Commit Graph

4 Commits

Author SHA1 Message Date
Lukas Lihotzki
96bb1c8e29 all, lib/logger: Refactor SetDebug calls (#6054) 2019-10-04 13:03:34 +02:00
Jakob Borg
f7fc0c1d3e all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
Jakob Borg
76af9ba53d Implement facility based logger, debugging via REST API
This implements a new debug/trace infrastructure based on a slightly
hacked up logger. Instead of the traditional "if debug { ... }" I've
rewritten the logger to have no-op Debugln and Debugf, unless debugging
has been enabled for a given "facility". The "facility" is just a
string, typically a package name.

This will be slightly slower than before; but not that much as it's
mostly a function call that returns immediately. For the cases where it
matters (the Debugln takes a hex.Dump() of something for example, and
it's not in a very occasional "if err != nil" branch) there is an
l.ShouldDebug(facility) that is fast enough to be used like the old "if
debug".

The point of all this is that we can now toggle debugging for the
various packages on and off at runtime. There's a new method
/rest/system/debug that can be POSTed a set of facilities to enable and
disable debug for, or GET from to get a list of facilities with
descriptions and their current debug status.

Similarly a /rest/system/log?since=... can grab the latest log entries,
up to 250 of them (hardcoded constant in main.go) plus the initial few.

Not implemented in this commit (but planned) is a simple debug GUI
available on /debug that shows the current log in an easily pasteable
format and has checkboxes to enable the various debug facilities.

The debug instructions to a user then becomes "visit this URL, check
these boxes, reproduce your problem, copy and paste the log". The actual
log viewer on the hypothetical /debug URL can poll regularly for new log
entries and this bypass the 250 line limit.

The existing STTRACE=foo variable is still obeyed and just sets the
start state of the system.
2015-10-03 18:09:53 +02:00
Jakob Borg
7705a6c1f1 mv internal lib 2015-08-09 09:35:26 +02:00