Create IAM Role for FluentD

This section will guide you through creating an IAM role for FluentD on your EKS cluster.

Fast Forward

If you already have an IAM role for your FluentD, expand this box to fast-forward.

  1. Go to your GitOps repository, inside your rok-tools management environment:

    root@rok-tools:~# cd ~/ops/deployments

  2. Restore the required context from previous sections:

    root@rok-tools:~/ops/deployments# source <(cat deploy/env.{envvars-aws,eks-cluster})
    root@rok-tools:~/ops/deployments# export AWS_DEFAULT_REGION EKS_CLUSTER

  3. Specify the name of the IAM role for your FluentD:

    root@rok-tools:~/ops/deployments# export FLUENTD_EKS_IAM_ROLE=<ROLE>

    Replace <ROLE> with the name of the IAM role for your FluentD, for example:

    root@rok-tools:~/ops/deployments# export FLUENTD_EKS_IAM_ROLE=rok-\ > ${AWS_DEFAULT_REGION?}-${EKS_CLUSTER?}-fluentd

  4. Save your state:

    root@rok-tools:~/ops/deployments# j2 deploy/env.fluentd-eks-iam.j2 \ > -o deploy/env.fluentd-eks-iam

  5. Commit your changes:

    root@rok-tools:~/ops/deployments# git commit \ > -am "Create IAM Role for FluentD"

  6. Proceed to the Verify section.

See also

Check Your Environment

To create this role, you are going to deploy a CloudFormation stack. When working with AWS CloudFormation stacks to manage resources, not only do you need sufficient permissions on AWS CloudFormation, but also on the underlying resources that are defined in the template.

In order to create an IAM role with proper IAM policies attached to it for your EKS Cluster FluentD using AWS CloudFormation you need permissions for the following actions:

  • Deploy AWS CloudFormation stacks.
  • Create IAM roles.
  • Create IAM policies.
  • Attach managed IAM policies to IAM roles.

Note

If you do not have the above permissions, contact your AWS administrator to grant sufficient permissions to your IAM user or deploy the below AWS CloudFormation stack for you.

Procedure

  1. Go to your GitOps repository, inside your rok-tools management environment:

    root@rok-tools:~# cd ~/ops/deployments

  2. Restore the required context from previous sections:

    root@rok-tools:~/ops/deployments# source <(cat deploy/env.{envvars-aws,eks-cluster,\ > eks-identity})
    root@rok-tools:~/ops/deployments# export AWS_ACCOUNT_ID AWS_DEFAULT_REGION \ > EKS_CLUSTER_OIDC EKS_CLUSTER

  3. Set the name of the IAM role for FluentD:

    root@rok-tools:~/ops/deployments# export FLUENTD_EKS_IAM_ROLE=rok-\ > ${AWS_DEFAULT_REGION?}-${EKS_CLUSTER?}-fluentd

  4. Verify that the IAM role name you specified is not longer than 64 characters:

    root@rok-tools:~/ops/deployments# [[ ${#FLUENTD_EKS_IAM_ROLE} -le 64 ]] && echo OK || echo FAIL OK

    Troubleshooting

    The output of the command is FAIL

    Go back to step 3 and specify a shorter name. Ensure the new name is not already in use.

  5. Set the name of the CloudFormation stack you will deploy:

    root@rok-tools:~/ops/deployments# export FLUENTD_EKS_IAM_CF=rok-${AWS_DEFAULT_REGION?}-${EKS_CLUSTER?}-fluentd

  6. Verify that the CloudFormation stack name you specified is not longer than 128 characters:

    root@rok-tools:~/ops/deployments# [[ ${#FLUENTD_EKS_IAM_CF} -le 128 ]] && echo OK || echo FAIL OK

    Troubleshooting

    The output of the command is FAIL

    Go back to step 5 and specify a shorter name. Ensure the new name is not already in use.

  7. Generate the AWS CloudFormation stack:

    root@rok-tools:~/ops/deployments# j2 rok/eks/fluentd-eks-iam-resources.yaml.j2 \ > -o rok/eks/fluentd-eks-iam-resources.yaml

    Alternatively, download the fluentd-eks-iam-resources CloudFormation template provided below and use it locally.

    fluentd-eks-iam-resources.yaml
    Download file
    1Metadata:
    2 Rok::StackName: <FLUENTD_EKS_IAM_CF>
    3
    4-18
    4Resources:
    5 FluentDRole:
    6 Type: AWS::IAM::Role
    7 Description: Fluentd Role
    8 Properties:
    9 RoleName: <FLUENTD_EKS_IAM_ROLE>
    10 AssumeRolePolicyDocument:
    11 Version: '2012-10-17'
    12 Statement:
    13 - Effect: Allow
    14 Action: sts:AssumeRoleWithWebIdentity
    15 Principal:
    16 Federated: arn:aws:iam::<AWS_ACCOUNT_ID>:oidc-provider/<EKS_CLUSTER_OIDC>
    17 Condition:
    18 StringEquals:
    19 <EKS_CLUSTER_OIDC>:sub: system:serviceaccount:amazon-cloudwatch:fluentd
    20 ManagedPolicyArns:
    21 - !Sub "arn:${AWS::Partition}:iam::aws:policy/CloudWatchAgentServerPolicy"

  8. Save your state:

    root@rok-tools:~/ops/deployments# j2 deploy/env.fluentd-eks-iam.j2 \ > -o deploy/env.fluentd-eks-iam

  9. Commit your changes:

    root@rok-tools:~/ops/deployments# git commit \ > -am "Create IAM Role for FluentD"

  10. Deploy the CloudFormation stack:

    root@rok-tools:~/ops/deployments# aws cloudformation deploy \ > --stack-name ${FLUENTD_EKS_IAM_CF?} \ > --template-file rok/eks/fluentd-eks-iam-resources.yaml \ > --capabilities CAPABILITY_NAMED_IAM Waiting for changeset to be created.. Waiting for stack create/update to complete Successfully created/updated stack - rok-us-west-2-arrikto-cluster-fluentd

    Troubleshooting

    AccessDenied

    If the above command fails with an error message similar to the following:

    An error occurred (AccessDenied) when calling the DescribeStacks operation: User: arn:aws:iam::123456789012:user/user is not authorized to perform: cloudformation:DescribeStacks on resource: arn:aws:cloudformation:us-east-1:123456789012:stack/rok-us-east-1-arriko-cluster-fluentd/e84c63f0-3247-11ec-9c73-0a316e131472

    it means that your IAM user does not have sufficient permissions to perform an action necessary to deploy an AWS CloudFormation stack.

    To proceed, Check Your Environment and contact your AWS administrator to grant sufficient permissions to your IAM user or deploy the AWS CloudFormation stack for you.

    Failed to create/update the stack

    If the above command fails with an error message similar to the following:

    Failed to create/update the stack. Run the following command to fetch the list of events leading up to the failure aws cloudformation describe-stack-events --stack-name rok-us-east-1-arriko-cluster-fluentd

    describe the events of the CloudFormation stack to identify the root cause of the failure:

    root@rok-tools:~/ops/deployments# aws cloudformation describe-stack-events --stack-name ${FLUENTD_EKS_IAM_CF?}

    • A stack event like the following:

      { "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/rok-us-east-1-arriko-cluster-fluentd/599bc930-7b3f-11eb-ac1c-029efe3a90a0", "EventId": "rok-us-east-1-arriko-cluster-fluentd-CREATE_FAILED-2021-03-02T10:09:27.457Z", "StackName": "rok-us-east-1-arriko-cluster-fluentd", "LogicalResourceId": "FluentDRole", "PhysicalResourceId": "", "ResourceType": "AWS::IAM::Role", "Timestamp": "2021-03-02T10:09:27.457000+00:00", "ResourceStatus": "CREATE_FAILED", "ResourceStatusReason": "rok-us-east-1-arrikto-cluster-fluentd already exists in stack arn:aws:cloudformation:es-east-1:123456789012:stack/rok-us-east-1-arrikto-another-cluster-fluentd/e84c63f0-3247-11ec-9c73-0a316e131472", "ResourceProperties": "{\"ManagedPolicyArns\":[\"arn:aws:iam::123456789012:policy/rok-us-east-1-arrikto-cluster-fluentd\"],\"RoleName\":\"rok-us-east-1-arrikto-cluster-fluentd\",\"AssumeRolePolicyDocument\":{\"Version\":\"2012-10-17\",\"Statement\":[{\"Condition\":{\"StringEquals\":{\"oidc.eks.eu-central-1.amazonaws.com/id/123456789ABCDEFGHIJKLMNOPQRSTUVW:sub\":\"system:serviceaccount:kube-system:fluentd\"}},\"Action\":\"sts:AssumeRoleWithWebIdentity\",\"Effect\":\"Allow\",\"Principal\":{\"Federated\":\"arn:aws:iam::123456789012:oidc-provider/oidc.eks.eu-central-1.amazonaws.com/id/123456789ABCDEFGHIJKLMNOPQRSTUVW\"}}]}}" }

      means that the IAM role or IAM policy that the AWS CloudFormation stack defines already exist, leading to name conflicts.

