Add support for the openstack-loadbalancer charm

When CephNFS is related to the openstack-loadbalancer, all
NFS connections are load-balanced through a TCP loadbalancer
running with a VIP and passed back, round-robin, to the
nfs-ganesha servers providing service.

metadata.yaml

@@ -19,9 +19,8 @@ extra-bindings:
 requires:
   ceph-client:
     interface: ceph-client
-  hacluster:
+  loadbalancer:
-    interface: hacluster
+    interface: openstack-loadbalancer
-    scope: container
 peers:
   cluster:
     interface: ceph-nfs-peer

osci.yaml

@@ -3,14 +3,13 @@
       - charm-unit-jobs
     check:
       jobs:
-      - octopus
+      - focal-pacific
-      - pacific
     vars:
       needs_charm_build: true
-      charm_build_name: ceph-iscsi
+      charm_build_name: ceph-nfs
       build_type: charmcraft
 - job:
-    name: focal-octopus
+    name: focal-pacific
     parent: func-target
     dependencies:
       - osci-lint
@@ -18,12 +17,5 @@
       - tox-py36
       - tox-py37
       - tox-py38
-    vars:
-      tox_extra_args: focal-octopus
-- job:
-    name: focal-pacific
-    parent: func-target
-    dependencies: &smoke-jobs
-      - focal-octopus
     vars:
       tox_extra_args: focal-pacific

requirements.txt

@@ -3,3 +3,4 @@ git+https://github.com/juju/charm-helpers.git#egg=charmhelpers
 git+https://github.com/canonical/operator.git#egg=ops
 git+https://opendev.org/openstack/charm-ops-interface-ceph-client#egg=interface_ceph_client
 git+https://github.com/ChrisMacNaughton/charm-ops-openstack.git@feature/charm-instance-to-relation-adapter#egg=ops_openstack
+git+https://github.com/openstack-charmers/ops-interface-openstack-loadbalancer#egg=interface_openstack_loadbalancer

src/charm.py

@@ -27,6 +27,9 @@ import charmhelpers.core.host as ch_host
 import charmhelpers.core.templating as ch_templating
 import interface_ceph_client.ceph_client as ceph_client
 import interface_ceph_nfs_peer
+
+import interface_openstack_loadbalancer.loadbalancer as ops_lb_interface
+
 # TODO: Add the below class functionaity to action / relations
 from ganesha import GaneshaNfs
 
@@ -132,6 +135,9 @@ class CephNfsCharm(
 
     SERVICES = ['nfs-ganesha']
 
+    LB_SERVICE_NAME = "nfs-ganesha"
+    NFS_PORT = 2049
+
     RESTART_MAP = {
         str(GANESHA_CONF): SERVICES,
         str(CEPH_CONF): SERVICES,
@@ -153,6 +159,9 @@ class CephNfsCharm(
         self.peers = interface_ceph_nfs_peer.CephNfsPeers(
             self,
             'cluster')
+        self.ingress = ops_lb_interface.OSLoadbalancerRequires(
+            self,
+            'loadbalancer')
         self.adapters = CephNFSAdapters(
             (self.ceph_client, self.peers),
             contexts=(CephNFSContext(self),),
@@ -181,6 +190,12 @@ class CephNfsCharm(
         self.framework.observe(
             self.peers.on.reload_nonce,
             self.on_reload_nonce)
+        self.framework.observe(
+            self.ingress.on.lb_relation_ready,
+            self._request_loadbalancer)
+        self.framework.observe(
+            self.ingress.on.lb_configured,
+            self.render_config)
         # Actions
         self.framework.observe(
             self.on.create_share_action,
@@ -201,6 +216,20 @@ class CephNfsCharm(
             self.revoke_access_action
         )
 
+    def _request_loadbalancer(self, _) -> None:
+        """Send request to create loadbalancer"""
+        self.ingress.request_loadbalancer(
+            self.LB_SERVICE_NAME,
+            self.NFS_PORT,
+            self.NFS_PORT,
+            self._get_bind_ip(),
+            'tcp')
+
+    def _get_bind_ip(self) -> str:
+        """Return the IP to bind the dashboard to"""
+        binding = self.model.get_binding('public')
+        return str(binding.network.ingress_address)
+
     def config_get(self, key, default=None):
         """Retrieve config option.
 
@@ -347,10 +376,16 @@ class CephNfsCharm(
     def access_address(self) -> str:
         """Return the IP to advertise Ganesha on"""
         binding = self.model.get_binding('public')
-        if self.model.get_relation('hacluster'):
+        ingress_address = str(binding.network.ingress_address)
-            return self.config_get('vip')
+        if self.ingress.relations:
+            lb_response = self.ingress.get_frontend_data()
+            if lb_response:
+                lb_config = lb_response[self.LB_SERVICE_NAME]
+                return [i for d in lb_config.values() for i in d['ip']][0]
+            else:
+                return ingress_address
         else:
-            return str(binding.network.ingress_address)
+            return ingress_address
 
     def create_share_action(self, event):
         if not self.model.unit.is_leader():

test-requirements.txt

@@ -13,4 +13,3 @@ oslo.i18n<4.0.0
 git+https://github.com/openstack-charmers/zaza.git#egg=zaza
 git+https://github.com/openstack-charmers/zaza-openstack-tests.git#egg=zaza.openstack
 pytz    # workaround for 14.04 pip/tox
-pyudev  # for ceph-* charm unit tests (not mocked?)

tests/bundles/focal-pacific.yaml

@@ -8,22 +8,29 @@ applications:
     charm: ../../ceph-nfs.charm
     num_units: 2
   ceph-osd:
-    charm: cs:~openstack-charmers-next/ceph-osd
+    charm: ch:ceph-osd
     num_units: 3
     storage:
       osd-devices: '2,10G'
     options:
-      osd-devices: '/dev/test-non-existent'
+      source: cloud:focal-wallaby
   ceph-mon:
-    charm: cs:~openstack-charmers-next/ceph-mon
+    charm: ch:ceph-mon
     num_units: 3
     options:
       monitor-count: '3'
       expected-osd-count: 6
+      source: cloud:focal-wallaby
   ceph-fs:
-    charm: cs:~openstack-charmers-next/ceph-fs
+    charm: ch:ceph-fs
     num_units: 1
-
+  loadbalancer:
+    charm: ch:openstack-loadbalancer
+    num_units: 3
+  hacluster:
+    charm: ch:hacluster
+    options:
+      cluster_count: 3
 relations:
   - - 'ceph-mon:client'
     - 'ceph-nfs:ceph-client'
@@ -31,3 +38,7 @@ relations:
     - 'ceph-mon:osd'
   - - 'ceph-fs'
     - 'ceph-mon'
+  - - ceph-nfs
+    - loadbalancer
+  - - 'loadbalancer:ha'
+    - 'hacluster:ha'

tests/bundles/overlays/focal-pacific.yaml.j2

@@ -0,0 +1,4 @@
+applications:
+  loadbalancer:
+    options:
+        vip: '{{ TEST_VIP00 }}'