Merge pull request #24 from datalust/dev

2.0.0 Release

Author: nblumhardt

Build.ps1

@@ -14,7 +14,7 @@ if($LASTEXITCODE -ne 0) { exit 1 }
 
 $branch = @{ $true = $env:APPVEYOR_REPO_BRANCH; $false = $(git symbolic-ref --short -q HEAD) }[$env:APPVEYOR_REPO_BRANCH -ne $NULL];
 $revision = @{ $true = "{0:00000}" -f [convert]::ToInt32("0" + $env:APPVEYOR_BUILD_NUMBER, 10); $false = "local" }[$env:APPVEYOR_BUILD_NUMBER -ne $NULL];
-$suffix = @{ $true = ""; $false = "$($branch.Substring(0, [math]::Min(10,$branch.Length)))-$revision"}[$branch -eq "master" -and $revision -ne "local"]
+$suffix = @{ $true = ""; $false = "$($branch.Substring(0, [math]::Min(10,$branch.Length)))-$revision"}[$branch -eq "main" -and $revision -ne "local"]
 
 echo "build: Version suffix is $suffix"
 

appveyor.yml

@@ -1,8 +1,6 @@
 version: '{build}'
 skip_tags: true
-image: Visual Studio 2017
-configuration: Release
-install:
+image: Visual Studio 2022
 build_script:
 - ps: ./Build.ps1
 test: off
@@ -11,10 +9,10 @@ artifacts:
 deploy:
 - provider: NuGet
   api_key:
-    secure: ABsZ0uLbAvoUFXnkUJ/DZwQwGQ1EIKzvSOm3aFSUZ0kY4lTBIQhI38KxrNFahQRB
+    secure: bkES4Ho0Cs/3Ws1PP7fYfSZop6K8VfqAAEFUR25eQRCJXVDPa+atx3alsaMhzVdo
   skip_symbols: true
   on:
-    branch: /^(master|dev)$/
+    branch: /^(main|dev)$/
 - provider: GitHub
   auth_token:
     secure: hX+cZmW+9BCXy7vyH8myWsYdtQHyzzil9K5yvjJv7dK9XmyrGYYDj/DPzMqsXSjo

asset/seq-input-healthcheck-2.png

@@ -16,34 +16,33 @@
 using System.IO;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
-using Serilog.Events;
-using Serilog.Filters.Expressions;
+using Serilog.Expressions;
 using Serilog.Formatting.Compact.Reader;
 using Serilog.Formatting.Json;
 
-namespace Seq.Input.HealthCheck
+namespace Seq.Input.HealthCheck.Data
 {
     public class JsonDataExtractor
     {
-        static readonly JsonValueFormatter ValueFormatter = new JsonValueFormatter("$type");
+        static readonly JsonValueFormatter ValueFormatter = new("$type");
         static readonly JsonSerializer Serializer = JsonSerializer.Create(new JsonSerializerSettings
         {
             DateParseHandling = DateParseHandling.None
         });
 
-        readonly Func<JToken, JToken> _extract;
+        readonly Func<JToken?, JToken> _extract;
 
         public JsonDataExtractor(string expression)
         {
             if (expression == "@Properties")
             {
-                _extract = v => v;
+                _extract = v => v ?? JValue.CreateNull();
             }
             else
             {
-                var expr = FilterLanguage.CreateFilter(expression);
+                var expr = SerilogExpression.Compile(expression, nameResolver: new SeqSyntaxNameResolver());
                 _extract = v => {
-                    if (!(v is JObject obj))
+                    if (v is not JObject obj)
                         throw new ArgumentException("Data value extraction requires a JSON object response.");
 
                     if (!obj.ContainsKey("@t"))
@@ -52,16 +51,15 @@ public JsonDataExtractor(string expression)
                     var le = LogEventReader.ReadFromJObject(obj);
 
                     var value = expr(le);
+                    
+                    // `null` here means "undefined", but for most purposes this substitution is convenient.
                     if (value == null)
                         return JValue.CreateNull();
 
