Configure access to the EC2 Serial Console

To configure access to the serial console, you must grant serial console access at the account level and then configure IAM policies to grant access to your users. For Linux instances you must also configure a password-based user on every instance so that your users can use the serial console for troubleshooting.

Before commencing, be sure to check the prerequisites.

Levels of access to the EC2 Serial Console

By default, there is no access to the serial console at the account level. You need to explicitly grant access to the serial console at the account level. For more information, see Manage account access to the EC2 Serial Console.

You can use a service control policy (SCP) to allow access to the serial console within your organization. You can then have granular access control at the user level by using an IAM policy to control access. By using a combination of SCP and IAM policies, you have different levels of access control to the serial console.

Manage account access to the EC2 Serial Console

By default, there is no access to the serial console at the account level. You need to explicitly grant access to the serial console at the account level.

Grant permission to users to manage account access

To allow your users to manage account access to the EC2 serial console, you need to grant them the required IAM permissions.

The following policy grants permissions to view the account status, and to allow and prevent account access to the EC2 serial console.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:GetSerialConsoleAccessStatus",
                "ec2:EnableSerialConsoleAccess",
                "ec2:DisableSerialConsoleAccess"
            ],
            "Resource": "*"
        }
    ]
}

For more information, see Creating IAM policies in the IAM User Guide.

View account access status to the serial console

To view account access status to the serial console (AWS CLI)

Use the get-serial-console-access-status command to view account access status to the serial console.

aws ec2 get-serial-console-access-status --region us-east-1

In the following output, true indicates that the account is allowed access to the serial console.

The ManagedBy field indicates the entity that configured the setting. In this example, account indicates that the setting was configured directly in the account. A value of declarative-policy would mean the setting was configured by a declarative policy. For more information, see Declarative policies in the AWS Organizations User Guide.

{
    "SerialConsoleAccessEnabled": true,
    "ManagedBy": "account"
}

Grant account access to the serial console

To grant account access to the serial console (AWS CLI)

Use the enable-serial-console-access command to allow account access to the serial console.

aws ec2 enable-serial-console-access --region us-east-1

In the following output, true indicates that the account is allowed access to the serial console.

{
    "SerialConsoleAccessEnabled": true
}

Deny account access to the serial console

To deny account access to the serial console (AWS CLI)

Use the disable-serial-console-access command to prevent account access to the serial console.

aws ec2 disable-serial-console-access --region us-east-1

In the following output, false indicates that the account is denied access to the serial console.

{
    "SerialConsoleAccessEnabled": false
}

Configure IAM policies for EC2 Serial Console access

By default, your users do not have access to the serial console. Your organization must configure IAM policies to grant your users the required access. For more information, see Creating IAM policies in the IAM User Guide.

For serial console access, create a JSON policy document that includes the ec2-instance-connect:SendSerialConsoleSSHPublicKey action. This action grants a user permission to push the public key to the serial console service, which starts a serial console session. We recommend restricting access to specific EC2 instances. Otherwise, all users with this permission can connect to the serial console of all EC2 instances.

Explicitly allow access to the serial console

By default, no one has access to the serial console. To grant access to the serial console, you need to configure a policy to explicitly allow access. We recommend configuring a policy that restricts access to specific instances.

The following policy allows access to the serial console of a specific instance, identified by its instance ID.

Note that the DescribeInstances, DescribeInstanceTypes, and GetSerialConsoleAccessStatus actions do not support resource-level permissions, and therefore all resources, indicated by the * (asterisk), must be specified for these actions.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowDescribeInstances",
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances",
                "ec2:DescribeInstanceTypes",
                "ec2:GetSerialConsoleAccessStatus"
            ],
             "Resource": "*"
        },
        {
            "Sid": "AllowinstanceBasedSerialConsoleAccess",
            "Effect": "Allow",
            "Action": [
                "ec2-instance-connect:SendSerialConsoleSSHPublicKey"
            ],
            "Resource": "arn:aws:ec2:region:account-id:instance/i-0598c7d356eba48d7"
        }
    ]
}

Explicitly deny access to the serial console

The following IAM policy allows access to the serial console of all instances, denoted by the * (asterisk), and explicitly denies access to the serial console of a specific instance, identified by its ID.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowSerialConsoleAccess",
            "Effect": "Allow",
            "Action": [
                "ec2-instance-connect:SendSerialConsoleSSHPublicKey",
                "ec2:DescribeInstances",
                "ec2:DescribeInstanceTypes",
                "ec2:GetSerialConsoleAccessStatus"
            ],
            "Resource": "*"
        },
        {
            "Sid": "DenySerialConsoleAccess",
            "Effect": "Deny",
            "Action": [
                "ec2-instance-connect:SendSerialConsoleSSHPublicKey"
            ],
            "Resource": "arn:aws:ec2:region:account-id:instance/i-0598c7d356eba48d7"
        }
    ]
}

Use resource tags to control access to the serial console

You can use resource tags to control access to the serial console of an instance.

Attribute-based access control is an authorization strategy that defines permissions based on tags that can be attached to users and AWS resources. For example, the following policy allows a user to initiate a serial console connection for an instance only if that instance's resource tag and the principal's tag have the same SerialConsole value for the tag key.

For more information about using tags to control access to your AWS resources, see Controlling access to AWS resources in the IAM User Guide.

Note that the DescribeInstances, DescribeInstanceTypes, and GetSerialConsoleAccessStatus actions do not support resource-level permissions, and therefore all resources, indicated by the * (asterisk), must be specified for these actions.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowDescribeInstances",
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances",
                "ec2:DescribeInstanceTypes",
                "ec2:GetSerialConsoleAccessStatus"
            ],
            "Resource": "*"
        },
        {
            "Sid": "AllowTagBasedSerialConsoleAccess",
            "Effect": "Allow",
            "Action": [
                "ec2-instance-connect:SendSerialConsoleSSHPublicKey"
            ],
            "Resource": "arn:aws:ec2:region:account-id:instance/*",
            "Condition": {
                "StringEquals": {
                    "aws:ResourceTag/SerialConsole": "${aws:PrincipalTag/SerialConsole}"
                }
            }
        }
    ]
}

Set an OS user password on a Linux instance

You can connect to the serial console without a password. However, to use the serial console for troubleshooting a Linux instance, the instance must have a password-based OS user.

You can set the password for any OS user, including the root user. Note that the root user can modify all files, while each OS user might have limited permissions.

You must set a user password for every instance for which you will use the serial console. This is a one-time requirement for each instance.