fix: Enable session affinity to handle load accross multiple replicas

Author: Avijit-Microsoft

infra/avm/main.bicep

@@ -1236,6 +1236,7 @@ module containerApp './modules/compute/container-app.bicep' = {
 module containerAppMcp './modules/compute/container-app.bicep' = {
   name: take('module.container-app-mcp.${solutionName}', 64)
   params: {
+    stickySessionsAffinity : enableScalability? 'sticky': 'none'
     name: 'ca-mcp-${solutionSuffix}'
     location: location
     tags: tags

infra/avm/main.json

@@ -6,7 +6,7 @@
     "_generator": {
       "name": "bicep",
       "version": "0.44.1.10279",
-      "templateHash": "8714866940320286579"
+      "templateHash": "2099326972124864634"
     },
     "name": "Multi-Agent Custom Automation Engine - AVM",
     "description": "AVM orchestrator for the Multi-Agent Custom Automation Engine accelerator. Deploys the same logical resources and preserves the same outputs as infra\\main.bicep using local AVM wrapper modules."
@@ -51004,7 +51004,7 @@
             "_generator": {
               "name": "bicep",
               "version": "0.44.1.10279",
-              "templateHash": "9906697545075116207"
+              "templateHash": "10535819316717631477"
             }
           },
           "parameters": {
@@ -51142,6 +51142,17 @@
               "metadata": {
                 "description": "Enable Azure telemetry collection."
               }
+            },
+            "stickySessionsAffinity": {
+              "type": "string",
+              "defaultValue": "none",
+              "allowedValues": [
+                "none",
+                "sticky"
+              ],
+              "metadata": {
+                "description": "Optional. Bool indicating if the Container App should enable session affinity."
+              }
             }
           },
           "resources": {
@@ -51202,6 +51213,9 @@
                   },
                   "workloadProfileName": {
                     "value": "[parameters('workloadProfileName')]"
+                  },
+                  "stickySessionsAffinity": {
+                    "value": "[parameters('stickySessionsAffinity')]"
                   }
                 },
                 "template": {
@@ -52788,6 +52802,7 @@
         },
         "mode": "Incremental",
         "parameters": {
+          "stickySessionsAffinity": "[if(parameters('enableScalability'), createObject('value', 'sticky'), createObject('value', 'none'))]",
           "name": {
             "value": "[format('ca-mcp-{0}', variables('solutionSuffix'))]"
           },
@@ -52920,7 +52935,7 @@
             "_generator": {
               "name": "bicep",
               "version": "0.44.1.10279",
-              "templateHash": "9906697545075116207"
+              "templateHash": "10535819316717631477"
             }
           },
           "parameters": {
@@ -53058,6 +53073,17 @@
               "metadata": {
                 "description": "Enable Azure telemetry collection."
               }
+            },
+            "stickySessionsAffinity": {
+              "type": "string",
+              "defaultValue": "none",
+              "allowedValues": [
+                "none",
+                "sticky"
+              ],
+              "metadata": {
+                "description": "Optional. Bool indicating if the Container App should enable session affinity."
+              }
             }
           },
           "resources": {
@@ -53118,6 +53144,9 @@
                   },
                   "workloadProfileName": {
                     "value": "[parameters('workloadProfileName')]"
+                  },
+                  "stickySessionsAffinity": {
+                    "value": "[parameters('stickySessionsAffinity')]"
                   }
                 },
                 "template": {

infra/avm/modules/compute/container-app.bicep

@@ -62,6 +62,13 @@ param workloadProfileName string?
 @description('Enable Azure telemetry collection.')
 param enableTelemetry bool = true
 
+@allowed([
+  'none'
+  'sticky'
+])
+@description('Optional. Bool indicating if the Container App should enable session affinity.')
+param stickySessionsAffinity string = 'none'
+
 // ============================================================================
 // Container App (AVM)
 // ============================================================================
@@ -86,6 +93,7 @@ module containerApp 'br/public:avm/res/app/container-app:0.22.1' = {
     activeRevisionsMode: activeRevisionsMode
     scaleSettings: scaleSettings
     workloadProfileName: workloadProfileName
+    stickySessionsAffinity: stickySessionsAffinity
   }
 }