input {
        file {
                path => "/var/log/nginx/access.log"
                type => "nginx-access"
                sincedb_path => "/var/log/.nginxaccesssincedb"
        }
}
input {
        file {
                path => "/var/log/nginx/error.log"
                type => "nginx-error"
                sincedb_path => "/var/log/.nginxerrorsincedb"
        }
}
input {
        redis {
                host => "127.0.0.1"
                data_type => "list"
                key => "logstash"
        }
}
input {
        tcp {
                type => "syslog"
                port => "514"
        }
}
input {
        tcp {
                type => "VMware"
                port => "1514"
        }
}
input {
        tcp {
                type => "vCenter"
                port => "1515"
        }
}
input {
        tcp {
                type => "Netscaler"
                port => "1517"
        }
}
input {
        tcp {
                type => "eventlog"
                port => "3515"
                format => "json"
        }
}
input {
        tcp {
                type => "iis"
                port => "3525"
                codec => "json_lines"
        }
}
filter {
        if [type] == "syslog" {
                dns {
                        reverse => [ "host" ]
                        action => "replace"
                }
                mutate {
                        add_tag => [ "syslog" ]
                }
        }
        if [type] == "VMware" {
                mutate {
                        add_tag => "VMware"
                }
        }
        if [type] == "vCenter" {
                mutate {
                        add_tag => "vCenter"
                }
        }
        if [type] == "PFsense" {
                mutate {
                        add_tag => "PFsense"
                }
        }
        if [type] == "Netscaler" {
                mutate {
                        add_tag => "Netscaler"
                }
        }
        if [type] == "eventlog" {
                mutate {
                        add_tag => [ "WindowsEventLog" ]
                }
        }
        if [type] == "apache" {
                mutate {
                       add_tag => [ "apache" ]
                }
        }
        if [type] =~ "nginx" {
                mutate {
                        add_tag => [ "nginx" ]
                }
        }
        if [type] == "iis" {
                mutate {
                        add_tag => [ "IIS" ]
                }
        }
}
filter {
        if [type] == "syslog" {
                mutate {
                        remove_tag => "Ready"
                }
        }
}
# First layer of normal syslog parsing
filter {
        if "syslog" in [tags] {
                grok {
                        match => { "message" => "<%{POSINT:syslog_pri}>%{SYSLOGTIMESTAMP:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}" }
                        add_field => [ "received_at", "%{@timestamp}" ]
                        add_field => [ "received_from", "%{host}" ]
                }
                syslog_pri { }
                date {
                        match => [ "syslog_timestamp", "MMM d HH:mm:ss", "MMM dd HH:mm:ss" ]
                }
                if !("_grokparsefailure" in [tags]) {
                        mutate {
                                replace => [ "host", "%{syslog_hostname}" ]
                                replace => [ "@source_host", "%{syslog_hostname}" ]
                                replace => [ "@message", "%{syslog_message}" ]
                        }
                }
                if [syslog_hostname] =~ /.*?(nsvpx).*?(everythingshouldbevirtual.local)?/ {
                        mutate {
                                add_tag => [ "Netscaler" ]
                        }
                }
                if [syslog_hostname] =~ /.*?(pfsense).*?(everythingshouldbevirtual.local)?/ {
                        mutate {
                                add_tag => [ "PFSense" ]
                        }
                }
        }
}
# Setting up IPTables firewall parsing
filter {
        if "syslog" in [tags] {
                if "IPTables" in [message] {
                        grok {
                                match => { "message" => "%{IPTABLES}" }
                                patterns_dir => [ "/opt/logstash/patterns" ]
                        }
                        mutate {
                                add_tag => [ "IPTABLES" ]
                        }
                        geoip {
                                source => "src_ip"
                                target => "geoip"
