Implement Broker Redirects for Session and Messages (#3103)

src/Sdk/DTWebApi/WebApi/BrokerMigrationMessage.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace GitHub.DistributedTask.WebApi
+{
+    /// <summary>
+    /// Message that tells the runner to redirect itself to BrokerListener for messages.
+    /// (Note that we use a special Message instead of a simple 302. This is because 
+    /// the runner will need to apply the runner's token to the request, and it is
+    /// a security best practice to *not* blindly add sensitive data to redirects
+    /// 302s.)
+    /// </summary>
+    [DataContract]
+    public class BrokerMigrationMessage
+    {
+        public static readonly string MessageType = "BrokerMigration";
+
+        public BrokerMigrationMessage()
+        {
+        }
+
+        public BrokerMigrationMessage(
+            Uri brokerUrl)
+        {
+            this.BrokerBaseUrl = brokerUrl;
+        }
+
+        /// <summary>
+        /// The base url for the broker listener
+        /// </summary>
+        [DataMember]
+        public Uri BrokerBaseUrl
+        {
+            get;
+            internal set;
+        }
+    }
+}

src/Sdk/DTWebApi/WebApi/TaskAgentSession.cs

@@ -75,5 +75,12 @@ namespace GitHub.DistributedTask.WebApi
             get;
             set;
         }
+
+        [DataMember(EmitDefaultValue = false, IsRequired = false)]
+        public BrokerMigrationMessage BrokerMigrationMessage
+        {
+            get;
+            set;
+        }
     }
 }

src/Sdk/WebApi/WebApi/BrokerHttpClient.cs

@@ -57,6 +57,7 @@ namespace GitHub.Actions.RunService.WebApi
         }
 
         public async Task<TaskAgentMessage> GetRunnerMessageAsync(
+            Guid? sessionId,
             string runnerVersion,
             TaskAgentStatus? status,
             string os = null,
@@ -69,6 +70,11 @@ namespace GitHub.Actions.RunService.WebApi
 
             List<KeyValuePair<string, string>> queryParams = new List<KeyValuePair<string, string>>();
 
+            if (sessionId != null)
+            {
+                queryParams.Add("sessionId", sessionId.Value.ToString());
+            }
+
             if (status != null)
             {
                 queryParams.Add("status", status.Value.ToString());
@@ -111,5 +117,55 @@ namespace GitHub.Actions.RunService.WebApi
 
             throw new Exception($"Failed to get job message: {result.Error}");
         }
+
+        public async Task<TaskAgentSession> CreateSessionAsync(
+
+           TaskAgentSession session,
+           CancellationToken cancellationToken = default)
+        {
+            var requestUri = new Uri(Client.BaseAddress, "session");
+            var requestContent = new ObjectContent<TaskAgentSession>(session, new VssJsonMediaTypeFormatter(true));
+
+            var result = await SendAsync<TaskAgentSession>(
+                new HttpMethod("POST"),
+                requestUri: requestUri,
+                content: requestContent,
+                cancellationToken: cancellationToken);
+
+            if (result.IsSuccess)
+            {
+                return result.Value;
+            }
+
+            if (result.StatusCode == HttpStatusCode.Forbidden)
+            {
+                throw new AccessDeniedException(result.Error);
+            }
+
+            if (result.StatusCode == HttpStatusCode.Conflict)
+            {
+                throw new TaskAgentSessionConflictException(result.Error);
+            }
+
+            throw new Exception($"Failed to create broker session: {result.Error}");
+        }
+
+        public async Task DeleteSessionAsync(
+            CancellationToken cancellationToken = default)
+        {
+            var requestUri = new Uri(Client.BaseAddress, $"session");
+
+            var result = await SendAsync<object>(
+                new HttpMethod("DELETE"),
+                requestUri: requestUri,
+                cancellationToken: cancellationToken);
+
+            if (result.IsSuccess)
+            {
+                return;
+            }
+
+            throw new Exception($"Failed to delete broker session: {result.Error}");
+        }
     }
 }