Adding --check to run a serials network test against GitHub or GHES. (#900)

* add --check.

src/Runner.Listener/Checks/ActionsCheck.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public sealed class ActionsCheck : RunnerService, ICheckExtension
+    {
+        private string _logFile = null;
+
+        public int Order => 2;
+
+        public string CheckName => "GitHub Actions Connection";
+
+        public string CheckDescription => "Make sure the actions runner have access to the GitHub Actions Service.";
+
+        public string CheckLog => _logFile;
+
+        public string HelpLink => "https://github.com/actions/runner/blob/main/docs/checks/actions.md";
+
+        public Type ExtensionType => typeof(ICheckExtension);
+
+        public override void Initialize(IHostContext hostContext)
+        {
+            base.Initialize(hostContext);
+            _logFile = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Diag), StringUtil.Format("{0}_{1:yyyyMMdd-HHmmss}-utc.log", nameof(ActionsCheck), DateTime.UtcNow));
+        }
+
+        // runner access to actions service
+        public async Task<bool> RunCheck(string url, string pat)
+        {
+            await File.AppendAllLinesAsync(_logFile, HostContext.WarnLog());
+            await File.AppendAllLinesAsync(_logFile, HostContext.CheckProxy());
+
+            var checkTasks = new List<Task<CheckResult>>();
+            string githubApiUrl = null;
+            string actionsTokenServiceUrl = null;
+            string actionsPipelinesServiceUrl = null;
+            var urlBuilder = new UriBuilder(url);
+            if (UrlUtil.IsHostedServer(urlBuilder))
+            {
+                urlBuilder.Host = $"api.{urlBuilder.Host}";
+                urlBuilder.Path = "";
+                githubApiUrl = urlBuilder.Uri.AbsoluteUri;
+                actionsTokenServiceUrl = "https://vstoken.actions.githubusercontent.com/_apis/health";
+                actionsPipelinesServiceUrl = "https://pipelines.actions.githubusercontent.com/_apis/health";
+            }
+            else
+            {
+                urlBuilder.Path = "api/v3";
+                githubApiUrl = urlBuilder.Uri.AbsoluteUri;
+                urlBuilder.Path = "_services/vstoken/_apis/health";
+                actionsTokenServiceUrl = urlBuilder.Uri.AbsoluteUri;
+                urlBuilder.Path = "_services/pipelines/_apis/health";
+                actionsPipelinesServiceUrl = urlBuilder.Uri.AbsoluteUri;
+            }
+
+            // check github api
+            checkTasks.Add(CheckUtil.CheckDns(githubApiUrl));
+            checkTasks.Add(CheckUtil.CheckPing(githubApiUrl));
+            checkTasks.Add(HostContext.CheckHttpsRequests(githubApiUrl, pat, expectedHeader: "X-GitHub-Request-Id"));
+
+            // check actions token service
+            checkTasks.Add(CheckUtil.CheckDns(actionsTokenServiceUrl));
+            checkTasks.Add(CheckUtil.CheckPing(actionsTokenServiceUrl));
+            checkTasks.Add(HostContext.CheckHttpsRequests(actionsTokenServiceUrl, pat, expectedHeader: "x-vss-e2eid"));
+
+            // check actions pipelines service
+            checkTasks.Add(CheckUtil.CheckDns(actionsPipelinesServiceUrl));
+            checkTasks.Add(CheckUtil.CheckPing(actionsPipelinesServiceUrl));
+            checkTasks.Add(HostContext.CheckHttpsRequests(actionsPipelinesServiceUrl, pat, expectedHeader: "x-vss-e2eid"));
+
+            var result = true;
+            while (checkTasks.Count > 0)
+            {
+                var finishedCheckTask = await Task.WhenAny<CheckResult>(checkTasks);
+                var finishedCheck = await finishedCheckTask;
+                result = result && finishedCheck.Pass;
+                await File.AppendAllLinesAsync(_logFile, finishedCheck.Logs);
+                checkTasks.Remove(finishedCheckTask);
+            }
+
+            await Task.WhenAll(checkTasks);
+            return result;
+        }
+    }
+}

src/Runner.Listener/Checks/CheckUtil.cs

@@ -0,0 +1,351 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Tracing;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Net.NetworkInformation;
+using System.Threading;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+using GitHub.Services.Common;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public static class CheckUtil
+    {
+        public static List<string> WarnLog(this IHostContext hostContext)
+        {
+            var logs = new List<string>();
