Demo Auto Lock

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1. Enable Auto-Lock on Your Swarm

docker swarm update --autolock=true

SWMKEY-1-izfTZG1yXBjIOY3VBkIHFDI+WcnpqeJKYV6daZW3o

docker swarm init --autolock=true

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2. Store the Unlock Key Securely

echo "SWMKEY-1-izfTZG1yXBjIOY3VBkIHFDI+WcnpqeJKYV6daZW3o" > /tmp/swarm-unlock.key
chmod 600 /tmp/swarm-unlock.key

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3. Quick Reference: Swarm Auto-Lock Commands

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4. Verify Cluster Health on Manager 1

[root@manager1 ~]# docker node ls
ID                        HOSTNAME       STATUS  AVAILABILITY  MANAGER STATUS  ENGINE VERSION
kvbht486wmj881wp5vqxp53 * manager1       Ready   Active        Leader          19.03.8
u8imabedhzsu4cawtoz6jh32   manager3       Ready   Active        Reachable       19.03.8
s2ymqdbtfal661imydx31rlno  manager2       Ready   Active        Reachable       19.03.8
38oehhk79ss5rk2coejcavha   worker1        Ready   Active                        19.03.8
k4gc50oc0n8k6jm3f6bm2bph   worker3        Ready   Active                        19.03.8
1pqddmh2fcoy79vq9najr841d  worker2        Ready   Active                        19.03.8

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5. Test Auto-Lock on Manager 2

1. Restart Docker on manager2:
   [root@manager2 ~]# systemctl stop docker
   [root@manager2 ~]# systemctl start docker
   
2. Attempt a Swarm command (should fail):
   [root@manager2 ~]# docker node ls
   Error response from daemon: Swarm is encrypted and needs to be unlocked...
   
3. Unlock the Swarm with your saved key:
   [root@manager2 ~]# docker swarm unlock
   Please enter unlock key: [paste contents of /tmp/swarm-unlock.key]
   
4. Confirm the node list again:
   [root@manager2 ~]# docker node ls
   ID                        HOSTNAME       STATUS  AVAILABILITY  MANAGER STATUS  ENGINE VERSION
   xbvhtg486wmj881wp5vkqx53 * manager1       Ready   Active        Leader          19.03.8
   u8imabedhzsu4cawtoz6jh32   manager3       Ready   Active        Reachable       19.03.8
   s2ymqdbtfal661imydx31rlno * manager2       Ready   Active        Reachable       19.03.8
   38oehhth79bsfs7kco2jcvah   worker1        Ready   Active                        19.03.8
   k4gcc5ooc0nm8xgl36fmb2pd   worker3        Ready   Active                        19.03.8
   1pqddmhd2f0y7vq9najr841d   worker2        Ready   Active                        19.03.8
   

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Links and References

• Docker Swarm Overview
• Swarm Mode Commands
• Managing Docker Secrets