[ovs-dev] [PATCH v2] Introduce ovs-appctl command to monitor HVs sb connection status

[Lorenzo Bianconi]

Add 'connection-status' command to ovs-appctl utility in order to check
if a given chassis is currently connected to SB db

Co-authored-by: aginwala <aginwala at ebay.com>
Signed-off-by: aginwala <aginwala at ebay.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
---
Changes since v1:
- add unit tests for ovs-appctl -t ovn-controller connection-status
  command
- use jsonrpc_session_is_connected() in ovsdb_idl_is_connected routine
---
 lib/ovsdb-idl.c                     |  6 +++++
 lib/ovsdb-idl.h                     |  1 +
 ovn/controller/ovn-controller.8.xml |  5 +++++
 ovn/controller/ovn-controller.c     | 17 +++++++++++++++
 tests/ovn-controller.at             | 34 +++++++++++++++++++++++++++++
 5 files changed, 63 insertions(+)

diff --git a/lib/ovsdb-idl.c b/lib/ovsdb-idl.c
index ae0a55c3a..f181ae831 100644
--- a/lib/ovsdb-idl.c
+++ b/lib/ovsdb-idl.c
@@ -922,6 +922,12 @@ ovsdb_idl_is_alive(const struct ovsdb_idl *idl)
            idl->state != IDL_S_ERROR;
 }
 
+bool
+ovsdb_idl_is_connected(const struct ovsdb_idl *idl)
+{
+    return jsonrpc_session_is_connected(idl->session);
+}
+
 /* Returns the last error reported on a connection by 'idl'.  The return value
  * is 0 only if no connection made by 'idl' has ever encountered an error and
  * a negative response to a schema request has never been received. See
diff --git a/lib/ovsdb-idl.h b/lib/ovsdb-idl.h
index ea18b22f5..5f933b628 100644
--- a/lib/ovsdb-idl.h
+++ b/lib/ovsdb-idl.h
@@ -80,6 +80,7 @@ void ovsdb_idl_force_reconnect(struct ovsdb_idl *);
 void ovsdb_idl_verify_write_only(struct ovsdb_idl *);
 
 bool ovsdb_idl_is_alive(const struct ovsdb_idl *);
+bool ovsdb_idl_is_connected(const struct ovsdb_idl *idl);
 int ovsdb_idl_get_last_error(const struct ovsdb_idl *);
 
 void ovsdb_idl_set_probe_interval(const struct ovsdb_idl *, int probe_interval);
diff --git a/ovn/controller/ovn-controller.8.xml b/ovn/controller/ovn-controller.8.xml
index 0eff2113f..0861edbc4 100644
--- a/ovn/controller/ovn-controller.8.xml
+++ b/ovn/controller/ovn-controller.8.xml
@@ -388,6 +388,11 @@
         0x800</code>.
       </p>
       </dd>
+
+      <dt><code>connection-status</code></dt>
+      <dd>
+        Show OVN SBDB connection status for the chassis.
+      </dd>
       </dl>
     </p>
 
diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c
index 6ee72a9fa..3338d3318 100644
--- a/ovn/controller/ovn-controller.c
+++ b/ovn/controller/ovn-controller.c
@@ -66,6 +66,7 @@ VLOG_DEFINE_THIS_MODULE(main);
 static unixctl_cb_func ovn_controller_exit;
 static unixctl_cb_func ct_zone_list;
 static unixctl_cb_func inject_pkt;
+static unixctl_cb_func ovn_controller_conn_show;
 
 #define DEFAULT_BRIDGE_NAME "br-int"
 #define DEFAULT_PROBE_INTERVAL_MSEC 5000
@@ -588,6 +589,9 @@ main(int argc, char *argv[])
         ovsdb_idl_create(ovnsb_remote, &sbrec_idl_class, true, true));
     ovsdb_idl_set_leader_only(ovnsb_idl_loop.idl, false);
 
+    unixctl_command_register("connection-status", "", 0, 0,
+                             ovn_controller_conn_show, ovnsb_idl_loop.idl);
+
     struct ovsdb_idl_index *sbrec_chassis_by_name
         = chassis_index_create(ovnsb_idl_loop.idl);
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath
@@ -1061,3 +1065,16 @@ update_probe_interval(const struct ovsrec_open_vswitch_table *ovs_table,
 
     ovsdb_idl_set_probe_interval(ovnsb_idl, interval);
 }
+
+static void
+ovn_controller_conn_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                         const char *argv[] OVS_UNUSED, void *idl_)
+{
+    char *result = "not connected";
+    struct ovsdb_idl *idl = idl_;
+
+    if (idl && ovsdb_idl_is_connected(idl)) {
+       result = "connected";
+    }
+    unixctl_command_reply(conn, result);
+}
diff --git a/tests/ovn-controller.at b/tests/ovn-controller.at
index ecc6a50da..13e88a0cc 100644
--- a/tests/ovn-controller.at
+++ b/tests/ovn-controller.at
@@ -228,3 +228,37 @@ as ovn-sb
 OVS_APP_EXIT_AND_WAIT([ovsdb-server])
 
 AT_CLEANUP
+
+# Check ovn-controller connection status to Southbound database
+AT_SETUP([ovn-controller - check sbdb connection])
+AT_KEYWORDS([ovn])
+ovn_init_db ovn-sb
+
+net_add n1
+sim_add hv
+as hv
+ovs-vsctl \
+    -- add-br br-phys \
+    -- add-br br-eth0 \
+    -- add-br br-eth1 \
+    -- add-br br-eth2
+ovn_attach n1 br-phys 192.168.0.1
+
+check_sbdb_connection () {
+    test "$(ovs-appctl -t ovn-controller connection-status)" = "$1"
+}
+
+OVS_WAIT_UNTIL([check_sbdb_connection connected])
+
+ovs-vsctl set open . external_ids:ovn-remote=tcp:192.168.0.10:6642
+OVS_WAIT_UNTIL([check_sbdb_connection 'not connected'])
+
+# reset the remote for clean-up
+ovs-vsctl set open . external_ids:ovn-remote=unix:$ovs_base/ovn-sb/ovn-sb.sock
+# Gracefully terminate daemons
+OVN_CLEANUP_SBOX([hv])
+OVN_CLEANUP_VSWITCH([main])
+as ovn-sb
+OVS_APP_EXIT_AND_WAIT([ovsdb-server])
+
+AT_CLEANUP
-- 
2.17.1