Fastai make pr branch to python (#1891)

* Basic argparser

* Shell scripts wrappers

* Bash script ported

* Docstring

* Fixing commands, better output

* Git token or failure

* Abort script on missing token

tools/fastai-make-pr-branch-py

@@ -28,24 +28,28 @@ notes:
 import argparse
 import os
 from os.path import basename, exists
-from textwrap import dedent
+from pathlib import Path
+import re
 import sys
 from subprocess import call, PIPE, Popen
-from pathlib import Path
+from textwrap import dedent
+
 
 PY3 = sys.version_info >= (3, 0)
 ME = basename(sys.argv[0])
 ORIG_USER_NAME = 'fastai'
+ENV_VAR = 'GITHUB_TOKEN'
 
 
 def main():
+    check_token()
     args = parse_args()
-    was_already_forked = fork_if_needed(args.url, args.user_name, args.repo_name)
+    was_already_forked = fork_if_needed(args)
     need_clone = clone_is_needed(args.url)
     if need_clone:
         clone(args.url, args.path)
     run_after_git_clone()
-    track_upstream(args.orig_repo_url)
+    track_upstream(strip_token(args.orig_repo_url))
     if was_already_forked:
         sync_with_master(args)
     create_branch(args.new_branch_name)
@@ -57,7 +61,7 @@ def parse_args():
     parser = SysExitArgumentParser(usage=__doc__.format(me=ME))
     parser.add_argument(
         'auth',
-        metavar='AUTH', choices={'ssh', 'https'},
+        metavar='AUTH', choices={'https'},  # no ssh support for now
         help='ssh or https (use ssh if your github account is setup to use ssh)'
     )
     parser.add_argument(
@@ -75,12 +79,25 @@ def parse_args():
         metavar='BR',
         help='name of the branch to create'
     )
+    parser.add_argument(
+        '-orig', '--orig-user-name',
+        metavar='ORIG', required=False, default=ORIG_USER_NAME,
+        help='name of original repository user (default: %(default)s)'
+    )
 
     args = parser.parse_args()
-    args.prefix = 'git@github.com:' if args.auth == 'ssh' else 'https://github.com/'
+    args.token = os.environ[ENV_VAR]
+    args.prefix = f'https://{args.token}@github.com'
+
+    # support token access only
+    # if args.auth == 'ssh':
+    #     args.prefix = f'git@github.com:'
+    # else:
+    #     args.prefix = f'https://{args.token}@github.com/'
+
     args.path = f'{args.repo_name}-{args.new_branch_name}'
     args.url = f'{args.prefix}{args.user_name}/{args.repo_name}.git'
-    args.orig_repo_url = f'{args.prefix}{ORIG_USER_NAME}/{args.repo_name}.git'
+    args.orig_repo_url = f'{args.prefix}{args.orig_user_name}/{args.repo_name}.git'
 
     return args
 
@@ -94,16 +111,49 @@ def check_curl_is_available():
         sys.exit(1)
 
 
-def fork_if_needed(url, user, repo):
+def check_token():
+    if ENV_VAR not in os.environ:
+        print(dedent('''
+            *** WARNING! ***
+            
+            The HTTPS authentication method requires to explicitly enter your Github user's credentials.
+            Unfortunately, up to the moment the tool doesn't support secured credentials entering. Therefore,
+            you need to have a GITHUB_TOKEN environment variable set to use HTTPS authentication method.
+            Please use the following instruction to setup token, or switch to SSH. 
+            
+                1. Create an access token:
+                
+                    https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line
+                    
+                2. Copy the token and save it as an environment variable:
+                
+                    $ echo "export GITHUB_TOKEN=<your-token>" >> ~/.bashrc
+                    $ source ~/.bashrc
+                    
+                3. Now the token is used for an access.
+            
+            Also, if you would like to help to improve this tool and enable the possibility to safely 
+            enter the credentials, please submit a PR! Check the following discussion to know more:
+            
+                https://forums.fast.ai/t/port-fastai-make-pr-branch-from-bash-to-python/29853/28
+                
+            *** WARNING! ***
+        '''))
+        sys.exit(1)
+
+
+def fork_if_needed(args):
     "Fork the repo if it hasn't been forked yet."
+    url, user, orig, repo = args.url, args.user_name, args.orig_user_name, args.repo_name
     print('\n\n*** Checking if we need to fork')
     if run_and_check_success(f'git ls-remote {url} >/dev/null 2>&1'):
         print(f'{url} is already forked')
         return True
     else:
         print(f"{url} doesn't exist - need to fork")
         check_curl_is_available()
-        run(f"curl -u {user} https://api.github.com/repos/fastai/{repo}/forks -d ''")
+        creds = user if args.auth == 'ssh' else f'{user}:{args.token}'
+        run(f"curl -u {creds} https://api.github.com/repos/{orig}/{repo}/forks -d ''")
         return False
 
 
@@ -149,15 +199,15 @@ def track_upstream(orig_repo_url):
 def sync_with_master(args):
     "Sync the forked repo master with the upstream master if it hasn't been just forked."
     user, repo = args.user_name, args.repo_name
-    print(f'\n\n*** Syncing {user}/master with {ORIG_USER_NAME}/master')
+    print(f'\n\n*** Syncing {user}/master with {args.orig_user_name}/master')
     run('git fetch upstream')
     run('git checkout master')
     # XXX: this will fail if the user was committing directly to their forked `master` branch is
     ok = run_and_check_success('git merge --no-edit upstream/master')
     if not ok:
         run('git merge --abort')
         print(dedent(f'''
-            Error: {user}/{repo}/master can't be merged with {ORIG_USER_NAME}/{repo}/master.
+            Error: {user}/{repo}/master can't be merged with {args.orig_user_name}/{repo}/master.
             You must merge manually, or reset {user}/{repo}/master.
             See:  https://docs-dev.fast.ai/git.html#how-to-reset-your-forked-master-branch
             Aborting."
@@ -219,6 +269,11 @@ def print_instructions(args, need_clone):
     '''))
 
 
+def strip_token(url):
+    "Removes HTTPS token part from the URL string."
+    return re.sub("[\d\w]+@github.com", "github.com", url)
+
+
 # --------------
 # Shell wrappers
 # --------------
@@ -245,15 +300,19 @@ def run(command):
         print(out)
 
 
+# (devforfu): Would it be better to replace with a different implementation?
+#
+#    https://forums.fast.ai/t/port-fastai-make-pr-branch-from-bash-to-python/29853/20
+#
 def run_and_return_output(command):
     "Returns (return-code, stdout, stderr)."
     p = Popen(command, stdout=PIPE, stderr=PIPE, shell=True)
-    output, err = p.communicate()
+    out, err = p.communicate()
     rc = p.returncode
-    if PY3:
-        output = output.decode("ascii")
-        err = err.decode("ascii")
-    return rc, output.strip(), err.strip()
+    if PY3 and out: out = out.decode("utf-8")
+    if PY3 and err: err = err.decode("utf-8")
+    return rc, out.strip(), err.strip()
+
 
 
 def run_and_read_all(command):