syslog-ng

Sumo Logic supports syslog clients such as syslog-ng. This document has instructions on how to configure your server to send syslog data. If syslog data does not appear in Sumo Logic, refer to the Troubleshooting section in Cloud Syslog Source.

Set up TLS

Set up Transport Layer Security (TLS).

Download the DigiCert certificate from https://www.digicert.com/CACerts/DigiCertHighAssuranceEVRootCA.crt.

syslog-ng

For syslog-ng place the certificate in the configuration directory and the syslog-ng client will pick up the certificate working from that directory. To set up your DigiCert certificate follow these steps:

Check if you have the directory /etc/syslog-ng/ca.d

If you don’t, create it with this command:

$ sudo mkdir -pv /etc/syslog-ng/ca.d

Then run:

$ cd /etc/syslog-ng/ca.d
$ sudo wget -O digicert_ca.der https://www.digicert.com/CACerts/DigiCertHighAssuranceEVRootCA.crt
$ sudo openssl x509 -inform der -in digicert_ca.der -out digicert_ca.crt
$ sudo ln -s digicert_ca.crt `openssl x509 -noout -hash -in digicert_ca.crt`.0

Send data to a Cloud Syslog Source with syslog-ng

If you are new to syslog-ng, follow this link to install syslog-ng. 

This section shows how to configure a syslog client using syslog-ng that will send the syslog message to be received by the Sumo cloud syslog service. You must specify a template, a destination, and a source.

Edit the syslog-ng config file:

$ sudo vim /etc/syslog-ng/syslog-ng.conf

Define a template with the correct format for Sumo. Messages must be in this format to be accepted, and the ordering of the $ fields must be as shown.

template t_sumo_syslog {
    template("<$PRI>1 $ISODATE $HOST $PROGRAM $PID $MSGID [E5kTyaEcth45/DU81M236oU4vM8j1ZaqTpWgjXB6lod7cFTeq09zzMn5ErmM0O/3@41123] $MSG\n"); template_escape(no);
 };

Replace the sample token, E5kTyaEcth45/DU81M236oU4vM8j1ZaqTpWgjXB6lod7cFTeq09zzMn5ErmM0O/3@41123, with your token.

Define a destination to use the Sumo endpoint. The following TCP destination option example specifies the endpoint (syslog.collection.YOUR_DEPLOYMENT.sumologic.com) and TCP TLS port 651. It also includes the ca-dir for your CA certificate. Finally, it specifies that only trusted certificates will be accepted for connectivity to the remote endpoint.

destination d_sumo_tls {
    syslog("syslog.collection.YOUR_DEPLOYMENT.sumologic.com"
        port("6514")
        template(t_sumo_syslog)
        transport(tls)
        tls(
            ca-dir("/etc/syslog-ng/ca.d")
            peer_verify("required-trusted")
        )
    );
};

If you choose to use the syslog destination option, the following example applies. For reference, see syslog destination options in the syslog-ng open source documentation. You must include the token in the message body instead of in the structured data field for the syslog destination.

destination d_sumo_tls {
    syslog("syslog.collection.YOUR_DEPLOYMENT.sumologic.com"
        port("6514")
        template(t_sumo_syslog)
        transport(tls)
        tls(
            ca-dir("/etc/syslog-ng/ca.d")
            peer_verify("required-trusted")
        )
    );
};

Specify which logs will be sent to the Sumo destination. This example specifies an existing syslog-ng source (s_sys), applies a syslog-ng filter (f_default), and specifies the use of the Sumo Logic endpoint (d_sumo_tls).

log {
    source(s_sys);
    filter(f_default);
    destination(d_sumo_tls);
};

Once you are done with syslog-ng.conf file update, restart the syslog-ng server:

$ sudo /etc/init.d/syslog-ng restart

Check the status of the syslog-ng server after it restarts. All of the following commands should return success messages.

$ service syslog-ng status
$ systemctl status syslog-ng.service
$ journalctl -xe

Troubleshooting

If you receive errors while restarting the syslog-ng server you can troubleshoot by viewing logs at /var/log/syslog.

$ tail /var/log/syslog

or 

$ vi /var/log/syslog