boto3 client NoRegionError: You must specify a region error only sometimes

Question

I have a boto3 client :

boto3.client('kms')

But it happens on new machines, They open and close dynamically.

    if endpoint is None:
        if region_name is None:
            # Raise a more specific error message that will give
            # better guidance to the user what needs to happen.
            raise NoRegionError()

Why is this happening? and why only part of the time?

Because boto3 client can't find AWS profile from set of default credentials method : http://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html. — mootmoot, Nov 02 '16 at 11:26

score 426 · Accepted Answer · edited Feb 07 '19 at 00:45

426

One way or another you must tell boto3 in which region you wish the kms client to be created. This could be done explicitly using the region_name parameter as in:

kms = boto3.client('kms', region_name='us-west-2')

or you can have a default region associated with your profile in your ~/.aws/config file as in:

[default]
region=us-west-2

or you can use an environment variable as in:

export AWS_DEFAULT_REGION=us-west-2

but you do need to tell boto3 which region to use.

edited Feb 07 '19 at 00:45

PythonJin

3,289
4
32
38

answered Nov 02 '16 at 10:39

garnaat

37,899
7
109
98

2

How do I know myself which region to use? – jononomo Mar 31 '17 at 17:05
1

If you are trying to access existing resources choose the region in which those resources exist. If you are going to create new resources, most people choose a region which is closest to them geographically for faster response times. Not all regions support the same set of services so if you need a particular service make sure you choose a region that supports it. – garnaat Apr 01 '17 at 18:18
I guess my question is: how do I know which region I have already chosen? I suppose it must be in the AWS UI somewhere... – jononomo Apr 03 '17 at 14:13
1

To find out which regions provide which services: Amazon Web Services Region Table https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/ – Nick May 23 '17 at 04:53
2

do you know why "export AWS_DEFAULT_REGION=us-west-2" or ~/.aws/config file not working – fatih tekin Nov 28 '17 at 20:44
I was looking for this answer in regard to SNS. Worked as well. – Strabek Nov 15 '18 at 11:58
works as well with `boto3.resource('service_name', region_name='us-west-2')` – openwonk Aug 13 '19 at 00:21
6

I wish boto3 could just use the region of the ec2 instance that's running the code. – Selçuk Cihan Feb 06 '20 at 09:26
1

Yeah I have my AWS_DEFAULT_REGION set and still no workey – ThisGuyCantEven Feb 25 '20 at 15:53
Why is it not finding my creds even though I input them exactly as they should be? – Blairg23 Apr 07 '20 at 19:41

score 15 · Answer 2 · edited May 29 '19 at 20:08

15

os.environ['AWS_DEFAULT_REGION'] = 'your_region_name'

In my case sensitivity mattered.

edited May 29 '19 at 20:08

Suit Boy Apps

3,005
8
36
54

answered May 29 '19 at 19:19

Anthony G

151
1
2

score 6 · Answer 3 · edited Nov 25 '19 at 23:13

For Python 2 I have found that the boto3 library does not source the region from the ~/.aws/config if the region is defined in a different profile to default. So you have to define it in the session creation.

session = boto3.Session(
    profile_name='NotDefault',
    region_name='ap-southeast-2'
)

print(session.available_profiles)

client = session.client(
    'ec2'
)

Where my ~/.aws/config file looks like this:

[default]
region=ap-southeast-2

[NotDefault]
region=ap-southeast-2

I do this because I use different profiles for different logins to AWS, Personal and Work.

score 4 · Answer 4 · answered Jul 24 '18 at 18:34

4

I believe, by default, boto picks the region which is set in aws cli. You can run command #aws configure and press enter (it shows what creds you have set in aws cli with region)twice to confirm your region.

answered Jul 24 '18 at 18:34

josh eversman

41
1

score 3 · Answer 5 · edited Dec 06 '19 at 09:19

3

you can also set environment variables in the script itself, rather than passing region_name parameter

os.environ['AWS_DEFAULT_REGION'] = 'your_region_name'

case sensitivity may matter.

edited Dec 06 '19 at 09:19

Ben Watson

3,882
4
33
55

answered May 14 '19 at 12:55

Abhishek Garg

71
5

`AWS_DEFAULT_REGION` is case sensitive. – Jaime M. Jul 09 '19 at 09:20
It should be: `os.environ['AWS_DEFAULT_REGION'] = 'us-east-1'` (upper case) – Joe Dec 04 '19 at 05:36

score 0 · Answer 6 · answered Dec 24 '19 at 05:27

For those using CloudFormation template. You can set AWS_DEFAULT_REGION environment variable using UserData and AWS::Region. For example,

MyInstance1:
    Type: AWS::EC2::Instance                
    Properties:                           
        ImageId: ami-04b9e92b5572fa0d1 #ubuntu
        InstanceType: t2.micro
        UserData: 
            Fn::Base64: !Sub |
                    #!/bin/bash -x

                    echo "export AWS_DEFAULT_REGION=${AWS::Region}" >> /etc/profile

score 0 · Answer 7 · answered Sep 15 '20 at 06:59

Alternatively you can run the following (aws cli)

aws configure --profile $PROFILE_NAME

it'll prompt you for the region.

notice in ~/.aws/config it's:

[default]
region = ap-southeast-1
output = json

[profile prod]
region = ap-southeast-1
output = json

[profile profile name] in the square brackets

boto3 client NoRegionError: You must specify a region error only sometimes

7 Answers7

Linked

Related