Merge pull request #17555 from agocke/new-gh-merge-tool

Add a new Azure Function-based merge tool

src/Tools/Github/GithubMergeTool.sln

+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26206.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GithubMergeTool", "GithubMergeTool\GithubMergeTool.csproj", "{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}"
+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(ProjectConfigurationPlatforms) = postSolution
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|x64.ActiveCfg = Debug|x64
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|x64.Build.0 = Debug|x64
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|x86.ActiveCfg = Debug|x86
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Debug|x86.Build.0 = Debug|x86
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|x64.ActiveCfg = Release|x64
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|x64.Build.0 = Release|x64
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|x86.ActiveCfg = Release|x86
+		{EE2E9B45-BCB6-4CFB-A8CD-93B9F3535F86}.Release|x86.Build.0 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

src/Tools/Github/GithubMergeTool/GithubMergeTool.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Text;
+using System.Threading.Tasks;
+using Newtonsoft.Json.Linq;
+
+namespace GithubMergeTool
+{
+    public class GithubMergeTool
+    {
+        private static readonly Uri GithubBaseUri = new Uri("https://api.github.com/");
+
+        private readonly HttpClient _client;
+
+        public GithubMergeTool(
+            string username,
+            string password)
+        {
+            var client = new HttpClient();
+            client.BaseAddress = GithubBaseUri;
+
+            var authArray = Encoding.ASCII.GetBytes($"{username}:{password}");
+            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
+                "Basic",
+                Convert.ToBase64String(authArray));
+            client.DefaultRequestHeaders.Add(
+                "user-agent",
+                "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2;)");
+
+            _client = client;
+        }
+
+        /// <summary>
+        /// Create a merge PR.
+        /// </summary>
+        /// <returns>
+        /// null if the merge PR was completed without error. Otherwise,
+        /// the response which had an error is returned. Note that a response
+        /// with an <see cref="HttpStatusCode" /> value 422 is returned if a PR
+        /// cannot be created because the <paramref name="srcBranch"/> creates
+        /// all the commits in the <paramref name="destBranch"/>.
+        /// </returns>
+        public async Task<HttpResponseMessage> CreateMergePr(
+            string repoOwner,
+            string repoName,
+            string srcBranch,
+            string destBranch)
+        {
+            // Get the SHA for the source branch
+            var response = await _client.GetAsync($"repos/{repoOwner}/{repoName}/git/refs/heads/{srcBranch}");
+
+            if (response.StatusCode != HttpStatusCode.OK)
+            {
+                return response;
+            }
+
+            var jsonBody = JObject.Parse(await response.Content.ReadAsStringAsync());
+
+            if (jsonBody.Type == JTokenType.Array)
+            {
+                // Branch doesn't exist
+                return response;
+            }
+
+            var srcSha = ((JValue)jsonBody["object"]["sha"]).ToObject<string>();
+
+            // Generate a new branch name for the merge branch
+            var prBranchName = $"merges/{srcBranch}-to-{destBranch}-{DateTime.UtcNow.ToString("yyyMMdd-HHmmss")}";
+
+            // Create a branch on the repo
+            var body = $@"
+{{
+    ""ref"": ""refs/heads/{prBranchName}"",
+    ""sha"": ""{srcSha}""
+}}";
+
+            response = await _client.PostAsyncAsJson($"repos/{repoOwner}/{repoName}/git/refs", body);
+
+            if (response.StatusCode != HttpStatusCode.Created)
+            {
+                return response;
+            }
+
+            const string newLine = @"
+";
+
+            var prMessage = $@"
+This is an automatically generated pull request from {srcBranch} into {destBranch}.
+
+``` bash
+git fetch --all
+git checkout {prBranchName}
+git reset --hard upstream/{destBranch}
+git merge upstream/{srcBranch}
+# Fix merge conflicts
+git commit
+git push {prBranchName} --force
+```
+
+Once all conflicts are resolved and all the tests pass, you are free to merge the pull request.";
+
+            prMessage = prMessage.Replace(newLine, "\\n");
+
+            // Create a PR from the new branch to the dest
+            body = $@"
+{{
+    ""title"": ""Merge {srcBranch} to {destBranch}"",
+    ""body"": ""{prMessage}"",
+    ""head"": ""{prBranchName}"",
+    ""base"": ""{destBranch}""
+}}";
+
+            response = await _client.PostAsyncAsJson($"repos/{repoOwner}/{repoName}/pulls", body);
+
+            jsonBody = JObject.Parse(await response.Content.ReadAsStringAsync());
+
+            // 422 (Unprocessable Entity) indicates there were no commits to merge
+            if (response.StatusCode == (HttpStatusCode)422)
+            {
+                return response;
+            }
+
+            return null;
+        }
+    }
+}

