CONTRIB: opentracing: add the OpenTracing filter
This commit adds the OpenTracing filter (hereinafter we will use the
abbreviated name 'the OT filter') to the contrib tree.
The OT filter adds native support for using distributed tracing in HAProxy.
This is enabled by sending an OpenTracing compliant request to one of the
supported tracers; such as Datadog, Jaeger, Lightstep and Zipkin tracers.
Please note: tracers are not listed by any preference, but alphabetically.
The OT filter is a standard HAProxy filter, so what applies to others also
applies to this one (of course, by that I mean what is described in the
documentation, more precisely in the doc/internals/filters.txt file).
The OT filter activation is done explicitly by specifying it in the HAProxy
configuration. If this is not done, the OT filter in no way participates
in the work of HAProxy.
As for the impact on HAProxy speed, this is documented with several tests
located in the test directory, and the result is found in the README-speed-*
files. In short, the speed of operation depends on the way it is used and
the complexity of the configuration, from an almost immeasurable impact to
a significant deceleration (5x and more). I think that in some normal use
the speed of HAProxy with the filter on will be quite satisfactory with a
slowdown of less than 4%.
The OT filter allows intensive use of ACLs, which can be defined anywhere in
the configuration. Thus, it is possible to use the filter only for those
connections that are of interest to us.
More detailed documentation related to the operation, configuration and use
of the filter can be found in the contrib/opentracing directory.
To make the OpenTracing filter easier to configure and compile, several
entries have been added to the Makefile. When running the make utility,
it is possible to use several new arguments:
USE_OT=1 : enable the OpenTracing filter
OT_DEBUG=1 : compile the OpenTracing filter in debug mode
OT_INC=path : force the include path to libopentracing-c-wrapper
OT_LIB=path : force the lib path to libopentracing-c-wrapper
OT_RUNPATH=1 : add libopentracing-c-wrapper RUNPATH to haproxy executable
If USE_OT is set, then an additional Makefile from the contrib/opentracing
directory is included in the compilation process.
diff --git a/Makefile b/Makefile
index feb8010..95d52ca 100644
--- a/Makefile
+++ b/Makefile
@@ -53,6 +53,7 @@
# USE_SYSTEMD : enable sd_notify() support.
# USE_OBSOLETE_LINKER : use when the linker fails to emit __start_init/__stop_init
# USE_THREAD_DUMP : use the more advanced thread state dump system. Automatic.
+# USE_OT : enable the OpenTracing filter
#
# Options can be forced by specifying "USE_xxx=1" or can be disabled by using
# "USE_xxx=" (empty string). The list of enabled and disabled options for a
@@ -102,6 +103,10 @@
# LUA_INC : force the include path to lua
# LUA_LIB_NAME : force the lib name (or automatically evaluated, by order of
# priority : lua5.3, lua53, lua).
+# OT_DEBUG : compile the OpenTracing filter in debug mode
+# OT_INC : force the include path to libopentracing-c-wrapper
+# OT_LIB : force the lib path to libopentracing-c-wrapper
+# OT_RUNPATH : add RUNPATH for libopentracing-c-wrapper to haproxy executable
# IGNOREGIT : ignore GIT commit versions if set.
# VERSION : force haproxy version reporting.
# SUBVERS : add a sub-version (eg: platform, model, ...).
@@ -296,7 +301,7 @@
USE_GETADDRINFO USE_OPENSSL USE_LUA USE_FUTEX USE_ACCEPT4 \
USE_CLOSEFROM USE_ZLIB USE_SLZ USE_CPU_AFFINITY USE_TFO USE_NS \
USE_DL USE_RT USE_DEVICEATLAS USE_51DEGREES USE_WURFL USE_SYSTEMD \
- USE_OBSOLETE_LINKER USE_PRCTL USE_THREAD_DUMP USE_EVPORTS
+ USE_OBSOLETE_LINKER USE_PRCTL USE_THREAD_DUMP USE_EVPORTS USE_OT
#### Target system options
# Depending on the target platform, some options are set, as well as some
@@ -759,6 +764,10 @@
OPTIONS_OBJS += src/namespace.o
endif
+ifneq ($(USE_OT),)
+include contrib/opentracing/Makefile
+endif
+
#### Global link options
# These options are added at the end of the "ld" command line. Use LDFLAGS to
# add options at the beginning of the "ld" command line if needed.