Update log streaming to support both connection string and Instrumentation Key

release_notes.md

@@ -14,3 +14,4 @@
 - Update `func init` to default to the .NET 8 template for in-proc apps (#4557)
 - Implement (2 second) graceful timeout period for the CLI shutdown (#4540)
 - Overwrite `AZURE_FUNCTIONS_ENVIRONMENT` to `Development` if it is already set (#4563)
+- Update log streaming to support both connection string and instrumentation Key (#4586)

src/Cli/func/Actions/AzureActions/LogStreamAction.cs

@@ -17,6 +17,7 @@ namespace Azure.Functions.Cli.Actions.AzureActions
     internal class LogStreamAction : BaseFunctionAppAction
     {
         private const string ApplicationInsightsIKeySetting = "APPINSIGHTS_INSTRUMENTATIONKEY";
+        private const string ApplicationInsightsConnectionString = "APPLICATIONINSIGHTS_CONNECTION_STRING";
         private const string LiveMetricsUriTemplate = "https://portal.azure.com/#blade/AppInsightsExtension/QuickPulseBladeV2/ComponentId/{0}/ResourceId/{1}";
 
         public bool UseBrowser { get; set; }
@@ -44,9 +45,9 @@ public override async Task RunAsync()
                 return;
             }
 
-            if (functionApp.IsLinux && functionApp.IsDynamic)
+            if (functionApp.IsFlex || (functionApp.IsLinux && functionApp.IsDynamic))
             {
-                throw new CliException("Log stream is not currently supported in Linux Consumption Apps. " +
+                throw new CliException("Log stream is not currently supported in Linux Consumption and Flex Apps. " +
                     "Please use --browser to open Azure Application Insights Live Stream in the Azure portal.");
             }
 
@@ -92,14 +93,24 @@ public override async Task RunAsync()
 
         public async Task OpenLiveStreamInBrowser(Site functionApp, IEnumerable<ArmSubscription> allSubscriptions)
         {
-            if (!functionApp.AzureAppSettings.ContainsKey(ApplicationInsightsIKeySetting))
+            string iKey;
+
+            // First, check for a connection string. If it's not available, default to using the Instrumentation Key.
+            if (functionApp.AzureAppSettings.TryGetValue(ApplicationInsightsConnectionString, out var connectionString))
+            {
+                iKey = Utilities.ExtractIKeyFromConnectionString(connectionString);
+            }
+            else if (functionApp.AzureAppSettings.TryGetValue(ApplicationInsightsIKeySetting, out var instrumentationKey))
+            {
+                iKey = instrumentationKey;
+            }
+            else
             {
-                throw new CliException($"Missing {ApplicationInsightsIKeySetting} App Setting. " +
+                throw new CliException($"Missing {ApplicationInsightsConnectionString} App Setting. " +
                     $"Please make sure you have Application Insights configured with your function app.");
             }
 
-            var iKey = functionApp.AzureAppSettings[ApplicationInsightsIKeySetting];
-            if (string.IsNullOrEmpty(iKey))
+            if (string.IsNullOrWhiteSpace(iKey))
             {
                 throw new CliException("Invalid Instrumentation Key found. Please make sure that the Application Insights is configured correctly.");
             }

src/Cli/func/Common/Utilities.cs

@@ -293,5 +293,46 @@ internal static bool IsMinifiedVersion()
 
             return false;
         }
+
+        internal static string ExtractIKeyFromConnectionString(string connectionString)
+        {
+            if (string.IsNullOrEmpty(connectionString))
+            {
+                return null;
+            }
+
+            var span = connectionString.AsSpan();
+            var start = 0;
+
+            while (start < span.Length)
+            {
+                var semicolonIndex = span.Slice(start).IndexOf(';');
+                var length = semicolonIndex == -1 ? span.Length - start : semicolonIndex;
+                var segment = span.Slice(start, length).Trim();
+
+                start += length + (semicolonIndex == -1 ? 0 : 1);
+
+                if (segment.IsEmpty)
+                {
+                    continue;
+                }
+
+                int equalsIndex = segment.IndexOf('=');
+                if (equalsIndex <= 0 || equalsIndex >= segment.Length - 1)
+                {
+                    continue;
+                }
+
+                var key = segment.Slice(0, equalsIndex).Trim();
+                var value = segment.Slice(equalsIndex + 1).Trim();
+
+                if (key.Equals("InstrumentationKey", StringComparison.OrdinalIgnoreCase))
+                {
+                    return value.ToString();
+                }
+            }
+
+            return null;
+        }
     }
 }

test/Cli/Func.UnitTests/HelperTests/UtilitiesTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See LICENSE in the project root for license information.
 
 using Microsoft.Azure.WebJobs.Script.Configuration;
@@ -77,5 +77,25 @@ public void Test_IsMinifiedVersion(bool expected)
             File.Delete(filePath);
             Assert.Equal(expected, output);
         }
+
+        [Theory]
+        [InlineData(null, null)]
+        [InlineData("", null)]
+        [InlineData(";", null)]
+        [InlineData("InstrumentationKey=abc123;", "abc123")]
+        [InlineData("InstrumentationKey=abc123;IngestionEndpoint=https://...", "abc123")]
+        [InlineData("  InstrumentationKey  =   abc123    ;", "abc123")]
+        [InlineData("InstrumentationKey=abc123;OtherKey=xyz", "abc123")]
+        [InlineData("otherKey=xyz;InstrumentationKey=abc123;", "abc123")]
+        [InlineData("InstrumentationKey=ABC123", "ABC123")]
+        [InlineData("instrumentationkey=abc123", "abc123")]
+        [InlineData("InstrumentationKey= ;", null)]
+        [InlineData("SomeKey=SomeValue;AnotherKey=AnotherValue", null)]
+        public void ExtractIKeyFromConnectionString_ReturnsExpectedInstrumentationKey(string connectionString, string expected)
+        {
+            var actual = Utilities.ExtractIKeyFromConnectionString(connectionString);
+
+            Assert.Equal(expected, actual);
+        }
     }
 }