When 'log' directive was implemented, the internal representation was
named 'struct logsrv', because the 'log' directive would directly point
to the log target, which used to be a (UDP) log server exclusively at
that time, hence the name.
But things have become more complex, since today 'log' directive can point
to ring targets (implicit, or named) for example.
Indeed, a 'log' directive does no longer reference the "final" server to
which the log will be sent, but instead it describes which log API and
parameters to use for transporting the log messages to the proper log
destination.
So now the term 'logsrv' is rather confusing and prevents us from
introducing a new level of abstraction because they would be mixed
with logsrv.
So in order to better designate this 'log' directive, and make it more
generic, we chose the word 'logger' which now replaces logsrv everywhere
it was used in the code (including related comments).
This is internal rewording, so no functional change should be expected
on user-side.
The filter was using "now" in visible output in debug mode, that's
not correct, we should rather use "date" since it's visible. No
backport is needed as it was mostly emphasized by commit 28360dc
("MEDIUM: clock: force internal time to wrap early after boot")
in 2.8..
It's always good to replace "hard-coded" values with something that looks
less "hard-coded" (even though that doesn't change anything in the code).
This is done here using FLT_OT_PARSE_INVALID_enum enum.
This patch must be backported as far as 2.4.
If the OpenTracing filter is compiled using the 'OT_DEBUG=1' option, then
log messages are printed to stderr when the filter is running. In the log
one can then find (among other things) the order in which the function is
called and the value that the function returns (if it is not a void type).
Prior to applying this patch, no value returned by a function was logged.
Log output example:
[ 1] 0.038807 [OT]: flt_ot_init_per_thread(0x56365bd45ec0, 0x56365bd48210) {
[ 1] 0.038807 [OT]: ot_start(0x56365bd58920, 0x56365bd4e3a0, 0x7f561acba168:(nil)) {
[ 1] 0.038807 [OT]: } = 0
[ 1] 0.038807 [OT]: } = 0
This patch must be backported as far as 2.4.
Due to a recent change in the handling of haproxy variables, their use for
OpenTracing context transfer has been excluded from the compilation process.
The use of variables can be re-enabled if the newly defined variable
OT_USE_VARS is set to 1 when calling the 'make' utility. However,
this should not be used for now as the compilation will end in error.
This change prevents the use of haproxy variables to convey the OpenTracing
context. This means that the 'use-vars' parameter cannot be used in the
OpenTracing filter configuration for 'inject' and 'extract' operations.
An example configuration that uses this feature is in the test/ctx
directory, while the script to run that test is test/run-ctx.sh.
Then, the 'sess.ot.uuid' variable is no longer set when initializing the
OpenTracing session. This means that this variable can still be used in
the OpenTracing configuration, but its contents will be empty.
This patch solves the problem reported in github issue #1204, where the
OpenTracing filter cannot communicate with the selected tracer if HAProxy
is run in daemon mode.
This commit also solves github issue #1274, where the problem manifests
itself when using the 'chroot' keyword in the HAProxy configuration.
This is solved so that the initialization of the OpenTracing plugin is
split into two operations, first the plugin (dynamic library) is loaded
before switching the HAProxy to daemon mode (or chroot) and then the
tracer thread is started.
This means that nothing is retrieved from the file system in runtime.
After applying this commit, opentracing C wrapper version 1.1.0 should be
used because the earlier version does not have separated initialization
functions.
This resolves GitHub issues #1204 and #1274.
It is possible that some arguments within the configuration line are not
specified; that is, they are set to a blank string.
For example:
keyword '' arg_2
In that case the content of the args field will be like this:
args[0]: 'keyword'
args[1]: NULL pointer
args[2]: 'arg_2'
args[3 .. MAX_LINE_ARGS): NULL pointers
The previous way of calculating the number of arguments (as soon as a
null pointer is encountered) could not place an argument on an empty
string.
All of the above is essential for passing the OpenTracing context via
the HTTP headers (keyword 'inject'), where one of the arguments is the
context name prefix. This way we can set an empty prefix, which is very
useful if we get context from some other process that can't add a prefix
to that data; or we want to pass the context to some process that cannot
handle the prefix of that data.
In commit 9533a7038 new parameters have been added to the declaration
of function parse_logsrv().
This patch should be backported to all branches where the OpenTracing
filter is located.
This one is the last optional module to build with haproxy, so let's move
it to addons/. It was renamed to "ot" as it was the only one whose USE_*
option did not match the directory name, now this is consistent.
Few changes were required, only the Makefile, and doc were adjusted, as
the directory was already self-contained and relocatable.
