ui: derive LB algorithm dropdown from network's Lb provider capability

Before this change, both the public LB form (LoadBalancing.vue) and the internal LB form (network.js Internal LB action) hard-coded the algorithm dropdown to ['source', 'roundrobin', 'leastconn']. Every Lb provider got the same three options regardless of what the provider actually supported, so a user could pick "leastconn" against, e.g., the OVN provider, only to get the rule rejected later by validateLBRule. The capability is already declared (NetworkElement.getCapabilities() -> Service.Lb -> Capability.SupportedLBAlgorithms) and surfaced by listNetworks - we just weren't reading it. LoadBalancing.vue (public LB - the create modal and the edit-rule modal): - Replaces the three static <a-select-option>s with a v-for over a new `supportedAlgorithms` data field defaulting to the legacy ['roundrobin', 'leastconn', 'source'] (so providers/networks that don't declare the capability behave exactly as before). - Adds fetchLbCapabilities() (called from fetchData) which: * resolves the network id from resource.associatednetworkid or resource.networkid, * looks up the network via listNetworks, * walks service[name=Lb].capability[name=SupportedLbAlgorithms] and splits the CSV into the dropdown list, * snaps newRule.algorithm to the first supported value if the previous default falls outside the new set, * swallows any error so we never break the page on a backend hiccup. listNetworks is the right endpoint here. listNetworkOfferings hard-codes only SupportedLBIsolation/ElasticLb/InlineMode/VmAutoScaling for the Lb service in createNetworkOfferingResponse, while createNetworkResponse walks the live provider's getCapabilities() and exposes everything we declared - including SupportedLbAlgorithms. network.js (internal LB action): - Leaves the static option list in place but flags the spot with a TODO. Driving this declaratively requires AutogenView to support an async or function-valued `mapping[field].options`, which is a framework-level change and out of scope for this UI patch. A follow-up can convert the declarative mapping to a SFC and adopt the same approach as the public LB form. The change is provider-agnostic: it benefits every Lb provider that correctly declares SupportedLBAlgorithms. OVN gets {roundrobin, source}; VirtualRouter keeps {roundrobin, leastconn, source}; Netscaler/F5/etc. will reflect whatever they declare, and providers without the capability fall back to the legacy three. This commit is intentionally self-contained on top of the OVN plugin work so it can be cherry-picked into a dedicated upstream PR. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
msinhore · Apr 28, 2026 · Apr 29, 2026 · Apr 30, 2026 · da709bb94137793811bc03614ed7337c2f8c8934
commit da709bb94137793811bc03614ed7337c2f8c8934
diff --git a/ui/src/config/section/network.js b/ui/src/config/section/network.js
@@ -1139,6 +1139,11 @@ export default {
           args: ['name', 'description', 'sourceipaddress', 'sourceport', 'instanceport', 'algorithm', 'networkid', 'sourceipaddressnetworkid', 'scheme'],
           mapping: {
             algorithm: {
+              // TODO: derive from the selected network's offering capabilities
+              // (service Lb, SupportedLBAlgorithms) - mirrors what LoadBalancing.vue
+              // does for public LB. Doing it here requires AutogenView to support
+              // an async/function-valued `options`, which is a framework change
+              // outside the scope of this UI patch.
