Add recipe to build CIPD package with relocatable Conda environment.

scripts/slave/recipe_modules/conda/resources/butcher_conda.py

Index: scripts/slave/recipe_modules/conda/resources/butcher_conda.py
diff --git a/scripts/slave/recipe_modules/conda/resources/butcher_conda.py b/scripts/slave/recipe_modules/conda/resources/butcher_conda.py
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index 0000000000000000000000000000000000000000..53031c75a2310e42af05051789d224740a9820d9
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+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Attempts to remove references to Conda installation directory to make the
+environment more relocatable in exchange for its modifiability.
+
+No new package can be installed into a butchered environment.
+
+Works great on Mac and Win, but doesn't really makes the environment prefix
+independent on Linux, since Linux binaries like to have prefix hardcoded.
+
+Everything seems to work even on Linux though, but watch out for weirdness.
+
+Helpful links:
+  https://github.com/conda/conda-recipes
+  http://conda.pydata.org/docs/building/meta-yaml.html#relocatable
+"""
+
+import ast
+import glob
+import os
+import shutil
+import sys
+
+
+IS_WIN = sys.platform in ('win32', 'cygwin')
+
+
+def main(conda_dir):
+  butcher_bin(conda_dir)
+  butcher_conda_meta(conda_dir)
+  butcher_include(conda_dir)
+  butcher_lib(conda_dir)
+  butcher_pkgs(conda_dir)
+  butcher_pyqt(conda_dir)
+
+
+def butcher_bin(conda_dir):
+  if IS_WIN:
+    bin_dir = os.path.join(conda_dir, 'Library', 'bin')
+  else:
+    bin_dir = os.path.join(conda_dir, 'bin')
+
+  whitelist = [
+    'python', # relative symlink to python2.7, keep it, it's cute
+  ]
+  blacklist = [
+    'c_rehash',        # perl script with references to local prefix
+    'cairo-trace',     # not needed
+    'freetype-config', # we won't be linking to freetype
+    'libpng16-config', # same
+    'xml2-config',     # same
+    'pyuic4',          # just use PyQt4/uic/pyuic.py directly
+    'pyuic4.bat',      # same
+    'qt.conf',         # Qt manages to work without it
+  ]
+
+  def is_naughty_shell_script(path):
+    """True if script's shebang points to local prefix."""
+    if IS_WIN:
+      return False
+    with open(path, 'r') as f:
+      return f.read(1024).startswith('#!' + bin_dir)
+
+  # Remove meaningless symlinks and shell scripts that'll broke when relocated.
+  # 'python' stays, it is all that matters.
+  for p in os.listdir(bin_dir):
+    full = os.path.join(bin_dir, p)
+    kill_it = not (p in whitelist or os.path.isdir(full)) and (
+      p in blacklist or
+      os.path.islink(full) or
+      is_naughty_shell_script(full))
+    if kill_it:
+      kill_file(full)
+
+
+def butcher_conda_meta(conda_dir):
+  # 'conda-meta' contains history of local commands with full paths, as well
+  # as ton of *.json files referencing local paths. We aren't going to install
+  # any more conda packages, no need for meta files.
+  kill_dir(os.path.join(conda_dir, 'conda-meta'))
+
+
+def butcher_include(conda_dir):
+  # Header files? Where we're going we don't need header files.
+  # But in case we do, a special care must be given to openssl/opensslconf.h,
+  # it references local prefix.
+  kill_dir(os.path.join(conda_dir, 'include'))
+
+
+def butcher_lib(conda_dir):
+  if IS_WIN:
+    lib = os.path.join(conda_dir, 'Library', 'lib')
+  else:
+    lib = os.path.join(conda_dir, 'lib')
+
+  # We aren't going to build Tk\Tcl extensions, it's not 80s.
+  kill_file(os.path.join(lib, 'tclConfig.sh'))
+  kill_file(os.path.join(lib, 'tkConfig.sh'))
+
+  # That's all for Win.
+  if IS_WIN:
+    return
+
+  # We won't be using cmake.
+  kill_dir(os.path.join(lib, 'cmake'))
+
+  # We aren't going to build C stuff, kill libtool and pkg-config files.
+  kill_glob(os.path.join(lib, '*.la'))
+  kill_glob(os.path.join(lib, 'cairo', '*.la'))
+  kill_dir(os.path.join(lib, 'pkgconfig'))
+
+  # We aren't be building python extensions at all, in fact.
+  kill_file(os.path.join(lib, 'python2.7', 'config', 'Makefile'))
+
+  # This file looks important, let's patch it instead of removing.
+  sysconf = os.path.join(lib, 'python2.7', '_sysconfigdata.py')
+  if patch_file(sysconf, conda_dir):
+    kill_file(os.path.join(lib, 'python2.7', '_sysconfigdata.pyc'))
+    kill_file(os.path.join(lib, 'python2.7', '_sysconfigdata.pyo'))
+
+
+def butcher_pkgs(conda_dir):
+  # pkgs contains unpacked Conda packages that act as source of hardlinks that
+  # gets installed into actual prefix. Since its hard links, it's OK to remove
+  # originals (thus "converting" hardlinks into regular files).
+  kill_dir(os.path.join(conda_dir, 'pkgs')) # TODO: Windows?
+
+
+def butcher_pyqt(conda_dir):
+  if IS_WIN:
+    prefix = os.path.join(conda_dir, 'Library')
+  else:
+    prefix = conda_dir
+
+  # We won't be using qmake.
+  kill_glob(os.path.join(prefix, 'lib', '*.prl'))
+  kill_dir(os.path.join(prefix, 'mkspecs'))
+
+  # We don't care about Qt4 tests.
+  kill_dir(os.path.join(prefix, 'tests', 'qt4'))
+
+  if not IS_WIN:
+    # We won't by using PyQt build system.
+    kill_file(
+        os.path.join(
+            conda_dir, 'lib', 'python2.7', 'site-packages', 'sipconfig.py'))
+
+    # This file looks important, let's patch it instead.
+    patch_file(
+        os.path.join(
+            conda_dir, 'lib', 'python2.7', 'site-packages',
+            'PyQt4', 'pyqtconfig.py'),
+        conda_dir)
+  else:
+    kill_file(os.path.join(conda_dir, 'qt.conf'))
+
+
+###
+
+
+def patch_file(path, prefix):
+  """Replaces references to 'prefix' with '/opt/fake-python-prefix'."""
+  with open(path, 'rb') as f:
+    blob = f.read()
+  if prefix.endswith('/') or prefix.endswith('\\'):
+    prefix = prefix[:-1]
+  if IS_WIN:
+    fake_prefix = 'C:\\fake-python-prefix'
+  else:
+    fake_prefix = '/opt/fake-python-prefix'
+  modified = blob.replace(prefix, fake_prefix)
+  if modified != blob:
+    print 'Patching %s' % os.path.basename(path)
+    with open(path, 'wb') as f:
+      f.write(modified)
+    return True
+  return False
+
+
+def kill_file(path):
+  if os.path.exists(path) or os.path.lexists(path):
+    print 'Removing %s' % os.path.basename(path)
+    os.remove(path)
+
+
+def kill_dir(path):
+  if os.path.exists(path):
+    print 'Removing %s directory' % os.path.basename(path)
+    shutil.rmtree(path)
+
+
+def kill_glob(path):
+  for p in glob.glob(path):
+    kill_file(p)
+
+
+if __name__ == '__main__':
+  sys.exit(main(os.path.abspath(sys.argv[1])))