Add recipe to build CIPD package with relocatable Conda environment.

scripts/slave/recipe_modules/conda/api.py

Index: scripts/slave/recipe_modules/conda/api.py
diff --git a/scripts/slave/recipe_modules/conda/api.py b/scripts/slave/recipe_modules/conda/api.py
new file mode 100644
index 0000000000000000000000000000000000000000..b52141a100d142350feecd417aa8e246398359eb
--- /dev/null
+++ b/scripts/slave/recipe_modules/conda/api.py
@@ -0,0 +1,120 @@
+# 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.
+
+"""Functions to work with Miniconda python environment.
+
+See http://conda.pydata.org/miniconda.html
+"""
+
+from recipe_engine import recipe_api
+
+
+class CondaEnv(object):
+  def __init__(self, module_api, version, path):
+    self._module_api = module_api
+    self.version = version
+    self.path = path
+    self._wiped = False
+
+  def __enter__(self, *_args):
+    return self
+
+  def __exit__(self, *_args):
+    self.wipe()
+
+  @property
+  def conda_exe(self):
+    """Path to 'conda' executable."""
+    if self._module_api.m.platform.is_win:
+      return self.path.join('Scripts', 'conda.exe')
+    return self.path.join('bin', 'conda')
+
+  def install(self, pkg):
+    """Installs a conda package into the environment."""
+    return self._call(['install', pkg])
+
+  def convert_to_cipd_package(self, package_name, output_file):
+    """Packages Conda environment as CIPD package.
+
+    It also breaks it in the process (by irreversibly mutating it to be
+    prefix independent, as much as possible). It is not possible to install
+    new packages into the environment once it has been mutated.
+
+    Args:
+      package_name: name of the CIPD package, 'infra/conda_python/linux-amd64'.
+      output_file: path to put *.cipd package to.
+    """
+    self._call(['clean', '--tarballs', '--index-cache', '--packages'])
+    self._module_api.m.python(
+        'make conda env location independent',
+        self._module_api.resource('butcher_conda.py'),
+        args=[self.path])
+    self._module_api.m.cipd.build(
+        input_dir=self.path,
+        output_package=output_file,
+        package_name=package_name,
+        install_mode='copy')
+
+  def wipe(self):
+    """Wipes the directory with Conda installation."""
+    if not self._wiped:
+      self._wiped = True
+      self._module_api.m.file.rmtree('removing conda', self.path)
+
+  def _call(self, cmd):
+    return self._module_api.m.step(
+        ' '.join(['conda'] + cmd),
+        [self.conda_exe] + cmd + ['--yes'],
+        env={'PYTHONPATH': None})
+
+
+class CondaApi(recipe_api.RecipeApi):
+  def install(self, version, path):
+    """Downloads Miniconda installer for given version and executes it.
+
+    Args:
+      version: version of Miniconda to install, e.g. 'Miniconda2-3.18.3'.
+      path: prefix to install Miniconda into.
+
+    Returns:
+      Instance of CondaEnv, that also optionally acts as context manager that
+      deletes the environment on exit.
+    """
+    # Construct URL to installer. See https://repo.continuum.io/miniconda/.
+    os = {
+      'linux': 'Linux',
+      'mac': 'MacOSX',
+      'win': 'Windows',
+    }[self.m.platform.name]
+    arch = {
+      32: 'x86',
+      64: 'x86_64',
+    }[self.m.platform.bits]
+    ext = '.exe' if self.m.platform.is_win else '.sh'
+    url = (
+        'https://repo.continuum.io/miniconda/%s-%s-%s%s' %
+        (version, os, arch, ext))
+
+    # Fetch installer into temp directory and install Conda to 'path'.
+    # We acknowledge the license agreement.
+    tmp = self.m.path.mkdtemp('conda')
+    installer = tmp.join(url[url.rfind('/')+1:])
+    try:
+      self.m.url.fetch_to_file(
+          url=url,
+          path=installer,
+          step_name='fetch miniconda installer',
+          attempts=5)
+      # See http://conda.pydata.org/docs/help/silent.html
+      if self.m.platform.is_win:
+        install_cmd = [
+          installer, '/InstallationType=JustMe', '/AddToPath=0',
+          '/RegisterPython=0', '/S', '/D=' + str(path),
+        ]
+      else:
+        install_cmd = ['/bin/bash', installer, '-b', '-p', path]
+      self.m.step('install miniconda', install_cmd, env={'PYTHONPATH': ''})
+      return CondaEnv(self, version, path)
+    finally:
+      self.m.file.rmtree('remove miniconda installer', tmp)