Allow MongoDB to be unavailable

sillsdev · May 28, 2024 · 408c086 · 408c086
1 parent b4e4061
commit 408c086
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Showing 2 changed files with 17 additions and 0 deletions.
diff --git a/backend/LexBoxApi/GraphQL/CustomTypes/IsLanguageForgeProjectDataLoader.cs b/backend/LexBoxApi/GraphQL/CustomTypes/IsLanguageForgeProjectDataLoader.cs
@@ -22,6 +22,9 @@ protected override async Task<IReadOnlyDictionary<string, bool>> LoadBatchAsync(
         IReadOnlyList<string> projectCodes,
         CancellationToken cancellationToken)
     {
+        if (!await _systemDbContext.IsAvailable())
+            return new Dictionary<string, bool>();
+
         return await MongoExtensions.ToAsyncEnumerable(_systemDbContext.Projects.AsQueryable()
             .Select(p => p.ProjectCode)
             .Where(projectCode => projectCodes.Contains(projectCode)))

diff --git a/backend/LfClassicData/SystemDbContext.cs b/backend/LfClassicData/SystemDbContext.cs
@@ -1,4 +1,5 @@
 using LfClassicData.Entities;
+using MongoDB.Bson;
 using MongoDB.Driver;
 
 namespace LfClassicData;
@@ -7,6 +8,7 @@ public class SystemDbContext
 {
     public const string SystemDbName = "scriptureforge";
     private readonly IMongoDatabase _mongoDatabase;
+    private bool? _isAvailable;
 
     public SystemDbContext(MongoClient mongoClient)
     {
@@ -17,4 +19,16 @@ public SystemDbContext(MongoClient mongoClient)
 
     internal IMongoCollection<User> Users { get; }
     public IMongoCollection<LfProject> Projects { get; }
+
+    public async Task<bool> IsAvailable()
+    {
+        if (_isAvailable is null or false)
+        {
+            _isAvailable = await Task.Run(() =>
+            {
+                return _mongoDatabase.RunCommandAsync((Command<BsonDocument>)"{ping:1}").Wait(100);
+            });
+        }
+        return _isAvailable.Value;
+    }
 }