-                    if (!(value is LogEventPropertyValue lepv))
-                        return JToken.FromObject(value);
-
                     var sw = new StringWriter();
-                    ValueFormatter.Format(lepv, sw);
+                    ValueFormatter.Format(value, sw);
                     return Serializer.Deserialize<JToken>(
-                        new JsonTextReader(new StringReader(sw.ToString())));
+                        new JsonTextReader(new StringReader(sw.ToString())))!;
                 };
             }
         }

src/Seq.Input.HealthCheck/JsonDataExtractor.cs renamed to src/Seq.Input.HealthCheck/Data/JsonDataExtractor.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+using Serilog.Events;
+using Serilog.Expressions;
+
+namespace Seq.Input.HealthCheck.Data
+{
+    public class SeqSyntaxNameResolver: NameResolver
+    {
+        // ReSharper disable once UnusedMember.Global
+        // ReSharper disable once ReturnTypeCanBeNotNullable
+        public static LogEventPropertyValue? Has(LogEventPropertyValue? value)
+        {
+            return new ScalarValue(value != null);
+        }
+    
+        public override bool TryResolveFunctionName(string name, [NotNullWhen(true)] out MethodInfo? implementation)
+        {
+            if ("Has".Equals(name, StringComparison.OrdinalIgnoreCase))
+            {
+                implementation = GetType().GetMethod("Has", BindingFlags.Static | BindingFlags.Public)!;
+                return true;
+            }
+
+            implementation = null;
+            return false;
+        }
+
+        public override bool TryResolveBuiltInPropertyName(string alias, [NotNullWhen(true)] out string? target)
+        {
+            target = alias switch
+            {
+                "Exception" => "x",
+                "Level" => "l",
+                "Message" => "m",
+                "MessageTemplate" => "mt",
+                "Properties" => "p",
+                "Timestamp" => "t",
+                _ => null
+            };
+        
+            return target != null;
+        }
+    }
+}

src/Seq.Input.HealthCheck/Data/SeqSyntaxNameResolver.cs

@@ -17,6 +17,11 @@
 using System.IO;
 using System.Net.Http;
 using Seq.Apps;
+using Seq.Input.HealthCheck.Data;
+using Seq.Input.HealthCheck.Util;
+// ReSharper disable MemberCanBePrivate.Global
+// ReSharper disable UnusedAutoPropertyAccessor.Global
+// ReSharper disable AutoPropertyCanBeMadeGetOnly.Global
 
 namespace Seq.Input.HealthCheck
 {
@@ -25,14 +30,30 @@ namespace Seq.Input.HealthCheck
     public class HealthCheckInput : SeqApp, IPublishJson, IDisposable
     {
         readonly List<HealthCheckTask> _healthCheckTasks = new List<HealthCheckTask>();
-        HttpClient _httpClient;
+        HttpClient? _httpClient;
 
         [SeqAppSetting(
             DisplayName = "Target URLs",
             HelpText = "The HTTP or HTTPS URL that the health check will periodically GET. Multiple URLs " +
                        "can be checked; enter one per line.",
             InputType = SettingInputType.LongText)]
-        public string TargetUrl { get; set; }
+        public string TargetUrl { get; set; } = null!;
+
+        [SeqAppSetting(InputType = SettingInputType.Password, IsOptional = true, DisplayName = "Authentication Header",
+            HelpText = "An optional `Name: Value` header, stored as sensitive data, for authentication purposes.")]
+        public string? AuthenticationHeader { get; set; }
+        
+        [SeqAppSetting(InputType = SettingInputType.LongText, IsOptional = true, DisplayName = "Other Headers",
+            HelpText = "Additional headers to send with the request, one per line in `Name: Value` format.")]
+        public string? OtherHeaders { get; set; }
+        
+        [SeqAppSetting(
+            DisplayName = "Bypass HTTP caching",
+            IsOptional = true,
+            HelpText = "If selected, the unique probe id will be appended to the target URL query string as " +
+                "`" + HttpHealthCheck.ProbeIdParameterName  + "`, in order to disable any " +
+                "intermediary HTTP caching. The `Cache-Control: no-store` header will also be sent.")]
+        public bool BypassHttpCaching { get; set; }
 