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ****     !!! WARNING !!! ");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ****     DO NOT share the log in public place! The log may contains secrets in plain text. ");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ****     !!! WARNING !!! ");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+            logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            return logs;
+        }
+
+        public static List<string> CheckProxy(this IHostContext hostContext)
+        {
+            var logs = new List<string>();
+            if (!string.IsNullOrEmpty(hostContext.WebProxy.HttpProxyAddress) ||
+                !string.IsNullOrEmpty(hostContext.WebProxy.HttpsProxyAddress))
+            {
+                logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Runner is behind web proxy {hostContext.WebProxy.HttpsProxyAddress ?? hostContext.WebProxy.HttpProxyAddress} ");
+                logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return logs;
+        }
+
+        public static async Task<CheckResult> CheckDns(string targetUrl)
+        {
+            var result = new CheckResult();
+            var url = new Uri(targetUrl);
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Try DNS lookup for {url.Host} ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                IPHostEntry host = await Dns.GetHostEntryAsync(url.Host);
+                foreach (var address in host.AddressList)
+                {
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Resolved DNS for {url.Host} to '{address}'");
+                }
+
+                result.Pass = true;
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Resolved DNS for {url.Host} failed with error: {ex}");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return result;
+        }
+
+        public static async Task<CheckResult> CheckPing(string targetUrl)
+        {
+            var result = new CheckResult();
+            var url = new Uri(targetUrl);
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Try ping {url.Host} ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                using (var ping = new Ping())
+                {
+                    var reply = await ping.SendPingAsync(url.Host);
+                    if (reply.Status == IPStatus.Success)
+                    {
+                        result.Pass = true;
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Ping {url.Host} ({reply.Address}) succeed within to '{reply.RoundtripTime} ms'");
+                    }
+                    else
+                    {
+                        result.Pass = false;
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Ping {url.Host} ({reply.Address}) failed with '{reply.Status}'");
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Ping api.github.com failed with error: {ex}");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return result;
+        }
+
+        public static async Task<CheckResult> CheckHttpsRequests(this IHostContext hostContext, string url, string pat, string expectedHeader)
+        {
+            var result = new CheckResult();
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Send HTTPS Request to {url} ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                using (var _ = new HttpEventSourceListener(result.Logs))
+                using (var httpClientHandler = hostContext.CreateHttpClientHandler())
+                using (var httpClient = new HttpClient(httpClientHandler))
+                {
+                    httpClient.DefaultRequestHeaders.UserAgent.AddRange(hostContext.UserAgents);
+                    if (!string.IsNullOrEmpty(pat))
+                    {
+                        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("token", pat);
+                    }
+
+                    var response = await httpClient.GetAsync(url);
+
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http status code: {response.StatusCode}");
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http response headers: {response.Headers}");
+
+                    var responseContent = await response.Content.ReadAsStringAsync();
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http response body: {responseContent}");
+                    if (response.IsSuccessStatusCode)
+                    {
+                        if (response.Headers.Contains(expectedHeader))
+                        {
+                            result.Pass = true;
