refactor(load-task): build docker command in the logical order

Author: ahal

src/taskgraph/docker.py

@@ -540,24 +540,15 @@ def load_task(
         if isatty:
             command.append("-t")
 
-        command.append(image_tag)
-
-        if task_command:
-            command.extend(task_command)
-
-        if volumes:
-            for k, v in volumes.items():
-                command[2:2] = ["-v", f"{k}:{v}"]
-
         if remove:
-            command.insert(2, "--rm")
+            command.append("--rm")
 
         if env:
             envfile = tempfile.NamedTemporaryFile("w+", delete=False)
             envfile.write("\n".join([f"{k}={v}" for k, v in env.items()]))
             envfile.close()
 
-            command.insert(2, f"--env-file={envfile.name}")
+            command.append(f"--env-file={envfile.name}")
 
         if exec_command:
             initfile = tempfile.NamedTemporaryFile("w+", delete=False)
@@ -576,7 +567,16 @@ def load_task(
             )
             initfile.close()
 
-            command[2:2] = ["-v", f"{initfile.name}:/builds/worker/.bashrc"]
+            command.extend(["-v", f"{initfile.name}:/builds/worker/.bashrc"])
+
+        if volumes:
+            for k, v in volumes.items():
+                command.extend(["-v", f"{k}:{v}"])
+
+        command.append(image_tag)
+
+        if task_command:
+            command.extend(task_command)
 
         logger.info(f"Running: {' '.join(command)}")
         proc = subprocess.run(command)

test/test_docker.py

@@ -136,15 +136,15 @@ def test_load_task(run_load_task):
     expected = [
         "docker",
         "run",
-        "-v",
-        re.compile(f"{tempfile.gettempdir()}/tmp.*:/builds/worker/.bashrc"),
+        "-i",
+        "-t",
         re.compile(f"--env-file={tempfile.gettempdir()}/tmp.*"),
         "-v",
-        "/another/host:/another/container",
+        re.compile(f"{tempfile.gettempdir()}/tmp.*:/builds/worker/.bashrc"),
         "-v",
         "/host/path:/container/path",
-        "-i",
-        "-t",
+        "-v",
+        "/another/host:/another/container",
         "image/tag",
         "bash",
         "-c",
@@ -239,9 +239,9 @@ def test_load_task_env_init_and_remove(mocker, run_load_task):
     # Verify subprocess was called with the correct env file and init file
     mocks["subprocess_run"].assert_called_once()
     actual = mocks["subprocess_run"].call_args[0][0]
-    assert actual[3] == "/tmp/test_initfile:/builds/worker/.bashrc"
-    assert actual[4] == "--env-file=/tmp/test_envfile"
-    assert actual[5] == "--rm"
+    assert actual[4] == "--rm"
+    assert actual[5] == "--env-file=/tmp/test_envfile"
+    assert actual[6:8] == ["-v", "/tmp/test_initfile:/builds/worker/.bashrc"]
 
 
 @pytest.mark.parametrize(