                                add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                                add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                        }
                        mutate {
                                convert => [ "[geoip][coordinates]", "float" ]
                        }
                }
        }
}
# Setting up IPTables actions
filter {
        if "IPTABLES" in [tags] {
                grok {
                        match => [
                                "message", "IPTables-%{WORD:iptables_action}"
                        ]
                }
                grok {
                        match => [
                                "message", "PROTO=%{WORD:iptables_proto}"
                        ]
                }
                mutate {
                        remove_field => [ "proto" ]
                }
                mutate {
                        rename => [ "iptables_proto", "proto" ]
                }
        }
}
# Setting up HAProxy parsing
filter {
        if "syslog" in [tags] {
                if [syslog_program] == "haproxy" {
                        grok {
                                break_on_match => false
                                match => [
                                        "message", "%{HAPROXYHTTP}",
                                        "message", "%{HAPROXYTCP}"
                                ]
                                add_tag => [ "HAProxy" ]
                        }
                        geoip {
                                source => "client_ip"
                                target => "geoip"
                                add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                                add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                        }
                        mutate {
                                convert => [ "[geoip][coordinates]", "float" ]
                                replace => [ "host", "%{@source_host}" ]
                                rename => [ "http_status_code", "response" ]
                                rename => [ "http_request", "request" ]
                                rename => [ "client_ip", "src_ip" ]
                        }
                }
        }
}
# Setting up KeepAliveD parsing
filter {
        if "syslog" in [tags] {
                if [syslog_program] =~ /Keepalived/ {
                        mutate {
                                add_tag => [ "KeepAliveD" ]
                        }
                }
        }
}
# Filtering for SSH logins either failed or successful
filter {
        if "syslog" in [tags] {
                if [syslog_program] == "sshd" {
                        if "Failed password" in [message] {
                                grok {
                                        break_on_match => false
                                        match => [
                                                "message", "invalid user %{DATA:UserName} from %{IP:src_ip}",
                                                "message", "for %{DATA:UserName} from %{IP:src_ip}"
                                        ]
                                }
                                mutate {
                                        add_tag => [ "SSH_Failed_Login" ]
                                }
                        }
                        if "Accepted password" in [message] {
                                grok {
                                        match => [
                                                "message", "for %{DATA:UserName} from %{IP:src_ip}"
                                        ]
                                }
                                mutate {
                                        add_tag => [ "SSH_Successful_Login" ]
                                }
                        }
                        geoip {
                                source => "src_ip"
                                target => "geoip"
                                add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                                add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                        }
                        mutate {
                                convert => [ "[geoip][coordinates]", "float" ]
                        }
                }
        }
}
# Setting up VMware ESX(i) log parsing
filter {
        if "VMware" in [tags] {
                multiline {
                        pattern => "-->"
                        what => "previous"
                }