         [SeqAppSetting(
             DisplayName = "Interval (seconds)",
@@ -47,22 +68,14 @@ public class HealthCheckInput : SeqApp, IPublishJson, IDisposable
                        "The expression will be evaluated against the response to produce a `Data` property" +
                        " on the resulting event. Use the special value `@Properties` to capture the whole " +
                        "response. The response must be UTF-8 `application/json` for this to be applied.")]
-        public string DataExtractionExpression { get; set; }
-
-        [SeqAppSetting(
-            DisplayName = "Bypass HTTP caching",
-            IsOptional = true,
-            HelpText = "If selected, the unique probe id will be appended to the target URL query string as " +
-                       "`" + HttpHealthCheck.ProbeIdParameterName  + "`, in order to disable any " +
-                       "intermediary HTTP caching. The `Cache-Control: no-store` header will also be sent.")]
-        public bool BypassHttpCaching { get; set; }
-
+        public string? DataExtractionExpression { get; set; }
+        
         public void Start(TextWriter inputWriter)
         {
             _httpClient = HttpHealthCheckClient.Create();
             var reporter = new HealthCheckReporter(inputWriter);
 
-            JsonDataExtractor extractor = null;
+            JsonDataExtractor? extractor = null;
             if (!string.IsNullOrWhiteSpace(DataExtractionExpression))
                 extractor = new JsonDataExtractor(DataExtractionExpression);
 
@@ -73,6 +86,7 @@ public void Start(TextWriter inputWriter)
                     _httpClient,
                     App.Title,
                     targetUrl,
+                    HeaderSettingFormat.FromSettings(AuthenticationHeader, OtherHeaders),
                     extractor,
                     BypassHttpCaching);
 

src/Seq.Input.HealthCheck/HealthCheckInput.cs

@@ -16,6 +16,8 @@
 using System.Globalization;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+// ReSharper disable UnusedAutoPropertyAccessor.Global
+// ReSharper disable MemberCanBePrivate.Global
 
 namespace Seq.Input.HealthCheck
 {
@@ -25,14 +27,14 @@ class HealthCheckResult
         public DateTime UtcTimestamp { get; }
 
         [JsonProperty("@x", DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string Exception { get; }
+        public string? Exception { get; }
 
         [JsonProperty("@mt")]
         public string MessageTemplate { get; } =
             "Health check {Method} {TargetUrl} {Outcome} with status code {StatusCode} in {Elapsed:0.000} ms";
 
         [JsonProperty("@l", DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string Level { get; }
+        public string? Level { get; }
 
         [JsonProperty("@r")]
         public string[] Renderings => new[] {Elapsed.ToString("0.000", CultureInfo.InvariantCulture)};
@@ -43,18 +45,18 @@ class HealthCheckResult
         public string Outcome { get; }
         public double Elapsed { get; }
         public int? StatusCode { get; }
-        public string ContentType { get; }
+        public string? ContentType { get; }
         public long? ContentLength { get; }
         public string ProbeId { get; }
 
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string InitialContent { get; }
+        public string? InitialContent { get; }
 
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public JToken Data { get; }
+        public JToken? Data { get; }
 
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string ProbedUrl { get; }
+        public string? ProbedUrl { get; }
 
         public HealthCheckResult(
             DateTime utcTimestamp,
@@ -63,15 +65,15 @@ public HealthCheckResult(
             string targetUrl,            
             string outcome,
             string probeId,
-            string level,
+            string? level,
             double elapsed,
             int? statusCode,
-            string contentType,
+            string? contentType,
             long? contentLength,
-            string initialContent,
-            Exception exception,
-            JToken data,
-            string probedUrl)
+            string? initialContent,
+            Exception? exception,
+            JToken? data,
+            string? probedUrl)
         {
             if (utcTimestamp.Kind != DateTimeKind.Utc)
                 throw new ArgumentException("The timestamp must be UTC.", nameof(utcTimestamp));

src/Seq.Input.HealthCheck/HealthCheckResult.cs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Net.Http;
@@ -21,6 +22,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Newtonsoft.Json.Linq;
+using Seq.Input.HealthCheck.Data;
 using Seq.Input.HealthCheck.Util;
 
 namespace Seq.Input.HealthCheck
@@ -29,36 +31,38 @@ class HttpHealthCheck
     {
         readonly string _title;
         readonly string _targetUrl;
-        readonly JsonDataExtractor _extractor;
+        readonly List<(string, string)> _headers;
+        readonly JsonDataExtractor? _extractor;
         readonly bool _bypassHttpCaching;
         readonly HttpClient _httpClient;
         readonly byte[] _buffer = new byte[2048];
 
         public const string ProbeIdParameterName = "__probe";
 
