An Identity and Access Management (IAM) policy, which specifies access controls for Google Cloud resources.
A Policy is a collection of bindings. A binding binds one or more members, or principals, to a single role. Principals can be user accounts, service accounts, Google groups, and domains (such as G Suite). A role is a named list of permissions; each role can be an IAM predefined role or a user-created custom role.
For some types of Google Cloud resources, a binding can also specify a condition, which is a logical expression that allows access to a resource only if the expression evaluates to true. A condition can add constraints based on attributes of the request, the resource, or both. To learn which resources support conditions in their IAM policies, see the IAM documentation.
Valid values are 0, 1, and 3. Requests that specify an invalid value are rejected.
Any operation that affects conditional role bindings must specify version 3. This requirement applies to the following operations:
Getting a policy that includes a conditional role binding
Adding a conditional role binding to a policy
Changing a conditional role binding in a policy
Removing any role binding, with or without a condition, from a policy that includes conditions
Important: If you use IAM Conditions, you must include the etag field whenever you call setIamPolicy. If you omit this field, then IAM allows you to overwrite a version 3 policy with a version 1 policy, and all of the conditions in the version 3 policy are lost.
If a policy does not include any conditions, operations on that policy may specify any valid version or leave the field unset.
To learn which resources support conditions in their IAM policies, see the IAM documentation.
Associates a list of members, or principals, with a role. Optionally, may specify a condition that determines how and when the bindings are applied. Each of the bindings must contain at least one principal.
The bindings in a Policy can refer to up to 1,500 principals; up to 250 of these principals can be Google groups. Each occurrence of a principal counts towards these limits. For example, if the bindings grant 50 different roles to user:alice@example.com, and not to any other principal, then you can add another 1,450 principals to the bindings in the Policy.
etag is used for optimistic concurrency control as a way to help prevent simultaneous updates of a policy from overwriting each other. It is strongly suggested that systems make use of the etag in the read-modify-write cycle to perform policy updates in order to avoid race conditions: An etag is returned in the response to getIamPolicy, and systems are expected to put that etag in the request to setIamPolicy to ensure that their change will be applied to the same version of the policy.
Important: If you use IAM Conditions, you must include the etag field whenever you call setIamPolicy. If you omit this field, then IAM allows you to overwrite a version 3 policy with a version 1 policy, and all of the conditions in the version 3 policy are lost.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2023-10-19 UTC."],[[["An IAM policy controls access to Google Cloud resources, using `bindings` to link `members` (principals) to specific `roles`, defining their permissions."],["`Bindings` can include a `condition`, a logical expression that further refines access based on request or resource attributes, enabling conditional access control."],["IAM policies have a `version` field, and if conditions are present, the policy must be version `3`; using the `etag` field during updates is crucial to prevent overwriting or losing conditions."],["The `etag` field is essential for managing concurrent updates to IAM policies, ensuring that modifications are based on the current policy version, especially when using conditions."],["The `Policy` JSON contains the key-value pairs `version`, `bindings`, `auditConfigs`, and `etag` that hold the specific information for the policy in question."]]],[]]