      To proceed, go back to step 3, specify a different name for the resources that already exist and follow the rest of the guide.

    • A stack event like the following:

      { "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/rok-us-east-1-arriko-cluster-fluentd/415eef80-7b46-11eb-b047-06980f530fec", "EventId": "rok-us-east-1-arriko-cluster-fluentd-CREATE_FAILED-2021-03-02T10:09:27.457Z", "StackName": "rok-us-east-1-arriko-cluster-fluentd", "LogicalResourceId": "FluentDRole", "PhysicalResourceId": "", "ResourceType": "AWS::IAM::Role", "Timestamp": "2021-03-02T10:58:54.216000+00:00", "ResourceStatus": "CREATE_FAILED", "ResourceStatusReason": "API: iam:CreateRole User: arn:aws:iam::123456789012:user/user is not authorized to perform: iam:CreateRole on resource: arn:aws:iam::123456789012:role/rok-us-east-1-arrikto-cluster-fluentd", "ResourceProperties": "{\"ManagedPolicyArns\":[\"arn:aws:iam::123456789012:policy/rok-us-east-1-arrikto-cluster-fluentd\"],\"RoleName\":\"rok-us-east-1-arrikto-cluster-fluentd\",\"AssumeRolePolicyDocument\":{\"Version\":\"2012-10-17\",\"Statement\":[{\"Condition\":{\"StringEquals\":{\"oidc.eks.eu-central-1.amazonaws.com/id/123456789ABCDEFGHIJKLMNOPQRSTUVW:sub\":\"system:serviceaccount:kube-system:fluentd\"}},\"Action\":\"sts:AssumeRoleWithWebIdentity\",\"Effect\":\"Allow\",\"Principal\":{\"Federated\":\"arn:aws:iam::123456789012:oidc-provider/oidc.eks.eu-central-1.amazonaws.com/id/123456789ABCDEFGHIJKLMNOPQRSTUVW\"}}]}}" }

      means that your IAM user does not have sufficient permissions to create the resources that the AWS CloudFormation stack defines.

      To proceed, Check Your Environment and contact your AWS administrator to grant your IAM user sufficient permissions or deploy the AWS CloudFormation stack for you.

    ValidationError

    If the above command fails with an error message similar to the following:

    An error occurred (ValidationError) when calling the CreateChangeSet operation: Stack:arn:aws:cloudformation:us-east-1:123456789012:stack/rok-us-east-1-arriko-cluster-fluentd/671606f0-eb2b-11eb-8afb-0217413c9ed2 is in ROLLBACK_COMPLETE state and can not be updated.

    delete the stack and deploy it again.

Verify

  1. Go to your GitOps repository, inside your rok-tools management environment:

    root@rok-tools:~# cd ~/ops/deployments

  2. Restore the required context from previous sections:

    root@rok-tools:~/ops/deployments# source <(cat deploy/env.fluentd-eks-iam)
    root@rok-tools:~/ops/deployments# export FLUENTD_EKS_IAM_ROLE

  3. Verify that the IAM role exists:

    root@rok-tools:~/ops/deployments# aws iam get-role \ > --role-name ${FLUENTD_EKS_IAM_ROLE?} \ > --query Role.RoleName \ > --output text && echo OK rok-us-east-1-arrikto-cluster-fluentd OK

  4. Verify that the AmazonEKSClusterPolicy is attached to your IAM role for FluentD:

    root@rok-tools:~/ops/deployments# POLICIES=$(aws iam list-attached-role-policies \ > --role-name ${FLUENTD_EKS_IAM_ROLE?} \ > --query 'length(AttachedPolicies[? > PolicyArn==`arn:aws:iam::aws:policy/CloudWatchAgentServerPolicy`])') && \ > ((POLICIES==1)) && \ > echo OK || \ > echo FAIL OK

Summary

You have successfully created an IAM role for FluentD on your EKS cluster.

What’s Next

The next step is to deploy FluentD on your EKS cluster.