Change compress to use communicate instead of wait

Also move default_image_name into imgutils so it can be used in other
places.

When running from lorax-composer the wait() call wasn't waiting until
the tar was finished. I think this is due to gevent monkey-patching
something. Using communicate() solves this problem.

src/pylorax/imgutils.py

@@ -62,7 +62,7 @@ def compress(command, rootdir, outfile, compression="xz", compressargs=None):
         archive = Popen(command, stdin=find.stdout, stdout=PIPE, cwd=rootdir)
         comp = Popen([compression] + compressargs,
                      stdin=archive.stdout, stdout=open(outfile, "wb"))
-        comp.wait()
+        (_stdout, _stderr) = comp.communicate()
         return comp.returncode
     except OSError as e:
         logger.error(e)
@@ -308,6 +308,18 @@ def estimate_size(rootdir, graft=None, fstype=None, blocksize=4096, overhead=128
         total = max(256*1024*1024, total) # btrfs minimum size: 256MB
     return total
 
+def default_image_name(compression, basename):
+    """ Return a default image name with the correct suffix for the compression type.
+
+    :param str compression: Compression type
+    :param str basename: Base filename
+    :returns: basename with compression suffix
+
+    If the compression is unknown it defaults to xz
+    """
+    SUFFIXES = {"xz": ".xz", "gzip": ".gz", "bzip2": ".bz2", "lzma": ".lzma"}
+    return basename + SUFFIXES.get(compression, ".xz")
+
 ######## Execution contexts - use with the 'with' statement ##############
 
 class LoopDev(object):

src/pylorax/installer.py

@@ -288,11 +288,13 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
     else:
         # If anaconda failed the disk image may still be in use by dm
         execWithRedirect("anaconda-cleanup", [])
-        dm_name = os.path.splitext(os.path.basename(disk_img))[0]
+
-        dm_path = "/dev/mapper/"+dm_name
+        if disk_img:
-        if os.path.exists(dm_path):
+            dm_name = os.path.splitext(os.path.basename(disk_img))[0]
-            dm_detach(dm_path)
+            dm_path = "/dev/mapper/"+dm_name
-            loop_detach(get_loop_name(disk_img))
+            if os.path.exists(dm_path):
+                dm_detach(dm_path)
+                loop_detach(get_loop_name(disk_img))
 
     if selinux_enforcing:
         selinux.security_setenforce(1)
@@ -307,6 +309,7 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
 
         rc = mktar(ROOT_PATH, disk_img, opts.compression, compress_args)
         shutil.rmtree(ROOT_PATH)
+        log.info("tar finished with rc=%d", rc)
 
         if rc:
             raise InstallError("novirt_install failed")

src/sbin/livemedia-creator

@@ -36,7 +36,7 @@ from pylorax import vernum
 from pylorax.creator import DRACUT_DEFAULT, mount_boot_part_over_root
 from pylorax.creator import make_appliance, make_image, make_livecd, make_live_images
 from pylorax.creator import make_runtime, make_squashfs
-from pylorax.imgutils import copytree
+from pylorax.imgutils import copytree, default_image_name
 from pylorax.imgutils import Mount, PartitionMount, umount
 from pylorax.installer import InstallError
 from pylorax.sysutils import joinpaths
@@ -223,19 +223,6 @@ def setup_logging(opts):
     program_log.addHandler(fh)
 
 
-def default_image_name(compression, basename):
-    """ Return a default image name with the correct suffix for the compression type.
-
-    :param str compression: Compression type
-    :param str basename: Base filename
-    :returns: basename with compression suffix
-
-    If the compression is unknown it defaults to xz
-    """
-    SUFFIXES = {"xz": ".xz", "gzip": ".gz", "bzip2": ".bz2", "lzma": ".lzma"}
-    return basename + SUFFIXES.get(compression, ".xz")
-
-
 def main():
     # parse the arguments
     parser = lorax_parser()