systemd netlogd

systemd-netlogd

Transfère les messages du journal vers d'autres hôtes sur le réseau à l'aide du protocole Syslog (RFC 5424 et RFC 3339). Il peut être configuré pour envoyer des messages à des adresses unicast et multicast. systemd-netlogd s'exécute avec son propre utilisateur systemd-journal-netlog. Commence à envoyer des journaux lorsque le réseau est actif et arrête l'envoi dès que le réseau est en panne (utilise le réseau SD). Il lit le journal et le transmet au réseau un par un. Il n'utilise aucun espace disque supplémentaire. systemd-netlogd prend en charge UDP, TCP, TLS et DTLS (Datagram Transport Layer Security RFC 6012).

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Installation à partir des sources

Installez les dépendances de build :

 # On Debian/Ubuntu
sudo apt install build-essential gperf libcap-dev libsystemd-dev pkg-config meson python3-sphinx
# On CentOS/RHEL/Fedora
sudo dnf group install 'Development Tools'
sudo dnf install gperf libcap-devel pkg-config systemd-devel meson python3-sphinx

Construire et installer :

 make
sudo make install

Création de l'utilisateur :

sudo useradd -r -d / -s /usr/sbin/nologin -g systemd-journal systemd-journal-netlog

ou via les utilisateurs système

/usr/lib/sysusers.d/systemd-netlogd.conf

 # Type   Name                    ID                      GECOS   Home directory  Shell
u       systemd-journal-netlog  -:systemd-journal       -       /               /bin/nologin

Configuration

systemd-netlogd lit les fichiers de configuration nommés /etc/systemd/netlogd.conf et /etc/systemd/netlogd.conf.d/*.conf .

OPTIONS DE LA SECTION [RÉSEAU]

 The "[Network]" section only applies for UDP multicast address and Port:

Address=
    Controls whether log messages received by the systemd-netlogd daemon shall be forwarded to a unicast UDP address or multicast UDP network group in syslog RFC 5424 format. The the address string format is similar to socket units. See systemd.socket(1)

Protocol=
    Specifies whether to use udp, tcp, tls or dtls (Datagram Transport Layer Security) protocol. Defaults to udp.

LogFormat=
    Specifies whether to use RFC 5424 format or RFC 3339 format. Takes one of rfc5424 or rfc3339. Defaults to rfc5424.

Directory=
    Takes a directory path. Specifies whether to operate on the specified journal directory DIR instead of the default runtime and system journal paths.
          
Namespace=
    Takes a journal namespace identifier string as argument. If not specified the data collected by the default namespace is shown. If specified shows the log data of the specified namespace instead. If the namespace is specified as "*" data from all namespaces is shown, interleaved. If the namespace identifier is prefixed with "+" data from the specified namespace and the default namespace is shown, interleaved, but no other.

ConnectionRetrySec=
    Specifies the minimum delay before subsequent attempts to contact a Log server are made. Takes a time span value. The default unit is seconds, but other units may be specified, see systemd.time(5). Defaults to 30 seconds and must not be smaller than 1 second.

TLSCertificateAuthMode=
    Specifies whether to validate the certificate. Takes one of no, allow, deny, warn. Defaults to 'deny' which rejects certificates failed to validate.

TLSServerCertificate=
    Specify a custom certificate to validate the server against. Takes a path to a certificate file in PEM format.

KeepAlive=
    Takes a boolean argument. If true, the TCP/IP stack will send a keep alive message after 2h (depending on the configuration of /proc/sys/net/ipv4/tcp_keepalive_time) for all TCP streams accepted on this socket. This controls the SO_KEEPALIVE socket option (see socket(7) and the TCP Keepalive HOWTO for details.) Defaults to false.

KeepAliveTimeSec=
    Takes time (in seconds) as argument. The connection needs to remain idle before TCP starts sending keepalive probes. This controls the TCP_KEEPIDLE socket option (see socket(7) and the TCP Keepalive HOWTO for details.) Default value is 7200 seconds (2 hours).

