Fix unclosed files

Python will eventually close open files, but it is recommended to
explicitly close them instead of waiting for the gc or program exit.

This fixes all the uses of open...read/write in the codebase, mostly in
tests.

src/pylorax/sysutils.py

@@ -45,8 +45,8 @@ def joinpaths(*args, **kwargs):
 
 
 def touch(fname):
-    # python closes the file when it goes out of scope
+    with open(fname, "w") as f:
-    open(fname, "w").write("")
+        f.write("")
 
 
 def replace(fname, find, sub):

tests/lib.py

@@ -96,7 +96,8 @@ def create_git_repo():
         test_results["second"].append(os.path.join("only-bps/", f))
 
     # Add a dotfile as well
-    open(os.path.join(repodir, "only-bps/.bpsrc"), "w").write("dotfile test\n")
+    with open(os.path.join(repodir, "only-bps/.bpsrc"), "w") as f:
+        f.write("dotfile test\n")
     test_results["second"].append("only-bps/.bpsrc")
     test_results["second"] = sorted(test_results["second"])
 

tests/pylorax/test_creator.py

@@ -37,8 +37,10 @@ from pylorax.sysutils import joinpaths
 def mkFakeBoot(root_dir):
     """Create a fake kernel and initrd"""
     os.makedirs(joinpaths(root_dir, "boot"))
-    open(joinpaths(root_dir, "boot", "vmlinuz-4.18.13-200.fc28.x86_64"), "w").write("I AM A FAKE KERNEL")
+    with open(joinpaths(root_dir, "boot", "vmlinuz-4.18.13-200.fc28.x86_64"), "w") as f:
-    open(joinpaths(root_dir, "boot", "initramfs-4.18.13-200.fc28.x86_64.img"), "w").write("I AM A FAKE INITRD")
+        f.write("I AM A FAKE KERNEL")
+    with open(joinpaths(root_dir, "boot", "initramfs-4.18.13-200.fc28.x86_64.img"), "w") as f:
+        f.write("I AM A FAKE INITRD")
 
 
 class CreatorTest(unittest.TestCase):
@@ -92,13 +94,15 @@ class CreatorTest(unittest.TestCase):
 
         # A fake disk image
         with tempfile.NamedTemporaryFile(prefix="lorax.test.disk.") as disk_img:
-            open(disk_img.name, "wb").write(b"THIS IS A FAKE DISK IMAGE FILE")
+            with open(disk_img.name, "wb") as f:
+                f.write(b"THIS IS A FAKE DISK IMAGE FILE")
             with tempfile.NamedTemporaryFile(prefix="lorax.test.appliance.") as output_xml:
                 make_appliance(disk_img.name, "test-appliance", appliance_template, output_xml.name,
                               ["eth0", "eth1"], ram=4096, vcpus=8, arch="x86_64",
                               title="Lorax Test", project="Fedora", releasever="30")
 
-                print(open(output_xml.name).read())
+                with open(output_xml.name) as f:
+                    print(f.read())
                 # Parse the XML and check for known fields
                 tree = ET.parse(output_xml.name)
                 image = tree.getroot()
@@ -127,13 +131,16 @@ class CreatorTest(unittest.TestCase):
             template = joinpaths(lorax_templates, "pxe-live/pxe-config.tmpl")
 
             # Make a fake kernel and initrd
-            open(joinpaths(work_dir, "vmlinuz-4.18.13-200.fc28.x86_64"), "w").write("I AM A FAKE KERNEL")
+            with open(joinpaths(work_dir, "vmlinuz-4.18.13-200.fc28.x86_64"), "w") as f:
-            open(joinpaths(work_dir, "initramfs-4.18.13-200.fc28.x86_64.img"), "w").write("I AM A FAKE INITRD")
+                f.write("I AM A FAKE KERNEL")
+            with open(joinpaths(work_dir, "initramfs-4.18.13-200.fc28.x86_64.img"), "w") as f:
+                f.write("I AM A FAKE INITRD")
 
             # Create the PXE_CONFIG in work_dir
             create_pxe_config(template, work_dir, live_image_name, add_pxe_args)
-            print(open(joinpaths(work_dir, "PXE_CONFIG")).read())
+            with open(joinpaths(work_dir, "PXE_CONFIG")) as f:
-            pxe_config = open(joinpaths(work_dir, "PXE_CONFIG")).read()
+                pxe_config = f.read()
+            print(pxe_config)
             self.assertTrue("vmlinuz-4.18.13-200.fc28.x86_64" in pxe_config)
             self.assertTrue("initramfs-4.18.13-200.fc28.x86_64.img" in pxe_config)
             self.assertTrue("/live-rootfs.squashfs.img ostree=/mnt/sysimage/" in pxe_config)

tests/pylorax/test_executils.py

@@ -66,7 +66,8 @@ class ExecUtilsTest(unittest.TestCase):
             self.assertEqual(rc, 1)
 
             tmp_f.file.close()
-            logged_text = open(tmp_f.name, "r").readlines()[-1].strip()
+            with open(tmp_f.name, "r") as f:
+                logged_text = f.readlines()[-1].strip()
             self.assertEqual(logged_text, "The Once-ler was here.")
         finally:
             os.unlink(tmp_f.name)

