add email notifications for SnapshotService errors

ref #12

src/FilterLists.Agent/Program.cs

@@ -28,7 +28,7 @@ public static void Main()
         private static void BuildConfigurationRoot() =>
             configurationRoot = new ConfigurationBuilder()
                                 .SetBasePath(Directory.GetCurrentDirectory())
-                                .AddJsonFile("appsettings.json", true)
+                                .AddJsonFile("appsettings.json", false)
                                 .Build();
 
         private static void InstantiateTelemetryClient()

src/FilterLists.Agent/appsettings.json

@@ -6,10 +6,21 @@
 */
 {
   "ApplicationInsights": {
-    "InstrumentationKey": "InstrumentationKeyValue"
+    "InstrumentationKey": ""
   },
   "ConnectionStrings": {
-    "FilterListsConnection": "FilterListsConnectionValue"
+    "FilterListsConnection": ""
+  },
+  "SendGrid": {
+    "ApiKey": "",
+    "From": {
+      "Name": "",
+      "EmailAddress": ""
+    },
+    "To": {
+      "Name": "",
+      "EmailAddress": ""
+    }
   },
   "DataDirectory": {
     "Path": "..\\..\\data"

src/FilterLists.Api/appsettings.json

@@ -6,10 +6,21 @@
 */
 {
   "ApplicationInsights": {
-    "InstrumentationKey": "InstrumentationKeyValue"
+    "InstrumentationKey": ""
   },
   "ConnectionStrings": {
-    "FilterListsConnection": "FilterListsConnectionValue"
+    "FilterListsConnection": ""
+  },
+  "SendGrid": {
+    "ApiKey": "",
+    "From": {
+      "Name": "",
+      "EmailAddress": ""
+    },
+    "To": {
+      "Name": "",
+      "EmailAddress": ""
+    }
   },
   "DataDirectory": {
     "Path": "..\\..\\data"

src/FilterLists.Services/DependencyInjection/Extensions/ConfigureServicesCollection.cs

@@ -35,6 +35,7 @@ public static void AddFilterListsAgentServices(this IServiceCollection services,
                                 x => x.MigrationsAssembly("FilterLists.Api"))
                             .EnableSensitiveDataLogging());
             services.TryAddScoped<SnapshotService>();
+            services.TryAddScoped<EmailService>();
             services.AddAutoMapper();
         }
     }

src/FilterLists.Services/EmailService.cs

@@ -0,0 +1,38 @@
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using Microsoft.Extensions.Configuration;
+using SendGrid;
+using SendGrid.Helpers.Mail;
+
+namespace FilterLists.Services
+{
+    [UsedImplicitly]
+    public class EmailService
+    {
+        private readonly SendGridClient sendGridClient;
+        private readonly EmailAddress fromEmailAddress;
+        private readonly EmailAddress toEmailAddress;
+
+        public EmailService(IConfiguration configuration)
+        {
+            var sendGridConfig = configuration.GetSection("SendGrid");
+            sendGridClient = new SendGridClient(sendGridConfig.GetValue<string>("ApiKey"));
+            fromEmailAddress = new EmailAddress(sendGridConfig.GetSection("From").GetValue<string>("EmailAddress"),
+                sendGridConfig.GetSection("From").GetValue<string>("Name"));
+            toEmailAddress = new EmailAddress(sendGridConfig.GetSection("To").GetValue<string>("EmailAddress"),
+                sendGridConfig.GetSection("To").GetValue<string>("Name"));
+        }
+
+        public async Task SendEmailAsync(string subjectBody, string message)
+        {
+            var msg = new SendGridMessage
+            {
+                From = fromEmailAddress,
+                Subject = "[FilterLists] " + subjectBody,
+                PlainTextContent = message
+            };
+            msg.AddTo(toEmailAddress);
+            await sendGridClient.SendEmailAsync(msg);
+        }
+    }
+}

src/FilterLists.Services/FilterLists.Services.csproj

@@ -20,6 +20,7 @@
     <PackageReference Include="JetBrains.Annotations" Version="2018.2.1" />
     <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.4.0" />
     <PackageReference Include="Microsoft.DotNet.Analyzers.Compatibility" Version="0.2.12-alpha" />
+    <PackageReference Include="SendGrid" Version="9.9.0" />
   </ItemGroup>
 
   <ItemGroup>

src/FilterLists.Services/Service.cs

@@ -9,6 +9,7 @@ public class Service
     {
         protected readonly IConfigurationProvider ConfigurationProvider;
         protected readonly FilterListsDbContext DbContext;
+        protected readonly EmailService EmailService;
 
         public Service(FilterListsDbContext dbContext) => DbContext = dbContext;
 
@@ -17,5 +18,13 @@ public Service(FilterListsDbContext dbContext, IConfigurationProvider configurat
             DbContext = dbContext;
             ConfigurationProvider = configurationProvider;
         }
+
+        public Service(FilterListsDbContext dbContext, IConfigurationProvider configurationProvider,
+            EmailService emailService)
+        {
+            DbContext = dbContext;
+            ConfigurationProvider = configurationProvider;
+            EmailService = emailService;
+        }
     }
 }

src/FilterLists.Services/Snapshot/SnapshotDe.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 using System.Net;
 using System.Net.Http;
+using System.Text;
 using System.Threading.Tasks;
 using FilterLists.Data;
 using FilterLists.Data.Entities.Junctions;
@@ -18,12 +19,14 @@ public class SnapshotDe
 
         private const int BatchSize = 1000;
         private readonly FilterListsDbContext dbContext;
+        private readonly EmailService emailService;
         private readonly FilterListViewUrlDto list;
         private Data.Entities.Snapshot snapshot;
 
-        public SnapshotDe(FilterListsDbContext dbContext, FilterListViewUrlDto list)
+        public SnapshotDe(FilterListsDbContext dbContext, EmailService emailService, FilterListViewUrlDto list)
         {
             this.dbContext = dbContext;
+            this.emailService = emailService;
             this.list = list;
         }
 
@@ -62,12 +65,14 @@ private async Task<string> TryGetContent()
             catch (WebException we)
             {
                 snapshot.HttpStatusCode = ((int)((HttpWebResponse)we.Response).StatusCode).ToString();
+                await SendWebExceptionEmail();
                 return null;
             }
-            catch (Exception)
+            catch (Exception e)
             {
                 //TODO: log exception (#148)
                 snapshot.HttpStatusCode = null;
+                await SendExceptionEmail(e);
                 return null;
             }
         }
@@ -85,9 +90,28 @@ private async Task<string> GetContent()
                 }
             }
 
+            await SendWebExceptionEmail();
             return null;
         }
 
+        private async Task SendWebExceptionEmail()
+        {
+            var message = new StringBuilder();
+            message.AppendLine("Snapshot WebException");
+            message.AppendLine("FilterListId: " + snapshot.FilterList.Id);
+            message.AppendLine("HTTP Status Code: " + snapshot.HttpStatusCode);
+            await emailService.SendEmailAsync("Snapshot WebException", message.ToString());
+        }
+
+        private async Task SendExceptionEmail(Exception e)
+        {
+            var message = new StringBuilder();
+            message.AppendLine("Snapshot Exception");
+            message.AppendLine("FilterListId: " + snapshot.FilterList.Id);
+            message.AppendLine("Exception: " + e.Message);
+            await emailService.SendEmailAsync("Snapshot Exception", message.ToString());
+        }
+
         private async Task SaveSnapshotInBatches(string content)
         {
             var rawRules = GetRawRules(content);

src/FilterLists.Services/Snapshot/SnapshotService.cs

@@ -19,8 +19,9 @@ public class SnapshotService : Service
         private static readonly IList<uint> IgnoreLists =
             new ReadOnlyCollection<uint>(new List<uint> {48, 149, 173, 185, 186, 187, 188, 189, 352});
 
-        public SnapshotService(FilterListsDbContext dbContext, IConfigurationProvider configurationProvider)
-            : base(dbContext, configurationProvider)
+        public SnapshotService(FilterListsDbContext dbContext, IConfigurationProvider configurationProvider,
+            EmailService emailService)
+            : base(dbContext, configurationProvider, emailService)
         {
         }
 
@@ -54,7 +55,7 @@ await DbContext
                   .ToListAsync();
 
         private IEnumerable<SnapshotDe> GetSnapshots(IEnumerable<FilterListViewUrlDto> lists) =>
-            lists.Select(list => new SnapshotDe(DbContext, list));
+            lists.Select(list => new SnapshotDe(DbContext, EmailService, list));
 
         private static async Task SaveSnapshots(IEnumerable<SnapshotDe> snapshots)
         {