pbuilder: generalize hook support code

1 files changed, 38 insertions, 11 deletions

diff --git a/mdbp/pbuilder.py b/mdbp/pbuilder.py
index 6eba440..e074ed4 100644
--- a/mdbp/pbuilder.py
+++ b/mdbp/pbuilder.py
@@ -27,6 +27,27 @@ def find_basetgz(distribution: str,
             return basetgz
     raise ValueError("unsupported distribution %s" % distribution)
 
+
+@contextlib.contextmanager
+def hookdir() -> typing.Iterator[
+    typing.Tuple[pathlib.Path, typing.Callable[[str, str], None]]
+]:
+    """A context manager that returns a pair of a hook directory suitable for
+    pbuilder and a function for adding hooks to the directory.
+    """
+    with tempfile.TemporaryDirectory() as tdir:
+        directory = pathlib.Path(tdir)
+        counter = 0
+
+        def addhook(key: str, content: str, prio: str = "50") -> None:
+            nonlocal counter
+            hookpath = directory / ("%s%s%05X" % (key, prio, counter))
+            hookpath.write_text(content)
+            hookpath.chmod(0o755)
+
+        yield (directory, addhook)
+
+
 def main() -> None:
     """Entry point for mdbp-pbuilder backend"""
     parser = argparse.ArgumentParser()
@@ -87,24 +108,30 @@ def main() -> None:
                 "--configfile",
                 str(stack.enter_context(temporary_static_file(pbuilderrc))),
             ])
-        hookdir = pathlib.Path(
-            stack.enter_context(tempfile.TemporaryDirectory()))
-        hook = hookdir / "D50aptupdate"
-        hook.write_text("""#/bin/sh
+        hookdirname, addhook = stack.enter_context(hookdir())
+        addhook(
+            "D",
+            """#/bin/sh
 set -e
 apt-get --error-on=any update
 %s dist-upgrade
-""" % shlex.join(apt_get))
-        hook.chmod(0o755)
+"""
+            % shlex.join(apt_get),
+        )
         if build.get("lintian", {}).get("run", False):
-            hook = hookdir / "B90lintian"
-            hook.write_text("""#!/bin/sh
+            addhook(
+                "B",
+                """#!/bin/sh
 set -e
 %s install lintian
 runuser -u pbuilder -- lintian %s "${BUILDDIR:-/tmp/buildd}"/*.changes
-""" % (shlex.join(apt_get), shlex.join(build["lintian"].get("options", []))))
-            hook.chmod(0o755)
-        cmd.extend(["--hookdir", str(hookdir), *args.pbuilderopts,
+"""
+                % (
+                    shlex.join(apt_get),
+                    shlex.join(build["lintian"].get("options", [])),
+                ),
+            )
+        cmd.extend(["--hookdir", str(hookdirname), *args.pbuilderopts,
                     str(stack.enter_context(get_dsc(build)))])
         ret = subprocess.call(cmd, env=compute_env(build),
                               stdout=None if enablelog