tests/integration: Automate 'build_fail' manual test

Signed-off-by: Monika Kairaityte <monika@kibit.lt>

tests/integration/build_fail/README.md

@@ -1,22 +0,0 @@
-# Test podman-compose with build (fail scenario)
-
-```shell
-podman-compose build || echo $?
-```
-
-expected output would be something like
-
-```
-STEP 1/3: FROM busybox
-STEP 2/3: RUN this_command_does_not_exist
-/bin/sh: this_command_does_not_exist: not found
-Error: building at STEP "RUN this_command_does_not_exist": while running runtime: exit status 127
-
-exit code: 127
-```
-
-Expected `podman-compose` exit code:
-```shell
-echo $?
-127
-```

tests/integration/test_podman_compose_build_fail.py

@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+
+import os
+import unittest
+
+from tests.integration.test_podman_compose import podman_compose_path
+from tests.integration.test_podman_compose import test_path
+from tests.integration.test_utils import RunSubprocessMixin
+
+
+def compose_yaml_path():
+    """ "Returns the path to the compose file used for this test module"""
+    base_path = os.path.join(test_path(), "build_fail")
+    return os.path.join(base_path, "docker-compose.yml")
+
+
+class TestComposeBuildFail(unittest.TestCase, RunSubprocessMixin):
+    def test_build_fail(self):
+        output, error = self.run_subprocess_assert_returncode(
+            [
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path(),
+                "build",
+            ],
+            expected_returncode=127,
+        )
+        self.assertIn("RUN this_command_does_not_exist", str(output))
+        self.assertIn("this_command_does_not_exist: not found", str(error))
+        self.assertIn("while running runtime: exit status 127", str(error))