1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
.. _guide_migration_s3:
Amazon S3
=========
Boto 2.x contains a number of customizations to make working with Amazon S3 buckets and keys easy. Boto3 exposes these same objects through its resources interface in a unified and consistent way.
Creating the connection
-----------------------
Boto3 has both low-level clients and higher-level resources. For Amazon S3, the higher-level resources are the most similar to Boto 2.x's ``s3`` module::
# Boto 2.x
import boto
s3_connection = boto.connect_s3()
# Boto3
import boto3
s3 = boto3.resource('s3')
Creating a bucket
-----------------
Creating a bucket in Boto 2 and Boto3 is very similar, except that in Boto3 all action parameters must be passed via keyword arguments and a bucket configuration must be specified manually::
# Boto 2.x
s3_connection.create_bucket('mybucket')
s3_connection.create_bucket('mybucket', location=Location.USWest)
# Boto3
s3.create_bucket(Bucket='mybucket')
s3.create_bucket(Bucket='mybucket', CreateBucketConfiguration={
'LocationConstraint': 'us-west-1'})
Storing data
------------
Storing data from a file, stream, or string is easy::
# Boto 2.x
from boto.s3.key import Key
key = Key('hello.txt')
key.set_contents_from_file('/tmp/hello.txt')
# Boto3
s3.Object('mybucket', 'hello.txt').put(Body=open('/tmp/hello.txt', 'rb'))
Accessing a bucket
------------------
Getting a bucket is easy with Boto3's resources, however these do not automatically validate whether a bucket exists::
# Boto 2.x
bucket = s3_connection.get_bucket('mybucket', validate=False)
exists = s3_connection.lookup('mybucket')
# Boto3
import botocore
bucket = s3.Bucket('mybucket')
exists = True
try:
s3.meta.client.head_bucket(Bucket='mybucket')
except botocore.exceptions.ClientError as e:
# If a client error is thrown, then check that it was a 404 error.
# If it was a 404 error, then the bucket does not exist.
error_code = e.response['Error']['Code']
if error_code == '404':
exists = False
Deleting a bucket
-----------------
All of the keys in a bucket must be deleted before the bucket itself can be deleted::
# Boto 2.x
for key in bucket:
key.delete()
bucket.delete()
# Boto3
for key in bucket.objects.all():
key.delete()
bucket.delete()
Iteration of buckets and keys
-----------------------------
Bucket and key objects are no longer iterable, but now provide collection attributes which can be iterated::
# Boto 2.x
for bucket in s3_connection:
for key in bucket:
print(key.name)
# Boto3
for bucket in s3.buckets.all():
for key in bucket.objects.all():
print(key.key)
Access controls
---------------
Getting and setting canned access control values in Boto3 operates on an ``ACL`` resource object::
# Boto 2.x
bucket.set_acl('public-read')
key.set_acl('public-read')
# Boto3
bucket.Acl().put(ACL='public-read')
obj.Acl().put(ACL='public-read')
It's also possible to retrieve the policy grant information::
# Boto 2.x
acp = bucket.get_acl()
for grant in acp.acl.grants:
print(grant.display_name, grant.permission)
# Boto3
acl = bucket.Acl()
for grant in acl.grants:
print(grant['Grantee']['DisplayName'], grant['Permission'])
Boto3 lacks the grant shortcut methods present in Boto 2.x, but it is still fairly simple to add grantees::
# Boto 2.x
bucket.add_email_grant('READ', 'user@domain.tld')
# Boto3
bucket.Acl.put(GrantRead='emailAddress=user@domain.tld')
Key metadata
------------
It's possible to set arbitrary metadata on keys::
# Boto 2.x
key.set_metadata('meta1', 'This is my metadata value')
print(key.get_metadata('meta1'))
# Boto3
key.put(Metadata={'meta1': 'This is my metadata value'})
print(key.metadata['meta1'])
Managing CORS configurations
---------------------------
Allows you to manage the cross-origin resource sharing configuration for S3 buckets::
# Boto 2.x
cors = bucket.get_cors()
config = CORSConfiguration()
config.add_rule('GET', '*')
bucket.set_cors(config)
bucket.delete_cors()
# Boto3
cors = bucket.Cors()
config = {
'CORSRules': [
{
'AllowedMethods': ['GET'],
'AllowedOrigins': ['*']
}
]
}
cors.put(CORSConfiguration=config)
cors.delete()
|
