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/src/group.c b/contrib/opentracing/src/group.c
new file mode 100644
index 0000000..f9fdecc
--- /dev/null
+++ b/contrib/opentracing/src/group.c
@@ -0,0 +1,354 @@
+/***
+ * 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.
+ */
+#include "include.h"
+
+
+#define FLT_OT_GROUP_DEF(a,b,c) { a, b, c },
+const struct flt_ot_group_data flt_ot_group_data[] = { FLT_OT_GROUP_DEFINES };
+#undef FLT_OT_GROUP_DEF
+
+
+/***
+ * NAME
+ * flt_ot_group_action -
+ *
+ * ARGUMENTS
+ * rule -
+ * px -
+ * sess -
+ * s -
+ * opts -
+ *
+ * DESCRIPTION
+ * This is the action_ptr callback of a rule associated to the
+ * FLT_OT_ACTION_GROUP action.
+ *
+ * RETURN VALUE
+ * The function returns ACT_RET_CONT if processing is finished (with error or
+ * not), otherwise, it returns ACT_RET_YIELD if the action is in progress.
+ */
+static enum act_return flt_ot_group_action(struct act_rule *rule, struct proxy *px, struct session *sess, struct stream *s, int opts)
+{
+ const struct filter *filter;
+ const struct flt_conf *fconf;
+ const struct flt_ot_conf *conf;
+ const struct flt_ot_conf_group *conf_group;
+ const struct flt_ot_runtime_context *rt_ctx = NULL;
+ const struct flt_ot_conf_ph *ph_scope;
+ char *err = NULL;
+ int i, rc;
+
+ FLT_OT_FUNC("%p, %p, %p, %p, %d", rule, px, sess, s, opts);
+
+ FLT_OT_DBG(3, "from: %d, arg.act %p:{ %p %p %p %p }", rule->from, &(rule->arg.act), rule->arg.act.p[0], rule->arg.act.p[1], rule->arg.act.p[2], rule->arg.act.p[3]);
+
+ fconf = rule->arg.act.p[FLT_OT_ARG_FLT_CONF];
+ conf = rule->arg.act.p[FLT_OT_ARG_CONF];
+ conf_group = ((const struct flt_ot_conf_ph *)(rule->arg.act.p[FLT_OT_ARG_GROUP]))->ptr;
+
+ if ((fconf == NULL) || (conf == NULL) || (conf_group == NULL)) {
+ FLT_OT_LOG(LOG_ERR, FLT_OT_ACTION_GROUP ": internal error, invalid group action");
+
+ FLT_OT_RETURN(ACT_RET_CONT);
+ }
+
+ if (conf->tracer->flag_disabled) {
+ FLT_OT_DBG(1, "filter '%s' disabled, group action '%s' ignored", conf->id, conf_group->id);
+
+ FLT_OT_RETURN(ACT_RET_CONT);
+ }
+
+ /* Find the OpenTracing filter instance from the current stream. */
+ list_for_each_entry(filter, &(s->strm_flt.filters), list)
+ if (filter->config == fconf) {
+ rt_ctx = filter->ctx;
+
+ break;
+ }
+
+ if (rt_ctx == NULL) {
+ FLT_OT_DBG(1, "cannot find filter, probably not attached to the stream");
+
+ FLT_OT_RETURN(ACT_RET_CONT);
+ }
+ else if (flt_ot_is_disabled(filter FLT_OT_DBG_ARGS(, -1))) {
+ FLT_OT_RETURN(ACT_RET_CONT);
+ }
+ else {
+ FLT_OT_DBG(3, "run group '%s'", conf_group->id);
+ FLT_OT_DBG_CONF_GROUP("run group ", conf_group);
+ }
+
+ /*
+ * Check the value of rule->from; in case it is incorrect,
+ * report an error.