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http request 'GET' to {url} succeed");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                        }
+                        else
+                        {
+                            result.Pass = false;
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http request 'GET' to {url} succeed but doesn't have expected HTTP Header.");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                        }
+                    }
+                    else
+                    {
+                        result.Pass = false;
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Http request 'GET' to {url} failed with {response.StatusCode}");
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                        result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ");
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Https request 'GET' to {url} failed with error: {ex}");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return result;
+        }
+
+        public static async Task<CheckResult> DownloadExtraCA(this IHostContext hostContext, string url, string pat)
+        {
+            var result = new CheckResult();
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Download SSL Certificate from {url} ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+
+                var uri = new Uri(url);
+                var env = new Dictionary<string, string>()
+                {
+                    { "HOSTNAME", uri.Host },
+                    { "PORT", uri.IsDefaultPort ? (uri.Scheme.ToLowerInvariant() == "https" ? "443" : "80") : uri.Port.ToString() },
+                    { "PATH", uri.AbsolutePath },
+                    { "PAT", pat }
+                };
+
+                var proxy = hostContext.WebProxy.GetProxy(uri);
+                if (proxy != null)
+                {
+                    env["PROXYHOST"] = proxy.Host;
+                    env["PROXYPORT"] = proxy.IsDefaultPort ? (proxy.Scheme.ToLowerInvariant() == "https" ? "443" : "80") : proxy.Port.ToString();
+                    if (hostContext.WebProxy.HttpProxyUsername != null ||
+                        hostContext.WebProxy.HttpsProxyUsername != null)
+                    {
+                        env["PROXYUSERNAME"] = hostContext.WebProxy.HttpProxyUsername ?? hostContext.WebProxy.HttpsProxyUsername;
+                        env["PROXYPASSWORD"] = hostContext.WebProxy.HttpProxyPassword ?? hostContext.WebProxy.HttpsProxyPassword;
+                    }
+                    else
+                    {
+                        env["PROXYUSERNAME"] = "";
+                        env["PROXYPASSWORD"] = "";
+                    }
+                }
+                else
+                {
+                    env["PROXYHOST"] = "";
+                    env["PROXYPORT"] = "";
+                    env["PROXYUSERNAME"] = "";
+                    env["PROXYPASSWORD"] = "";
+                }
+
+                using (var processInvoker = hostContext.CreateService<IProcessInvoker>())
+                {
+                    processInvoker.OutputDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} [STDOUT] {args.Data}");
+                        }
+                    });
+
+                    processInvoker.ErrorDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} [STDERR] {args.Data}");
+                        }
+                    });
+
+                    var downloadCertScript = Path.Combine(hostContext.GetDirectory(WellKnownDirectory.Bin), "checkScripts", "downloadCert");
+                    var node12 = Path.Combine(hostContext.GetDirectory(WellKnownDirectory.Externals), "node12", "bin", $"node{IOUtil.ExeExtension}");
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Run '{node12} \"{downloadCertScript}\"' ");
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} {StringUtil.ConvertToJson(env)}");
+                    await processInvoker.ExecuteAsync(
+                        hostContext.GetDirectory(WellKnownDirectory.Root),
+                        node12,
+                        $"\"{downloadCertScript}\"",
+                        env,
+                        true,
+                        CancellationToken.None);
+                }
+
+                result.Pass = true;
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Download SSL Certificate from '{url}' failed with error: {ex}");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return result;
+        }
+    }
+
