Provide option to specify arguments for container jobs and services

src/Runner.Worker/Container/ContainerInfo.cs

@@ -36,6 +36,7 @@ public ContainerInfo(IHostContext hostContext, Pipelines.JobContainer container,
             this.ContainerImage = containerImage;
             this.ContainerDisplayName = $"{container.Alias}_{Pipelines.Validation.NameValidation.Sanitize(containerImage)}_{Guid.NewGuid().ToString("N").Substring(0, 6)}";
             this.ContainerCreateOptions = container.Options;
+            this.ContainerEntryPointArgs = string.Join(" ", container.Args);
             _environmentVariables = container.Environment;
             this.IsJobContainer = isJobContainer;
             this.ContainerNetworkAlias = networkAlias;

src/Sdk/DTPipelines/Pipelines/JobContainer.cs

@@ -57,6 +57,15 @@ public IList<String> Ports
             set;
         }
 
+        /// <summary>
+        /// Gets or sets the arguments used for the container instance.
+        /// </summary>
+        public IList<String> Args
+        {
+            get;
+            set;
+        }
+
         /// <summary>
         /// Gets or sets the credentials used for pulling the container iamge.
         /// </summary>

src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConstants.cs

@@ -6,12 +6,13 @@ namespace GitHub.DistributedTask.Pipelines.ObjectTemplating
     [EditorBrowsable(EditorBrowsableState.Never)]
     public sealed class PipelineTemplateConstants
     {
+        public const String Args = "args";
         public const String Always = "always";
         public const String BooleanStepsContext = "boolean-steps-context";
         public const String BooleanStrategyContext = "boolean-strategy-context";
         public const String CancelTimeoutMinutes = "cancel-timeout-minutes";
         public const String Cancelled = "cancelled";
-        public const String Clean= "clean";
+        public const String Clean = "clean";
         public const String Container = "container";
         public const String ContinueOnError = "continue-on-error";
         public const String Credentials = "credentials";

src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs

@@ -302,6 +302,17 @@ internal static JobContainer ConvertToJobContainer(
                         case PipelineTemplateConstants.Credentials:
                             result.Credentials = ConvertToContainerCredentials(containerPropertyPair.Value);
                             break;
+                        case PipelineTemplateConstants.Args:
+                            var args = containerPropertyPair.Value.AssertSequence($"{PipelineTemplateConstants.Container} {propertyName}");
+                            var argList = new List<String>(args.Count);
+                            foreach (var argItem in args)
+                            {
+                                var argString = argItem.AssertString($"{PipelineTemplateConstants.Container} {propertyName} {argItem.ToString()}").Value;
+                                argList.Add(argString);
+                            }
+                            result.Args = argList;
+                            break;
+
                         default:
                             propertyName.AssertUnexpectedValue($"{PipelineTemplateConstants.Container} key");
                             break;