                grok {
                        break_on_match => true
                        match => [
                                "message", "<%{POSINT:syslog_pri}>%{TIMESTAMP_ISO8601:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{SYSLOGPROG:syslog_program}: (?<message-body>(?<message_system_info>(?:\[%{DATA:message_thread_id} %{DATA:syslog_level} \'%{DATA:message_service}\'\ ?%{DATA:message_opID}])) \[%{DATA:message_service_info}]\ (?<syslog_message>(%{GREEDYDATA})))",
                                "message", "<%{POSINT:syslog_pri}>%{TIMESTAMP_ISO8601:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{SYSLOGPROG:syslog_program}: (?<message-body>(?<message_system_info>(?:\[%{DATA:message_thread_id} %{DATA:syslog_level} \'%{DATA:message_service}\'\ ?%{DATA:message_opID}])) (?<syslog_message>(%{GREEDYDATA})))",
                                "message", "<%{POSINT:syslog_pri}>%{TIMESTAMP_ISO8601:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{SYSLOGPROG:syslog_program}: %{GREEDYDATA:syslog_message}"
                        ]
                }
                syslog_pri { }
                date {
                        match => [ "syslog_timestamp", "YYYY-MM-ddHH:mm:ss,SSS" ]
                        timezone => "UTC"
                }
                mutate {
                        replace => [ "@source_host", "%{syslog_hostname}" ]
                }
                mutate {
                        replace => [ "@message", "%{syslog_message}" ]
                }
                if "Device naa" in [message] {
                        grok {
                                break_on_match => false
                                match => [
                                        "message", "Device naa.%{WORD:device_naa} performance has %{WORD:device_status}%{GREEDYDATA} of %{INT:datastore_latency_from}%{GREEDYDATA} to %{INT:datastore_latency_to}",
                                        "message", "Device naa.%{WORD:device_naa} performance has %{WORD:device_status}%{GREEDYDATA} from %{INT:datastore_latency_from}%{GREEDYDATA} to %{INT:datastore_latency_to}"
                                ]
                        }
                }
                if "connectivity issues" in [message] {
                        grok {
                                match => [
                                        "message", "Hostd: %{GREEDYDATA} : %{DATA:device_access} to volume %{DATA:device_id} %{DATA:datastore} (following|due to)"
                                ]
                        }
                }
                if "WARNING" in [message] {
                        grok {
                                match => [
                                        "message", "WARNING: %{GREEDYDATA:vmware_warning_msg}"
                                ]
                        }
                }
        }
}
# Setting up VMware vCenter parsing
filter {
        if "vCenter" in [tags] {
                grok {
                        break_on_match => true
                        match => [
                                "message", "<%{INT:syslog_pri}>%{SYSLOGTIMESTAMP} %{IPORHOST:syslog_hostname} %{TIMESTAMP_ISO8601:syslog_timestamp} (?<message-body>(?<message_system_info>(?:\[%{DATA:message_thread_id} %{DATA:syslog_level} \'%{DATA:message_service}\'\ ?%{DATA:message_opID}])) \[%{DATA:message_service_info}]\ (?<syslog_message>(%{GREEDYDATA})))",
                                "message", "<%{INT:syslog_pri}>%{SYSLOGTIMESTAMP} %{IPORHOST:syslog_hostname} %{TIMESTAMP_ISO8601:syslog_timestamp} (?<message-body>(?<message_system_info>(?:\[%{DATA:message_thread_id} %{DATA:syslog_level} \'%{DATA:message_service}\'\ ?%{DATA:message_opID}])) (?<syslog_message>(%{GREEDYDATA})))",
                                "message", "<%{INT:syslog_pri}>%{SYSLOGTIMESTAMP} %{IPORHOST:syslog_hostname} %{TIMESTAMP_ISO8601:syslog_timestamp} %{GREEDYDATA:syslog_message}"
                        ]
                }
                syslog_pri { }
                date {
                        match => [ "syslog_timestamp", "YYYY-MM-ddHH:mm:ss,SSS" ]
                        timezone => "UTC"
                }
                mutate {
                        replace => [ "@source_host", "%{syslog_hostname}" ]
                        replace => [ "@message", "%{syslog_message}" ]
                }
        }
}
# Setting up PFsense Firewall parsing
filter {
    if "PFSense" in [tags] {
        grok {
            add_tag => [ "firewall" ]
