Revert "cros_sdk: support downloading both xz and bz2 images"

This reverts commit 8b9b634d260cd56df929094b056f8d145d6dd189

Seems to have broken the sdk builder:
http://build.chromium.org/p/chromiumos/builders/chromiumos%20sdk/builds/1606/steps/cbuildbot/logs/stdio

INFO: RunCommand: ['cros_sdk', '--chroot', 'new-sdk-chroot', '--download', '--replace', '--url', 'file:///b/cbuild/built-sdk.tbz2'] in /b/cbuild
Attempting download: file:///b/cbuild/built-sdk.tbz2
cros_sdk: Unhandled exception:
Traceback (most recent call last):
  File "/b/cbuild/chromite/bin/cros_sdk", line 67, in <module>
    ret = target()
  File "/b/cbuild/chromite/scripts/cros_sdk.py", line 398, in main
    chroot_path, options.replace)
  File "/b/cbuild/chromite/scripts/cros_sdk.py", line 205, in CreateChroot
    sdk = FetchRemoteTarballs(urls)
  File "/b/cbuild/chromite/scripts/cros_sdk.py", line 126, in FetchRemoteTarballs
    raise Exception('No valid URLs found!')
Exception: No valid URLs found!
Change-Id: I1b921eb728bc4d7dd995617f0110d3250811806b
Reviewed-on: https://gerrit.chromium.org/gerrit/21845
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_sdk.py b/scripts/cros_sdk.py
index 2cd3b32..848058a 100644
--- a/scripts/cros_sdk.py
+++ b/scripts/cros_sdk.py
@@ -21,8 +21,6 @@
 
 
 DEFAULT_URL = 'https://commondatastorage.googleapis.com/chromiumos-sdk/'
-SDK_SUFFIXES = ['.tbz2', '.tar.xz']
-
 SRC_ROOT = os.path.realpath(constants.SOURCE_ROOT)
 SDK_DIR = os.path.join(SRC_ROOT, 'sdks')
 OVERLAY_DIR = os.path.join(SRC_ROOT, 'src/third_party/chromiumos-overlay')
@@ -74,24 +72,17 @@
   return buf[1].strip('"')
 
 
-def GetArchStageTarballs(tarballArch, version):
+def GetArchStageTarball(tarballArch, version):
   """Returns the URL for a given arch/version"""
   D = { 'x86_64': 'cros-sdk-' }
   try:
-    return [DEFAULT_URL + D[tarballArch] + version + x for x in SDK_SUFFIXES]
+    return DEFAULT_URL + D[tarballArch] + version + '.tbz2'
   except KeyError:
     raise SystemExit('Unsupported arch: %s' % (tarballArch,))
 
 
-def FetchRemoteTarballs(urls):
-  """Fetches a tarball given by url, and place it in sdk/.
-
-  Args:
-    urls: List of URLs to try to download. Download will stop on first success.
-
-  Returns:
-    Full path to the downloaded file
-  """
+def FetchRemoteTarball(url):
+  """Fetches a tarball given by url, and place it in sdk/."""
 
   def RunCurl(args, **kwargs):
     """Runs curl and wraps around all necessary hacks."""
@@ -109,22 +100,6 @@
 
     return result
 
-  def RemoteTarballExists(url):
-    """Tests if a remote tarball exists."""
-    result = RunCurl(['-I', url],
-                     redirect_stdout=True, redirect_stderr=True,
-                     print_cmd=False)
-    header = result.output.splitlines()[0]
-    return header.find('200 OK') != -1
-
-  url = None
-  for url in urls:
-    print 'Attempting download: %s' % url
-    if RemoteTarballExists(url):
-      break
-  else:
-    raise Exception('No valid URLs found!')
-
   tarball_name = os.path.basename(urlparse.urlparse(url).path)
   tarball_dest = os.path.join(SDK_DIR, tarball_name)
 
@@ -140,6 +115,7 @@
 
   curl_opts = ['-f', '--retry', '5', '-L', '-y', '30',
                '--output', tarball_dest]
+  print 'Downloading sdk: "%s"' % url
   if not url.startswith('file://') and os.path.exists(tarball_dest):
     # Only resume for remote URLs. If the file is local, there's no
     # real speedup, and using the same filename for different files
@@ -176,7 +152,7 @@
 
   stage = None
   if stage_url:
-    stage = FetchRemoteTarballs([stage_url])
+    stage = FetchRemoteTarball(stage_url)
 
   if stage:
     cmd.extend(['--stage3_path', stage])
@@ -197,12 +173,15 @@
 
   # Based on selections, fetch the tarball
   if sdk_url:
-    urls = [sdk_url]
+    url = sdk_url
   else:
     arch = GetHostArch()
-    urls = GetArchStageTarballs(arch, sdk_version)
+    if sdk_version:
+      url = GetArchStageTarball(arch, sdk_version)
+    else:
+      url = GetArchStageTarball(arch)
 
-  sdk = FetchRemoteTarballs(urls)
+  sdk = FetchRemoteTarball(url)
 
   # TODO(zbehan): Unpack and install
   # For now, we simply call make_chroot on the prebuilt chromeos-sdk.
@@ -232,11 +211,11 @@
 
 
 def _CreateLockFile(path):
-  """Create a lockfile via sudo that is writable by current user."""
-  cros_build_lib.SudoRunCommand(['touch', path], print_cmd=False)
-  cros_build_lib.SudoRunCommand(['chown', str(os.getuid()), path],
-                                print_cmd=False)
-  cros_build_lib.SudoRunCommand(['chmod', '644', path], print_cmd=False)
+   """Create a lockfile via sudo that is writable by current user."""
+   cros_build_lib.SudoRunCommand(['touch', path], print_cmd=False)
+   cros_build_lib.SudoRunCommand(['chown', str(os.getuid()), path],
+                                 print_cmd=False)
+   cros_build_lib.SudoRunCommand(['chmod', '644', path], print_cmd=False)
 
 
 def EnterChroot(chroot_path, chrome_root, chrome_root_mount, additional_args):
@@ -263,7 +242,7 @@
 
 def main(argv):
   # TODO(ferringb): make argv required once depot_tools is fixed.
-  usage = """usage: %prog [options] [VAR1=val1 .. VARn=valn -- <args>]
+  usage="""usage: %prog [options] [VAR1=val1 .. VARn=valn -- <args>]
 
 This script manages a local CrOS SDK chroot. Depending on the flags,
 it can download, build or enter a chroot.