Bug 1879592 - Create a "recipes" directory for shared Docker image snippets. r=dandarnell

Differential Revision: https://phabricator.services.mozilla.com/D201572

--HG--
rename : taskcluster/docker/tb-snap/make_venv.sh => taskcluster/docker/recipes/make_venv.sh
extra : amend_source : 5ee9f2666dd065c7581c39f0db270008148b2a06

taskcluster/docker/recipes/make_venv.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+# Arguments: $1 - path to the requirements file
+# Arguments: $2 - name of virtualenv to create under /builds/worker/venvs
+#
+# The script will be create the environment and install from the
+# requirements file.
+# It's up to the image itself to figure out how to use it.
+set -xe
+
+VENV_DIR=${VENV_DIR:-"/builds/worker/venvs"}
+VENV_NAME=${2:-"venv"}
+
+# Ensure venvs directory exists
+mkdir -p "$VENV_DIR" && cd "$VENV_DIR"
+
+# Create Python virtual environment and install dependencies
+python3 -m venv --system-site-packages "$VENV_NAME"
+source "./$VENV_NAME/bin/activate"
+python3 -m pip install -r "$1"