            match => [ "message", "<(?<evtid>.*)>(?<datetime>(?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Oct(?:ober)?|Nov(?:ember)?|Dec(?:ember)?)\s+(?:(?:0[1-9])|(?:[12][0-9])|(?:3[01])|[1-9]) (?:2[0123]|[01]?[0-9]):(?:[0-5][0-9]):(?:[0-5][0-9])) (?<prog>.*?): (?<msg>.*)" ]
        }
        mutate {
            gsub => ["datetime","  "," "]
        }
        date {
            match => [ "datetime", "MMM dd HH:mm:ss" ]
        }
        mutate {
            replace => [ "message", "%{msg}" ]
        }
        mutate {
            remove_field => [ "msg", "datetime", "prog" ]
        }
    }
    if [syslog_program] =~ /^pf$/ {
        mutate {
            add_tag => [ "packetfilter" ]
        }
        multiline {
            pattern => "^\s+|^\t\s+"
            what => "previous"
        }
        mutate {
            remove_field => [ "msg", "datetime" ]
            remove_tag => [ "multiline" ]
        }
        grok {
            match => [ "message", "rule (?<rule>.*)\(.*\): (?<action>pass|block) .* on (?<iface>.*): .* proto (?<proto>TCP|UDP|IGMP|ICMP) .*\n\s*(?<src_ip>(\d+\.\d+\.\d+\.\d+))\.?(?<src_port>(\d*)) [<|>] (?<dst_ip>(\d+\.\d+\.\d+\.\d+))\.?(?<dst_port>(\d*)):" ]
        }
    }
    if [syslog_program] =~ /^dhcpd$/ {
        if [message] =~ /^DHCPACK|^DHCPREQUEST|^DHCPOFFER/ {
            grok {
                match => [ "message", "(?<action>.*) (on|for|to) (?<src_ip>[0-2]?[0-9]?[0-9]\.[0-2]?[0-9]?[0-9]\.[0-2]?[0-9]?[0-9]\.[0-2]?[0-9]?[0-9]) .*(?<mac_address>[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]).* via (?<iface>.*)" ]
            }
        }
        if [message] =~ /^DHCPDISCOVER/ {
            grok {
                match => [ "message", "(?<action>.*) from (?<mac_address>[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]).* via (?<iface>.*)" ]
            }
        }
        if [message] =~ /^DHCPINFORM/ {
            grok {
                match => [ "message", "(?<action>.*) from (?<src_ip>.*).* via (?<iface>.*)" ]
            }
        }
   }
   if "_grokparsefailure" in [tags] {
        drop { }
   }
}
filter {
        if "PFSense" in [tags] {
                mutate {
                        replace => [ "@source_host", "%{syslog_hostname}" ]
                        replace => [ "@message", "%{syslog_message}" ]
                }
        }
}
# Setting up Citrix Netscaler parsing
filter {
        if "Netscaler" in [tags] {
                grok {
                        break_on_match => true
                        match => [
                                "message", "<%{POSINT:syslog_pri}> %{DATE_US}:%{TIME} GMT %{SYSLOGHOST:syslog_hostname} %{GREEDYDATA:netscaler_message} : %{DATA} %{INT:netscaler_spcbid} - %{DATA} %{IP:clientip} - %{DATA} %{INT:netscaler_client_port} - %{DATA} %{IP:netscaler_vserver_ip} - %{DATA} %{INT:netscaler_vserver_port} %{GREEDYDATA:netscaler_message} - %{DATA} %{WORD:netscaler_session_type}",
                                "message", "<%{POSINT:syslog_pri}> %{DATE_US}:%{TIME} GMT %{SYSLOGHOST:syslog_hostname} %{GREEDYDATA:netscaler_message}"
                        ]
                }
                syslog_pri { }
                geoip {
                        source => "clientip"
                        target => "geoip"
                        add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                        add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                }
                mutate {
                        add_field => [ "src_ip", "%{clientip}" ]
                        convert => [ "[geoip][coordinates]", "float" ]
                        replace => [ "@source_host", "%{host}" ]
                        replace => [ "@message", "%{netscaler_message}" ]
                }
        }
}
# Setting up Apache web server parsing
filter {
        if [type] == "apache" {
                grok {
                        pattern => "%{COMBINEDAPACHELOG}"
                }
                geoip {
                        source => "clientip"
                        target => "geoip"
                        add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                        add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                }
                mutate {
                        add_field => [ "src_ip", "%{clientip}" ]
                        convert => [ "[geoip][coordinates]", "float" ]
                        replace => [ "@source_host", "%{host}" ]
                        replace => [ "@message", "%{message}" ]
                        rename => [ "verb" , "method" ]
                }
                grok {
                        match => [
                                "message", "%{DATA:apache_vhost} "
                        ]
                }
