Appendix G. Examples using the Secure Token Service APIs

These examples are using Python’s boto3 module to interface with the Ceph Object Gateway’s implementation of the Secure Token Service (STS). In these examples, TESTER2 assumes a role created by TESTER1, as to access S3 resources owned by TESTER1 based on the permission policy attached to the role.

The AssumeRole example creates a role, assigns a policy to the role, then assumes a role to get temporary credentials and access to S3 resources using those temporary credentials.

The AssumeRoleWithWebIdentity example authenticates users using an external application with Keycloak, an OpenID Connect identity provider, assumes a role to get temporary credentials and access S3 resources according to the permission policy of the role.

AssumeRole Example

import boto3

iam_client = boto3.client('iam',
aws_access_key_id=ACCESS_KEY_OF_TESTER1,
aws_secret_access_key=SECRET_KEY_OF_TESTER1,
endpoint_url=<IAM URL>,
region_name=''
)

policy_document = "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam:::user/TESTER1\"]},\"Action\":[\"sts:AssumeRole\"]}]}"

role_response = iam_client.create_role(
AssumeRolePolicyDocument=policy_document,
Path='/',
RoleName='S3Access',
)

role_policy = "{\"Version\":\"2012-10-17\",\"Statement\":{\"Effect\":\"Allow\",\"Action\":\"s3:*\",\"Resource\":\"arn:aws:s3:::*\"}}"

response = iam_client.put_role_policy(
RoleName='S3Access',
PolicyName='Policy1',
PolicyDocument=role_policy
)

sts_client = boto3.client('sts',
aws_access_key_id=ACCESS_KEY_OF_TESTER2,
aws_secret_access_key=SECRET_KEY_OF_TESTER2,
endpoint_url=<STS URL>,
region_name='',
)

response = sts_client.assume_role(
RoleArn=role_response['Role']['Arn'],
RoleSessionName='Bob',
DurationSeconds=3600
)

s3client = boto3.client('s3',
aws_access_key_id = response['Credentials']['AccessKeyId'],
aws_secret_access_key = response['Credentials']['SecretAccessKey'],
aws_session_token = response['Credentials']['SessionToken'],
endpoint_url=<S3 URL>,
region_name='',)

bucket_name = 'my-bucket'
s3bucket = s3client.create_bucket(Bucket=bucket_name)
resp = s3client.list_buckets()

AssumeRoleWithWebIdentity Example

import boto3

iam_client = boto3.client('iam',
aws_access_key_id=ACCESS_KEY_OF_TESTER1,
aws_secret_access_key=SECRET_KEY_OF_TESTER1,
endpoint_url=<IAM URL>,
region_name=''
)

oidc_response = iam_client.create_open_id_connect_provider(
    Url=<URL of the OpenID Connect Provider>,
    ClientIDList=[
        <Client id registered with the IDP>
    ],
    ThumbprintList=[
        <IDP THUMBPRINT>
 ]
)

policy_document = "{\"Version\":\"2012-10-17\",\"Statement\":\[\{\"Effect\":\"Allow\",\"Principal\":\{\"Federated\":\[\"arn:aws:iam:::oidc-provider/localhost:8080/auth/realms/demo\"\]\},\"Action\":\[\"sts:AssumeRoleWithWebIdentity\"\],\"Condition\":\{\"StringEquals\":\{\"localhost:8080/auth/realms/demo:app_id\":\"customer-portal\"\}\}\}\]\}"
role_response = iam_client.create_role(
AssumeRolePolicyDocument=policy_document,
Path='/',
RoleName='S3Access',
)

role_policy = "{\"Version\":\"2012-10-17\",\"Statement\":{\"Effect\":\"Allow\",\"Action\":\"s3:*\",\"Resource\":\"arn:aws:s3:::*\"}}"

response = iam_client.put_role_policy(
    RoleName='S3Access',
    PolicyName='Policy1',
    PolicyDocument=role_policy
)

sts_client = boto3.client('sts',
aws_access_key_id=ACCESS_KEY_OF_TESTER2,
aws_secret_access_key=SECRET_KEY_OF_TESTER2,
endpoint_url=<STS URL>,
region_name='',
)

response = client.assume_role_with_web_identity(
RoleArn=role_response['Role']['Arn'],
RoleSessionName='Bob',
DurationSeconds=3600,
WebIdentityToken=<Web Token>
)

s3client = boto3.client('s3',
aws_access_key_id = response['Credentials']['AccessKeyId'],
aws_secret_access_key = response['Credentials']['SecretAccessKey'],
aws_session_token = response['Credentials']['SessionToken'],
endpoint_url=<S3 URL>,
region_name='',)

bucket_name = 'my-bucket'
s3bucket = s3client.create_bucket(Bucket=bucket_name)
resp = s3client.list_buckets()

Additional Resources

  • See the Test S3 Access section of the Red Hat Ceph Storage Object Gateway Configuration and Administration Guide for more details on using Python’s boto module.