+    // EventSource listener for dotnet debug trace for HTTP and SSL
+    public sealed class HttpEventSourceListener : EventListener
+    {
+        private readonly List<string> _logs;
+        private readonly object _lock = new object();
+        private readonly Dictionary<string, HashSet<string>> _ignoredEvent = new Dictionary<string, HashSet<string>>
+        {
+            {
+                "Private.InternalDiagnostics.System.Net.Http",
+                new HashSet<string>
+                {
+                    "Info",
+                    "Associate"
+                }
+            },
+            {
+                "Private.InternalDiagnostics.System.Net.Security",
+                new HashSet<string>
+                {
+                    "Info",
+                    "SslStreamCtor",
+                    "SecureChannelCtor",
+                    "NoDelegateNoClientCert",
+                    "CertsAfterFiltering",
+                    "UsingCachedCredential",
+                    "SspiSelectedCipherSuite"
+                }
+            }
+        };
+
+        public HttpEventSourceListener(List<string> logs)
+        {
+            _logs = logs;
+            if (Environment.GetEnvironmentVariable("ACTIONS_RUNNER_TRACE_ALL_HTTP_EVENT") == "1")
+            {
+                _ignoredEvent.Clear();
+            }
+        }
+
+        protected override void OnEventSourceCreated(EventSource eventSource)
+        {
+            base.OnEventSourceCreated(eventSource);
+
+            if (eventSource.Name == "Private.InternalDiagnostics.System.Net.Http" ||
+                eventSource.Name == "Private.InternalDiagnostics.System.Net.Security")
+            {
+                EnableEvents(eventSource, EventLevel.Verbose, EventKeywords.All);
+            }
+        }
+
+        protected override void OnEventWritten(EventWrittenEventArgs eventData)
+        {
+            base.OnEventWritten(eventData);
+            lock (_lock)
+            {
+                if (_ignoredEvent.TryGetValue(eventData.EventSource.Name, out var ignored) &&
+                    ignored.Contains(eventData.EventName))
+                {
+                    return;
+                }
+
+                _logs.Add($"{DateTime.UtcNow.ToString("O")} [START {eventData.EventSource.Name} - {eventData.EventName}]");
+                _logs.AddRange(eventData.Payload.Select(x => string.Join(Environment.NewLine, x.ToString().Split(Environment.NewLine).Select(y => $"{DateTime.UtcNow.ToString("O")} {y}"))));
+                _logs.Add($"{DateTime.UtcNow.ToString("O")} [END {eventData.EventSource.Name} - {eventData.EventName}]");
+            }
+        }
+    }
+}

src/Runner.Listener/Checks/GitCheck.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public sealed class GitCheck : RunnerService, ICheckExtension
+    {
+        private string _logFile = null;
+        private string _gitPath = null;
+
+        public int Order => 3;
+
+        public string CheckName => "Git Certificate/Proxy Validation";
+
+        public string CheckDescription => "Make sure the git cli can access to GitHub.com or the GitHub Enterprise Server.";
+
+        public string CheckLog => _logFile;
+
+        public string HelpLink => "https://github.com/actions/runner/blob/main/docs/checks/git.md";
+
+        public Type ExtensionType => typeof(ICheckExtension);
+
+        public override void Initialize(IHostContext hostContext)
+        {
+            base.Initialize(hostContext);
+            _logFile = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Diag), StringUtil.Format("{0}_{1:yyyyMMdd-HHmmss}-utc.log", nameof(GitCheck), DateTime.UtcNow));
+            _gitPath = WhichUtil.Which("git");
+        }
+
+        // git access to ghes/gh 
+        public async Task<bool> RunCheck(string url, string pat)
+        {
+            await File.AppendAllLinesAsync(_logFile, HostContext.WarnLog());
+            await File.AppendAllLinesAsync(_logFile, HostContext.CheckProxy());
+
+            if (string.IsNullOrEmpty(_gitPath))
+            {
+                await File.AppendAllLinesAsync(_logFile, new[] { $"{DateTime.UtcNow.ToString("O")} Can't verify git with GitHub.com or GitHub Enterprise Server since git is not installed." });
+                return false;
+            }
+
+            var checkGit = await CheckGit(url, pat);
+            var result = checkGit.Pass;
+            await File.AppendAllLinesAsync(_logFile, checkGit.Logs);
+
+            // try fix SSL error by providing extra CA certificate.
