Log Engine CLI Parameter

The –log-engine parameter allows to specify what logging engine to be used, which is practically about the format of the log messages. If not set at all, then Kamailio does the classic style of line-based plain text log messages.

The value of this parameter can be –log-engine=name or –log-engine=name:data.

The name of the log engine can be:

• json - write logs in structured JSON format
  • the data for json log engine can be a set of character flags:
    • a - add log prefix as a special field
    • A - do not add log prefix
    • c - add Call-ID (when available) as a dedicated JSON attribute
    • j - the log prefix and message fields are printed in JSON structure format, detecting if they are enclosed in between { } or adding them as a text field
    • M - strip EOL (’\n’) from the value of the log message field
    • N - do not add EOL at the end of JSON document
    • p - the log prefix is printed as it is in the root json document, it has to start with comma (,) and be a valid set of json fields
    • U - CEE (Common Event Expression) schema format - https://cee.mitre.org/language/1.0-beta1/core-profile.html

Example of JSON logs when running Kamailio with “–log-engine=json:M” :

{ "idx": 1, "pid": 18239, "level": "DEBUG", "module": "maxfwd", "file": "mf_funcs.c", "line": 74, "function": "is_maxfwd_present", "logprefix": "{1 1 OPTIONS 715678756@192.168.188.20} ", "message": "value = 70 " }

{ "idx": 1, "pid": 18239, "level": "DEBUG", "module": "core", "file": "core/socket_info.c", "line": 644, "function": "grep_sock_info", "logprefix": "{1 1 OPTIONS 715678756@192.168.188.20} ", "message": "checking if host==us: 9==9 && [127.0.0.1] == [127.0.0.1]" }

Example config for printing log message with j flag:

xinfo("{ \"src_ip\": \"$si\", \"method\": \"$rm\", \"text\": \"request received\" }");

Example config for printing log messages with p flag:

log_prefix=", \"src_ip\": \"$si\", \"tv\": $TV(Sn), \"mt\": $mt, \"ua\": \"$(ua{s.escape.common})\", \"cseq\": \"$hdr(CSeq)\""