naming.py revision 8d2b206a675ec20ea07100c35df34e65ee1e45e8 
1# -*- coding: utf-8 -*-
2# Copyright 2012 Google Inc. All Rights Reserved.
3#
4# Licensed under the Apache License, Version 2.0 (the "License");
5# you may not use this file except in compliance with the License.
6# You may obtain a copy of the License at
7#
8#     http://www.apache.org/licenses/LICENSE-2.0
9#
10# Unless required by applicable law or agreed to in writing, software
11# distributed under the License is distributed on an "AS IS" BASIS,
12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13# See the License for the specific language governing permissions and
14# limitations under the License.
15"""Additional help about gsutil object and bucket naming."""
16
17from __future__ import absolute_import
18
19from gslib.help_provider import HelpProvider
20
21_DETAILED_HELP_TEXT = ("""
22<B>BUCKET NAME REQUIREMENTS</B>
23  Google Cloud Storage has a single namespace, so you will not be allowed
24  to create a bucket with a name already in use by another user. You can,
25  however, carve out parts of the bucket name space corresponding to your
26  company's domain name (see "DOMAIN NAMED BUCKETS").
27
28  Bucket names must conform to standard DNS naming conventions. This is
29  because a bucket name can appear in a DNS record as part of a CNAME
30  redirect. In addition to meeting DNS naming requirements, Google Cloud
31  Storage imposes other requirements on bucket naming. At a minimum, your
32  bucket names must meet the following requirements:
33
34  - Bucket names must contain only lowercase letters, numbers, dashes (-), and
35    dots (.).
36
37  - Bucket names must start and end with a number or letter.
38
39  - Bucket names must contain 3 to 63 characters. Names containing dots can
40    contain up to 222 characters, but each dot-separated component can be
41    no longer than 63 characters.
42
43  - Bucket names cannot be represented as an IPv4 address in dotted-decimal
44    notation (for example, 192.168.5.4).
45
46  - Bucket names cannot begin with the "goog" prefix.
47
48  - For DNS compliance, you should not have a period adjacent to another
49    period or dash. For example, ".." or "-." or ".-" are not acceptable.
50
51
52<B>OBJECT NAME REQUIREMENTS</B>
53  Object names can contain any sequence of Unicode characters, of length 1-1024
54  bytes when UTF-8 encoded. Object names must not contain CarriageReturn,
55  CarriageReturnLineFeed, or the XML-disallowed surrogate blocks (xFFFE
56  or xFFFF).
57
58  We strongly recommend that you abide by the following object naming
59  conventions:
60
61  - Avoid using control characters that are illegal in XML 1.0 in your object
62    names (#x7F-#x84 and #x86-#x9F). These characters will cause XML listing
63    issues when you try to list your objects.
64
65  - Avoid using "#" in your object names. gsutil interprets object names ending
66    with #<numeric string> as version identifiers, so including "#" in object
67    names can make it difficult or impossible to perform various operations on
68    such objects using gsutil (see 'gsutil help versions').
69
70  - Avoid using "[", "]", "*", or "?" in your object names. gsutil interprets
71    these characters as wildcards, so including any of these characters in
72    object names can make it difficult or impossible to perform various wildcard
73    operations using gsutil (see 'gsutil help wildcards').
74
75  See also 'gsutil help encoding' about file/object name encoding requirements
76  and potential interoperability concerns.
77
78
79<B>DOMAIN NAMED BUCKETS</B>
80  You can carve out parts of the Google Cloud Storage bucket name space
81  by creating buckets with domain names (like "example.com").
82
83  Before you can create a bucket name containing one or more '.' characters,
84  the following rules apply:
85
86  - If the name is a syntactically valid DNS name ending with a
87    currently-recognized top-level domain (such as .com), you will be required
88    to verify domain ownership.
89  - Otherwise you will be disallowed from creating the bucket.
90
91  If your project needs to use a domain-named bucket, you need to have
92  a team member both verify the domain and create the bucket. This is
93  because Google Cloud Storage checks for domain ownership against the
94  user who creates the bucket, so the user who creates the bucket must
95  also be verified as an owner or manager of the domain.
