# Ensure that Swarm Manager is Run in Auto-Lock Mode

- Source: https://support.icompaas.com/support/solutions/articles/62000234377-ensure-that-swarm-manager-is-run-in-auto-lock-mode
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS Docker Benchmark v1.7.0](https://support.icompaas.com/support/solutions/62000112687) › [CIS Docker Benchmark](https://support.icompaas.com/support/solutions/folders/62000169241)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability:**

-   **Level 1**  
    

**Description:**

Docker Swarm auto-lock mode enables an additional layer of security by locking the manager nodes. When this mode is enabled, an unlock key is required to start the manager node after a restart or a crash, ensuring that unauthorized access is prevented.  

**Rationale:**

Enabling auto-lock mode on a Swarm manager node is a critical security measure. It ensures that even if an attacker gains access to a manager node, they cannot take control or modify the Swarm configuration without the unlock key. This adds protection for the secrets and other sensitive configurations in the Swarm.  

**Impact:**

Pros:  

-   Enhances security by preventing unauthorized access to the Swarm manager.  
    
-   Protects the integrity of secrets and configurations in the cluster.  
    

Cons:  

-   The unlock key needs to be securely managed and stored, as losing it may result in an inability to restart the manager nodes.  
    

**Default Value:**

By default, auto-lock is not enabled on Swarm manager nodes.  

**Pre-requisites:**

-   Swarm mode must be enabled.  
    
-   Access to Docker Swarm manager node with administrative privileges.  
    
-   A secure method of storing the unlock key is required.
    

**Remediation:**

**Test Plan:**

**Using AWS Console:**

1.  Navigate to the EC2 instance running Docker Swarm manager.  
    
2.  Check if auto-lock mode is enabled by running:  
    

docker swarm unlock-key

3.  If it’s not enabled, ensure you configure it as per the steps below.  
    

**Using AWS CLI:**

1.  Connect to the EC2 instance running Docker Swarm manager.  
    
2.  Run the following command to verify the current unlock key:  
    

docker swarm unlock-key

**Implementation Plan:**

**Using AWS Console:**

1.  Connect to the EC2 instance running Docker Swarm manager.  
    
2.  Run the following command to enable auto-lock:  
    

docker swarm init --autolock

3.  After the Swarm manager is initialized, securely store the unlock key displayed by Docker.  
    

**Using AWS CLI:**

1.  Use SSM to remotely enable auto-lock mode on the Docker Swarm manager.  
    
2.  Run the following command:  
    

aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["docker swarm init --autolock"\]'

3.  Securely store the unlock key displayed by Docker.  
    

**Backout Plan:**

**Using AWS Console:**

1.  Connect to the EC2 instance running Docker Swarm manager.  
    
2.  Disable auto-lock mode using the following command:  
    

docker swarm unlock

3.  Ensure that no changes are made to the Swarm configuration that would compromise its security.  
    

**Using AWS CLI:**

1.  Use SSM to remotely disable auto-lock mode on the Docker Swarm manager.  
    
2.  Run the following command:  
    

aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["docker swarm unlock"\]'

**References:**

-   CIS Docker Benchmark v1.7  
    
-   Docker Documentation: [https://docs.docker.com/](https://docs.docker.com/)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.