install

if hash curl 2>/dev/null
then
  DOWNLOAD_CMD="curl -s --fail --retry 5 --max-time 30 "
  O_ARG=" -o "
  CONSOLE_ARG=""
  PUT_METHOD_ARG=" -X PUT "
  HEADER_ARG=" --head "
else
  DOWNLOAD_CMD="wget --quiet --tries=5 --timeout=30 "
  O_ARG=" -O "
  CONSOLE_ARG=" -qO- "
  PUT_METHOD_ARG=" --method=PUT "
  HEADER_ARG=" -S --spider "
fi

#define inspector constants
AGENT_CONFIG_FILE=/opt/aws/awsagent/etc/agent.cfg
AGENT_EXEC=/opt/aws/awsagent/bin/awsagent
AGENT_KMOD=/opt/aws/awsagent/kmods/amznmon64.ko
AGENT_KMOD_DIR=/opt/aws/awsagent/kmods
AGENT_KMOD_NAME=amznmon64.ko
AGENT_INIT_SCRIPT="/etc/init.d/awsagent"
AGENT_ENV_CONFIG="/etc/init.d/awsagent.env"
INSTALL_CONFIG_FILE=/opt/aws/awsagent/etc/install.cfg

#Domain specific configuration
INSTALLER_EXT=""
BUCKET="aws-agent.us-west-2"

#check if environment environment file exists and if so source it
if [[ -f "${AGENT_ENV_CONFIG}" ]]; then
  source "${AGENT_ENV_CONFIG}"
fi


#check if environment override file exists and if so source it
if [[ -f "${ROOTDIRECTORY}/environmentOverride" ]]; then
    source "${ROOTDIRECTORY}/environmentOverride"
fi

#handle installer options
while getopts ":u:" opt; do
    case $opt in
        u)
            echo "Forced update specified as argument is : $OPTARG"
            if [[ $(basename "${BASH_SOURCE[0]}" ) = "install" ]]; then
                CRON_UPDATE_AGENT=$OPTARG
            fi
            ;;
        \?)
            echo "Invalid option: -$OPTARG"
            usage
            exit 1
            ;;
        :)
            echo "Option -$OPTARG requires an argument." 
            usage
            exit 1
            ;;
    esac
done

#call the os info function to get details
get_os_info 

check_awsagent_condition

KERNEL_VERSION=`callUname -r`

if [[ -z "${KERNEL_VERSION}" ]]; then
    handle_status "NO_KERNEL_VERSION"
fi

KERNEL_GROUP=$(echo "${KERNEL_VERSION}" | cut -f 1-2 -d'.')
KERNEL_VERSION_WO_ARCH=$(basename ${KERNEL_VERSION} .x86_64)

echo "Distribution of the machine is ${DIST}." 
echo "Distribution type of the machine is ${DIST_TYPE}."
echo "Revision of the distro is ${REV}."
echo "Kernel version of the machine is ${KERNEL_VERSION}."

IMDSV2_TOKEN=$( ${DOWNLOAD_CMD} ${CONSOLE_ARG} ${PUT_METHOD_ARG} --header "X-aws-ec2-metadata-token-ttl-seconds: 21600" http://169.254.169.254/latest/api/token)

IMDSV2_TOKEN_HEADER=""

if [[ -n "${IMDSV2_TOKEN}" ]]; then
    IMDSV2_TOKEN_HEADER=" --header X-aws-ec2-metadata-token:${IMDSV2_TOKEN} "
fi

#gather all meta data information
METADATA_AZ=$( ${DOWNLOAD_CMD} ${CONSOLE_ARG} ${IMDSV2_TOKEN_HEADER} http://169.254.169.254/latest/meta-data/placement/availability-zone)
METADATA_INSTANCE_TYPE=$( ${DOWNLOAD_CMD} ${CONSOLE_ARG} ${IMDSV2_TOKEN_HEADER} http://169.254.169.254/latest/meta-data/instance-type)
METADATA_REGION=$( echo $METADATA_AZ | sed -e 's/[a-z]*$//' )

if [[ -n "${METADATA_REGION}" ]]; then
    REGION=${METADATA_REGION}
else
    echo "No region information was obtained."
    handle_status "NO_REGION_INFO"
fi

#check if the obtained region is supported by inspector
if in_array SUPPORTED_REGIONS "${REGION}"; then
    echo "$(hostname -f) is an EC2 instance reporting region as ${REGION}."
else
    echo "Aws Agent is only supported in ${SUPPORTED_REGIONS[@]}"
    handle_status "UNSUPPORTED_REGION" ${REGION}
fi

#Base url formation
if [[ -z "${INSTALLER_EXT}" ]]; then
    BUCKET="aws-agent.${REGION}"
fi

BASE_URL="https://s3.dualstack.${REGION}.amazonaws.com/${BUCKET}"