+ */
+ for (i = 0; i < FLT_OT_TABLESIZE(flt_ot_group_data); i++)
+ if (flt_ot_group_data[i].act_from == rule->from)
+ break;
+
+ if (i >= FLT_OT_TABLESIZE(flt_ot_group_data)) {
+ FLT_OT_LOG(LOG_ERR, FLT_OT_ACTION_GROUP ": internal error, invalid rule->from=%d", rule->from);
+
+ FLT_OT_RETURN(ACT_RET_CONT);
+ }
+
+ list_for_each_entry(ph_scope, &(conf_group->ph_scopes), list) {
+ rc = flt_ot_scope_run(s, rt_ctx->filter, &(s->res), ph_scope->ptr, NULL, SMP_OPT_DIR_RES, &err);
+ if ((rc == FLT_OT_RET_ERROR) && (opts & ACT_OPT_FINAL)) {
+ /* XXX */
+ }
+ }
+
+ FLT_OT_RETURN(ACT_RET_CONT);
+}
+
+
+/***
+ * NAME
+ * flt_ot_group_check -
+ *
+ * ARGUMENTS
+ * rule -
+ * px -
+ * err -
+ *
+ * DESCRIPTION
+ * This is the check_ptr callback of a rule associated to the
+ * FLT_OT_ACTION_GROUP action.
+ *
+ * RETURN VALUE
+ * The function returns 1 in success case, otherwise,
+ * it returns 0 and err is filled.
+ */
+static int flt_ot_group_check(struct act_rule *rule, struct proxy *px, char **err)
+{
+ struct flt_conf *fconf_tmp, *fconf = NULL;
+ struct flt_ot_conf *conf;
+ struct flt_ot_conf_ph *ph_group;
+ const char *filter_id;
+ const char *group_id;
+ bool flag_found = 0;
+ int i;
+
+ FLT_OT_FUNC("%p, %p, %p:%p", rule, px, FLT_OT_DPTR_ARGS(err));
+
+ filter_id = rule->arg.act.p[FLT_OT_ARG_FILTER_ID];
+ group_id = rule->arg.act.p[FLT_OT_ARG_GROUP_ID];
+
+ FLT_OT_DBG(2, "checking filter_id='%s', group_id='%s'", filter_id, group_id);
+
+ /*
+ * Check the value of rule->from; in case it is incorrect,
+ * report an error.
+ */
+ for (i = 0; i < FLT_OT_TABLESIZE(flt_ot_group_data); i++)
+ if (flt_ot_group_data[i].act_from == rule->from)
+ break;
+
+ if (i >= FLT_OT_TABLESIZE(flt_ot_group_data)) {
+ FLT_OT_ERR("internal error, unexpected rule->from=%d, please report this bug!", rule->from);
+
+ FLT_OT_RETURN(0);
+ }
+
+ /*
+ * Try to find the OpenTracing filter by checking all filters
+ * for the proxy <px>.
+ */
+ list_for_each_entry(fconf_tmp, &(px->filter_configs), list) {
+ conf = fconf_tmp->conf;
+
+ if (fconf_tmp->id != ot_flt_id) {
+ /* This is not an OpenTracing filter. */
+ continue;
+ }
+ else if (strcmp(conf->id, filter_id) == 0) {
+ /* This is the good filter ID. */
+ fconf = fconf_tmp;
+
+ break;
+ }
+ }
+
+ if (fconf == NULL) {
+ FLT_OT_ERR("unable to find the OpenTracing filter '%s' used by the " FLT_OT_ACTION_GROUP " '%s'", filter_id, group_id);
+
+ FLT_OT_RETURN(0);
+ }
+
+ /*
+ * Attempt to find if the group is defined in the OpenTracing filter
+ * configuration.
+ */
+ list_for_each_entry(ph_group, &(conf->tracer->ph_groups), list)
+ if (strcmp(ph_group->id, group_id) == 0) {
+ flag_found = 1;
+
+ break;
+ }
+
+ if (!flag_found) {
+ FLT_OT_ERR("unable to find group '%s' in the OpenTracing filter '%s' configuration", group_id, filter_id);
+
+ FLT_OT_RETURN(0);
+ }
+
+ FLT_OT_FREE_CLEAR(rule->arg.act.p[FLT_OT_ARG_FILTER_ID]);
+ FLT_OT_FREE_CLEAR(rule->arg.act.p[FLT_OT_ARG_GROUP_ID]);
+
+ rule->arg.act.p[FLT_OT_ARG_FLT_CONF] = fconf;
+ rule->arg.act.p[FLT_OT_ARG_CONF] = conf;
+ rule->arg.act.p[FLT_OT_ARG_GROUP] = ph_group;
+
+ FLT_OT_RETURN(1);
+}
+
+
+/***
+ * NAME
+ * flt_ot_group_release -
+ *
+ * ARGUMENTS
+ * rule -
+ *
+ * DESCRIPTION
+ * This is the release_ptr callback of a rule associated to the
+ * FLT_OT_ACTION_GROUP action.
