Refactor *_gen_project hooks (#1490)

* Fix ./hooks/pre_gen_project.py asking user to select an option once only

+ prettify output

* Fix pre_gen hook not really exiting when it should

* Refactor & prettify ./hooks/post_gen_project.py

* Ensure same POSTGRES_USER is set across environments

+ get rid of env.example in favor of pre-generated .env.

docs/settings.rst

@@ -22,7 +22,7 @@ DJANGO_ADMIN_URL                        n/a                         r'^admin/'
 DJANGO_CACHES                           CACHES (default)            locmem                                         redis
 DJANGO_DATABASES                        DATABASES (default)         See code                                       See code
 DJANGO_DEBUG                            DEBUG                       True                                           False
-DJANGO_SECRET_KEY                       SECRET_KEY                  CHANGEME!!!                                    raises error
+DJANGO_SECRET_KEY                       SECRET_KEY                  !!!SET DJANGO_SECRET_KEY!!!                    raises error
 DJANGO_SECURE_BROWSER_XSS_FILTER        SECURE_BROWSER_XSS_FILTER   n/a                                            True
 DJANGO_SECURE_SSL_REDIRECT              SECURE_SSL_REDIRECT         n/a                                            True
 DJANGO_SECURE_CONTENT_TYPE_NOSNIFF      SECURE_CONTENT_TYPE_NOSNIFF n/a                                            True

hooks/post_gen_project.py

@@ -1,219 +1,257 @@
 """
-Does the following:
+NOTE:
+    the below code is to be maintained Python 2.x-compatible
+    as the whole Cookiecutter Django project initialization
+    can potentially be run in Python 2.x environment
+    (at least so we presume in `pre_gen_project.py`).
 
-1. Generates and saves random secret key
+TODO: ? restrict Cookiecutter Django project initialization to Python 3.x environments only
-2. Removes the taskapp if celery isn't going to be used
-3. Removes the .idea directory if PyCharm isn't going to be used
-4. Copy files from /docs/ to {{ cookiecutter.project_slug }}/docs/
-
-    TODO: this might have to be moved to a pre_gen_hook
-
-A portion of this code was adopted from Django's standard crypto functions and
-utilities, specifically:
-    https://github.com/django/django/blob/master/django/utils/crypto.py
 """
-from __future__ import print_function
+
 import os
 import random
 import shutil
 import string
+import sys
 
-# Get the root project directory
-PROJECT_DIRECTORY = os.path.realpath(os.path.curdir)
-
-# Use the system PRNG if possible
 try:
+    # Inspired by
+    # https://github.com/django/django/blob/master/django/utils/crypto.py
     random = random.SystemRandom()
     using_sysrandom = True
 except NotImplementedError:
     using_sysrandom = False
 
-
+PROJECT_DIR_PATH = os.path.realpath(os.path.curdir)
-def get_random_string(length=50):
-    """
-    Returns a securely generated random string.
-    The default length of 12 with the a-z, A-Z, 0-9 character set returns
-    a 71-bit value. log_2((26+26+10)^12) =~ 71 bits
-    """
-    punctuation = string.punctuation.replace('"', '').replace("'", '')
-    punctuation = punctuation.replace('\\', '')
-    if using_sysrandom:
-        return ''.join(random.choice(
-            string.digits + string.ascii_letters + punctuation
-        ) for i in range(length))
-
-    print(
-        "Cookiecutter Django couldn't find a secure pseudo-random number generator on your system."
-        " Please change change your SECRET_KEY variables in conf/settings/local.py and env.example"
-        " manually."
-    )
-    return "CHANGEME!!"
 
