setup_venv: Added get_venv_dependencies function.

Added a get_venv_dependencies() function in setup_venv.py which
returns VENV_DEPENDENCIES according to the vendor and os_version.
The reason for adding this function was because python-dev will be
depreciated in Focal but can be used as python2-dev so when adding
support for Focal VENV_DEPENDENCIES should to be os_version dependent.

scripts/lib/create-production-venv

@@ -10,7 +10,7 @@ if ZULIP_PATH not in sys.path:
 
 from scripts.lib.zulip_tools import os_families, overwrite_symlink, run, parse_os_release
 from scripts.lib.setup_venv import (
-    setup_virtualenv, VENV_DEPENDENCIES, REDHAT_VENV_DEPENDENCIES,
+    setup_virtualenv, get_venv_dependencies, REDHAT_VENV_DEPENDENCIES,
     FEDORA_VENV_DEPENDENCIES
 )
 
@@ -20,6 +20,9 @@ args = parser.parse_args()
 
 # install dependencies for setting up the virtualenv
 distro_info = parse_os_release()
+vendor = distro_info['ID']
+os_version = distro_info['VERSION_ID']
+VENV_DEPENDENCIES = get_venv_dependencies(vendor, os_version)
 if "debian" in os_families():
     run(["apt-get", "-y", "install"] + VENV_DEPENDENCIES)
 elif "fedora" in os_families():

scripts/lib/setup_venv.py

@@ -23,7 +23,6 @@ VENV_DEPENDENCIES = [
     "libldap2-dev",
     "libmemcached-dev",
     "python3-dev",          # Needed to install typed-ast dependency of mypy
-    "python-dev",
     "python3-pip",
     "python-pip",
     "virtualenv",
@@ -45,6 +44,10 @@ VENV_DEPENDENCIES = [
     "jq",                   # Used by scripts/lib/install-node to check yarn version
 ]
 
+# python-dev is depreciated in Focal but can be used as python2-dev.
+# So it is removed from VENV_DEPENDENCIES and added here.
+PYTHON_DEV_DEPENDENCY = "python{}-dev"
+
 COMMON_YUM_VENV_DEPENDENCIES = [
     "libffi-devel",
     "freetype-devel",
@@ -99,6 +102,13 @@ YUM_THUMBOR_VENV_DEPENDENCIES = [
     "gifsicle",
 ]
 
+def get_venv_dependencies(vendor, os_version):
+    # type: (str, str) -> List[str]
+    if vendor == 'ubuntu' and os_version == '20.04':
+        return VENV_DEPENDENCIES + [PYTHON_DEV_DEPENDENCY.format("2"), ]
+    else:
+        return VENV_DEPENDENCIES + [PYTHON_DEV_DEPENDENCY.format(""), ]
+
 def install_venv_deps(pip, requirements_file, python2):
     # type: (str, str, bool) -> None
     pip_requirements = os.path.join(ZULIP_PATH, "requirements", "pip2.txt" if python2 else "pip.txt")

tools/lib/provision.py

@@ -16,7 +16,7 @@ from scripts.lib.zulip_tools import run_as_root, ENDC, WARNING, \
     get_dev_uuid_var_path, FAIL, os_families, parse_os_release, \
     overwrite_symlink
 from scripts.lib.setup_venv import (
-    VENV_DEPENDENCIES, REDHAT_VENV_DEPENDENCIES,
+    get_venv_dependencies, REDHAT_VENV_DEPENDENCIES,
     THUMBOR_VENV_DEPENDENCIES, YUM_THUMBOR_VENV_DEPENDENCIES,
     FEDORA_VENV_DEPENDENCIES
 )
@@ -108,6 +108,8 @@ else:
             print("See: https://zulip.readthedocs.io/en/latest/development/setup-vagrant.html")
     sys.exit(1)
 
+VENV_DEPENDENCIES = get_venv_dependencies(vendor, os_version)
+
 COMMON_DEPENDENCIES = [
     "memcached",
     "rabbitmq-server",