               options: ['source', 'roundrobin', 'leastconn']
             },
             scheme: {

diff --git a/ui/src/views/network/LoadBalancing.vue b/ui/src/views/network/LoadBalancing.vue
@@ -49,9 +49,7 @@
             :filterOption="(input, option) => {
               return option.label.toLowerCase().indexOf(input.toLowerCase()) >= 0
             }" >
-            <a-select-option value="roundrobin" :label="$t('label.lb.algorithm.roundrobin')">{{ $t('label.lb.algorithm.roundrobin') }}</a-select-option>
-            <a-select-option value="leastconn" :label="$t('label.lb.algorithm.leastconn')">{{ $t('label.lb.algorithm.leastconn') }}</a-select-option>
-            <a-select-option value="source" :label="$t('label.lb.algorithm.source')">{{ $t('label.lb.algorithm.source') }}</a-select-option>
+            <a-select-option v-for="algo in supportedAlgorithms" :key="algo" :value="algo" :label="$t('label.lb.algorithm.' + algo)">{{ $t('label.lb.algorithm.' + algo) }}</a-select-option>
           </a-select>
         </div>
         <div class="form__item">
@@ -436,9 +434,7 @@
             :filterOption="(input, option) => {
               return option.label.toLowerCase().indexOf(input.toLowerCase()) >= 0
             }" >
-            <a-select-option value="roundrobin" :label="$t('label.lb.algorithm.roundrobin')">{{ $t('label.lb.algorithm.roundrobin') }}</a-select-option>
-            <a-select-option value="leastconn" :label="$t('label.lb.algorithm.leastconn')">{{ $t('label.lb.algorithm.leastconn') }}</a-select-option>
-            <a-select-option value="source" :label="$t('label.lb.algorithm.source')">{{ $t('label.lb.algorithm.source') }}</a-select-option>
+            <a-select-option v-for="algo in supportedAlgorithms" :key="algo" :value="algo" :label="$t('label.lb.algorithm.' + algo)">{{ $t('label.lb.algorithm.' + algo) }}</a-select-option>
           </a-select>
         </div>
         <div v-if="lbProvider !== 'Netris'" class="edit-rule__item">
@@ -872,6 +868,10 @@ export default {
         cidrlist: ''
       },
       lbProvider: null,
+      // Populated from the network's offering capabilities (service Lb,
+      // SupportedLBAlgorithms). Defaults to the union we historically hard-coded so
+      // legacy networks/offerings without an explicit cap keep working.
+      supportedAlgorithms: ['roundrobin', 'leastconn', 'source'],
       addVmModalVisible: false,
       addVmModalLoading: false,
       addVmModalNicLoading: false,
@@ -1089,6 +1089,48 @@ export default {
       this.fetchListTiers()
       this.fetchLBRules()
       this.fetchZone()
+      this.fetchLbCapabilities()
+    },
+    /**
+     * Loads the SupportedLbAlgorithms capability from the network's Lb service.
+     * The capability lives at network.service[name=Lb].capability[name=SupportedLbAlgorithms]
+     * with a CSV value like "roundrobin,source". Falls back to the legacy
+     * static list when the lookup fails so providers that don't declare it
+     * keep their pre-existing behaviour.
+     *
+     * Note: listNetworks is the right endpoint here (not listNetworkOfferings):
+     * the offering response hard-codes only SupportedLBIsolation/ElasticLb/
+     * InlineMode/VmAutoScaling for the Lb service, while the network response
+     * walks the live provider's getCapabilities() and exposes everything we
+     * declared. The capability name on the wire is "SupportedLbAlgorithms"
+     * (note the lowercase 'b' in 'Lb') - that's how Capability.SupportedLBAlgorithms.getName()
+     * serialises.
+     */
+    fetchLbCapabilities () {
+      const networkId = this.resource?.associatednetworkid || this.resource?.networkid
+      if (!networkId) {
+        return
+      }
+      getAPI('listNetworks', { id: networkId, listall: true }).then(json => {
+        const network = json?.listnetworksresponse?.network?.[0]
+        const lbService = network?.service?.find(s => s.name === 'Lb')
+        const algoCap = lbService?.capability?.find(c => c.name === 'SupportedLbAlgorithms')
+        if (algoCap && algoCap.value) {
+          const algos = algoCap.value.split(',').map(s => s.trim()).filter(s => s)
+          if (algos.length > 0) {
+            this.supportedAlgorithms = algos
+            // If the default algorithm is not in the supported set, switch to the
+            // first one so the dropdown shows a valid selection from the start.
+            if (!algos.includes(this.newRule.algorithm)) {
+              this.newRule.algorithm = algos[0]
+            }
+          }
+        }
+      }).catch(error => {
+        // Swallow - we just keep the default list. Don't pop a notification
+        // because this is non-fatal background data.
+        console.warn('Failed to load LB algorithm capabilities; using defaults', error)
+      })
     },
     fetchVpc () {
       if (!this.resource.vpcid) {