tests/pylorax/test_imgutils.py

@@ -45,7 +45,8 @@ def mkfakerootdir(rootdir):
     for f in files:
         if not os.path.isdir(joinpaths(rootdir, os.path.dirname(f))):
             os.makedirs(joinpaths(rootdir, os.path.dirname(f)))
-        open(joinpaths(rootdir, f), "w").write("I AM FAKE FILE %s" % f.upper())
+        with open(joinpaths(rootdir, f), "w") as ff:
+            ff.write("I AM FAKE FILE %s" % f.upper())
 
 def mkfakebootdir(bootdir):
     """Populate a fake /boot directory with a kernel and initrd
@@ -53,8 +54,10 @@ def mkfakebootdir(bootdir):
     :param bootdir: An existing directory to create files/dirs under
     :type bootdir: str
     """
-    open(joinpaths(bootdir, "vmlinuz-4.18.13-200.fc28.x86_64"), "w").write("I AM A FAKE KERNEL")
+    with open(joinpaths(bootdir, "vmlinuz-4.18.13-200.fc28.x86_64"), "w") as f:
-    open(joinpaths(bootdir, "initramfs-4.18.13-200.fc28.x86_64.img"), "w").write("I AM A FAKE INITRD")
+        f.write("I AM A FAKE KERNEL")
+    with open(joinpaths(bootdir, "initramfs-4.18.13-200.fc28.x86_64.img"), "w") as f:
+        f.write("I AM A FAKE INITRD")
 
 def mkfakediskimg(disk_img):
     """Create a fake partitioned disk image

tests/pylorax/test_ltmpl.py

@@ -177,7 +177,9 @@ class LoraxTemplateRunnerTestCase(unittest.TestCase):
         """Test append, and install template commands"""
         self.runner.run("install-cmd.tmpl")
         self.assertTrue(os.path.exists(joinpaths(self.root_dir, "/etc/lorax-test")))
-        self.assertEqual(open(joinpaths(self.root_dir, "/etc/lorax-test")).read(), "TESTING LORAX TEMPLATES\n")
+        with open(joinpaths(self.root_dir, "/etc/lorax-test")) as f:
+            data = f.read()
+        self.assertEqual(data, "TESTING LORAX TEMPLATES\n")
         self.assertTrue(os.path.exists(joinpaths(self.root_dir, "/etc/lorax-test-dest")))
 
     def test_installimg(self):
@@ -194,7 +196,9 @@ class LoraxTemplateRunnerTestCase(unittest.TestCase):
         """Test append, and replace template command"""
         self.runner.run("replace-cmd.tmpl")
         self.assertTrue(os.path.exists(joinpaths(self.root_dir, "/etc/lorax-replace")))
-        self.assertEqual(open(joinpaths(self.root_dir, "/etc/lorax-replace")).read(), "Running 1.2.3 for lorax\n")
+        with open(joinpaths(self.root_dir, "/etc/lorax-replace")) as f:
+            data = f.read()
+        self.assertEqual(data, "Running 1.2.3 for lorax\n")
 
     def test_treeinfo(self):
         """Test treeinfo template command"""

tests/pylorax/test_sysutils.py

@@ -27,7 +27,8 @@ class SysUtilsTest(unittest.TestCase):
         self.assertEqual(joinpaths("foo", "bar", "baz"), "foo/bar/baz")
 
         with tempfile.TemporaryDirectory() as tdname:
-            open(os.path.join(tdname, "real-file"), "w").write("lorax test file")
+            with open(os.path.join(tdname, "real-file"), "w") as f:
+                f.write("lorax test file")
             os.symlink(os.path.join(tdname, "real-file"), os.path.join(tdname, "link-file"))
 
             self.assertEqual(joinpaths(tdname, "link-file", follow_symlinks=True),
@@ -46,7 +47,9 @@ class SysUtilsTest(unittest.TestCase):
         f.close()
         replace(f.name, "@AARDVARKS@", "ant eaters")
 
-        self.assertEqual(open(f.name).readline(), "A few words to apply ant eaters testing\n")
+        with open(f.name) as fr:
+            line = fr.readline()
+        self.assertEqual(line, "A few words to apply ant eaters testing\n")
         os.unlink(f.name)
 
     @unittest.skipUnless(os.geteuid() == 0, "requires root privileges")
@@ -61,7 +64,8 @@ class SysUtilsTest(unittest.TestCase):
 
     def test_remove(self):
         remove_file="/var/tmp/lorax-test-remove-file"
-        open(remove_file, "w").write("test was here")
+        with open(remove_file, "w") as f:
+            f.write("test was here")
         remove(remove_file)
         self.assertFalse(os.path.exists(remove_file))
 
@@ -69,7 +73,8 @@ class SysUtilsTest(unittest.TestCase):
         with tempfile.TemporaryDirectory() as tdname:
             path = os.path.join("one", "two", "three")
             os.makedirs(os.path.join(tdname, path))
-            open(os.path.join(tdname, path, "lorax-link-test-file"), "w").write("test was here")
+            with open(os.path.join(tdname, path, "lorax-link-test-file"), "w") as f:
+                f.write("test was here")
 
             linktree(os.path.join(tdname, "one"), os.path.join(tdname, "copy"))