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/parser.h b/contrib/opentracing/include/parser.h
new file mode 100644
index 0000000..5e7b298
--- /dev/null
+++ b/contrib/opentracing/include/parser.h
@@ -0,0 +1,148 @@
+/***
+ * 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_PARSER_H_
+#define _OPENTRACING_PARSER_H_
+
+#define FLT_OT_SCOPE "OT"
+
+/*
+ * filter FLT_OT_OPT_NAME FLT_OT_OPT_FILTER_ID <FLT_OT_OPT_FILTER_ID_DEFAULT> FLT_OT_OPT_CONFIG <file>
+ */
+#define FLT_OT_OPT_NAME "opentracing"
+#define FLT_OT_OPT_FILTER_ID "id"
+#define FLT_OT_OPT_FILTER_ID_DEFAULT "ot-filter"
+#define FLT_OT_OPT_CONFIG "config"
+
+#define FLT_OT_PARSE_SECTION_TRACER_ID "ot-tracer"
+#define FLT_OT_PARSE_SECTION_GROUP_ID "ot-group"
+#define FLT_OT_PARSE_SECTION_SCOPE_ID "ot-scope"
+
+#define FLT_OT_PARSE_SPAN_ROOT "root"
+#define FLT_OT_PARSE_SPAN_REF_CHILD "child-of"
+#define FLT_OT_PARSE_SPAN_REF_FOLLOWS "follows-from"
+#define FLT_OT_PARSE_CTX_AUTONAME "-"
+#define FLT_OT_PARSE_CTX_USE_HEADERS "use-headers"
+#define FLT_OT_PARSE_CTX_USE_VARS "use-vars"
+#define FLT_OT_PARSE_OPTION_HARDERR "hard-errors"
+#define FLT_OT_PARSE_OPTION_DISABLED "disabled"
+#define FLT_OT_PARSE_OPTION_NOLOGNORM "dontlog-normal"
+
+/*
+ * A description of the macro arguments can be found in the structure
+ * flt_ot_parse_data definition
+ */
+#define FLT_OT_PARSE_TRACER_DEFINES \
+ FLT_OT_PARSE_TRACER_DEF( ID, 0, 1, 2, 2, "ot-tracer", " <name>") \
+ FLT_OT_PARSE_TRACER_DEF( ACL, 0, 1, 3, 0, "acl", " <name> <criterion> [flags] [operator] <value> ...") \
+ FLT_OT_PARSE_TRACER_DEF( LOG, 0, 1, 2, 0, "log", " { global | <addr> [len <len>] [format <fmt>] <facility> [<level> [<minlevel>]] }") \
+ FLT_OT_PARSE_TRACER_DEF( CONFIG, 0, 0, 2, 2, "config", " <file>") \
+ FLT_OT_PARSE_TRACER_DEF( PLUGIN, 0, 0, 2, 2, "plugin", " <file>") \
+ FLT_OT_PARSE_TRACER_DEF( GROUPS, 0, 0, 2, 0, "groups", " <name> ...") \
+ FLT_OT_PARSE_TRACER_DEF( SCOPES, 0, 0, 2, 0, "scopes", " <name> ...") \
+ FLT_OT_PARSE_TRACER_DEF( RATE_LIMIT, 0, 0, 2, 2, "rate-limit", " <value>") \
+ FLT_OT_PARSE_TRACER_DEF( OPTION, 0, 0, 2, 2, "option", " { disabled | dontlog-normal | hard-errors }") \
+ FLT_OT_PARSE_TRACER_DEF(DEBUG_LEVEL, 0, 0, 2, 2, "debug-level", " <value>")
+
+#define FLT_OT_PARSE_GROUP_DEFINES \
+ FLT_OT_PARSE_GROUP_DEF( ID, 0, 1, 2, 2, "ot-group", " <name>") \
+ FLT_OT_PARSE_GROUP_DEF(SCOPES, 0, 0, 2, 0, "scopes", " <name> ...")
