TOMODACHI SHELL

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readonly ZONES_DIR="/var/named";
readonly DNS_QUERY_CHECK_DATA="${BACKGROUND_DATA}/dns_query_check.data";
readonly DNS_QUERY_CHECK_ERRORS="${BACKGROUND_DATA}/dns_query_check.errors";
readonly DNS_QUERY_CASES=(named_zone_duplicate);
readonly REASON_UNKNOWN="unknown";
readonly DUPLICATE_ZONE="duplicate_definition_in_named_conf";

named_zone_duplicate() {
        local zone_duplicate_keyword="already exists previous definition";

        if [[ "$named_restart_result" =~ "$zone_duplicate_keyword" ]]; then
                dns_query_data[dnq_query_issue_reason]="$DUPLICATE_ZONE";
                # Backup the current, broken /etc/named.conf
                local named_conf="/etc/named.conf";
                local named_conf_bkp="/etc/$(basename "$named_conf")_$(date '+%F_%H-%M-%S')";
                mv "$named_conf" "$named_conf_bkp";
                # Rebuild /etc/named.conf
                local named_rebuild_result=$(/usr/local/cpanel/scripts/rebuilddnsconfig 2>&1);
                if [[ $? -eq 0 ]]; then
                        dns_query_data[service_status]="$SERVICE_ACTIVE";
                        dns_query_data[auto_fix_status]="$AUTO_FIX_SUCCESS";
                        return 0;
                else
                        # Reverse changes in case the rebuilddnsconfig script failed
                        mv -f "$named_conf_bkp" "$named_conf";
                        dns_query_data[service_status]="$SERVICE_DOWN"
                        dns_query_data[auto_fix_status]="$AUTO_FIX_FAIL";
                        dns_query_data[named_rebuild_result]=$(base64 -w0 <<< "$named_rebuild_result");
                        return 0;
                fi;
        else
                # Check for a different issue
                return 1;
        fi;
}

ns_pointed_to_server_check(){
        local ips="$1";
        local ip_a=$(ip a);
        for ip in $ips; do
                if [[ $ip_a =~ " $ip/" ]]; then
                        # One of the NS is pointed to the server
                        return 0;
                else
                        # None of the NS are pointed to the server
                        return 1;
                fi;
        done;
}

create_hostname_zone(){
        whmapi1 adddns domain="$(hostname)" trueowner='root' ip="${server_ips[0]}" 1>/dev/null 2>&1;
        /scripts/restartsrv_named 1>/dev/null 2>&1;

        local dig_res=$(dig $(hostname) @${server_ips[0]});
        local dig_answer_section=$(grep -A1 "ANSWER SECTION:" <<< "$dig_res");

        if [[ $dig_answer_section =~ "${server_ips[0]}" ]]; then
                dns_query_data[service_status]="$SERVICE_ACTIVE";
                dns_query_data[auto_fix_status]="$AUTO_FIX_SUCCESS";
        else
                dns_query_data[service_status]="$SERVICE_DOWN"
                dns_query_data[auto_fix_status]="$AUTO_FIX_FAIL";
                dns_query_data[dig_result]="$(sed -z "s/\n/\\\n/g" <<< "$dig_res")";
        fi;
}

fix_hostname_record(){
        local zones_backup_dir="${ZONES_DIR}/named_zone_bkp_$(date +%F)";
        local zone_file="${ZONES_DIR}/$(hostname).db";
        local serial="$(grep -A5 SOA $zone_file | grep -oE "[0-9]{10,}")";
        mkdir $zones_backup_dir 2>/dev/null;
        rsync ${ZONES_DIR}/$(hostname).db "$zones_backup_dir";

        sed -i -E "/$(hostname).[\s\t]+[0-9]+[\s\t]+IN[\s\t]+A/d" $zone_file
        whmapi1 mass_edit_dns_zone zone="$(hostname)" serial="$serial" add='{"dname":"'$(hostname).'", "ttl":14400, "record_type":"A", "data":["'${server_ips[0]}'"]}' 1>/dev/null 2>&1;
        sleep 5;
        local dig_res=$(dig $(hostname) @${server_ips[0]});
        local dig_answer_section=$(grep -A1 "ANSWER SECTION:" <<< "$dig_res");

        if [[ $dig_answer_section =~ "${server_ips[0]}" ]]; then
                dns_query_data[service_status]="$SERVICE_ACTIVE";
                dns_query_data[auto_fix_status]="$AUTO_FIX_SUCCESS";
        else
                dns_query_data[service_status]="$SERVICE_DOWN"
                dns_query_data[auto_fix_status]="$AUTO_FIX_FAIL";
                dns_query_data[dig_result]="$(sed -z "s/\n/\\\n/g" <<< "$dig_res")";
        fi;
}

hostname_zone_fix(){
        if [[ $(file ${ZONES_DIR}/$(hostname).db) =~ ": cannot open" ]]; then
                create_hostname_zone;
        else
                fix_hostname_record;
        fi;
}

named_service_check(){
        local named_initial_status="$(/scripts/restartsrv_named --status 2>&1)";
        local named_restart;

        local disabled="$(grep named:1 /etc/chkserv.d/chkservd.conf)";
        local inactive="service is down";
        local active="is running";

        if [[ -z "$disabled" ]]; then
                # The named service was disabled manually
                dns_query_data[service_status]="$SERVICE_DISABLED";
                dns_query_data[auto_fix_status]="$AUTO_FIX_NOPE";
                return 1;
        elif [[ "$named_initial_status" =~ $active ]]; then
                # The named service is running
                hostname_check;
                return 0;
        else
                /scripts/restartsrv_named --start 1>/dev/null 2>&1;
                named_restart="$(/scripts/restartsrv_named --status 2>&1)";

                if [[ "$named_restart" =~ "$inactive" ]]; then
                        # The named service has failed to start
                        dns_query_data[service_status]="$SERVICE_DOWN"
                        dns_query_data[auto_fix_status]="$AUTO_FIX_FAIL";
                        return 1;
                else
                        # The named service was restarted successfully
                        return 0;
                fi;
        fi;
}

hostname_check(){
        readarray -t server_ips <<< "$(whmapi1 listips | grep -P "public_ip:" | grep -oE "([0-9]{1,3}\.){3}[0-9]{1,3}$")";
        local dig_res=$(dig $(hostname) @${server_ips[0]});
        local dig_answer_section=$(grep -A1 "ANSWER SECTION:" <<< "$dig_res");
        local hostname_ip=$(grep -P "[\s\t]+A[\s\t]+" <<< "$dig_answer_section" | grep -oP "([0-9]{1,3}\.){3}[0-9]{1,3}");

        if [[ ! $(ip a) =~ " ${hostname_ip}/" ]]; then
                # The hostname is not pointed
                # Check if NS are pointed to the server
                local ns_ips=$(grep -A2 ";; ADDITIONAL SECTION:" <<< "$dig_res" | grep -oP "([0-9]{1,3}\.){3}[0-9]{1,3}");
                ns_pointed_to_server_check "$ns_ips" && {
                        # At least one NS is pointed to the server
                        # Create zone for hostname or the A record
                        hostname_zone_fix;
                } || {
                        # NS are not pointed to the server
                        dns_query_data[service_status]="$SERVICE_DOWN";
                        dns_query_data[dig_result]="$(json_escape <<< "$dig_res")";
                };
        else
                # Hostname is pointed
                dns_query_data[service_status]="$SERVICE_ACTIVE";
        fi;
}

dns_query_check_main(){
        declare -A dns_query_data;
        local server_ips=();

        local named_restart_result;
        local named_restart_return_code=0; # Expected to be running by default
        local disabled="$(grep named:1 /etc/chkserv.d/chkservd.conf)";

        # In case the named service is not running, restart it
        if ! /scripts/restartsrv_named --status &>/dev/null; then
                named_restart_result="$(/scripts/restartsrv_named 2>&1)";
                named_restart_return_code=$?;
        fi;

        if [[ -z "$disabled" ]]; then
                # The named service was disabled manually
                dns_query_data[service_status]="$SERVICE_DISABLED";
                dns_query_data[auto_fix_status]="$AUTO_FIX_NOPE";
        elif [[ $named_restart_return_code -eq 0 ]]; then
                # The named service is running
                # Check if the server hostname is pointed to the server
                hostname_check;
        else
                # The named service is not running, look for reasons and attempt to fix
                for case in ${!DNS_QUERY_CASES[@]}; do
                        # Each DNS_QUERY_CASES function should return 0 if the issues was identified
                        if eval ${DNS_QUERY_CASES[$case]}; then
                                break;
                        fi;
                done;

                if [[ -z ${dns_query_data[dnq_query_issue_reason]} ]]; then
                        dns_query_data[dnq_query_issue_reason]="$REASON_UNKNOWN";
                fi;
        fi;

        bash_arr_to_json dns_query_data "${!dns_query_data[@]}" > "$DNS_QUERY_CHECK_DATA";
}

dns_query_check(){
        run_check_in_background "dns_query_check_main" "$DNS_QUERY_CHECK_DATA" "$DNS_QUERY_CHECK_ERRORS"\
                "${CHECK_LOCKS_DIR}/${FUNCNAME}.lock";
}