src/Tools/Github/GithubMergeTool/GithubMergeTool.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net46</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="System.Net.Http" />
+  </ItemGroup>
+
+</Project>

src/Tools/Github/GithubMergeTool/HttpClientExtensions.cs

+using System.Net.Http;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace GithubMergeTool
+{
+    internal static class HttpClientExtensions
+    {
+        public static Task<HttpResponseMessage> PostAsyncAsJson(this HttpClient client, string requestUri, string body)
+            => client.PostAsync(requestUri, new StringContent(body, Encoding.UTF8, "application/json"));
+    }
+}

src/Tools/Github/GithubMergeTool/Properties/launchSettings.json

+{
+  "profiles": {
+    "GithubMergeTool": {
+      "commandName": "Executable",
+      "executablePath": "C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Enterprise\\MSBuild\\15.0\\Bin\\Roslyn\\csi.exe",
+      "commandLineArgs": "MakeMergePRs.csx",
+      "workingDirectory": "bin/Debug/net46"
+    }
+  }
+}
\ No newline at end of file

src/Tools/Github/GithubMergeTool/auth.csx

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+#r "System.Web"
+
+using Microsoft.Azure.KeyVault;
+using Microsoft.IdentityModel.Clients.ActiveDirectory;
+using System.Web.Configuration;
+using static System.Environment;
+
+private const string KeyVaultUrl = "https://roslyninfra.vault.azure.net:443";
+
+public static async Task<string> GetSecret(string secretName)
+{
+    var kv = new KeyVaultClient(new KeyVaultClient.AuthenticationCallback(GetAccessToken));
+    var secret = await kv.GetSecretAsync(KeyVaultUrl, secretName);
+    return secret.Value;
+}
+
+private static async Task<string> GetAccessToken(string authority, string resource, string scope)
+{
+    var ctx = new AuthenticationContext(authority);
+    var clientId = WebConfigurationManager.AppSettings["ClientId"];
+    var clientSecret = WebConfigurationManager.AppSettings["ClientSecret"];
+    var clientCred = new ClientCredential(clientId, clientSecret);
+
+    var authResult = await ctx.AcquireTokenAsync(resource, clientCred);
+    return authResult.AccessToken;
+}
\ No newline at end of file

src/Tools/Github/GithubMergeTool/run.csx

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+#r "GithubMergeTool.dll"
+
+#load "auth.csx"
+
+using System;
+using System.Net;
+using System.Threading.Tasks;
+
+private static string VslsnapGithubAuthToken = null;
+
+private static TraceWriter Log = null;
+
+private static async Task MakeGithubPr(string repoOwner, string repoName, string srcBranch, string destBranch)
+{    
+    var gh = new GithubMergeTool.GithubMergeTool("vslsnap@users.noreply.github.com", VslsnapGithubAuthToken);
+
+    Log.Info($"Merging from {srcBranch} to {destBranch}");
+
+    var result = await gh.CreateMergePr(repoOwner, repoName, srcBranch, destBranch);
+
+    if (result != null)
+    {
+        if (result.StatusCode == (HttpStatusCode)422)
+        {
+            Log.Info("PR not created -- all commits are present in base branch");
+        }
+        else
+        {
+            Log.Error($"Error creating PR. GH response code: {result.StatusCode}");
+        }
+    }
+    else
+    {
+        Log.Info("PR created successfully");
+    }
+}
+
+private static Task MakeRoslynPr(string srcBranch, string destBranch)
+    => MakeGithubPr("dotnet", "roslyn", srcBranch, destBranch);
+
+private static async Task RunAsync()
+{
+    VslsnapGithubAuthToken = await GetSecret("vslsnap-github-auth-token");
+
+    // Roslyn branches
+    await MakeRoslynPr("dev15.0.x", "dev15.1.x");
+    await MakeRoslynPr("dev15.1.x", "master");
+    await MakeRoslynPr("master", "dev16");
+}
+
+public static void Run(TimerInfo myTimer, TraceWriter log)
+{
+    Log = log;
+
+    log.Info($"C# Timer trigger function executed at: {DateTime.Now}");
+
+    RunAsync().GetAwaiter().GetResult();
+}