Merge pull request #33 from chriskuehl/fix-exec-failures

Exit nonzero if exec fails

dumb-init.c

@@ -128,6 +128,15 @@ int main(int argc, char *argv[]) {
         }
 
         execvp(argv[1], &argv[1]);
+
+        // if this point is reached, exec failed, so we should exit nonzero
+        fprintf(
+            stderr,
+            "dumb-init: %s: %s\n",
+            argv[1],
+            strerror(errno)
+        );
+        exit(2);
     } else {
         pid_t killed_pid;
         int exit_status, status;

tests/child_processes_test.py

@@ -123,3 +123,14 @@ def test_processes_dont_receive_term_on_exit_if_no_setsid(
         assert child_stdout.readline() == str(signum).encode('ascii') + b'\n'
 
     os.kill(child_pid, signal.SIGKILL)
+
+
+def test_fails_nonzero_with_bad_exec(both_debug_modes, both_setsid_modes):
+    """If dumb-init can't exec as requested, it should exit nonzero."""
+    proc = Popen(('dumb-init', '/doesnotexist'), stderr=PIPE)
+    proc.wait()
+    assert proc.returncode != 0
+    assert (
+        b'dumb-init: /doesnotexist: No such file or directory\n'
+        in proc.stderr
+    )

tox.ini

@@ -9,3 +9,10 @@ commands =
 
 [testenv:pre-commit]
 commands = pre-commit {posargs}
+
+[flake8]
+max-line-length = 119
+
+[pep8]
+# autopep8 will rewrite lines to be shorter, even though we raised the length
+ignore = E501