Scripts to download files from google storage based on sha1 sums

third_party/gsutil/gslib/addlhelp/acls.py

+# Copyright 2012 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from gslib.help_provider import HELP_NAME
+from gslib.help_provider import HELP_NAME_ALIASES
+from gslib.help_provider import HELP_ONE_LINE_SUMMARY
+from gslib.help_provider import HelpProvider
+from gslib.help_provider import HELP_TEXT
+from gslib.help_provider import HelpType
+from gslib.help_provider import HELP_TYPE
+
+_detailed_help_text = ("""
+<B>OVERVIEW</B>
+  Access Control Lists (ACLs) allow you to control who can read and write
+  your data, and who can read and write the ACLs themselves.
+
+  If not specified at the time an object is uploaded (e.g., via the gsutil cp
+  -a option), objects will be created with a default object ACL set on the
+  bucket (see "gsutil help setdefacl"). You can change the ACL on an object
+  or bucket using the gsutil setacl command (see "gsutil help setacl").
+
+
+<B>BUCKET VS OBJECT ACLS</B>
+  In Google Cloud Storage, the bucket ACL works as follows:
+
+    - Users granted READ access are allowed to list the bucket contents.
+
+    - Users granted WRITE access are allowed READ access and also are
+      allowed to write and delete objects in that bucket -- including
+      overwriting previously written objects.
+
+    - Users granted FULL_CONTROL access are allowed WRITE access and also
+      are allowed to read and write the bucket's ACL.
+
+  The object ACL works as follows:
+
+    - Users granted READ access are allowed to read the object's data and
+      metadata.
+
+    - Users granted FULL_CONTROL access are allowed READ access and also
+      are allowed to read and write the object's ACL.
+
+  A couple of points are worth noting, that sometimes surprise users:
+
+  1. There is no WRITE access for objects; attempting to set an ACL with WRITE
+     permission for an object will result in an error.
+
+  2. The bucket ACL plays no role in determining who can read objects; only the
+     object ACL matters for that purpose. This is different from how things
+     work in Linux file systems, where both the file and directory permission
+     control file read access. It also means, for example, that someone with
+     FULL_CONTROL over the bucket may not have read access to objects in
+     the bucket.  This is by design, and supports useful cases. For example,
+     you might want to set up bucket ownership so that a small group of
+     administrators have FULL_CONTROL on the bucket (with the ability to
+     delete data to control storage costs), but not grant those users read
+     access to the object data (which might be sensitive data that should
+     only be accessed by a different specific group of users).
+
+
+<B>CANNED ACLS</B>
+  The simplest way to set an ACL on a bucket or object is using a "canned
+  ACL". The available canned ACLs are:
+
+  project-private            Gives permission to the project team based on their
+                             roles. Anyone who is part of the team has READ
+                             permission, and project owners and project editors
+                             have FULL_CONTROL permission. This is the default
+                             ACL for newly created buckets. This is also the
+                             default ACL for newly created objects unless the
+                             default object ACL for that bucket has been
+                             changed. For more details see
+                             "gsutil help projects".
+
+  private                    Gives the requester (and only the requester)
+                             FULL_CONTROL permission for a bucket or object.
+
+  public-read                Gives the requester FULL_CONTROL permission and
+                             gives all users READ permission. When you apply
+                             this to an object, anyone on the Internet can
+                             read the object without authenticating.
+
+  public-read-write          Gives the requester FULL_CONTROL permission and
+                             gives all users READ and WRITE permission. This
+                             ACL applies only to buckets.
+
+  authenticated-read         Gives the requester FULL_CONTROL permission and
+                             gives all authenticated Google account holders
+                             READ permission.
+
+  bucket-owner-read          Gives the requester FULL_CONTROL permission and
+                             gives the bucket owner READ permission. This is
+                             used only with objects.
+
+  bucket-owner-full-control  Gives the requester FULL_CONTROL permission and
+                             gives the bucket owner FULL_CONTROL
+                             permission. This is used only with objects.
+
+
+<B>ACL XML</B>
+  When you use a canned ACL, it is translated into an XML representation
+  that can later be retrieved and edited to specify more fine-grained
+  detail about who can read and write buckets and objects. By running
+  the gsutil getacl command you can retrieve the ACL XML, and edit it to
+  customize the permissions.
