#10: Crashes on startup if DNS is not available [retry Gandi API requ…

…est every 15 seconds forever]
Aldaviva · Feb 11, 2025 · 7bdc5b6 · 7bdc5b6
1 parent 524c4ef
commit 7bdc5b6
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Showing 3 changed files with 23 additions and 5 deletions.
diff --git a/GandiDynamicDns/DynamicDnsService.cs b/GandiDynamicDns/DynamicDnsService.cs
@@ -3,6 +3,7 @@
 using Microsoft.Extensions.Options;
 using System.Diagnostics;
 using System.Net;
+using ThrottleDebounce;
 using Unfucked;
 using Unfucked.STUN;
 
@@ -27,11 +28,15 @@ public class DynamicDnsServiceImpl(DnsManager dns, ISelfWanAddressClient stun, I
 #endif
 
     protected override async Task ExecuteAsync(CancellationToken ct) {
-        if ((await dns.fetchDnsRecords(configuration.Value.subdomain, configuration.Value.domain, DnsRecordType.A, ct)).FirstOrDefault() is { } existingIpAddress) {
-            try {
-                selfWanAddress = IPAddress.Parse(existingIpAddress);
-            } catch (FormatException) { }
-        }
+        await Retrier.Attempt(async _ => {
+                if ((await dns.fetchDnsRecords(configuration.Value.subdomain, configuration.Value.domain, DnsRecordType.A, ct)).FirstOrDefault() is { } existingIpAddress) {
+                    try {
+                        selfWanAddress = IPAddress.Parse(existingIpAddress);
+                    } catch (FormatException) { }
+                }
+            }, maxAttempts: null, delay: _ => TimeSpan.FromSeconds(15), ex => ex is HttpRequestException or TaskCanceledException,
+            beforeRetry: () => logger.LogWarning("Failed to fetch existing DNS record from Gandi HTTP API server, retrying"), ct);
+
         logger.LogInformation("On startup, the {fqdn} DNS A record was pointing to {address}", configuration.Value.fqdn, selfWanAddress?.ToString() ?? "(nothing)");
 
         while (!ct.IsCancellationRequested) {

diff --git a/GandiDynamicDns/GandiDynamicDns.csproj b/GandiDynamicDns/GandiDynamicDns.csproj
@@ -32,6 +32,7 @@
         <PackageReference Include="Microsoft.Extensions.Hosting.Systemd" Version="9.0.2" />
         <PackageReference Include="Microsoft.Extensions.Hosting.WindowsServices" Version="9.0.2" />
         <PackageReference Include="Stun.Net" Version="8.0.2" />
+        <PackageReference Include="ThrottleDebounce" Version="2.0.0" />
         <PackageReference Include="Unfucked" Version="0.0.0-beta4" />
         <PackageReference Include="Unfucked.Caching" Version="0.0.0-beta3" />
         <PackageReference Include="Unfucked.DI" Version="0.0.0-beta4" />

diff --git a/GandiDynamicDns/packages.lock.json b/GandiDynamicDns/packages.lock.json
@@ -49,6 +49,12 @@
           "Socks5": "1.0.2"
         }
       },
+      "ThrottleDebounce": {
+        "type": "Direct",
+        "requested": "[2.0.0, )",
+        "resolved": "2.0.0",
+        "contentHash": "/lt2PLUjE1bXCkPDVXXhZDzqaK3SmKwJ2EOq/a6ZbsgAWnRz3TqkqU0VyUncbh8bUIJQHCoPUxbwmjWeAbeIbw=="
+      },
       "Unfucked": {
         "type": "Direct",
         "requested": "[0.0.0-beta4, )",
@@ -752,6 +758,12 @@
           "Socks5": "1.0.2"
         }
       },
+      "ThrottleDebounce": {
+        "type": "Direct",
+        "requested": "[2.0.0, )",
+        "resolved": "2.0.0",
+        "contentHash": "/lt2PLUjE1bXCkPDVXXhZDzqaK3SmKwJ2EOq/a6ZbsgAWnRz3TqkqU0VyUncbh8bUIJQHCoPUxbwmjWeAbeIbw=="
+      },
       "Unfucked": {
         "type": "Direct",
         "requested": "[0.0.0-beta4, )",