feat: Support refreshable properties (#56)

* Refreshable properties

* Remove CRON for electrical heating

* Allow resetting RecurringCronExpression

source/ProcessManager.Core/Application/Registration/IOrchestrationRegister.cs

@@ -24,14 +24,27 @@ internal interface IOrchestrationRegister
     Task<IReadOnlyCollection<OrchestrationDescription>> GetAllByHostNameAsync(string hostName);
 
     /// <summary>
-    /// Durable Functions orchestration host's can use this method to register the orchestrations
+    /// Determine if <paramref name="hostDescription"/> is unknown to the register and needs to be registered;
+    /// or if it was previously disabled and needs to be enabled;
+    /// or if any refreshable property has changed.
+    /// </summary>
+    /// <param name="registerDescription">Orchestration description as described in the register.</param>
+    /// <param name="hostDescription">Orchestration description as described by the application host.</param>
+    /// <returns><see langword="true"/> if the orchestration description should be registered or updated; otherwise <see langword="false"/>.</returns>
+    bool ShouldRegisterOrUpdate(OrchestrationDescription? registerDescription, OrchestrationDescription hostDescription);
+
+    /// <summary>
+    /// Durable Functions orchestration host's can use this method to register or update the orchestrations
     /// they host.
     /// </summary>
-    Task RegisterAsync(OrchestrationDescription orchestrationDescription, string hostName);
+    /// <param name="hostDescription">Orchestration description as described by the application host.</param>
+    /// <param name="hostName">Name of the application host.</param>
+    Task RegisterOrUpdateAsync(OrchestrationDescription hostDescription, string hostName);
 
     /// <summary>
     /// Durable Functions orchestration host's can use this method to disable orchestrations they don't host anymore
     /// or want to disable for other reasons.
     /// </summary>
-    Task DeregisterAsync(OrchestrationDescription orchestrationDescription);
+    /// <param name="registerDescription">Orchestration description as described in the register.</param>
+    Task DeregisterAsync(OrchestrationDescription registerDescription);
 }

source/ProcessManager.Core/Application/Registration/OrchestrationRegisterExtensions.cs

@@ -55,8 +55,8 @@ public static async Task SynchronizeAsync(
                 .SingleOrDefault(x =>
                     x.UniqueName == hostDescription.UniqueName);
 
-            if (registerDescription == null || registerDescription.IsEnabled == false)
-                await register.RegisterAsync(hostDescription, hostName).ConfigureAwait(false);
+            if (register.ShouldRegisterOrUpdate(registerDescription, hostDescription))
+                await register.RegisterOrUpdateAsync(hostDescription, hostName).ConfigureAwait(false);
         }
     }
 }

source/ProcessManager.Core/Domain/OrchestrationDescription/OrchestrationDescription.cs

@@ -87,7 +87,7 @@ public string RecurringCronExpression
         {
             if (value != _recurringCronExpression)
             {
-                if (CrontabSchedule.TryParse(value) == null)
+                if (value != string.Empty && CrontabSchedule.TryParse(value) == null)
                     throw new ArgumentOutOfRangeException($"Invalid cron value '{value}'. See https://github.com/atifaziz/NCrontab/wiki/Crontab-Expression for expected format.");
 
                 _recurringCronExpression = value;

source/ProcessManager.Core/Infrastructure/Registration/OrchestrationRegister.cs

@@ -61,38 +61,66 @@ public async Task<IReadOnlyCollection<OrchestrationDescription>> GetAllByHostNam
     }
 
     /// <inheritdoc />
-    public async Task RegisterAsync(OrchestrationDescription orchestrationDescription, string hostName)
+    public bool ShouldRegisterOrUpdate(OrchestrationDescription? registerDescription, OrchestrationDescription hostDescription)
     {
-        ArgumentNullException.ThrowIfNull(orchestrationDescription);
+        return
+            registerDescription == null
+            || registerDescription.IsEnabled == false
+            || AnyRefreshablePropertyHasChanged(registerDescription, hostDescription);
+    }
+
+    /// <inheritdoc />
+    public async Task RegisterOrUpdateAsync(OrchestrationDescription hostDescription, string hostName)
+    {
+        ArgumentNullException.ThrowIfNull(hostDescription);
         ArgumentException.ThrowIfNullOrWhiteSpace(hostName);
 
-        var existing = await GetOrDefaultAsync(orchestrationDescription.UniqueName, isEnabled: null).ConfigureAwait(false);
-        if (existing == null)
+        var existingDescription = await GetOrDefaultAsync(hostDescription.UniqueName, isEnabled: null).ConfigureAwait(false);
+        if (existingDescription == null)
         {
-            // Enfore certain values
-            orchestrationDescription.HostName = hostName;
-            orchestrationDescription.IsEnabled = true;
-            _context.Add(orchestrationDescription);
+            // Enforce certain values
+            hostDescription.HostName = hostName;
+            hostDescription.IsEnabled = true;
+            _context.Add(hostDescription);
         }
         else
         {
-            existing.IsEnabled = true;
+            existingDescription.IsEnabled = true;
+            UpdateRefreshableProperties(existingDescription, hostDescription);
         }
 
         await _context.SaveChangesAsync().ConfigureAwait(false);
     }
 
     /// <inheritdoc />
-    public async Task DeregisterAsync(OrchestrationDescription orchestrationDescription)
+    public async Task DeregisterAsync(OrchestrationDescription registerDescription)
     {
-        ArgumentNullException.ThrowIfNull(orchestrationDescription);
+        ArgumentNullException.ThrowIfNull(registerDescription);
 
-        var existing = await GetOrDefaultAsync(orchestrationDescription.UniqueName, isEnabled: true).ConfigureAwait(false);
-        if (existing == null)
+        var existingDescription = await GetOrDefaultAsync(registerDescription.UniqueName, isEnabled: true).ConfigureAwait(false);
+        if (existingDescription == null)
             throw new InvalidOperationException("Orchestration description has not been registered or is not currently enabled.");
 
-        existing.IsEnabled = false;
+        existingDescription.IsEnabled = false;
 
         await _context.SaveChangesAsync().ConfigureAwait(false);
     }
+
+    private static bool AnyRefreshablePropertyHasChanged(
+        OrchestrationDescription registerDescription,
+        OrchestrationDescription hostDescription)
+    {
+        return registerDescription.RecurringCronExpression != hostDescription.RecurringCronExpression;
+    }
+
+    /// <summary>
+    /// Properties that can change the behaviour of the orchestation history should not be allowed to
+    /// change without bumping the version of the orchestration description.
+    /// </summary>
+    private static void UpdateRefreshableProperties(
+        OrchestrationDescription registerDescription,
+        OrchestrationDescription hostDescription)
+    {
+        registerDescription.RecurringCronExpression = hostDescription.RecurringCronExpression;
+    }
 }

source/ProcessManager.Orchestrations/Program.cs

@@ -98,8 +98,10 @@ OrchestrationDescription CreateDescription_Brs_021_ElectricalHeatingCalculation_
         canBeScheduled: true,
         functionName: nameof(Orchestration_Brs_021_ElectricalHeatingCalculation_V1));
 
-    // Runs at 12:00 and 17:00 every day
-    description.RecurringCronExpression = "0 12,17 * * *";
+    // DISABLED for now because ElectricalHeatingJob is currently failing
+    description.RecurringCronExpression = string.Empty;
+    ////// Runs at 12:00 and 17:00 every day
+    ////description.RecurringCronExpression = "0 12,17 * * *";
 
     foreach (var step in Orchestration_Brs_021_ElectricalHeatingCalculation_V1.Steps)
     {