Adds S3 storage backend

flask_admin/contrib/fileadmin.py

@@ -6,10 +6,16 @@ import re
 import shutil
 from operator import itemgetter
 
-from werkzeug import secure_filename
-
+try:
+    from boto import s3
+    from boto.s3.prefix import Prefix
+    from boto.s3.key import Key
+except ImportError:
+    s3 = None
+
+import dateutil.parser
 from flask import flash, redirect, abort, request, send_file
-
+from werkzeug import secure_filename
 from wtforms import fields, validators
 
 from flask_admin import form, helpers
@@ -19,6 +25,154 @@ from flask_admin.actions import action, ActionsMixin
 from flask_admin.babel import gettext, lazy_gettext
 
 
+class S3Storage(object):
+    """
+        Storage object representing files on an Amazon S3 bucket.
+
+        Usage::
+
+            from flask_admin.contrib.fileadmin import BaseFileAdmin, S3Storage
+
+            class MyS3Admin(BaseFileAdmin):
+                # Configure your class however you like
+                pass
+
+            fileadmin_view = MyS3Admin(storage=S3Storage(...))
+
+    """
+
+    def __init__(self, bucket_name, region, aws_access_key_id,
+                 aws_secret_access_key):
+        """
+            Constructor
+
+                :param bucket_name:
+                    Name of the bucket that the files are on.
+
+                :param region:
+                    Region that the bucket is located
+
+                :param aws_access_key_id:
+                    AWS Access Key ID
+
+                :param aws_secret_access_key:
+                    AWS Secret Access Key
+
+            Make sure the credentials have the correct permissions set up on
+            Amazon or else S3 will return a 403 FORBIDDEN error.
+        """
+
+        if not s3:
+            raise ValueError('Could not import boto. You can install boto by '
+                             'using pip install boto')
+
+        connection = s3.connect_to_region(region,
+                                          aws_access_key_id=aws_access_key_id,
+                                          aws_secret_access_key=
+                                          aws_secret_access_key)
+        self.bucket = connection.get_bucket(bucket_name)
+
+    def get_files(self, path, directory):
+        def _strip_path(name, path):
+            if name.startswith(path):
+                return name.replace(path, '', 1)
+            return name
+
+        def _remove_trailing_slash(name):
+            return name[:-1]
+
+        files = []
+        directories = []
+        if path and not path.endswith('/'):
+            path += '/'
+        for key in self.bucket.list(path, '/'):
+            if key.name == path:
+                continue
+            if isinstance(key, Prefix):
+                name = _remove_trailing_slash(_strip_path(key.name, path))
+                key_name = _remove_trailing_slash(key.name)
+                directories.append((name, key_name, True, 0, 0))
+            else:
+                last_modified = int(dateutil.parser.parse(key.last_modified)
+                                    .strftime('%s'))
+                name = _strip_path(key.name, path)
+                files.append((name, key.name, False, key.size, last_modified))
+        return directories + files
+
+    def _get_bucket_list_prefix(self, path):
+        parts = path.split('/')
+        if len(parts) == 1:
+            search = ''
+        else:
+            search = '/'.join(parts[:-1]) + '/'
+        return search
+
+    def _get_path_keys(self, path):
+        search = self._get_bucket_list_prefix(path)
+        return {key.name for key in self.bucket.list(search, '/')}
+
+    def is_dir(self, path):
+        keys = self._get_path_keys(path)
+        return path + '/' in keys
+
+    def path_exists(self, path):
+        if path == '':
+            return True
+        keys = self._get_path_keys(path)
+        return path in keys or path + '/' in keys
+
+    def get_base_path(self):
+        return ''
+
+    def get_breadcrumbs(self, path):
+        accumulator = []
+        breadcrumbs = []
+        for n in path.split('/'):
+            accumulator.append(n)
+            breadcrumbs.append((n, '/'.join(accumulator)))
+        return breadcrumbs
+
+    def send_file(self, file_path):
+        key = self.bucket.get_key(file_path)
+        if key is None:
+            raise ValueError()
+        return redirect(key.generate_url(3600))
+
+    def save_file(self, path, file_data):
+        key = Key(self.bucket, path)
+        key.set_contents_from_file(file_data.stream)
+
+    def delete_tree(self, directory):
+        self._check_empty_directory(directory)
+        self.bucket.delete_key(directory + '/')
+
+    def delete_file(self, file_path):
+        self.bucket.delete_key(file_path)
+
+    def make_dir(self, path, directory):
+        dir_path = '/'.join([path, directory + '/'])
+        key = Key(self.bucket, dir_path)
+        key.set_contents_from_string('')
+
+    def _check_empty_directory(self, path):
+        if not self._is_directory_empty(path):
+            raise ValueError(gettext('Cannot operate on non empty '
+                                     'directories'))
+        return True
+
+    def rename_path(self, src, dst):
+        if self.is_dir(src):
+            self._check_empty_directory(src)
+            src += '/'
+            dst += '/'
+        self.bucket.copy_key(dst, self.bucket.name, src)
+        self.delete_file(src)
+
+    def _is_directory_empty(self, path):
+        keys = self._get_path_keys(path + '/')
+        return len(keys) == 1
+
+
 class LocalFileStorage(object):
     def __init__(self, base_path):
         """