+            if (checkGit.SslError)
+            {
+                await File.AppendAllLinesAsync(_logFile, new[] { $"{DateTime.UtcNow.ToString("O")} Try fix SSL error by providing extra CA certificate." });
+                var downloadCert = await HostContext.DownloadExtraCA(url, pat);
+                await File.AppendAllLinesAsync(_logFile, downloadCert.Logs);
+
+                if (downloadCert.Pass)
+                {
+                    var recheckGit = await CheckGit(url, pat, extraCA: true);
+                    await File.AppendAllLinesAsync(_logFile, recheckGit.Logs);
+                    if (recheckGit.Pass)
+                    {
+                        await File.AppendAllLinesAsync(_logFile, new[] { $"{DateTime.UtcNow.ToString("O")} Fixed SSL error by providing extra CA certs." });
+                    }
+                }
+            }
+
+            return result;
+        }
+
+        private async Task<CheckResult> CheckGit(string url, string pat, bool extraCA = false)
+        {
+            var result = new CheckResult();
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Validate server cert and proxy configuration with Git ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                var repoUrlBuilder = new UriBuilder(url);
+                repoUrlBuilder.Path = "actions/checkout";
+                repoUrlBuilder.UserName = "gh";
+                repoUrlBuilder.Password = pat;
+
+                var gitProxy = "";
+                var proxy = HostContext.WebProxy.GetProxy(repoUrlBuilder.Uri);
+                if (proxy != null)
+                {
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Runner is behind http proxy '{proxy.AbsoluteUri}'");
+                    if (HostContext.WebProxy.HttpProxyUsername != null ||
+                        HostContext.WebProxy.HttpsProxyUsername != null)
+                    {
+                        var proxyUrlWithCred = UrlUtil.GetCredentialEmbeddedUrl(
+                            proxy,
+                            HostContext.WebProxy.HttpProxyUsername ?? HostContext.WebProxy.HttpsProxyUsername,
+                            HostContext.WebProxy.HttpProxyPassword ?? HostContext.WebProxy.HttpsProxyPassword);
+                        gitProxy = $"-c http.proxy={proxyUrlWithCred}";
+                    }
+                    else
+                    {
+                        gitProxy = $"-c http.proxy={proxy.AbsoluteUri}";
+                    }
+                }
+
+                using (var processInvoker = HostContext.CreateService<IProcessInvoker>())
+                {
+                    processInvoker.OutputDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} {args.Data}");
+                        }
+                    });
+
+                    processInvoker.ErrorDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} {args.Data}");
+                        }
+                    });
+
+                    var gitArgs = $"{gitProxy} ls-remote --exit-code {repoUrlBuilder.Uri.AbsoluteUri} HEAD";
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Run 'git {gitArgs}' ");
+
+                    var env = new Dictionary<string, string>
+                    {
+                        { "GIT_TRACE", "1" },
+                        { "GIT_CURL_VERBOSE", "1" }
+                    };
+
+                    if (extraCA)
+                    {
+                        env["GIT_SSL_CAINFO"] = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Root), "download_ca_cert.pem");
+                    }
+
+                    await processInvoker.ExecuteAsync(
+                        HostContext.GetDirectory(WellKnownDirectory.Root),
+                        _gitPath,
+                        gitArgs,
+                        env,
+                        true,
+                        CancellationToken.None);
+                }
+
+                result.Pass = true;
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     git ls-remote failed with error: {ex}");
+                if (result.Logs.Any(x => x.Contains("SSL Certificate problem", StringComparison.OrdinalIgnoreCase)))
+                {
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     git ls-remote failed due to SSL cert issue.");
+                    result.SslError = true;
+                }
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+
+            }
+
+            return result;
+        }
+    }
+}

src/Runner.Listener/Checks/ICheckExtension.cs

@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public interface ICheckExtension : IExtension
+    {
+        int Order { get; }
+        string CheckName { get; }
+        string CheckDescription { get; }
+        string CheckLog { get; }
+        string HelpLink { get; }
+        Task<bool> RunCheck(string url, string pat);
+    }
+
+    public class CheckResult
+    {
+        public CheckResult()
+        {
+            Logs = new List<string>();
+        }
+
+        public bool Pass { get; set; }
+
+        public bool SslError { get; set; }
+
+        public List<string> Logs { get; set; }
+    }
+}

src/Runner.Listener/Checks/InternetCheck.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public sealed class InternetCheck : RunnerService, ICheckExtension
+    {
+        private string _logFile = null;
+
+        public int Order => 1;
+
+        public string CheckName => "Internet Connection";
+
+        public string CheckDescription => "Make sure the actions runner have access to public internet.";
+
+        public string CheckLog => _logFile;
+
+        public string HelpLink => "https://github.com/actions/runner/blob/main/docs/checks/internet.md";
+
+        public Type ExtensionType => typeof(ICheckExtension);
+
+        public override void Initialize(IHostContext hostContext)
+        {
+            base.Initialize(hostContext);
+            _logFile = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Diag), StringUtil.Format("{0}_{1:yyyyMMdd-HHmmss}-utc.log", nameof(InternetCheck), DateTime.UtcNow));
+        }
+
+        // check runner access to api.github.com
+        public async Task<bool> RunCheck(string url, string pat)
+        {
+            await File.AppendAllLinesAsync(_logFile, HostContext.WarnLog());
+            await File.AppendAllLinesAsync(_logFile, HostContext.CheckProxy());
+
+            var checkTasks = new List<Task<CheckResult>>();
+            checkTasks.Add(CheckUtil.CheckDns("https://api.github.com"));
+            checkTasks.Add(CheckUtil.CheckPing("https://api.github.com"));
+
+            // We don't need to pass a PAT since it might be a token for GHES.
