From 03e8e8413d9c89a5b8fb05e912992e578bec285d Mon Sep 17 00:00:00 2001
From: Pavel Raiskup <praiskup@redhat.com>
Date: Jun 06 2019 07:31:27 +0000
Subject: [rpmbuild] clean /var/cache/mock automatically


This is to prevent "no space left on device" on / partition.
Since we recycle user-dedicated builder machines heavily, we need
to clean directories like

    $ ls -1 /var/cache/mock
    BUILD_ID-fedora-rawhide-x86_64
    BUILD_ID-fedora-rawhide-x86_64-bootstrap

which contain yum/dnf caches there (soon to be enabled), and
mock's root_cache.

If we don't do this, after several (tens?) of builds on the same
builder, the / partition might be wasted.  This is especially
important in Fedora Copr on aarch64 where we have small disks.

---

diff --git a/rpmbuild/copr_rpmbuild/builders/mock.py b/rpmbuild/copr_rpmbuild/builders/mock.py
index 30fa1a1..66f9658 100644
--- a/rpmbuild/copr_rpmbuild/builders/mock.py
+++ b/rpmbuild/copr_rpmbuild/builders/mock.py
@@ -9,6 +9,7 @@ from ..helpers import locate_spec, locate_srpm, CONF_DIRS, get_mock_uniqueext, G
 
 log = logging.getLogger("__main__")
 
+MOCK_CALL = ['unbuffer', 'mock']
 
 class MockBuilder(object):
     def __init__(self, task, sourcedir, resultdir, config):
@@ -34,10 +35,13 @@ class MockBuilder(object):
 
         spec = locate_spec(self.sourcedir)
         shutil.copy(spec, self.resultdir)
-        self.produce_srpm(spec, self.sourcedir, configdir, self.resultdir)
+        try:
+            self.produce_srpm(spec, self.sourcedir, configdir, self.resultdir)
 
-        srpm = locate_srpm(self.resultdir)
-        self.produce_rpm(srpm, configdir, self.resultdir)
+            srpm = locate_srpm(self.resultdir)
+            self.produce_rpm(srpm, configdir, self.resultdir)
+        finally:
+            self.clean_cache(configdir)
 
     def prepare_configs(self, configdir):
         site_config_path = os.path.join(configdir, "site-defaults.cfg")
@@ -65,8 +69,7 @@ class MockBuilder(object):
                                repos=self.repos, pkg_manager_conf=self.pkg_manager_conf)
 
     def produce_srpm(self, spec, sources, configdir, resultdir):
-        cmd = [
-            "unbuffer", "/usr/bin/mock",
+        cmd = MOCK_CALL + [
             "--buildsrpm",
             "--spec", spec,
             "--sources", sources,
@@ -94,9 +97,18 @@ class MockBuilder(object):
         if process.returncode != 0:
             raise RuntimeError("Build failed")
 
+    @classmethod
+    def clean_cache(cls, configdir):
+        """ Do best effort /var/mock/cache cleanup. """
+        cmd = MOCK_CALL + [
+            "--configdir", configdir,
+            "-r", "child",
+            "--scrub", "cache",
+        ]
+        subprocess.call(cmd) # ignore failure here, if any
 
     def produce_rpm(self, srpm, configdir, resultdir):
-        cmd = ["unbuffer", "/usr/bin/mock",
+        cmd = MOCK_CALL + [
                "--rebuild", srpm,
                "--configdir", configdir,
                "--resultdir", resultdir,
diff --git a/rpmbuild/tests/test_mock.py b/rpmbuild/tests/test_mock.py
index c5b3607..473c67e 100644
--- a/rpmbuild/tests/test_mock.py
+++ b/rpmbuild/tests/test_mock.py
@@ -87,7 +87,7 @@ class TestMockBuilder(unittest.TestCase):
         process = mock.MagicMock(returncode=0)
         popen_mock.return_value = process
         builder.produce_rpm("/path/to/pkg.src.rpm", "/path/to/configs", "/path/to/results")
-        assert_cmd = ['unbuffer', '/usr/bin/mock',
+        assert_cmd = ['unbuffer', 'mock',
                       '--rebuild', '/path/to/pkg.src.rpm',
                       '--configdir', '/path/to/configs',
                       '--resultdir', '/path/to/results',