        }
}
# Setting up Nginx web server parsing
filter {
        if [type] =~ "nginx" {
                grok {
                        pattern => "%{COMBINEDAPACHELOG}"
                }
                geoip {
                        source => "clientip"
                        target => "geoip"
                        add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                        add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                }
                mutate {
                        add_field => [ "src_ip", "%{clientip}" ]
                        convert => [ "[geoip][coordinates]", "float" ]
                        replace => [ "@source_host", "%{host}" ]
                        replace => [ "@message", "%{message}" ]
                        rename => [ "verb" , "method" ]
                }
                grok {
                        match => [
                                "message", "%{DATA:apache_vhost} "
                        ]
                }
        }
}
# Setting up Nginx errors parsing
filter {
        if [type] == "nginx-error" {
                grok {
                        match => [
                                "message", "(?<timestamp>%{YEAR}[./-]%{MONTHNUM}[./-]%{MONTHDAY}[- ]%{TIME}) \[%{LOGLEVEL:severity}\] %{POSINT:pid}#%{NUMBER}: %{GREEDYDATA:errormessage}(?:, client: (?<clientip>%{IP}|%{HOSTNAME}))(?:, server: %{IPORHOST:server})(?:, request: %{QS:request}) ??(?:, host: %{QS:host})",
                                "message", "(?<timestamp>%{YEAR}[./-]%{MONTHNUM}[./-]%{MONTHDAY}[- ]%{TIME}) \[%{LOGLEVEL:severity}\] %{POSINT:pid}#%{NUMBER}: %{GREEDYDATA:errormessage}(?:, client: (?<clientip>%{IP}|%{HOSTNAME}))(?:, server: %{IPORHOST:server})(?:, request: %{QS:request})(?:, upstream: %{QS:upstream})(?:;, host: %{QS:host})(?:, referrer: \"%{URI:referrer})"
                        ]
                }
        }
}
# Windows Eventlogs....Use NXLOG for client side logging
filter {
        if [type] == "eventlog" {
                grep {
                        match => { "EventReceivedTime"  => "\d+"}
                }
                mutate {
                        lowercase => [ "EventType", "FileName", "Hostname", "Severity" ]
                }
                mutate {
                        rename => [ "Hostname", "@source_host" ]
                }
                date {
                        match => [ "EventReceivedTime", "UNIX" ]
                }
                mutate {
                        rename => [ "Message", "@message" ]
                        rename => [ "Severity", "eventlog_severity" ]
                        rename => [ "SeverityValue", "eventlog_severity_code" ]
                        rename => [ "Channel", "eventlog_channel" ]
                        rename => [ "SourceName", "eventlog_program" ]
                        rename => [ "SourceModuleName", "nxlog_input" ]
                        rename => [ "Category", "eventlog_category" ]
                        rename => [ "EventID", "eventlog_id" ]
                        rename => [ "RecordNumber", "eventlog_record_number" ]
                        rename => [ "ProcessID", "eventlog_pid" ]
                }
        }
}
# Microsoft IIS logging....Use NXLOG for client side logging
filter {
        if [type] == "iis" {
                if [message] =~ "^#" {
                                drop {}
                }
                grok {
                        match => [
                                "message", "%{TIMESTAMP_ISO8601:logtime} %{IPORHOST:hostname} %{URIPROTO:cs_method} %{URIPATH:cs_stem} (?:%{NOTSPACE:cs_query}|-) %{NUMBER:src_port} %{NOTSPACE:cs_username} %{IP:clientip} %{NOTSPACE:cs_useragent} %{NUMBER:sc_status} %{NUMBER:sc_subresponse} %{NUMBER:sc_win32_status} %{NUMBER:timetaken}"
                        ]
                }
                date {
                        match => [ "logtime", "YYYY-MM-dd HH:mm:ss" ]
                        timezone => "UTC"
                }
                geoip {
                        source => "clientip"
                        target => "geoip"
                        add_field => [ "[geoip][coordinates]", "%{[geoip][longitude]}" ]
                        add_field => [ "[geoip][coordinates]", "%{[geoip][latitude]}"  ]
                }
                dns {
                        reverse => [ "hostname" ]
                        action => "replace"
                }
                mutate {
                        add_field => [ "src_ip", "%{clientip}" ]
                        convert => [ "[geoip][coordinates]", "float" ]