+            checkTasks.Add(HostContext.CheckHttpsRequests("https://api.github.com", pat: null, expectedHeader: "X-GitHub-Request-Id"));
+
+            var result = true;
+            while (checkTasks.Count > 0)
+            {
+                var finishedCheckTask = await Task.WhenAny<CheckResult>(checkTasks);
+                var finishedCheck = await finishedCheckTask;
+                result = result && finishedCheck.Pass;
+                await File.AppendAllLinesAsync(_logFile, finishedCheck.Logs);
+                checkTasks.Remove(finishedCheckTask);
+            }
+
+            await Task.WhenAll(checkTasks);
+            return result;
+        }
+    }
+}

src/Runner.Listener/Checks/NodeJsCheck.cs

@@ -0,0 +1,181 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+
+namespace GitHub.Runner.Listener.Check
+{
+    public sealed class NodeJsCheck : RunnerService, ICheckExtension
+    {
+        private string _logFile = null;
+
+        public int Order => 4;
+
+        public string CheckName => "Node.js Certificate/Proxy Validation";
+
+        public string CheckDescription => "Make sure the node.js have access to GitHub.com or the GitHub Enterprise Server.";
+
+        public string CheckLog => _logFile;
+
+        public string HelpLink => "https://github.com/actions/runner/blob/main/docs/checks/nodejs.md";
+
+        public Type ExtensionType => typeof(ICheckExtension);
+
+        public override void Initialize(IHostContext hostContext)
+        {
+            base.Initialize(hostContext);
+            _logFile = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Diag), StringUtil.Format("{0}_{1:yyyyMMdd-HHmmss}-utc.log", nameof(NodeJsCheck), DateTime.UtcNow));
+        }
+
+        // node access to ghes/gh
+        public async Task<bool> RunCheck(string url, string pat)
+        {
+            await File.AppendAllLinesAsync(_logFile, HostContext.WarnLog());
+            await File.AppendAllLinesAsync(_logFile, HostContext.CheckProxy());
+
+            // Request to github.com or ghes server
+            var urlBuilder = new UriBuilder(url);
+            if (UrlUtil.IsHostedServer(urlBuilder))
+            {
+                urlBuilder.Host = $"api.{urlBuilder.Host}";
+                urlBuilder.Path = "";
+            }
+            else
+            {
+                urlBuilder.Path = "api/v3";
+            }
+
+            var checkNode = await CheckNodeJs(urlBuilder.Uri.AbsoluteUri, pat);
+            var result = checkNode.Pass;
+            await File.AppendAllLinesAsync(_logFile, checkNode.Logs);
+
+            // try fix SSL error by providing extra CA certificate.
