README
¶
log
log enables query logging to standard output.
Syntax
log
- With no arguments, a query log entry is written to stdout in the common log format for all requests
log FILE
- FILE is the log file to create (or append to). The only valid name for FILE is stdout.
log [NAME] FILE [FORMAT]
NAME
is the name to match in order to be loggedFILE
is the log file (again only stdout is allowed here).FORMAT
is the log format to use (default is Common Log Format)
You can further specify the class of responses that get logged:
log [NAME] FILE [FORMAT] {
class [success|denial|error|all]
}
Here success
denial
and error
denotes the class of responses that should be logged. The
classes have the following meaning:
success
: successful responsedenial
: either NXDOMAIN or NODATA (name exists, type does not)error
: SERVFAIL, NOTIMP, REFUSED, etc. Anything that indicates the remote server is not willing to resolve the request.all
: the default - nothing is specified.
If no class is specified, it defaults to all.
Log File
The "log file" can only be stdout. CoreDNS expects another service to pick up this output and deal with it, i.e. journald when using systemd or Docker's logging capabilities.
Log Format
You can specify a custom log format with any placeholder values. Log supports both request and response placeholders.
The following place holders are supported:
{type}
: qtype of the request{name}
: qname of the request{class}
: qclass of the request{proto}
: protocol used (tcp or udp){when}
: time of the query{remote}
: client's IP address{size}
: request size in bytes{port}
: client's port{duration}
: response duration{rcode}
: response RCODE{rsize}
: response size{>rflags}
: response flags, each set flag will be displayed, e.g. "aa, tc". This includes the qr bit as well.{>bufsize}
: the EDNS0 buffer size advertised in the query{>do}
: is the EDNS0 DO (DNSSEC OK) bit set in the query{>id}
: query ID{>opcode}
: query OPCODE
The default Common Log Format is:
`{remote} - [{when}] "{type} {class} {name} {proto} {size} {>do} {>bufsize}" {rcode} {>rflags} {rsize} {duration}`
Examples
Log all requests to stdout
log stdout
Custom log format, for all zones (.
)
log . stdout "{proto} Request: {name} {type} {>id}"
Only log denials for example.org (and below to a file)
log example.org stdout {
class denial
}
Documentation
¶
Overview ¶
Package log implements basic but useful request (access) logging middleware.
Index ¶
Constants ¶
const ( // DefaultLogFilename is the default output name. This is the only supported value. DefaultLogFilename = "stdout" // CommonLogFormat is the common log format. CommonLogFormat = `{remote} ` + CommonLogEmptyValue + ` [{when}] "{type} {class} {name} {proto} {size} {>do} {>bufsize}" {rcode} {>rflags} {rsize} {duration}` // CommonLogEmptyValue is the common empty log value. CommonLogEmptyValue = "-" // CombinedLogFormat is the combined log format. CombinedLogFormat = CommonLogFormat + ` "{>opcode}"` // DefaultLogFormat is the default log format. DefaultLogFormat = CommonLogFormat )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Logger ¶
type Logger struct { Next middleware.Handler Rules []Rule ErrorFunc func(dns.ResponseWriter, *dns.Msg, int) // failover error handler }
Logger is a basic request logging middleware.