+
+#define FLT_OT_PARSE_SCOPE_DEFINES \
+ FLT_OT_PARSE_SCOPE_DEF( ID, 0, 1, 2, 2, "ot-scope", " <name>") \
+ FLT_OT_PARSE_SCOPE_DEF( SPAN, 0, 0, 2, 5, "span", " <name> [<reference>] [root]") \
+ FLT_OT_PARSE_SCOPE_DEF( TAG, 1, 0, 3, 0, "tag", " <name> <sample> ...") \
+ FLT_OT_PARSE_SCOPE_DEF( LOG, 1, 0, 3, 0, "log", " <name> <sample> ...") \
+ FLT_OT_PARSE_SCOPE_DEF(BAGGAGE, 1, 4, 3, 0, "baggage", " <name> <sample> ...") \
+ FLT_OT_PARSE_SCOPE_DEF( INJECT, 1, 3, 2, 4, "inject", " <name-prefix> [use-vars] [use-headers]") \
+ FLT_OT_PARSE_SCOPE_DEF(EXTRACT, 0, 3, 2, 3, "extract", " <name-prefix> [use-vars | use-headers]") \
+ FLT_OT_PARSE_SCOPE_DEF( FINISH, 0, 0, 2, 0, "finish", " <name> ...") \
+ FLT_OT_PARSE_SCOPE_DEF( ACL, 0, 1, 3, 0, "acl", " <name> <criterion> [flags] [operator] <value> ...") \
+ FLT_OT_PARSE_SCOPE_DEF( EVENT, 0, 0, 2, 0, "event", " <name> [{ if | unless } <condition>]")
+
+enum FLT_OT_PARSE_TRACER_enum {
+#define FLT_OT_PARSE_TRACER_DEF(a,b,c,d,e,f,g) FLT_OT_PARSE_TRACER_##a,
+ FLT_OT_PARSE_TRACER_DEFINES
+#undef FLT_OT_PARSE_TRACER_DEF
+};
+
+enum FLT_OT_PARSE_GROUP_enum {
+#define FLT_OT_PARSE_GROUP_DEF(a,b,c,d,e,f,g) FLT_OT_PARSE_GROUP_##a,
+ FLT_OT_PARSE_GROUP_DEFINES
+#undef FLT_OT_PARSE_GROUP_DEF
+};
+
+enum FLT_OT_PARSE_SCOPE_enum {
+#define FLT_OT_PARSE_SCOPE_DEF(a,b,c,d,e,f,g) FLT_OT_PARSE_SCOPE_##a,
+ FLT_OT_PARSE_SCOPE_DEFINES
+#undef FLT_OT_PARSE_SCOPE_DEF
+};
+
+enum FLT_OT_CTX_USE_enum {
+ FLT_OT_CTX_USE_VARS = 1 << 0,
+ FLT_OT_CTX_USE_HEADERS = 1 << 1,
+};
+
+struct flt_ot_parse_data {
+ int keyword; /* Keyword index. */
+ bool flag_check_id; /* Whether the group ID must be defined for the keyword. */
+ int check_name; /* Checking allowed characters in the name. */
+ int args_min; /* The minimum number of arguments required. */
+ int args_max; /* The maximum number of arguments allowed. */
+ const char *name; /* Keyword name. */
+ const char *usage; /* Usage text to be printed in case of an error. */
+};
+
+#define FLT_OT_PARSE_WARNING(f, ...) \
+ ha_warning("parsing [%s:%d] : " FLT_OT_FMT_TYPE FLT_OT_FMT_NAME "'" f "'\n", ##__VA_ARGS__);
+#define FLT_OT_PARSE_ALERT(f, ...) \
+ do { \
+ ha_alert("parsing [%s:%d] : " FLT_OT_FMT_TYPE FLT_OT_FMT_NAME "'" f "'\n", ##__VA_ARGS__); \
+ \
+ retval |= ERR_ABORT | ERR_ALERT; \
+ } while (0)
+#define FLT_OT_POST_PARSE_ALERT(f, ...) \
+ FLT_OT_PARSE_ALERT(f, flt_ot_current_config->cfg_file, ##__VA_ARGS__)
+
+#define FLT_OT_PARSE_ERR(e,f, ...) \
+ do { \
+ if (*(e) == NULL) \
+ (void)memprintf((e), f, ##__VA_ARGS__); \
+ \
+ retval |= ERR_ABORT | ERR_ALERT; \
+ } while (0)
+#define FLT_OT_PARSE_IFERR_ALERT() \
+ do { \
+ if (err == NULL) \
+ break; \
+ \
+ FLT_OT_PARSE_ALERT("%s", file, linenum, err); \
+ FLT_OT_ERR_FREE(err); \
+ } while (0)
+
+#endif /* _OPENTRACING_PARSER_H_ */
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */