Merge pull request #564 from achillesrasquinha/556

Backup, then Migrate Environments. (And not vice-versa)

bench/commands/__init__.py

@@ -1,8 +1,7 @@
 import click
 
-import os, shutil, tempfile
+import os, shutil
 import os.path as osp
-import contextlib
 import logging
 
 from datetime import datetime
@@ -83,24 +82,6 @@ bench_command.add_command(remote_urls)
 from bench.commands.install import install
 bench_command.add_command(install)
 
-@contextlib.contextmanager
-def tempchdir(dirpath, cleanup):
-	basedir = os.getcwd()
-	os.chdir(osp.expanduser(dirpath))
-	try:
-		yield
-	finally:
-		os.chdir(basedir)
-		cleanup()
-
-@contextlib.contextmanager
-def tempdir():
-	dirpath = tempfile.mkdtemp()
-	def cleanup():
-		shutil.rmtree(dirpath)
-	with tempchdir(dirpath, cleanup):
-		yield dirpath
-
 @click.command('migrate-env')
 @click.argument('python', type = click.Choice(['python2', 'python3']))
 @click.option('--no-backup', default = False, help = 'Do not backup the existing Virtual Environment')
@@ -108,37 +89,9 @@ def migrate_env(python, no_backup = False):
 	"""
 	Migrate Virtual Environment to desired Python Version.
 	"""
-
-	python = which(python)
-
-	path   = os.getcwd()
-	# This is with the assumption that a bench is set-up within path.
 	try:
-		with tempdir() as dirpath:
+		# This is with the assumption that a bench is set-up within path.
-			virtualenv = which('virtualenv')
+		path       = os.getcwd()
-
-			nvenv      = 'env'
-			pvenv      = osp.join(dirpath, nvenv)
-
-			exec_cmd('{virtualenv} --python {python} {pvenv}'.format(
-				virtualenv = virtualenv,
-				python     = python,
-				pvenv      = pvenv
-			), cwd = dirpath)
-
-			# TODO: Options
-
-			apps_path = osp.join(path, 'apps')
-			apps  = os.listdir(apps_path)
-			apps = ['frappe'] + [app for app in apps if app!='frappe']
-
-			for app in apps:
-				papp = osp.join(apps_path, app)
-				if osp.isdir(papp) and osp.exists(osp.join(papp, 'setup.py')):
-					pip = osp.join(pvenv, 'bin', 'pip')
-					exec_cmd('{pip} install -e {app}'.format(
-						pip = pip, app = papp
-					))
 
 		# I know, bad name for a flag. Thanks, Ameya! :| - <achilles@frappe.io>
 		if not no_backup:
@@ -156,16 +109,44 @@ def migrate_env(python, no_backup = False):
 			stamp  = datetime.now().strftime('%Y%m%d_%H%M%S')
 			dest   = osp.join(path, str(stamp))
 			
+			# WARNING: This is an archive, you might have to use virtualenv --relocate
+			# That's because virtualenv creates symlinks with shebangs pointing to executables.
+			
+			# ...and shutil.copytree is a f*cking mess.
 			os.rename(source, dest)
 			shutil.move(dest, target)
 		
 		log.debug('Setting up a New Virtual {python} Environment'.format(
 			python = python
 		))
-			source = pvenv
-			target = path
 		
-			shutil.move(source, target)
+		# Path to Python Executable (Basically $PYTHONPTH)
+		python     = which(python)
+
+
+		virtualenv = which('virtualenv')
+
+		nvenv      = 'env'
+		pvenv      = osp.join(path, nvenv)
+
+		exec_cmd('{virtualenv} --python {python} {pvenv}'.format(
+			virtualenv = virtualenv,
+			python     = python,
+			pvenv      = pvenv
+		), cwd = path)
+
+		# TODO: Options
+
+		papps  = osp.join(path, 'apps')
+		apps   = ['frappe'] + [app for app in os.listdir(papps) if app != 'frappe']
+
+		for app in apps:
+			papp = osp.join(papps, app)
+			if osp.isdir(papp) and osp.exists(osp.join(papp, 'setup.py')):
+				pip = osp.join(pvenv, 'bin', 'pip')
+				exec_cmd('{pip} install -e {app}'.format(
+					pip = pip, app = papp
+				))
 
 		log.debug('Migration Successful to {python}'.format(
 			python = python