MINOR: backend: Add srv_queue converter
The converter can be useful to look up a server queue from a dynamic value.
It takes an input value of type string, either a server name or
<backend>/<server> format and returns the number of queued sessions
on that server. Can be used in places where we want to look up
queued sessions from a dynamic name, like a cookie value (e.g.
req.cook(SRVID),srv_queue) and then make a decision to break
persistence or direct a request elsewhere.
Signed-off-by: Nenad Merdanovic <nmerdan@haproxy.com>
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 4e18f0f..20c39c7 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -13622,6 +13622,13 @@
Please note that this converter is only available when haproxy has been
compiled with USE_OPENSSL.
+srv_queue
+ Takes an input value of type string, either a server name or <backend>/<server>
+ format and returns the number of queued sessions on that server. Can be used
+ in places where we want to look up queued sessions from a dynamic name, like a
+ cookie value (e.g. req.cook(SRVID),srv_queue) and then make a decision to break
+ persistence or direct a request elsewhere.
+
strcmp(<var>)
Compares the contents of <var> with the input value of type string. Returns
the result as a signed integer compatible with strcmp(3): 0 if both strings
diff --git a/src/backend.c b/src/backend.c
index 917b612..1b01536 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -2286,6 +2286,38 @@
return 1;
}
+static int
+sample_conv_srv_queue(const struct arg *args, struct sample *smp, void *private)
+{
+ struct proxy *px;
+ struct server *srv;
+ char *bksep;
+
+ if (!smp_make_safe(smp))
+ return 0;
+
+ bksep = strchr(smp->data.u.str.area, '/');
+
+ if (bksep) {
+ *bksep = '\0';
+ px = proxy_find_by_name(smp->data.u.str.area, PR_CAP_BE, 0);
+ if (!px)
+ return 0;
+ smp->data.u.str.area = bksep + 1;
+ } else {
+ if (!(smp->px->cap & PR_CAP_BE))
+ return 0;
+ px = smp->px;
+ }
+
+ srv = server_find_by_name(px, smp->data.u.str.area);
+ if (!srv)
+ return 0;
+
+ smp->data.type = SMP_T_SINT;
+ smp->data.u.sint = srv->nbpend;
+ return 1;
+}
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
@@ -2313,7 +2345,8 @@
/* Note: must not be declared <const> as its list will be overwritten */
static struct sample_conv_kw_list sample_conv_kws = {ILH, {
- { "nbsrv", sample_conv_nbsrv, 0, NULL, SMP_T_STR, SMP_T_SINT },
+ { "nbsrv", sample_conv_nbsrv, 0, NULL, SMP_T_STR, SMP_T_SINT },
+ { "srv_queue", sample_conv_srv_queue, 0, NULL, SMP_T_STR, SMP_T_SINT },
{ /* END */ },
}};