 
-def set_secret_key(setting_file_location):
+def remove_file(file_path):
-    # Open locals.py
+    if os.path.exists(file_path):
-    with open(setting_file_location) as f:
+        os.remove(file_path)
-        file_ = f.read()
-
-    # Generate a SECRET_KEY that matches the Django standard
-    SECRET_KEY = get_random_string()
-
-    # Replace "CHANGEME!!!" with SECRET_KEY
-    file_ = file_.replace('CHANGEME!!!', SECRET_KEY, 1)
-
-    # Write the results to the locals.py module
-    with open(setting_file_location, 'w') as f:
-        f.write(file_)
 
 
-def make_secret_key(project_directory):
+def remove_open_source_project_only_files():
-    """Generates and saves random secret key"""
+    file_names = [
-    # Determine the local_setting_file_location
+        'CONTRIBUTORS.txt',
-    local_setting = os.path.join(
+    ]
-        project_directory,
+    for file_name in file_names:
-        'config/settings/local.py'
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
-    )
-
-    # local.py settings file
-    set_secret_key(local_setting)
-
-    env_file = os.path.join(
-        project_directory,
-        'env.example'
-    )
-
-    # env.example file
-    set_secret_key(env_file)
 
 
-def remove_file(file_name):
+def remove_gplv3_files():
-    if os.path.exists(file_name):
+    file_names = [
-        os.remove(file_name)
+        'COPYING',
+    ]
+    for file_name in file_names:
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
 
 
-def remove_task_app(project_directory):
+def remove_pycharm_files():
-    """Removes the taskapp if celery isn't going to be used"""
+    idea_dir_path = os.path.join(PROJECT_DIR_PATH, '.idea')
-    # Determine the local_setting_file_location
+    if os.path.exists(idea_dir_path):
-    task_app_location = os.path.join(
+        shutil.rmtree(idea_dir_path)
-        PROJECT_DIRECTORY,
-        '{{ cookiecutter.project_slug }}/taskapp'
-    )
-    shutil.rmtree(task_app_location)
 
-
+    docs_dir_path = os.path.join(PROJECT_DIR_PATH, 'docs', 'pycharm')
-def remove_pycharm_dir(project_directory):
+    if os.path.exists(docs_dir_path):
-    """
+        shutil.rmtree(docs_dir_path)
-    Removes directories related to PyCharm
-    if it isn't going to be used
-    """
-    idea_dir_location = os.path.join(PROJECT_DIRECTORY, '.idea/')
-    if os.path.exists(idea_dir_location):
-        shutil.rmtree(idea_dir_location)
-
-    docs_dir_location = os.path.join(PROJECT_DIRECTORY, 'docs/pycharm/')
-    if os.path.exists(docs_dir_location):
-        shutil.rmtree(docs_dir_location)
-
-
-def remove_heroku_files():
-    """
-    Removes files needed for heroku if it isn't going to be used
-    """
-    filenames = ["Procfile", "runtime.txt"]
-    for filename in ["Procfile", "runtime.txt"]:
-        file_name = os.path.join(PROJECT_DIRECTORY, filename)
-        remove_file(file_name)
 
 
 def remove_docker_files():
-    """
+    shutil.rmtree(os.path.join(PROJECT_DIR_PATH, 'compose'))
-    Removes files needed for docker if it isn't going to be used
-    """
-    for filename in ["local.yml", "production.yml", ".dockerignore"]:
-        filename = os.path.join(PROJECT_DIRECTORY, filename)
-        if os.path.exists(filename):
-            os.remove(filename)
 
-    shutil.rmtree(os.path.join(
+    file_names = [
-        PROJECT_DIRECTORY, "compose"
+        'local.yml',
-    ))
+        'production.yml',
+        '.dockerignore',
+    ]
+    for file_name in file_names:
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
+
+
+def remove_heroku_files():
+    file_names = [
+        'Procfile',
+        'runtime.txt',
+    ]
+    for file_name in file_names:
+        remove_file(os.path.join(PROJECT_DIR_PATH, file_name))
+
+
+def remove_paas_files():
+    none_paas_files_left = True
+
+    if '{{ cookiecutter.use_heroku }}'.lower() == 'n':
+        remove_heroku_files()
+        none_paas_files_left &= True
+    else:
+        none_paas_files_left &= False
+
+    if none_paas_files_left:
+        remove_file(os.path.join(PROJECT_DIR_PATH, 'requirements.txt'))
 