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_group_release(struct act_rule *rule)
+{
+ FLT_OT_FUNC("%p", rule);
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_group_parse -
+ *
+ * ARGUMENTS
+ * args -
+ * cur_arg -
+ * px -
+ * rule -
+ * err -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns ACT_RET_PRS_ERR if an error occurs, ACT_RET_PRS_OK otherwise.
+ */
+static enum act_parse_ret flt_ot_group_parse(const char **args, int *cur_arg, struct proxy *px, struct act_rule *rule, char **err)
+{
+ FLT_OT_FUNC("%p, %p, %p, %p, %p:%p", args, cur_arg, px, rule, FLT_OT_DPTR_ARGS(err));
+
+ if (!FLT_OT_ARG_ISVALID(*cur_arg) ||
+ !FLT_OT_ARG_ISVALID(*cur_arg + 1) ||
+ (FLT_OT_ARG_ISVALID(*cur_arg + 2) &&
+ (strcmp(args[*cur_arg + 2], FLT_OT_CONDITION_IF) != 0) &&
+ (strcmp(args[*cur_arg + 2], FLT_OT_CONDITION_UNLESS) != 0))) {
+ FLT_OT_ERR("expects: <filter-id> <group-id> [{ if | unless } ...]");
+
+ FLT_OT_RETURN(ACT_RET_PRS_ERR);
+ }
+
+ /* Copy the OpenTracing filter id. */
+ rule->arg.act.p[FLT_OT_ARG_FILTER_ID] = FLT_OT_STRDUP(args[*cur_arg]);
+ if (rule->arg.act.p[FLT_OT_ARG_FILTER_ID] == NULL) {
+ FLT_OT_ERR("%s : out of memory", args[*cur_arg]);
+
+ FLT_OT_RETURN(ACT_RET_PRS_ERR);
+ }
+
+ /* Copy the OpenTracing group id. */
+ rule->arg.act.p[FLT_OT_ARG_GROUP_ID] = FLT_OT_STRDUP(args[*cur_arg + 1]);
+ if (rule->arg.act.p[FLT_OT_ARG_GROUP_ID] == NULL) {
+ FLT_OT_ERR("%s : out of memory", args[*cur_arg + 1]);
+
+ FLT_OT_FREE_CLEAR(rule->arg.act.p[FLT_OT_ARG_FILTER_ID]);
+
+ FLT_OT_RETURN(ACT_RET_PRS_ERR);
+ }
+
+ rule->action = ACT_CUSTOM;
+ rule->action_ptr = flt_ot_group_action;
+ rule->check_ptr = flt_ot_group_check;
+ rule->release_ptr = flt_ot_group_release;
+
+ *cur_arg += 2;
+
+ FLT_OT_RETURN(ACT_RET_PRS_OK);
+}
+
+
+static struct action_kw_list tcp_req_action_kws = { ILH, {
+ { FLT_OT_ACTION_GROUP, flt_ot_group_parse },
+ { /* END */ },
+ }
+};
+
+INITCALL1(STG_REGISTER, tcp_req_cont_keywords_register, &tcp_req_action_kws);
+
+static struct action_kw_list tcp_res_action_kws = { ILH, {
+ { FLT_OT_ACTION_GROUP, flt_ot_group_parse },
+ { /* END */ },
+ }
+};
+
+INITCALL1(STG_REGISTER, tcp_res_cont_keywords_register, &tcp_res_action_kws);
+
+static struct action_kw_list http_req_action_kws = { ILH, {
+ { FLT_OT_ACTION_GROUP, flt_ot_group_parse },
+ { /* END */ },
+ }
+};
+
+INITCALL1(STG_REGISTER, http_req_keywords_register, &http_req_action_kws);
+
+static struct action_kw_list http_res_action_kws = { ILH, {
+ { FLT_OT_ACTION_GROUP, flt_ot_group_parse },
+ { /* END */ },
+ }
+};
+
+INITCALL1(STG_REGISTER, http_res_keywords_register, &http_res_action_kws);
+
+static struct action_kw_list http_after_res_actions_kws = { ILH, {
+ { FLT_OT_ACTION_GROUP, flt_ot_group_parse },
+ { /* END */ },
+ }
+};
+
+INITCALL1(STG_REGISTER, http_after_res_keywords_register, &http_after_res_actions_kws);
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */