Support replacement tokens in environment variables #377

src/Microsoft.Tye.Hosting/Model/Application.cs

@@ -50,9 +50,10 @@ public void PopulateEnvironment(Service service, Action<string, string> set, str
                 // Inject normal configuration
                 foreach (var pair in service.Description.Configuration)
                 {
+
                     if (pair.Value is object)
                     {
-                        set(pair.Name, pair.Value);
+                        set(pair.Name, TokenReplacement.ReplaceEnvironmentValues(pair.Value, bindings));
                     }
                     else if (pair.Source is object)
                     {

src/Microsoft.Tye.Hosting/TokenReplacement.cs

@@ -12,6 +12,31 @@ namespace Microsoft.Tye.Hosting
 {
     internal static class TokenReplacement
     {
+        public static string ReplaceEnvironmentValues(string text, List<EffectiveBinding> bindings)
+        {
+            var tokens = GetTokens(text);
+            foreach (var token in tokens)
+            {
+                var selectedBinding = ResolveEnvironmentToken(token, bindings);
+                if (selectedBinding is null)
+                {
+                    throw new InvalidOperationException($"No available substitutions found for token '{token}'.");
+                }
+
+                if (selectedBinding.Value.text == null) continue;
+                text = selectedBinding.Value.text;
+
+                var selectedBindingtokens = GetTokens(selectedBinding.Value.text);
+                foreach (var bindingtoken in selectedBindingtokens)
+                {
+                    var replacement = ReplaceValues(bindingtoken, selectedBinding.Value.binding, bindings);
+                    text = text.Replace(bindingtoken, replacement);
+                }
+
+            }
+            return text;
+        }
+
         public static string ReplaceValues(string text, EffectiveBinding binding, List<EffectiveBinding> bindings)
         {
             var tokens = GetTokens(text);
@@ -58,6 +83,41 @@ private static HashSet<string> GetTokens(string text)
 
             return tokens;
         }
+
+        private static (EffectiveBinding binding, string? text)? ResolveEnvironmentToken(string token, List<EffectiveBinding> bindings)
+        {
+            // The language we support for tokens is meant to be pretty DRY. It supports a few different formats:
+            //
+            // - ${host}: only allowed inside a connection string, it can refer to the binding.
+            // - ${env:SOME_VAR}: allowed anywhere. It can refer to any environment variable defined for *this* service.
+            // - ${service:myservice:port}: allowed anywhere. It can refer to the protocol/host/port of bindings.
+
+            var keys = token[2..^1].Split(':');
+            if (keys.Length == 3 && keys[0] == "service")
+            {
+                var binding = bindings.FirstOrDefault(b => b.Service == keys[1] && b.Name == null)!;
+                return (binding, GetValueFromBinding(binding, keys[2]));
+            }
+            else if (keys.Length == 4 && keys[0] == "service")
+            {
+                var binding  = bindings.FirstOrDefault(b => b.Service == keys[1] && b.Name == keys[2])!;
+                return (binding, GetValueFromBinding(binding, keys[3]));
+            }
+
+            return null;
+
+            string? GetValueFromBinding(EffectiveBinding binding, string key)
+            {
+                return key switch
+                {
+                    "protocol" => binding.Protocol,
+                    "host" => binding.Host,
+                    "port" => binding.Port?.ToString(CultureInfo.InvariantCulture),
+                    "connectionString" => binding.ConnectionString,
+                    _ => null,
+                };
+            }
+        }
 
         private static string? ResolveToken(string token, EffectiveBinding binding, List<EffectiveBinding> bindings)
         {

test/E2ETest/TyeRunTests.cs

@@ -1345,6 +1345,41 @@ public async Task RunWithDotnetEnvVarsDoesNotGetOverriddenByDefaultDotnetEnvVars
             });
         }
 
