MINOR: Add nbsrv sample converter
This is like the nbsrv() sample fetch function except that it works as
a converter so it can count the number of available servers of a backend
name retrieved using a sample fetch or an environment variable.
Signed-off-by: Nenad Merdanovic <nmerdan@haproxy.com>
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 8246531..78f0f13 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -12530,6 +12530,12 @@
This prefix is followed by a name. The separator is a '.'. The name may only
contain characters 'a-z', 'A-Z', '0-9', '.' and '_'.
+nbsrv
+ Takes an input value of type string, interprets it as a backend name and
+ returns the number of usable servers in that backend. Can be used in places
+ where we want to look up a backend from a dynamic name, like a result of a
+ map lookup.
+
neg
Takes the input value of type signed integer, computes the opposite value,
and returns the remainder as an signed integer. 0 is identity. This operator
diff --git a/include/proto/backend.h b/include/proto/backend.h
index 105807b..39a7f3d 100644
--- a/include/proto/backend.h
+++ b/include/proto/backend.h
@@ -46,6 +46,19 @@
struct server *get_server_uh(struct proxy *px, char *uri, int uri_len);
int be_lastsession(const struct proxy *be);
+/* Returns number of usable servers in backend */
+static inline int be_usable_srv(struct proxy *be)
+{
+ if (be->state == PR_STSTOPPED)
+ return 0;
+ else if (be->srv_act)
+ return be->srv_act;
+ else if (be->lbprm.fbck)
+ return 1;
+ else
+ return be->srv_bck;
+}
+
/* set the time of last session on the backend */
static void inline be_set_sess_last(struct proxy *be)
{
diff --git a/src/backend.c b/src/backend.c
index c9bc3ed..5e2b8fc 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1821,6 +1821,24 @@
return 1;
}
+static int sample_conv_nbsrv(const struct arg *args, struct sample *smp, void *private)
+{
+
+ struct proxy *px;
+
+ if (!smp_make_safe(smp))
+ return 0;
+
+ px = proxy_find_by_name(smp->data.u.str.str, PR_CAP_BE, 0);
+ if (!px)
+ return 0;
+
+ smp->data.type = SMP_T_SINT;
+ smp->data.u.sint = be_usable_srv(px);
+
+ return 1;
+}
+
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
@@ -1841,6 +1859,12 @@
{ /* END */ },
}};
+/* 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 },
+ { /* END */ },
+}};
+
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
@@ -1854,6 +1878,7 @@
static void __backend_init(void)
{
sample_register_fetches(&smp_kws);
+ sample_register_convs(&sample_conv_kws);
acl_register_keywords(&acl_kws);
}