96
97  To verify as the owner or manager of a domain, use the Google Webmaster
98  Tools verification process. The Webmaster Tools verification process
99  provides three methods for verifying an owner or manager of a domain:
100
101  1. Adding a special Meta tag to a site's homepage.
102  2. Uploading a special HTML file to a site.
103  3. Adding a DNS TXT record to a domain's DNS configuration.
104
105  Meta tag verification and HTML file verification are easier to perform and
106  are probably adequate for most situations. DNS TXT record verification is
107  a domain-based verification method that is useful in situations where a
108  site wants to tightly control who can create domain-named buckets. Once
109  a site creates a DNS TXT record to verify ownership of a domain, it takes
110  precedence over meta tag and HTML file verification. For example, you might
111  have two IT staff members who are responsible for managing your site, called
112  "example.com." If they complete the DNS TXT record verification, only they
113  would be able to create buckets called "example.com", "reports.example.com",
114  "downloads.example.com", and other domain-named buckets.
115
116  Site-Based Verification
117  -----------------------
118
119  If you have administrative control over the HTML files that make up a site,
120  you can use one of the site-based verification methods to verify that you
121  control or own a site. When you do this, Google Cloud Storage lets you
122  create buckets representing the verified site and any sub-sites - provided
123  nobody has used the DNS TXT record method to verify domain ownership of a
124  parent of the site.
125
126  As an example, assume that nobody has used the DNS TXT record method to verify
127  ownership of the following domains: abc.def.example.com, def.example.com,
128  and example.com. In this case, Google Cloud Storage lets you create a bucket
129  named abc.def.example.com if you verify that you own or control any of the
130  following sites:
131
132    http://abc.def.example.com
133    http://def.example.com
134    http://example.com
135
136  Domain-Based Verification
137  -------------------------
138
139  If you have administrative control over a domain's DNS configuration, you can
140  use the DNS TXT record verification method to verify that you own or control a
141  domain. When you use the domain-based verification method to verify that you
142  own or control a domain, Google Cloud Storage lets you create buckets that
143  represent any subdomain under the verified domain. Furthermore, Google Cloud
144  Storage prevents anybody else from creating buckets under that domain unless
145  you add their name to the list of verified domain owners or they have verified
146  their domain ownership by using the DNS TXT record verification method.
147
148  For example, if you use the DNS TXT record verification method to verify your
149  ownership of the domain example.com, Google Cloud Storage will let you create
150  bucket names that represent any subdomain under the example.com domain, such
151  as abc.def.example.com, example.com/music/jazz, or abc.example.com/music/jazz.
152
153  Using the DNS TXT record method to verify domain ownership supersedes
154  verification by site-based verification methods. For example, if you
155  use the Meta tag method or HTML file method to verify domain ownership
156  of http://example.com, but someone else uses the DNS TXT record method
157  to verify ownership of the example.com domain, Google Cloud Storage will
158  not allow you to create a bucket named example.com. To create the bucket
159  example.com, the domain owner who used the DNS TXT method to verify domain
160  ownership must add you to the list of verified domain owners for example.com.
161
162  The DNS TXT record verification method is particularly useful if you manage
163  a domain for a large organization that has numerous subdomains because it
164  lets you control who can create buckets representing those domain names.
165
166  Note: If you use the DNS TXT record verification method to verify ownership of
167  a domain, you cannot create a CNAME record for that domain. RFC 1034 disallows
168  inclusion of any other resource records if there is a CNAME resource record
169  present. If you want to create a CNAME resource record for a domain, you must
170  use the Meta tag verification method or the HTML file verification method.
171""")
172
173
174class CommandOptions(HelpProvider):
175  """Additional help about gsutil object and bucket naming."""
176
177  # Help specification. See help_provider.py for documentation.
178  help_spec = HelpProvider.HelpSpec(
179      help_name='naming',
180      help_name_aliases=['domain', 'limits', 'name', 'names'],
181      help_type='additional_help',
182      help_one_line_summary='Object and Bucket Naming',
183      help_text=_DETAILED_HELP_TEXT,
184      subcommand_help_text={},
185  )
186