-        static readonly UTF8Encoding ForgivingEncoding = new UTF8Encoding(false, false);
+        static readonly UTF8Encoding ForgivingEncoding = new(false, false);
         const int InitialContentChars = 16;
         const string OutcomeSucceeded = "succeeded", OutcomeFailed = "failed";
 
-        public HttpHealthCheck(HttpClient httpClient, string title, string targetUrl, JsonDataExtractor extractor, bool bypassHttpCaching)
+        public HttpHealthCheck(HttpClient httpClient, string title, string targetUrl,  List<(string, string)> headers, JsonDataExtractor? extractor, bool bypassHttpCaching)
         {
             _httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));
             _title = title ?? throw new ArgumentNullException(nameof(title));
             _targetUrl = targetUrl ?? throw new ArgumentNullException(nameof(targetUrl));
+            _headers = headers;
             _extractor = extractor;
             _bypassHttpCaching = bypassHttpCaching;
         }
-
+        
         public async Task<HealthCheckResult> CheckNow(CancellationToken cancel)
         {
             string outcome;
 
-            Exception exception = null;
+            Exception? exception = null;
             int? statusCode = null;
-            string contentType = null;
+            string? contentType = null;
             long? contentLength = null;
-            string initialContent = null;
-            JToken data = null;
+            string? initialContent = null;
+            JToken? data = null;
 
             var probeId = Nonce.Generate(12);
             var probedUrl = _bypassHttpCaching ?
@@ -73,6 +77,12 @@ public async Task<HealthCheckResult> CheckNow(CancellationToken cancel)
                 var request = new HttpRequestMessage(HttpMethod.Get, probedUrl);
                 request.Headers.Add("X-Correlation-ID", probeId);
 
+                foreach (var (name, value) in _headers)
+                {
+                    // This will throw if a header is duplicated (better for the user to detect this configuration problem).
+                    request.Headers.Add(name, value);
+                }
+
                 if (_bypassHttpCaching)
                     request.Headers.CacheControl = new CacheControlHeaderValue { NoStore = true };
 
@@ -82,7 +92,7 @@ public async Task<HealthCheckResult> CheckNow(CancellationToken cancel)
                 contentType = response.Content.Headers.ContentType?.ToString();
                 contentLength = response.Content.Headers.ContentLength;
 
-                var content = await response.Content.ReadAsStreamAsync();
+                var content = await response.Content.ReadAsStreamAsync(cancel);
                 (initialContent, data) = await DownloadContent(content, contentType, contentLength);
 
                 outcome = response.IsSuccessStatusCode ? OutcomeSucceeded : OutcomeFailed;
@@ -118,18 +128,18 @@ public async Task<HealthCheckResult> CheckNow(CancellationToken cancel)
         }
 
         // Either initial content, or extracted data
-        async Task<(string initialContent, JToken data)> DownloadContent(Stream body, string contentType, long? contentLength)
+        async Task<(string? initialContent, JToken? data)> DownloadContent(Stream body, string? contentType, long? contentLength)
         {
             if (_extractor == null ||
                 contentLength == 0 ||
                 contentType != "application/json; charset=utf-8" && contentType != "application/json")
             {
-                var read = await body.ReadAsync(_buffer, 0, _buffer.Length);
+                var read = await body.ReadAsync(_buffer);
                 var initial = ForgivingEncoding.GetString(_buffer, 0, Math.Min(read, InitialContentChars));
 
                 // Drain the response to avoid dropped connection errors on the server.
                 while (read > 0)
-                    read = await body.ReadAsync(_buffer, 0, _buffer.Length);
+                    read = await body.ReadAsync(_buffer);
 
                 return (initial, null);
             }