 
 def remove_grunt_files():
-    """
+    file_names = [
-    Removes files needed for grunt if it isn't going to be used
+        'Gruntfile.js',
-    """
+    ]
-    for filename in ["Gruntfile.js"]:
+    for file_name in file_names:
-        os.remove(os.path.join(
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
-            PROJECT_DIRECTORY, filename
+
-        ))
 
 def remove_gulp_files():
+    file_names = [
+        'gulpfile.js',
+    ]
+    for file_name in file_names:
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
+
+
+def remove_packagejson_file():
+    file_names = [
+        'package.json',
+    ]
+    for file_name in file_names:
+        os.remove(os.path.join(PROJECT_DIR_PATH, file_name))
+
+
+def remove_celery_app():
+    shutil.rmtree(os.path.join(PROJECT_DIR_PATH, '{{ cookiecutter.project_slug }}', 'taskapp'))
+
+
+def append_to_project_gitignore(path):
+    gitignore_file_path = os.path.join(PROJECT_DIR_PATH, '.gitignore')
+    with open(gitignore_file_path, 'a') as gitignore_file:
+        gitignore_file.write(path)
+        gitignore_file.write(os.linesep)
+
+
+def generate_random_string(length,
+                           using_digits=False,
+                           using_ascii_letters=False,
+                           using_punctuation=False):
     """
-    Removes files needed for grunt if it isn't going to be used
+    Example:
+        opting out for 50 symbol-long, [a-z][A-Z][0-9] string
+        would yield log_2((26+26+50)^50) ~= 334 bit strength.
     """
-    for filename in ["gulpfile.js"]:
+    if not using_sysrandom:
-        os.remove(os.path.join(
+        return None
-            PROJECT_DIRECTORY, filename
-        ))
 
-def remove_packageJSON_file():
+    symbols = []
-    """
+    if using_digits:
-    Removes files needed for grunt if it isn't going to be used
+        symbols += string.digits
-    """
+    if using_ascii_letters:
-    for filename in ["package.json"]:
+        symbols += string.ascii_letters
-        os.remove(os.path.join(
+    if using_punctuation:
-            PROJECT_DIRECTORY, filename
+        symbols += string.punctuation \
-        ))
+            .replace('"', '') \
-
+            .replace("'", '') \
-def remove_copying_files():
+            .replace('\\', '')
-    """
+    return ''.join([random.choice(symbols) for _ in range(length)])
-    Removes files needed for the GPLv3 licence if it isn't going to be used
-    """
-    for filename in ["COPYING"]:
-        os.remove(os.path.join(
-            PROJECT_DIRECTORY, filename
-        ))
 
 
-# IN PROGRESS
+def set_flag(file_path,
-# def copy_doc_files(project_directory):
+             flag,
-#     cookiecutters_dir = DEFAULT_CONFIG['cookiecutters_dir']
+             value=None,
-#     cookiecutter_django_dir = os.path.join(
+             *args,
-#         cookiecutters_dir,
+             **kwargs):
-#         'cookiecutter-django',
+    if value is None:
-#         'docs'
+        random_string = generate_random_string(*args, **kwargs)
-#     )
+        if random_string is None:
-#     target_dir = os.path.join(
+            import sys
-#         project_directory,
+            sys.stdout.write(
-#         'docs'
+                "We couldn't find a secure pseudo-random number generator on your system. "
-#     )
+                "Please, make sure to manually {} later.".format(flag)
-#     for name in os.listdir(cookiecutter_django_dir):
+            )
-#         if name.endswith('.rst') and not name.startswith('index'):
+            random_string = flag
-#             src = os.path.join(cookiecutter_django_dir, name)
+        value = random_string
-#             dst = os.path.join(target_dir, name)
-#             shutil.copyfile(src, dst)
 
-# 1. Generates and saves random secret key
+    with open(file_path, 'r+') as f:
-make_secret_key(PROJECT_DIRECTORY)
+        file_contents = f.read().replace(flag, value)
+        f.seek(0)
+        f.write(file_contents)
+        f.truncate()
 
-# 2. Removes the taskapp if celery isn't going to be used
+    return value
-if '{{ cookiecutter.use_celery }}'.lower() == 'n':
-    remove_task_app(PROJECT_DIRECTORY)
 
-# 3. Removes the .idea directory if PyCharm isn't going to be used
-if '{{ cookiecutter.use_pycharm }}'.lower() != 'y':
-    remove_pycharm_dir(PROJECT_DIRECTORY)
 
-# 4. Removes all heroku files if it isn't going to be used
+def set_django_secret_key(file_path):
-if '{{ cookiecutter.use_heroku }}'.lower() != 'y':
+    django_secret_key = set_flag(
-    remove_heroku_files()
+        file_path,
+        '!!!SET DJANGO_SECRET_KEY!!!',
+        length=50,
+        using_digits=True,
+        using_ascii_letters=True
+    )
+    return django_secret_key
 
-# 5. Removes all docker files if it isn't going to be used
+
-if '{{ cookiecutter.use_docker }}'.lower() != 'y':
+def set_postgres_user(file_path,
+                      value=None):
+    postgres_user = set_flag(
+        file_path,
+        '!!!SET POSTGRES_USER!!!',
+        value=value,
+        length=8,
+        using_ascii_letters=True
+    )
+    return postgres_user
+
+
+def set_postgres_password(file_path):
+    postgres_password = set_flag(
+        file_path,
+        '!!!SET POSTGRES_PASSWORD!!!',
+        length=42,
+        using_digits=True,
+        using_ascii_letters=True
+    )
+    return postgres_password
+
+
+def initialize_dotenv(postgres_user):
+    # Initializing `env.example` first.
+    envexample_file_path = os.path.join(PROJECT_DIR_PATH, 'env.example')
+    set_django_secret_key(envexample_file_path)
+    set_postgres_user(envexample_file_path, value=postgres_user)
+    set_postgres_password(envexample_file_path)
+    # Renaming `env.example` to `.env`.
+    dotenv_file_path = os.path.join(PROJECT_DIR_PATH, '.env')
+    shutil.move(envexample_file_path, dotenv_file_path)
+
+
+def initialize_localyml(postgres_user):
+    set_postgres_user(os.path.join(PROJECT_DIR_PATH, 'local.yml'), value=postgres_user)
+
+
+def initialize_local_settings():
+    set_django_secret_key(os.path.join(PROJECT_DIR_PATH, 'config', 'settings', 'local.py'))
+
+
+def initialize_test_settings():
+    set_django_secret_key(os.path.join(PROJECT_DIR_PATH, 'config', 'settings', 'test.py'))
+
+
+def main():
+    postgres_user = generate_random_string(length=16, using_ascii_letters=True)
+    initialize_dotenv(postgres_user)
+    initialize_localyml(postgres_user)
+    initialize_local_settings()
+    initialize_test_settings()
+
+    if '{{ cookiecutter.open_source_license }}' == 'Not open source':
+        remove_open_source_project_only_files()
+    elif '{{ cookiecutter.open_source_license}}' != 'GPLv3':
+        remove_gplv3_files()
+
+    if '{{ cookiecutter.use_pycharm }}'.lower() == 'n':
+        remove_pycharm_files()
+
+    if '{{ cookiecutter.use_docker }}'.lower() == 'n':
         remove_docker_files()
 
-# 6. Removes all JS task manager files if it isn't going to be used
+    remove_paas_files()
+
     if '{{ cookiecutter.js_task_runner}}'.lower() == 'gulp':
         remove_grunt_files()
     elif '{{ cookiecutter.js_task_runner}}'.lower() == 'grunt':
@@ -221,18 +259,25 @@ elif '{{ cookiecutter.js_task_runner}}'.lower() == 'grunt':
     else:
         remove_gulp_files()
         remove_grunt_files()
-    remove_packageJSON_file()
+        remove_packagejson_file()
 
-
+    if '{{ cookiecutter.js_task_runner }}'.lower() in ['grunt', 'gulp'] \
-# 9. Display a warning if use_docker and use_grunt are selected. Grunt isn't
+        and '{{ cookiecutter.use_docker }}'.lower() == 'y':
-#   supported by our docker config atm.
+        TERMINATOR = "\x1b[0m"
-if '{{ cookiecutter.js_task_runner }}'.lower() in ['grunt', 'gulp'] and '{{ cookiecutter.use_docker }}'.lower() == 'y':
+        INFO = "\x1b[1;33m [INFO]: "
-    print(
+        sys.stdout.write(
-        "You selected to use docker and a JS task runner. This is NOT supported out of the box for now. You "
+            INFO +
-        "can continue to use the project like you normally would, but you will need to add a "
+            "Docker and {} JS task runner ".format('{{ cookiecutter.js_task_runner }}'.lower().capitalize()) +
-        "js task runner service to your docker configuration manually."
+            "working together not supported yet. "
+            "You can continue using the generated project like you normally would, "
+            "however you would need to add a JS task runner service "
+            "to your Docker Compose configuration manually." +
+            TERMINATOR
         )
 
-# 10. Removes files needed for the GPLv3 licence if it isn't going to be used.
+    if '{{ cookiecutter.use_celery }}'.lower() == 'n':
-if '{{ cookiecutter.open_source_license}}' != 'GPLv3':
+        remove_celery_app()
-    remove_copying_files()
+
+
+if __name__ == '__main__':
+    main()

hooks/pre_gen_project.py

@@ -1,27 +1,59 @@
+"""
+NOTE:
+    the below code is to be maintained Python 2.x-compatible
+    as the whole Cookiecutter Django project initialization
+    can potentially be run in Python 2.x environment.
+
+TODO: ? restrict Cookiecutter Django project initialization to Python 3.x environments only
+"""
+
 project_slug = '{{ cookiecutter.project_slug }}'
-
 if hasattr(project_slug, 'isidentifier'):
-    assert project_slug.isidentifier(), 'Project slug should be valid Python identifier!'
+    assert project_slug.isidentifier(), "'{}' project slug is not a valid Python identifier.".format(project_slug)
 
-heroku = '{{ cookiecutter.use_heroku }}'.lower()
+using_docker = '{{ cookiecutter.use_docker }}'.lower()
-docker = '{{ cookiecutter.use_docker }}'.lower()
+if using_docker == 'n':
+    TERMINATOR = "\x1b[0m"
+    WARNING = "\x1b[1;33m [WARNING]: "
+    INFO = "\x1b[1;33m [INFO]: "
+    HINT = "\x1b[3;33m"
+    SUCCESS = "\x1b[1;32m [SUCCESS]: "
 
-if docker == 'n':
     import sys
 
     python_major_version = sys.version_info[0]
-
     if python_major_version == 2:
-		sys.stdout.write("WARNING: Cookiecutter Django does not support Python 2! Stability is guaranteed with Python 3.6+ only. Are you sure you want to proceed? (y/n)")
+        sys.stdout.write(
-
+            WARNING +
-		yes_options = set(['y'])
+            "Cookiecutter Django does not support Python 2. "
-		no_options = set(['n', ''])
+            "Stability is guaranteed with Python 3.6+ only, "
+            "are you sure you want to proceed (y/n)? " +
+            TERMINATOR
+        )
+        yes_options, no_options = frozenset(['y']), frozenset(['n'])
+        while True:
             choice = raw_input().lower()
-		if choice in no_options:
+            if choice in yes_options:
+                break
+            elif choice in no_options:
+                sys.stdout.write(
+                    INFO +
+                    "Generation process stopped as requested." +
+                    TERMINATOR
+                )
                 sys.exit(1)
-		elif choice in yes_options:
-			pass
             else:
-			sys.stdout.write("Please respond with %s or %s"
+                sys.stdout.write(
-				% (', '.join([o for o in yes_options if not o == ''])
+                    HINT +
-					, ', '.join([o for o in no_options if not o == ''])))
+                    "Please respond with {} or {}: ".format(
+                        ', '.join(["'{}'".format(o) for o in yes_options if not o == '']),
+                        ', '.join(["'{}'".format(o) for o in no_options if not o == ''])
+                    ) +
+                    TERMINATOR
+                )
+
+    sys.stdout.write(
+        SUCCESS +
+        "Project initialized, keep up the good work!" +
+        TERMINATOR
+    )