#check existing agent status to get the version information of the running agent
if [ "${DIST_TYPE}" = "ubuntu" ] || [ "${DIST_TYPE}" = "debian" ]; then
    EXISTING_AGENT_VERSION=$(dpkg-query -W -f='${VERSION}' "awsagent" | cut -f1 -d'-')
    rv=${PIPESTATUS[0]}
else
    EXISTING_AGENT_VERSION=$(rpm -qa "AwsAgent" --queryformat '%{VERSION}')
    rv=$?
fi
echo "Check for existing AwsAgent completed with error code:${rv}"
if [[ -z "${EXISTING_AGENT_VERSION}" ]]; then   
    EXISTING_AGENT_VERSION="0.0.0.0"
fi
   
echo "Existing version of agent installed is ${EXISTING_AGENT_VERSION}."

#get installed kernel module version based on kernel version in machine
get_installed_km_version
echo "Existing version of kernel module installed is ${EXISTING_KM_VERSION}."

#Agent and Kernel Param
AGENT_ID_PARAM="x-installer-version=1.1.1921.0&x-existing-version=${EXISTING_AGENT_VERSION}&x-uniq-os-id=${UNIQ_OS_ID}&x-instance-type=${METADATA_INSTANCE_TYPE}"
KERNEL_ID_PARAM="x-existing-km-version=${EXISTING_KM_VERSION}"
AGENT_INVENTORY_URL="${BASE_URL}/linux/latest/${AGENT_INVENTORY_FILE}"

BASE_METRIC_URL="https://s3.dualstack.${REGION}.amazonaws.com/${BUCKET}"
AGENT_INVENTORY_METRIC_URL="${BASE_METRIC_URL}/linux/latest/${AGENT_INVENTORY_FILE}"
AGENT_METRICS_URL="${AGENT_INVENTORY_METRIC_URL}?${AGENT_ID_PARAM}&${KERNEL_ID_PARAM}"


if [[  -n "${BASH_SOURCE[0]}"  &&  $(basename "${BASH_SOURCE[0]}" ) = "update"  ]]; then
    OP=update
    if [[ ! -f "${AGENT_EXEC}" ]]; then
        echo "Attempting update, but binary does not exist. Please run 'install' instead."
        handle_status "WRONG_EXEC_MODE" "update" 
    fi

    if [[ -s "${INSTALL_CONFIG_FILE}" ]]; then
        echo "Detected running as updater script, loading saved configuration from ${INSTALL_CONFIG_FILE}..."
        source ${INSTALL_CONFIG_FILE}
    fi

    COLLECT="$( getAgentStatus | grep -Ei "Collecting\s*:" | sed -re 's/Collecting\s*:\s*//i' )"

    if [[ "${COLLECT}" = "true" ]]; then
        echo "Agent is actively collecting at this time, cannot update agent while it is collecting data!"
        handle_status "AGENT_RUNNING_ASSESSMENT"
    elif [[ "${CRON_UPDATE_AGENT}" = "false" ]]; then
        echo "Update is not permitted according to configuration parameter mentioned as argument."
        handle_status "CRON_UPDATE_AGENT_DISABLED"
    else
        echo "Agent is inactive, continuing to update..."
    fi
fi
     
# Check that the dir exists and is owned by our euid (root)
if [[ ! -O "${SECURE_TMP_DIR}" ]]; then
    echo "Unable to create secure temporary directory ${SECURE_TMP_DIR}."
    handle_status "TMP_DIR_ERROR"
fi
chmod 700 "${SECURE_TMP_DIR}"

#get the public key
${DOWNLOAD_CMD} ${O_ARG} "${SECURE_TMP_DIR}/${PUBKEY_FILE}" "${BASE_URL}/linux/latest/${PUBKEY_FILE}"
res=$?
if [[ $res -ne 0 ]]; then
    echo "Download command failed with exist status code: ${res}"
    echo "Failed to download public key from the path ${BASE_URL}/linux/latest/${PUBKEY_FILE}" 
    handle_status "FILE_DOWNLOAD_ERROR" "${PUBKEY_FILE}"
fi

#get the awsagent inventory file
download_and_verify_sig "${AGENT_INVENTORY_URL}" "${AGENT_INVENTORY_FILE}"

#send start agent census metric
${DOWNLOAD_CMD} ${HEADER_ARG} "${AGENT_METRICS_URL}&x-op=${OP}&x-result=begin"

