MEDIUM: check: include server address and port in the send-state header
This fixes an issue that occurs when backend servers run on different
addresses or ports and you wish to healthcheck them via a consistent
port. For example, if you allocate backends dynamically as containers
that expose different ports and you use an inetd based healthchecking
component that runs on a dedicated port.
By adding the server address and port to the send-state header, the
healthcheck component can deduce which address and port to check by
reading the X-Haproxy-Server-State header out of the healthcheck and
parsing out the address and port.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 34a1e49..e0aa485 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -3109,6 +3109,14 @@
checks on the total number before transition, just as appears in the stats
interface. Next headers are in the form "<variable>=<value>", indicating in
no specific order some values available in the stats interface :
+ - a variable "address", containing the address of the backend server.
+ This corresponds to the <address> field in the server declaration. For
+ unix domain sockets, it will read "unix".
+
+ - a variable "port", containing the port of the backend server. This
+ corresponds to the <port> field in the server declaration. For unix
+ domain sockets, it will read "unix".
+
- a variable "name", containing the name of the backend followed by a slash
("/") then the name of the server. This can be used when a server is
checked in multiple backends.
diff --git a/src/checks.c b/src/checks.c
index 2ef14d1..89e5eee 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -494,6 +494,8 @@
int sv_state;
int ratio;
int hlen = 0;
+ char addr[46];
+ char port[6];
const char *srv_hlt_st[7] = { "DOWN", "DOWN %d/%d",
"UP %d/%d", "UP",
"NOLB %d/%d", "NOLB",
@@ -524,8 +526,11 @@
(s->state != SRV_ST_STOPPED) ? (s->check.health - s->check.rise + 1) : (s->check.health),
(s->state != SRV_ST_STOPPED) ? (s->check.fall) : (s->check.rise));
- hlen += snprintf(buffer + hlen, size - hlen, "; name=%s/%s; node=%s; weight=%d/%d; scur=%d/%d; qcur=%d",
- s->proxy->id, s->id,
+ addr_to_str(&s->addr, addr, sizeof(addr));
+ port_to_str(&s->addr, port, sizeof(port));
+
+ hlen += snprintf(buffer + hlen, size - hlen, "; address=%s; port=%s; name=%s/%s; node=%s; weight=%d/%d; scur=%d/%d; qcur=%d",
+ addr, port, s->proxy->id, s->id,
global.node,
(s->eweight * s->proxy->lbprm.wmult + s->proxy->lbprm.wdiv - 1) / s->proxy->lbprm.wdiv,
(s->proxy->lbprm.tot_weight * s->proxy->lbprm.wmult + s->proxy->lbprm.wdiv - 1) / s->proxy->lbprm.wdiv,