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我在 terraform 中创建了一个 IRSA 角色，以便 K8s 作业可以使用关联的服务帐户来访问 S3 存储桶，但我AccessDenied在作业中不断收到错误消息。

enable_irsa = true我首先在我们的模块中启用了我们的 EKS 集群中的 IRSA eks。

然后我创建了一个简单aws_iam_policy的：

resource "aws_iam_policy" "eks_s3_access_policy" {
  name = "eks_s3_access_policy"

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = [
          "s3:*",
        ]
        Effect   = "Allow"
        Resource = "arn:aws:s3:::*"
      },
    ]
  })
}

和一个iam-assumable-role-with-oidc：

module "iam_assumable_role_with_oidc_for_s3_access" {
  source  = "terraform-aws-modules/iam/aws//modules/iam-assumable-role-with-oidc"
  version = "~> 3.0"

  create_role = true
  role_name = "eks-s3-access"
  role_description = "Role to access s3 bucket"
  tags = { Role = "eks_s3_access_policy" }
  provider_url = replace(module.eks.cluster_oidc_issuer_url, "https://", "")
  role_policy_arns = [aws_iam_policy.eks_s3_access_policy.arn]
  number_of_role_policy_arns = 1
  oidc_fully_qualified_subjects = ["system:serviceaccount:default:my-user"]
}

我使用 Helm 创建了一个 K8s 服务帐户，例如：

Name:                my-user
Namespace:           default
Labels:              app.kubernetes.io/managed-by=Helm
Annotations:         eks.amazonaws.com/role-arn: arn:aws:iam::111111:role/eks-s3-access
                     meta.helm.sh/release-name: XXXX
                     meta.helm.sh/release-namespace: default
Image pull secrets:  <none>
Mountable secrets:   my-user-token-kwwpq
Tokens:              my-user-token-kwwpq
Events:              <none>

最后，使用来自作业模板的 K8s API 创建作业：

apiVersion: batch/v1
kind: Job
metadata:
  name: job
  namespace: default
spec:
  template:
  spec:
    serviceAccountName: my-user
    containers:
    - name: {{ .Chart.Name }}
      env:
      - name: AWS_ROLE_ARN
        value: arn:aws:iam::746181457053:role/eks-s3-access
      - name: AWS_WEB_IDENTITY_TOKEN_FILE
        value: /var/run/secrets/eks.amazonaws.com/serviceaccount/token
      volumeMounts:
      - mountPath: /var/run/secrets/eks.amazonaws.com/serviceaccount
        name: aws-iam-token
        readOnly: true
    volumes:
    - name: aws-iam-token
      projected:
        defaultMode: 420
        sources:
        - serviceAccountToken:
          audience: sts.amazonaws.com
          expirationSeconds: 86400
          path: token

但是，当作业尝试获取指定的凭据时，指定的令牌不存在：

2021-08-03 18:02:41  Refreshing temporary credentials failed during mandatory refresh period.
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/aiobotocore/credentials.py", line 291, in _protected_refresh
    metadata = await self._refresh_using()
  File "/usr/local/lib/python3.7/site-packages/aiobotocore/credentials.py", line 345, in fetch_credentials
    return await self._get_cached_credentials()
  File "/usr/local/lib/python3.7/site-packages/aiobotocore/credentials.py", line 355, in _get_cached_credentials
    response = await self._get_credentials()
  File "/usr/local/lib/python3.7/site-packages/aiobotocore/credentials.py", line 410, in _get_credentials
    kwargs = self._assume_role_kwargs()
  File "/usr/local/lib/python3.7/site-packages/aiobotocore/credentials.py", line 420, in _assume_role_kwargs
    identity_token = self._web_identity_token_loader()
  File "/usr/local/lib/python3.7/site-packages/botocore/utils.py", line 2365, in __call__
    with self._open(self._web_identity_token_path) as token_file:
FileNotFoundError: [Errno 2] No such file or directory: '/var/run/secrets/eks.amazonaws.com/serviceaccount/token'

根据https://aws.amazon.com/blogs/opensource/introducing-fine-grained-iam-roles-service-accounts/中的描述，webhook 通常会在创建 pod 时创建这些凭据。但是，由于我们在 k8s 集群中按需创建新的 k8s 作业，我怀疑 webhook 没有创建任何此类凭据。

如何请求从 K8s 集群中创建正确的凭证？有没有办法从集群中实例化 webhook？

4

1 回答 1

0

有几件事可能导致此失败。

  • 检查 IRSA 角色的所有设置。对于信任关系设置，检查命名空间的名称和服务帐户的名称是否正确。只有当这些设置与角色匹配时，才能担任角色。
  • 当 pod 正在运行时，尝试使用 shell 访问 pod。检查“AWS_*”环境变量的内容。检查 AWS_ROLE_ARN 指向正确的角色。检查 AWS_WEB_IDENTITY_TOKEN_FILE 指向的文件是否在其位置并且可读。只需尝试对cat文件执行 a 以查看它是否可读。
  • 如果您以非 root 用户运行 pod（出于安全原因建议这样做），请确保运行 pod 的用户有权访问该文件。如果没有，请调整 pod 的 securityContext。也许fsGroup这里的设置可以提供帮助。https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#security-context
  • 确保您的 pos 使用的 SDK 支持 IRSA。如果您使用的是较旧的 SDK，则可能不支持 IRSA。查看 IRSA 文档以了解受支持的 SDK 版本。https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts-minimum-sdk.html
于 2021-08-04T14:23:23.050 回答