AGENT_MANIFEST_URL="$(grep "${AGENT_MANIFEST_FILE}" "${SECURE_TMP_DIR}/${AGENT_INVENTORY_FILE}" | grep -v "${AGENT_MANIFEST_FILE}.sig" | cut -f2 -d' ')"
AGENT_VERSION_URL="$(grep "${AGENT_VERSION_FILE}" "${SECURE_TMP_DIR}/${AGENT_INVENTORY_FILE}" | grep -v "${AGENT_VERSION_FILE}.sig" | cut -f2 -d' ')"
if [[ -z "${AGENT_MANIFEST_URL}"  &&  -z "${AGENT_VERSION_URL}" ]]; then
    echo "Agent manifest file URL was not obtained. Please contact AWS support."
    handle_status "PARSE_ERROR" "${AGENT_MANIFEST_FILE} and ${AGENT_VERSION_FILE} are both empty"
fi

echo "AGENT_MANIFEST_URL: ${AGENT_MANIFEST_URL}"
echo "AGENT_VERSION_URL:  ${AGENT_VERSION_URL}"

download_and_verify_sig "${AGENT_MANIFEST_URL}" "${AGENT_MANIFEST_FILE}"
download_and_verify_sig "${AGENT_VERSION_URL}"  "${AGENT_VERSION_FILE}"

searchAgentManifest "${SECURE_TMP_DIR}/${AGENT_MANIFEST_FILE}" "${SECURE_TMP_DIR}/${AGENT_VERSION_FILE}"

echo "AGENT_PACKAGE_URL: ${AGENT_PACKAGE_URL}"
echo "EXPECTED_AGENT_PACKAGE_HASH: ${EXPECTED_AGENT_PACKAGE_HASH}"
echo "NEW_AGENT_VERSION:${NEW_AGENT_VERSION}"

if [[ -z "${NEW_AGENT_VERSION}" ]]; then
    handle_status "SANITY_CHECK_FAILURE" "NEW_AGENT_VERSION"
fi

DIST_TYPE_UPPERCASE=`uppercase "${DIST_TYPE}"`

#
# Check if we need to install agent 
#
need_install_agent=true
if [[ $(basename "${BASH_SOURCE[0]}" ) == "update" ]]; then
   if [[ "${EXISTING_AGENT_VERSION}" == "${NEW_AGENT_VERSION}" ]]; then
      need_install_agent=false
   fi
fi

#
# Check if we need to uninstall kernel module and uninstall it
#
if [[ "${EXISTING_KM_VERSION}" != "0.0.0.0" ]]; then
    uninstall_km ${AGENT_KMOD_DIR}
fi

if [[ "${need_install_agent}" == "true" ]]; then
    if [ "${DIST_TYPE}" = "ubuntu" ] || [ "${DIST_TYPE}" = "debian" ]; then
        AGENT_PACKAGE_NAME="awsagent.deb"
    else 
        AGENT_PACKAGE_NAME="AWSAgent.rpm"
    fi
    
    echo "AGENT_PACKAGE_NAME:${AGENT_PACKAGE_NAME}"
    download_and_install_agent_package ${AGENT_PACKAGE_NAME} ${AGENT_PACKAGE_URL} ${EXPECTED_AGENT_PACKAGE_HASH}
    
    umask 077
    # Save the config so we can update with the same parameters
    [[ -f ${INSTALL_CONFIG_FILE} ]] && mv -f ${INSTALL_CONFIG_FILE} ${INSTALL_CONFIG_FILE}.old
    echo "AGENT_CFG_KEY=${AGENT_CFG_KEY}" >> ${INSTALL_CONFIG_FILE}
    echo "CRON_UPDATE_AGENT=${CRON_UPDATE_AGENT}" >> ${INSTALL_CONFIG_FILE} 
fi

if [[ ! -f ${AGENT_CONFIG_FILE} && -f ${AGENT_CONFIG_FILE}.orig ]]; then
    cp ${AGENT_CONFIG_FILE}.orig ${AGENT_CONFIG_FILE}
fi

RUNNING_VERSION=$( getAgentStatus | grep -Ei "Agent\s*version" | sed -re 's/Agent\s*version\s*:\s*//i' )
ARSENAL_ENDPOINT=$( getAgentStatus | grep -Ei "Endpoint" | sed -re 's/Endpoint\s*:\s*//i' )

#send installer end metric 
${DOWNLOAD_CMD} ${HEADER_ARG} "${AGENT_METRICS_URL}&x-op=${OP}&x-result=SUCCESS&x-running-agent-version=${RUNNING_VERSION}"

executeEnvironmentCleanup

echo
echo "Notice:"
echo "By installing the Amazon Inspector Agent, you agree that your use is subject to the terms of your existing "
echo "AWS Customer Agreement or other agreement with Amazon Web Services, Inc. or its affiliates governing your "
echo "use of AWS services. You may not install and use the Amazon Inspector Agent unless you have an account in "
echo "good standing with AWS."
echo "*  *  *"
echo "Current running agent reports to arsenal endpoint: $ARSENAL_ENDPOINT"
echo "Current running agent reports version as: $RUNNING_VERSION"
echo "This install script was created to install agent version:1.1.1921.0"
echo "In most cases, these version numbers should be the same."
echo