BUG/MEDIUM: dns/server: fix incomatibility between SRV resolution and server state file
Server state file has no indication that a server is currently managed
by a DNS SRV resolution.
And thus, both feature (DNS SRV resolution and server state), when used
together, does not provide the expected behavior: a smooth experience...
This patch introduce the "SRV record name" in the server state file and
loads and applies it if found and wherever required.
This patch applies to haproxy-dev branch only. For backport, a specific patch
is provided for 1.8.
diff --git a/doc/management.txt b/doc/management.txt
index c78dc74..17f1505 100644
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -2130,6 +2130,7 @@
configuration.
srv_fqdn: Server FQDN.
srv_port: Server port.
+ srvrecord: DNS SRV record associated to this SRV.
show sess
Dump all known sessions. Avoid doing this on slow connections as this can
diff --git a/include/types/server.h b/include/types/server.h
index 8825928..8adc29b 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -126,10 +126,11 @@
"bk_f_forced_id " \
"srv_f_forced_id " \
"srv_fqdn " \
- "srv_port"
+ "srv_port " \
+ "srvrecord"
-#define SRV_STATE_FILE_MAX_FIELDS 19
-#define SRV_STATE_FILE_NB_FIELDS_VERSION_1 18
+#define SRV_STATE_FILE_MAX_FIELDS 20
+#define SRV_STATE_FILE_NB_FIELDS_VERSION_1 19
#define SRV_STATE_LINE_MAXLEN 512
/* server flags -- 32 bits */
diff --git a/src/proxy.c b/src/proxy.c
index 73aa118..c939e82 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -1429,6 +1429,7 @@
char srv_addr[INET6_ADDRSTRLEN + 1];
time_t srv_time_since_last_change;
int bk_f_forced_id, srv_f_forced_id;
+ char *srvrecord;
/* we don't want to report any state if the backend is not enabled on this process */
if (px->bind_proc && !(px->bind_proc & pid_bit))
@@ -1458,18 +1459,23 @@
bk_f_forced_id = px->options & PR_O_FORCED_ID ? 1 : 0;
srv_f_forced_id = srv->flags & SRV_F_FORCED_ID ? 1 : 0;
+ srvrecord = NULL;
+ if (srv->srvrq && srv->srvrq->name)
+ srvrecord = srv->srvrq->name;
+
chunk_appendf(buf,
"%d %s "
"%d %s %s "
"%d %d %d %d %ld "
"%d %d %d %d %d "
- "%d %d %s %u"
+ "%d %d %s %u %s"
"\n",
px->uuid, px->id,
srv->puid, srv->id, srv_addr,
srv->cur_state, srv->cur_admin, srv->uweight, srv->iweight, (long int)srv_time_since_last_change,
srv->check.status, srv->check.result, srv->check.health, srv->check.state, srv->agent.state,
- bk_f_forced_id, srv_f_forced_id, srv->hostname ? srv->hostname : "-", srv->svc_port);
+ bk_f_forced_id, srv_f_forced_id, srv->hostname ? srv->hostname : "-", srv->svc_port,
+ srvrecord ? srvrecord : "-");
if (ci_putchk(si_ic(si), &trash) == -1) {
si_applet_cant_put(si);
return 0;
diff --git a/src/server.c b/src/server.c
index 78d5a0f..766f5de 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2758,6 +2758,7 @@
const char *fqdn;
const char *port_str;
unsigned int port;
+ char *srvrecord;
fqdn = NULL;
port = 0;
@@ -2781,6 +2782,7 @@
* srv_f_forced_id: params[12]
* srv_fqdn: params[13]
* srv_port: params[14]
+ * srvrecord: params[15]
*/
/* validating srv_op_state */
@@ -2913,6 +2915,13 @@
}
}
+ /* SRV record
+ * NOTE: in HAProxy, SRV records must start with an underscore '_'
+ */
+ srvrecord = params[15];
+ if (srvrecord && *srvrecord != '_')
+ srvrecord = NULL;
+
/* don't apply anything if one error has been detected */
if (msg->data)
goto out;
@@ -3045,6 +3054,48 @@
}
}
}
+ /* If all the conditions below are validated, this means
+ * we're evaluating a server managed by SRV resolution
+ */
+ else if (fqdn && !srv->hostname && srvrecord) {
+ int res;
+
+ /* we can't apply previous state if SRV record has changed */
+ if (srv->srvrq && strcmp(srv->srvrq->name, srvrecord) != 0) {
+ chunk_appendf(msg, ", SRV record mismatch between configuration ('%s') and state file ('%s) for server '%s'. Previous state not applied", srv->srvrq->name, srvrecord, srv->id);
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ goto out;
+ }
+
+ /* create or find a SRV resolution for this srv record */
+ if (srv->srvrq == NULL && (srv->srvrq = find_srvrq_by_name(srvrecord, srv->proxy)) == NULL)
+ srv->srvrq = new_dns_srvrq(srv, srvrecord);
+ if (srv->srvrq == NULL) {
+ chunk_appendf(msg, ", can't create or find SRV resolution '%s' for server '%s'", srvrecord, srv->id);
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ goto out;
+ }
+
+ /* prepare DNS resolution for this server */
+ res = srv_prepare_for_resolution(srv, fqdn);
+ if (res == -1) {
+ chunk_appendf(msg, ", can't allocate memory for DNS resolution for server '%s'", srv->id);
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ goto out;
+ }
+
+ /* configure check.port accordingly */
+ if ((srv->check.state & CHK_ST_CONFIGURED) &&
+ !(srv->flags & SRV_F_CHECKPORT))
+ srv->check.port = port;
+
+ /* Unset SRV_F_MAPPORTS for SRV records.
+ * SRV_F_MAPPORTS is unfortunately set by parse_server()
+ * because no ports are provided in the configuration file.
+ * This is because HAProxy will use the port found into the SRV record.
+ */
+ srv->flags &= ~SRV_F_MAPPORTS;
+ }
if (port_str)
srv->svc_port = port;
@@ -3301,6 +3352,7 @@
* srv_f_forced_id: params[16] => srv_params[12]
* srv_fqdn: params[17] => srv_params[13]
* srv_port: params[18] => srv_params[14]
+ * srvrecord: params[19] => srv_params[15]
*/
if (arg >= 4) {
srv_params[srv_arg] = cur;