KeepAliveIntervalSec=
    Takes time (in seconds) as argument between individual keepalive probes, if the socket option SO_KEEPALIVE has been set on this socket. This controls the TCP_KEEPINTVL socket option (see socket(7) and the TCP Keepalive HOWTO for details.) Default value is 75 seconds.

KeepAliveProbes=
    Takes an integer as argument. It is the number of unacknowledged probes to send before considering the connection dead and notifying the application layer. This controls the TCP_KEEPCNT socket option (see socket(7) and the TCP Keepalive HOWTO for details.) Default value is 9.

SendBuffer=
    Takes an integer argument controlling the receive or send buffer sizes of this socket, respectively. This controls the SO_SNDBUF socket options (see socket(7) for details.). The usual suffixes K, M, G are supported and are understood to the base of 1024.

NoDelay=
    Takes a boolean argument. TCP Nagle's algorithm works by combining a number of small outgoing messages, and sending them all at once. This controls the TCP_NODELAY socket option (see tcp(7)). Defaults to false.

Paramètres facultatifs

 StructuredData=
    Meta information about the syslog message, which can be used for Cloud Based syslog servers, such as Loggly

UseSysLogStructuredData=
    A boolean. Specifies whether to extract SYSLOG_STRUCTURED_DATA= from journal. Defaults to false.

UseSysLogMsgId=
    A boolean. Specifies whether to extract SYSLOG_MSGID= from journal. Defaults to false.

ExcludeSyslogFacility=
    A list of strings. Specifies the syslog facilities to skip forwarding. Possible values are: "kern", "user", "mail", "daemon", "auth", "syslog", "lpr", "news", "uucp", "cron", "authpriv", "ftp", "ntp", "security", "console", "solaris-cron", "local0", "local1", "local2", "local3", "local4", "local5", "local6" and "local7".

ExcludeSyslogLevel=
    A list of strings. Specifies the syslog levels to skip forwarding. Possible values are: "emerg", "alert", "crit", "err", "warning", "notice", "info" and "debug".

EXEMPLE

Exemple 1.Multidiffusion UDP

[ Network ]
Address = 239.0 .0.1:6000
# Protocol=udp
# LogFormat=rfc5424

Exemple 2.UDP

[ Network ]
Address = 192.168 .8.101:514
# Protocol=udp
LogFormat =r fc3339

Exemple 3. Données structurées

[ Network ]
Address = 192.168 .8.101:514
# Protocol=udp
LogFormat =r fc5424
StructuredData =[ 1 ab456b6-90bb-6578-abcd-5b734584aaaa@41058]

Exemple 4. Données structurées Syslog personnalisées et ID de message

[ Network ]
Address = 192.168 .8.101:514
# Protocol=udp
LogFormat =r fc5424
UseSysLogStructuredData =y es
UseSysLogMsgId =y es

Exemple 5. Sauter des messages avec la fonction AUTH ou AUTHPRIV et des messages avec le niveau DEBUG

[ Network ]
Address = 192.168 .8.101:514
# Protocol=udp
LogFormat =r fc3339
ExcludeSyslogFacility =a uth authpriv
ExcludeSyslogLevel =d ebug

Exemple 6. TLS avec mode d'authentification de certificat

[ Network ]
Address = 192.168 .8.101:4433
Protocol =t ls
# LogFormat=rfc5424
TLSCertificateAuthMode =w arn

Exemple 7. DTLS avec mode d'authentification de certificat

[ Network ]
Address = 192.168 .8.101:4433
Protocol =d tls
# LogFormat=rfc5424
TLSCertificateAuthMode =a llow

Cas d'utilisation de UseSysLogStructuredData= et UseSysLogMsgId=

 sd_journal_send (
    "MESSAGE=%s" , "Message to process" ,
    "PRIORITY=%s" , "4" ,
    "SYSLOG_FACILITY=%s" , "1" ,
    "SYSLOG_MSGID=%s" , "1011" ,
    "SYSLOG_STRUCTURED_DATA=%s" , R "([exampleSDID@32473 iut=" 3 " eventSource=" Application "])" ,
    NULL
);