+        [ConditionalFact]
+        [SkipIfDockerNotRunning]
+        public async Task RunWithDotnetEnvVarsSelectorForAnotherServiceReplacement()
+        {
+            using var projectDirectory = CopyTestProjectDirectory("environment-variable-replacement");
+
+            var projectFile = new FileInfo(Path.Combine(projectDirectory.DirectoryPath, "tye.yaml"));
+            var outputContext = new OutputContext(_sink, Verbosity.Debug);
+            var application = await ApplicationFactory.CreateAsync(outputContext, projectFile);
+
+            var handler = new HttpClientHandler
+            {
+                ServerCertificateCustomValidationCallback = (a, b, c, d) => true,
+                AllowAutoRedirect = false
+            };
+
+            var client = new HttpClient(new RetryHandler(handler));
+
+            await RunHostingApplication(application, new HostOptions { Docker = true }, async (app, uri) =>
+            {
+                var backendUri = await GetServiceUrl(client, uri, "test-project");
+
+                var backendResponse = await client.GetAsync(backendUri);
+                Assert.True(backendResponse.IsSuccessStatusCode);
+
+                var response = await backendResponse.Content.ReadAsStringAsync();
+                var dict = JsonSerializer.Deserialize<Dictionary<string, string>>(response);
+
+                Assert.Contains(new KeyValuePair<string, string>("REDIS_CONNECTIONSTRING", "host.docker.internal:6379:mysupersecureP@ssword"), dict);
+                Assert.Contains(new KeyValuePair<string, string>("DOTNET_ENVIRONMENT", "dev"), dict);
+                Assert.Contains(new KeyValuePair<string, string>("ASPNETCORE_ENVIRONMENT", "dev"), dict);
+            });
+        }
+
+
         private async Task<string> GetServiceUrl(HttpClient client, Uri uri, string serviceName)
         {
             var serviceResult = await client.GetStringAsync($"{uri}api/v1/services/{serviceName}");

test/E2ETest/testassets/projects/environment-variable-replacement/single-project.sln

@@ -0,0 +1,34 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26124.0
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "test-project", "test-project\test-project.csproj", "{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|x64.Build.0 = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Debug|x86.Build.0 = Debug|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|x64.ActiveCfg = Release|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|x64.Build.0 = Release|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|x86.ActiveCfg = Release|Any CPU
+		{7D3606B2-7B8E-4ABB-BE0A-E0B18285D8F5}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

test/E2ETest/testassets/projects/environment-variable-replacement/test-project/Program.cs

@@ -0,0 +1,30 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace test_project
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            CreateHostBuilder(args).Build().Run();
+        }
+
+        public static IHostBuilder CreateHostBuilder(string[] args) =>
+            Host.CreateDefaultBuilder(args)
+                .ConfigureWebHostDefaults(webBuilder =>
+                {
+                    webBuilder.UseStartup<Startup>();
+                });
+    }
+}

test/E2ETest/testassets/projects/environment-variable-replacement/test-project/Properties/launchSettings.json

@@ -0,0 +1,27 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false, 
+    "anonymousAuthentication": true, 
+    "iisExpress": {
+      "applicationUrl": "http://localhost:18482",
+      "sslPort": 44344
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "test_project": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:5001;http://localhost:5000",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

test/E2ETest/testassets/projects/environment-variable-replacement/test-project/Startup.cs

@@ -0,0 +1,47 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace test_project
+{
+    public class Startup
+    {
+        // This method gets called by the runtime. Use this method to add services to the container.
+        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
+        public void ConfigureServices(IServiceCollection services)
+        {
+        }
+
+        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            app.UseRouting();
+
+            app.UseEndpoints(endpoints =>
+            {
+                endpoints.MapGet("/",
+                    () => Results.Json(new Dictionary<string, string>
+                    {
+                        { "DOTNET_ENVIRONMENT", Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT") },
+                        { "ASPNETCORE_ENVIRONMENT", Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") },
+                        { "REDIS_CONNECTIONSTRING", Environment.GetEnvironmentVariable("REDIS_CONNECTIONSTRING") }
+                    }));
+            });
+        }
+    }
+}

test/E2ETest/testassets/projects/environment-variable-replacement/test-project/test-project.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <RootNamespace>test_project</RootNamespace>
+  </PropertyGroup>
+
+</Project>

test/E2ETest/testassets/projects/environment-variable-replacement/tye.yaml

@@ -0,0 +1,23 @@
+# tye application configuration file
+# read all about it at https://github.com/dotnet/tye
+name: dotnet-env-replacement
+dashboardPort: 8090
+services:
+- name: test-project
+  project: test-project/test-project.csproj
+  env:
+    - name: DOTNET_ENVIRONMENT
+      value: "dev"
+    - name: ASPNETCORE_ENVIRONMENT
+      value: "dev"
+    - name: REDIS_CONNECTIONSTRING
+      value: "${service:redis:connectionString}"
+- name: redis
+  image: alpine # just need a tiny image to make the test run faster
+  env:
+    - name: RANDOMPASSWORD
+      value: "pass@word1"
+  bindings:
+    - port: 6379
+      connectionString: ${host}:${port}:${env:RANDOMPASSWORD} #I know not a real password, but I just want to prove the replacement
+