+
+  As an example, if you create an object in a bucket that has no default
+  object ACL set and then retrieve the ACL on the object, it will look
+  something like this:
+
+  <AccessControlList>
+    <Owner>
+      <ID>
+        00b4903a9740e42c29800f53bd5a9a62a2f96eb3f64a4313a115df3f3a776bf7
+      </ID>
+    </Owner>
+    <Entries>
+      <Entry>
+        <Scope type="GroupById">
+          <ID>
+            00b4903a9740e42c29800f53bd5a9a62a2f96eb3f64a4313a115df3f3a776bf7
+          </ID>
+        </Scope>
+        <Permission>
+          FULL_CONTROL
+        </Permission>
+      </Entry>
+      <Entry>
+        <Scope type="GroupById">
+          <ID>
+            00b4903a977fd817e9da167bc81306489181a110456bb635f466d71cf90a0d51
+          </ID>
+        </Scope>
+        <Permission>
+          FULL_CONTROL
+        </Permission>
+      </Entry>
+      <Entry>
+        <Scope type="GroupById">
+          <ID>
+            00b4903a974898cc8fc309f2f2835308ba3d3df1b889d3fc7e33e187d52d8e71
+          </ID>
+        </Scope>
+        <Permission>
+          READ
+        </Permission>
+      </Entry>
+    </Entries>
+  </AccessControlList>
+
+  The ACL consists of an Owner element and a collection of Entry elements,
+  each of which specifies a Scope and a Permission. Scopes are the way you
+  specify an individual or group of individuals, and Permissions specify what
+  access they're permitted.
+
+  This particular ACL grants FULL_CONTROL to two groups (which means members
+  of those groups are allowed to read the object and read and write the ACL),
+  and READ permission to a third group. The project groups are (in order)
+  the owners group, editors group, and viewers group.
+
+  The 64 digit hex identifiers used in this ACL are called canonical IDs,
+  and are used to identify predefined groups associated with the project that
+  owns the bucket. For more information about project groups, see "gsutil
+  help projects".
+
+  Here's an example of an ACL specified using the GroupByEmail and GroupByDomain
+  scopes:
+
+  <AccessControlList>
+    <Entries>
+      <Entry>
+        <Permission>
+          FULL_CONTROL
+        </Permission>
+        <Scope type="GroupByEmail">
+          <EmailAddress>travel-companion-owners@googlegroups.com</EmailAddress>
+        </Scope>
+      </Entry>
+      <Entry>
+        <Permission>
+          READ
+        </Permission>
+        <Scope type="GroupByDomain">
+          <Domain>example.com</Domain>
+        </Scope>
+      </Entry>
+    </Entries>
+  </AccessControlList>
+
+  This ACL grants members of an email group FULL_CONTROL, and grants READ
+  access to any user in a domain (which must be a Google Apps for Business
+  domain). By applying email group grants to a collection of objects
+  you can edit access control for large numbers of objects at once via
+  http://groups.google.com. That way, for example, you can easily and quickly
+  change access to a group of company objects when employees join and leave
+  your company (i.e., without having to individually change ACLs across
+  potentially millions of objects).
+
+
+<B>SHARING SCENARIOS</B>
+  For more detailed examples how to achieve various useful sharing use
+  cases see https://developers.google.com/storage/docs/collaboration
+""")
+
+
+class CommandOptions(HelpProvider):
+  """Additional help about Access Control Lists."""
+
+  help_spec = {
+    # Name of command or auxiliary help info for which this help applies.
+    HELP_NAME : 'acls',
+    # List of help name aliases.
+    HELP_NAME_ALIASES : ['acl', 'ACL', 'access control', 'access control list',
+                         'authorization', 'canned', 'canned acl'],
+    # Type of help:
+    HELP_TYPE : HelpType.ADDITIONAL_HELP,
+    # One line summary of this help.
+    HELP_ONE_LINE_SUMMARY : 'Working with Access Control Lists',
+    # The full help text.
+    HELP_TEXT : _detailed_help_text,
+  }