Factor out venv-creating code from provision.py.

Move setup_virtualenv and do_setup_virtualenv from provision.py to
scripts/lib/setup_venv.py.

provision.py

@@ -5,14 +5,11 @@ import logging
 import platform
 import subprocess
 
-if False:
-    # Don't add a runtime dependency on typing
-    from typing import List
-
 os.environ["PYTHONUNBUFFERED"] = "y"
 
 sys.path.append(os.path.dirname(os.path.abspath(__file__)))
 from zulip_tools import run
+from scripts.lib.setup_venv import setup_virtualenv
 
 SUPPORTED_PLATFORMS = {
     "Ubuntu": [
@@ -25,13 +22,8 @@ NPM_VERSION = '3.9.3'
 VENV_PATH = "/srv/zulip-venv"
 PY3_VENV_PATH = "/srv/zulip-py3-venv"
 ZULIP_PATH = os.path.dirname(os.path.abspath(__file__))
-VENV_CACHE_PATH = "/srv/zulip-venv-cache"
 TRAVIS_NODE_PATH = os.path.join(os.environ['HOME'], 'node')
 
-if '--travis' in sys.argv:
-    # In Travis CI, we don't have root access
-    VENV_CACHE_PATH = os.path.join(os.environ['HOME'], "zulip-venv-cache")
-
 if not os.path.exists(os.path.join(ZULIP_PATH, ".git")):
     print("Error: No Zulip git repository present!")
     print("To setup the Zulip development environment, you should clone the code")
@@ -154,40 +146,6 @@ def install_npm():
     run(['sudo', 'ln', '-sf', npm_exe, travis_npm])
 
 
-def setup_virtualenv(target_venv_path, requirements_file, virtualenv_args=None):
-    # type: (str, str, List[str]) -> None
-
-    # Check if a cached version already exists
-    path = os.path.join(ZULIP_PATH, 'tools', 'hash_reqs.py')
-    output = subprocess.check_output([path, requirements_file])
-    sha1sum = output.split()[0]
-    cached_venv_path = os.path.join(VENV_CACHE_PATH, sha1sum, os.path.basename(target_venv_path))
-    success_stamp = os.path.join(cached_venv_path, "success-stamp")
-    if not os.path.exists(success_stamp):
-        do_setup_virtualenv(cached_venv_path, requirements_file, virtualenv_args or [])
-        run(["touch", success_stamp])
-
-    print("Using cached Python venv from %s" % (cached_venv_path,))
-    run(["sudo", "ln", "-nsf", cached_venv_path, target_venv_path])
-    activate_this = os.path.join(target_venv_path, "bin", "activate_this.py")
-    exec(open(activate_this).read(), {}, dict(__file__=activate_this)) # type: ignore # https://github.com/python/mypy/issues/1577
-
-def do_setup_virtualenv(venv_path, requirements_file, virtualenv_args):
-    # type: (str, str, List[str]) -> None
-
-    # Setup Python virtualenv
-    run(["sudo", "rm", "-rf", venv_path])
-    run(["sudo", "mkdir", "-p", venv_path])
-    run(["sudo", "chown", "{}:{}".format(os.getuid(), os.getgid()), venv_path])
-    run(["virtualenv"] + virtualenv_args + [venv_path])
-
-    # Switch current Python context to the virtualenv.
-    activate_this = os.path.join(venv_path, "bin", "activate_this.py")
-    exec(open(activate_this).read(), {}, dict(__file__=activate_this)) # type: ignore # https://github.com/python/mypy/issues/1577
-
-    run(["pip", "install", "--upgrade", "pip"])
-    run(["pip", "install", "--no-deps", "--requirement", requirements_file])
-
 def main():
     # type: () -> int
     run(["sudo", "apt-get", "update"])

scripts/lib/setup_venv.py

@@ -0,0 +1,52 @@
+from __future__ import print_function
+
+import os
+import sys
+from os.path import dirname, abspath
+import subprocess
+from zulip_tools import run
+
+ZULIP_PATH = dirname(dirname(dirname(abspath(__file__))))
+VENV_CACHE_PATH = "/srv/zulip-venv-cache"
+
+if '--travis' in sys.argv:
+    # In Travis CI, we don't have root access
+    VENV_CACHE_PATH = os.path.join(os.environ['HOME'], "zulip-venv-cache")
+
+if False:
+    # Don't add a runtime dependency on typing
+    from typing import List
+
+def setup_virtualenv(target_venv_path, requirements_file, virtualenv_args=None):
+    # type: (str, str, List[str]) -> None
+
+    # Check if a cached version already exists
+    path = os.path.join(ZULIP_PATH, 'tools', 'hash_reqs.py')
+    output = subprocess.check_output([path, requirements_file])
+    sha1sum = output.split()[0]
+    cached_venv_path = os.path.join(VENV_CACHE_PATH, sha1sum, os.path.basename(target_venv_path))
+    success_stamp = os.path.join(cached_venv_path, "success-stamp")
+    if not os.path.exists(success_stamp):
+        do_setup_virtualenv(cached_venv_path, requirements_file, virtualenv_args or [])
+        run(["touch", success_stamp])
+
+    print("Using cached Python venv from %s" % (cached_venv_path,))
+    run(["sudo", "ln", "-nsf", cached_venv_path, target_venv_path])
+    activate_this = os.path.join(target_venv_path, "bin", "activate_this.py")
+    exec(open(activate_this).read(), {}, dict(__file__=activate_this)) # type: ignore # https://github.com/python/mypy/issues/1577
+
+def do_setup_virtualenv(venv_path, requirements_file, virtualenv_args):
+    # type: (str, str, List[str]) -> None
+
+    # Setup Python virtualenv
+    run(["sudo", "rm", "-rf", venv_path])
+    run(["sudo", "mkdir", "-p", venv_path])
+    run(["sudo", "chown", "{}:{}".format(os.getuid(), os.getgid()), venv_path])
+    run(["virtualenv"] + virtualenv_args + [venv_path])
+
+    # Switch current Python context to the virtualenv.
+    activate_this = os.path.join(venv_path, "bin", "activate_this.py")
+    exec(open(activate_this).read(), {}, dict(__file__=activate_this)) # type: ignore # https://github.com/python/mypy/issues/1577
+
+    run(["pip", "install", "--upgrade", "pip"])
+    run(["pip", "install", "--no-deps", "--requirement", requirements_file])