+            if (checkNode.SslError)
+            {
+                var downloadCert = await HostContext.DownloadExtraCA(urlBuilder.Uri.AbsoluteUri, pat);
+                await File.AppendAllLinesAsync(_logFile, downloadCert.Logs);
+
+                if (downloadCert.Pass)
+                {
+                    var recheckNode = await CheckNodeJs(urlBuilder.Uri.AbsoluteUri, pat, extraCA: true);
+                    await File.AppendAllLinesAsync(_logFile, recheckNode.Logs);
+                    if (recheckNode.Pass)
+                    {
+                        await File.AppendAllLinesAsync(_logFile, new[] { $"{DateTime.UtcNow.ToString("O")} Fixed SSL error by providing extra CA certs." });
+                    }
+                }
+            }
+
+            return result;
+        }
+
+        private async Task<CheckResult> CheckNodeJs(string url, string pat, bool extraCA = false)
+        {
+            var result = new CheckResult();
+            try
+            {
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Make Http request to {url} using node.js ");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+
+                // Request to github.com or ghes server
+                Uri requestUrl = new Uri(url);
+                var env = new Dictionary<string, string>()
+                {
+                    { "HOSTNAME", requestUrl.Host },
+                    { "PORT", requestUrl.IsDefaultPort ? (requestUrl.Scheme.ToLowerInvariant() == "https" ? "443" : "80") : requestUrl.Port.ToString() },
+                    { "PATH", requestUrl.AbsolutePath },
+                    { "PAT", pat }
+                };
+
+                var proxy = HostContext.WebProxy.GetProxy(requestUrl);
+                if (proxy != null)
+                {
+                    env["PROXYHOST"] = proxy.Host;
+                    env["PROXYPORT"] = proxy.IsDefaultPort ? (proxy.Scheme.ToLowerInvariant() == "https" ? "443" : "80") : proxy.Port.ToString();
+                    if (HostContext.WebProxy.HttpProxyUsername != null ||
+                        HostContext.WebProxy.HttpsProxyUsername != null)
+                    {
+                        env["PROXYUSERNAME"] = HostContext.WebProxy.HttpProxyUsername ?? HostContext.WebProxy.HttpsProxyUsername;
+                        env["PROXYPASSWORD"] = HostContext.WebProxy.HttpProxyPassword ?? HostContext.WebProxy.HttpsProxyPassword;
+                    }
+                    else
+                    {
+                        env["PROXYUSERNAME"] = "";
+                        env["PROXYPASSWORD"] = "";
+                    }
+                }
+                else
+                {
+                    env["PROXYHOST"] = "";
+                    env["PROXYPORT"] = "";
+                    env["PROXYUSERNAME"] = "";
+                    env["PROXYPASSWORD"] = "";
+                }
+
+                if (extraCA)
+                {
+                    env["NODE_EXTRA_CA_CERTS"] = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Root), "download_ca_cert.pem");
+                }
+
+                using (var processInvoker = HostContext.CreateService<IProcessInvoker>())
+                {
+                    processInvoker.OutputDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} [STDOUT] {args.Data}");
+                        }
+                    });
+
+                    processInvoker.ErrorDataReceived += new EventHandler<ProcessDataReceivedEventArgs>((sender, args) =>
+                    {
+                        if (!string.IsNullOrEmpty(args.Data))
+                        {
+                            result.Logs.Add($"{DateTime.UtcNow.ToString("O")} [STDERR] {args.Data}");
+                        }
+                    });
+
+                    var makeWebRequestScript = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Bin), "checkScripts", "makeWebRequest.js");
+                    var node12 = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Externals), "node12", "bin", $"node{IOUtil.ExeExtension}");
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} Run '{node12} \"{makeWebRequestScript}\"' ");
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} {StringUtil.ConvertToJson(env)}");
+                    await processInvoker.ExecuteAsync(
+                        HostContext.GetDirectory(WellKnownDirectory.Root),
+                        node12,
+                        $"\"{makeWebRequestScript}\"",
+                        env,
+                        true,
+                        CancellationToken.None);
+                }
+
+                result.Pass = true;
+            }
+            catch (Exception ex)
+            {
+                result.Pass = false;
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Make https request to {url} using node.js failed with error: {ex}");
+                if (result.Logs.Any(x => x.Contains("UNABLE_TO_VERIFY_LEAF_SIGNATURE") ||
+                                         x.Contains("UNABLE_TO_GET_ISSUER_CERT_LOCALLY") ||
+                                         x.Contains("SELF_SIGNED_CERT_IN_CHAIN")))
+                {
+                    result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****     Https request failed due to SSL cert issue.");
+                    result.SslError = true;
+                }
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ****                                                                                                       ****");
+                result.Logs.Add($"{DateTime.UtcNow.ToString("O")} ***************************************************************************************************************");
+            }
+
+            return result;
+        }
+    }
+}