From a03bf74d1f5e2ae66a8d054b798846724055869a Mon Sep 17 00:00:00 2001
From: YuviPanda <yuvipanda@gmail.com>
Date: Tue, 28 Jan 2025 20:31:26 -0800
Subject: [PATCH] Add a warning + check to make sure docker is installed

---
 repo2docker/docker.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/repo2docker/docker.py b/repo2docker/docker.py
index 64f056ba..6bd545a8 100644
--- a/repo2docker/docker.py
+++ b/repo2docker/docker.py
@@ -2,11 +2,9 @@
 Docker container engine for repo2docker
 """
 
-import subprocess
+import shutil
 import tarfile
 import tempfile
-from queue import Empty, Queue
-from threading import Thread
 
 from iso8601 import parse_date
 from traitlets import Dict
@@ -101,6 +99,8 @@ def build(
         platform=None,
         **kwargs,
     ):
+        if not shutil.which("docker"):
+            raise RuntimeError("The docker commandline client must be installed")
         args = ["docker", "buildx", "build", "--progress", "plain", "--load"]
         if buildargs:
             for k, v in buildargs.items():