{{cookiecutter.project_slug}}/config/settings/local.py

@@ -24,7 +24,7 @@ TEMPLATES[0]['OPTIONS']['debug'] = DEBUG
 # ------------------------------------------------------------------------------
 # See: https://docs.djangoproject.com/en/dev/ref/settings/#secret-key
 # Note: This key only used for development and testing.
-SECRET_KEY = env('DJANGO_SECRET_KEY', default='CHANGEME!!!')
+SECRET_KEY = env('DJANGO_SECRET_KEY', default='!!!SET DJANGO_SECRET_KEY!!!')
 
 # Mail settings
 # ------------------------------------------------------------------------------

{{cookiecutter.project_slug}}/config/settings/test.py

@@ -17,7 +17,7 @@ TEMPLATES[0]['OPTIONS']['debug'] = False
 # ------------------------------------------------------------------------------
 # See: https://docs.djangoproject.com/en/dev/ref/settings/#secret-key
 # Note: This key only used for development and testing.
-SECRET_KEY = env('DJANGO_SECRET_KEY', default='CHANGEME!!!')
+SECRET_KEY = env('DJANGO_SECRET_KEY', default='!!!SET DJANGO_SECRET_KEY!!!')
 
 # Mail settings
 # ------------------------------------------------------------------------------

{{cookiecutter.project_slug}}/env.example

@@ -1,7 +1,7 @@
 
 # PostgreSQL
-POSTGRES_PASSWORD=mysecretpass
+POSTGRES_PASSWORD=!!!SET POSTGRES_PASSWORD!!!
-POSTGRES_USER=postgresuser
+POSTGRES_USER=!!!SET POSTGRES_USER!!!
 CONN_MAX_AGE=
 
 # Domain name, used by caddy
@@ -11,7 +11,7 @@ DOMAIN_NAME={{ cookiecutter.domain_name }}
 # DJANGO_READ_DOT_ENV_FILE=True
 DJANGO_ADMIN_URL=
 DJANGO_SETTINGS_MODULE=config.settings.production
-DJANGO_SECRET_KEY=CHANGEME!!!
+DJANGO_SECRET_KEY=!!!SET DJANGO_SECRET_KEY!!!
 DJANGO_ALLOWED_HOSTS=.{{ cookiecutter.domain_name }}
 
 # AWS Settings

{{cookiecutter.project_slug}}/local.yml

@@ -15,7 +15,7 @@ services:
     volumes:
       - .:/app
     environment:
-      - POSTGRES_USER={{cookiecutter.project_slug}}
+      - POSTGRES_USER=!!!SET POSTGRES_USER!!!
       - USE_DOCKER=yes
     ports:
       - "8000:8000"
@@ -29,7 +29,7 @@ services:
       - postgres_data_local:/var/lib/postgresql/data
       - postgres_backup_local:/backups
     environment:
-      - POSTGRES_USER={{cookiecutter.project_slug}}
+      - POSTGRES_USER=!!!SET POSTGRES_USER!!!
 {% if cookiecutter.use_mailhog == 'y' %}
   mailhog:
     image: mailhog/mailhog:v1.0.0