From ce95d1b8baeaa954ce328259571c5563a1b9c935 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igr=20Alex=C3=A1nder=20Fern=C3=A1ndez=20Sa=C3=BAco?=
 <alexander.fernandez.sauco@gmail.com>
Date: Wed, 1 Apr 2020 11:42:07 -0400
Subject: [PATCH] DockerImagePuller checks the installed images first (#281)

* DockerImagePuller checks if the images is already installed before pull it

* Use --filter and --format options to filter and format the output docker images command

* Optimize usings

* Remove unused variable

* Improve PullContainerAsync implementation and also throws CommandException if docker images command failed

* Improve the approach to determine if it's installed and print the output of this command images in case of failure
---
 .../DockerImagePuller.cs                      | 31 ++++++++++++++-----
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/Microsoft.Tye.Hosting/DockerImagePuller.cs b/src/Microsoft.Tye.Hosting/DockerImagePuller.cs
index e88dfdce..3e661260 100644
--- a/src/Microsoft.Tye.Hosting/DockerImagePuller.cs
+++ b/src/Microsoft.Tye.Hosting/DockerImagePuller.cs
@@ -2,9 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 using Microsoft.Tye.Hosting.Model;
@@ -66,16 +64,33 @@ namespace Microsoft.Tye.Hosting
         {
             await Task.Yield();
 
+            var result = await ProcessUtil.RunAsync(
+                                    "docker",
+                                    $"images --filter \"reference={image}\" --format \"{{{{.ID}}}}\"",
+                                    throwOnError: false);
+
+            if (result.ExitCode != 0)
+            {
+                _logger.LogInformation("{Image}: " + result.StandardError, image);
+                throw new CommandException("Docker images command failed");
+            }
+
+            if (!string.IsNullOrWhiteSpace(result.StandardOutput))
+            {
+                _logger.LogInformation("Docker image {image} already installed", image);
+                return;
+            }
+
             var command = $"pull {image}";
 
             _logger.LogInformation("Running docker command {command}", command);
 
-            var result = await ProcessUtil.RunAsync(
-                           "docker",
-                           command,
-                           outputDataReceived: data => _logger.LogInformation("{Image}: " + data, image),
-                           errorDataReceived: data => _logger.LogInformation("{Image}: " + data, image),
-                           throwOnError: false);
+            result = await ProcessUtil.RunAsync(
+                             "docker",
+                             command,
+                             outputDataReceived: data => _logger.LogInformation("{Image}: " + data, image),
+                             errorDataReceived: data => _logger.LogInformation("{Image}: " + data, image),
+                             throwOnError: false);
 
             if (result.ExitCode != 0)
             {