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/contrib/opentracing/include/define.h b/contrib/opentracing/include/define.h
new file mode 100644
index 0000000..8769161
--- /dev/null
+++ b/contrib/opentracing/include/define.h
@@ -0,0 +1,104 @@
+/***
+ * Copyright 2020 HAProxy Technologies
+ *
+ * This file is part of the HAProxy OpenTracing filter.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#ifndef _OPENTRACING_DEFINE_H_
+#define _OPENTRACING_DEFINE_H_
+
+#define FLT_OT_DEREF(a,m,v) (((a) != NULL) ? (a)->m : (v))
+#define FLT_OT_DDEREF(a,m,v) ((((a) != NULL) && (*(a) != NULL)) ? (*(a))->m : (v))
+#define FLT_OT_TABLESIZE(a) (sizeof(a) / sizeof((a)[0]))
+#define FLT_OT_IN_RANGE(v,a,b) (((v) >= (a)) && ((v) <= (b)))
+#define FLT_OT_DPTR_ARGS(a) (a), ((a) == NULL) ? NULL : *(a)
+#define FLT_OT_ARG_ISVALID(n) ((args[n] != NULL) && *args[n])
+#define FLT_OT_TV_UDIFF(a,b) (((b)->tv_sec - (a)->tv_sec) * 1000000 + (b)->tv_usec - (a)->tv_usec)
+#define FLT_OT_U32_FLOAT(a,b) ((a) * (double)(b) / UINT32_MAX)
+#define FLT_OT_FLOAT_U32(a,b) ((uint32_t)((a) / (double)(b) * UINT32_MAX + 0.5))
+
+#define FLT_OT_STR_DASH_72 "------------------------------------------------------------------------"
+#define FLT_OT_STR_DASH_78 FLT_OT_STR_DASH_72 "------"
+#define FLT_OT_STR_FLAG_YN(a) (a) ? "yes" : "no"
+
+#define FLT_OT_STR_SIZE(a) (sizeof(a) - 1)
+#define FLT_OT_STR_ADDRSIZE(a) (a), FLT_OT_STR_SIZE(a)
+#define FLT_OT_STR_ISVALID(a) (((a) != NULL) && (*(a) != '\0'))
+#define FLT_OT_STR_CMP(S,s,l) (((l) == FLT_OT_STR_SIZE(S)) && (memcmp((s), FLT_OT_STR_ADDRSIZE(S)) == 0))
+#define FLT_OT_STR_ELLIPSIS(a,n) do { if ((a) != NULL) { if ((n) > 0) (a)[(n) - 1] = '\0'; if ((n) > 3) (a)[(n) - 2] = (a)[(n) - 3] = (a)[(n) - 4] = '.'; } } while (0)
+#define FLT_OT_NIBBLE_TO_HEX(a) ((a) + (((a) < 10) ? '0' : ('a' - 10)))
+
+#define FLT_OT_FREE(a) do { if ((a) != NULL) OTC_DBG_FREE(a); } while (0)
+#define FLT_OT_FREE_VOID(a) do { if ((a) != NULL) OTC_DBG_FREE((void *)(a)); } while (0)
+#define FLT_OT_FREE_CLEAR(a) do { if ((a) != NULL) { OTC_DBG_FREE(a); (a) = NULL; } } while (0)
+#define FLT_OT_STRDUP(s) OTC_DBG_STRDUP(s)
+#define FLT_OT_STRNDUP(s,n) OTC_DBG_STRNDUP((s), (n))
+#define FLT_OT_CALLOC(n,e) OTC_DBG_CALLOC((n), (e))
+#define FLT_OT_MALLOC(s) OTC_DBG_MALLOC((s))
+#define FLT_OT_MEMINFO() OTC_DBG_MEMINFO()
+
+#define FLT_OT_RUN_ONCE(f) do { static bool __f = 1; if (__f) { __f = 0; f; } } while (0)
+
+#define FLT_OT_LIST_ISVALID(a) (((a) != NULL) && ((a)->n != NULL) && ((a)->p != NULL))
+#define FLT_OT_LIST_DEL(a) do { if (FLT_OT_LIST_ISVALID(a)) LIST_DEL(a); } while (0)
+#define FLT_OT_LIST_DESTROY(t,h) \
+ do { \
+ struct flt_ot_conf_##t *_ptr, *_back; \
+ \
+ if (!FLT_OT_LIST_ISVALID(h) || LIST_ISEMPTY(h)) \
+ break; \
+ \
+ FLT_OT_DBG(2, "- deleting " #t " list %s", flt_ot_list_debug(h)); \
+ \
+ list_for_each_entry_safe(_ptr, _back, (h), list) \
+ flt_ot_conf_##t##_free(&_ptr); \
+ } while (0)
+
+#define FLT_OT_BUFFER_THR(b,m,n,p) \
+ static THREAD_LOCAL char b[m][n]; \
+ static THREAD_LOCAL size_t __idx = 0; \
+ char *p = b[__idx]; \
+ __idx = (__idx + 1) % (m)
+
+#define FLT_OT_ERR(f, ...) \
+ do { \
+ if ((err != NULL) && (*err == NULL)) \
+ (void)memprintf(err, f, ##__VA_ARGS__); \
+ } while (0)
+#define FLT_OT_ERR_APPEND(f, ...) \
+ do { \
+ if (err != NULL) \
+ (void)memprintf(err, f, ##__VA_ARGS__); \
+ } while (0)
+#define FLT_OT_ERR_FREE(p) \
+ do { \
+ if ((p) == NULL) \
+ break; \
+ \
+ FLT_OT_DBG(0, "%s:%d: ERROR: %s", __func__, __LINE__, (p)); \
+ FLT_OT_FREE_CLEAR(p); \
+ } while (0)
+
+#endif /* _OPENTRACING_DEFINE_H_ */
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */