Make rendering template in agent client temporary (#395)

Signed-off-by: Edwin Yu <[email protected]>

go/tasks/plugins/webapi/agent/plugin.go

@@ -68,13 +68,15 @@ func (p Plugin) Create(ctx context.Context, taskCtx webapi.TaskExecutionContextR
 		return nil, nil, err
 	}
 
+	var argTemplate []string
 	if taskTemplate.GetContainer() != nil {
 		templateParameters := template.Parameters{
 			TaskExecMetadata: taskCtx.TaskExecutionMetadata(),
 			Inputs:           taskCtx.InputReader(),
 			OutputPath:       taskCtx.OutputWriter(),
 			Task:             taskCtx.TaskReader(),
 		}
+		argTemplate = taskTemplate.GetContainer().Args
 		modifiedArgs, err := template.Render(ctx, taskTemplate.GetContainer().Args, templateParameters)
 		if err != nil {
 			return nil, nil, err
@@ -101,6 +103,11 @@ func (p Plugin) Create(ctx context.Context, taskCtx webapi.TaskExecutionContextR
 		return nil, nil, err
 	}
 
+	// Restore unrendered template for subsequent renders.
+	if taskTemplate.GetContainer() != nil {
+		taskTemplate.GetContainer().Args = argTemplate
+	}
+
 	return &ResourceMetaWrapper{
 		OutputPrefix:      outputPrefix,
 		AgentResourceMeta: res.GetResourceMeta(),