                        replace => [ "@source_host", "%{hostname}" ]
                        replace => [ "@message", "%{message}" ]
                        rename => [ "cs_method", "method" ]
                        rename => [ "cs_stem", "request" ]
                        rename => [ "cs_useragent", "agent" ]
                        rename => [ "cs_username", "username" ]
                        rename => [ "sc_status", "response" ]
                        rename => [ "timetaken", "time_request" ]
                }
        }
}
filter {
    if [type] == "mysql-slowquery" {
                multiline {
                        what => previous
                        pattern => "^\s"
                }
                grok { pattern => "^%{NUMBER:date} *%{NOTSPACE:time}" }
                mutate { replace => [ "time", "%{date} %{time}" ] }
                date {
                        match => [ "YYMMdd H:mm:ss", "YYMMdd HH:mm:ss" ]
                }
                mutate { remove => [ "time", "date" ] }
                split { }
        }
}
# Create @source_host_ip field for all devices for IP Tracking used along with src_ip and dst_ip fields
filter {
        if ![source_host_ip] {
                mutate {
                        add_field => [ "source_host_ip", "%{@source_host}" ]
                }
                dns {
                        resolve => [ "source_host_ip" ]
                        action => "replace"
                }
                mutate {
                        rename => [ "source_host_ip", "@source_host_ip" ]
                }
        }
}
# The below filter section will be used to remove unnecessary fields to keep ES memory cache from filling up with useless data
# The below filter section will be where you would want to comment certain types or tags out if trying to isolate a logging issue
filter {
        if [type] == "apache" {
                mutate {
                        remove_field => [ "clientip", "host", "timestamp" ]
                }
        }
        if [type] == "eventlog" {
                mutate {
                        remove => [ "SourceModuleType", "EventTimeWritten", "EventTime", "EventReceivedTime", "EventType" ]
                }
        }
        if [type] == "iis" {
                mutate {
                        remove_field => [ "clientip", "host", "hostname", "logtime" ]
                }
        }
        if [type] =~ "nginx" {
                mutate {
                        remove_field => [ "clientip", "host", "timestamp" ]
                }
        }
        if "Netscaler" in [tags] {
                mutate {
                        remove_field => [ "clientip" ]
                }
        }
        if [type] == "syslog" {
                mutate {
                        remove_field => [ "host", "received_at", "received_from", "syslog_hostname", "syslog_message", "syslog_timestamp" ]
                }
        }
        if [type] == "VMware" {
                mutate {
                        remove_field => [ "host", "program", "syslog_hostname", "syslog_message", "syslog_timestamp" ]
                }
        }
        if [type] == "vCenter" {
                mutate {
                        remove_field => [ "host", "message-body", "program", "syslog_hostname", "syslog_message", "syslog_timestamp" ]
                }
        }
}
#### Multicast discovery mode ####
# Send output to the ES cluster logstash-cluster using a predefined template
# The following settings will be used during the initial setup which will be used for using multicast ES nodes
# When changing to unicast discovery mode you need to comment out the following section and configure the unicast discovery mode in the next section
output {
        elasticsearch {
                cluster => "logstash-cluster"
                flush_size => 1
                manage_template => true
                template => "/opt/logstash/lib/logstash/outputs/elasticsearch/elasticsearch-template.json"
        }
}

#### Unicast discovery mode ####
# Send output to the ES cluster logstash-cluster using a predefined template
# The settings below will be used when you change to unicast discovery mode for all ES nodes
# Make sure to comment out the above multicast discovery mode section
#output {
#        elasticsearch {
#                cluster => "logstash-cluster"
#                host => "logstash"
#                port => "9300"
#                protocol => "node"
#                flush_size => "1"
#                manage_template => true
#                template => "/opt/logstash/lib/logstash/outputs/elasticsearch/elasticsearch-template.json"
#        }
#}