Two things everyone discovers too late in Lightsail. The first: the public IP a machine comes with when you create it changes when you stop and start it. If your domain points to it, the website disappears. The second: in Lightsail you cannot resize a machine while it is running; to move to a bigger plan you have to create a new machine from a snapshot. Both are solved together, and the static IP is what makes the change of plan invisible to your users.
Before you start: what each thing means
- Lightsail
- The simple version of Amazon's servers: machines with a fixed monthly price, with their own console.
- Plan
- The size of the Lightsail machine (processor, memory and disk) with its monthly price. Changing plan means changing size.
- Public IP
- The numeric address through which your machine is reached from the internet. The default one changes when you stop and start.
- Static IP
- A public address that you reserve and attach to your machine so that it never changes, and that you can move to another machine.
- Snapshot
- A complete copy of the machine's disk. It is the basis for creating the new machine with the bigger plan.
- A record
- The entry in your domain's DNS that says which IP address the website points to.
- Availability zone
- Each of the separate data centres within a region. Some resources only work within the same zone.
Step by step
Create and attach a static IP
In the Lightsail console, Networking tab, Create static IP. Choose your machine's region (the IP only works in its region), select the machine in the drop-down and give it a name that links it to the machine, for example
ip-web-tienda. When you create it, the machine starts using that IP immediately and the old one is released.While it is attached to a machine there is no extra cost. A static IP not attached to anything is charged, so if you delete a machine, release its IP as well or reassign it.
Point the domain to the static IP
Change your domain's A record so that it points to the new IP (in Route 53 or wherever your DNS is). From here on you can stop, start and, as you will see, even change machine without ever touching DNS again.
To change plan: take a snapshot
Open the machine, Snapshots tab, Create snapshot. If the machine runs a database and you want a perfect copy, stop it first from Lightsail (Stop button), wait until it is stopped and create the snapshot; that way there are no half-finished writes. If you cannot afford the stop, create it while running and accept a possible minor inconsistency.
Create the new machine with the bigger plan
When the snapshot is ready, in its menu choose Create new instance. Select the new plan: it will only let you choose one equal to or bigger than the original. Keep the same region and availability zone if you want to be able to reuse additional disks. Give it a new name (for example
web-tienda-2) and create it. In a few minutes you will have an exact copy, with more resources and a temporary public IP.Move the static IP to the new machine
Networking tab, click your static IP, Detach from the old machine and Attach to the new one. The domain already points to that IP, so the website is served from the big machine straight away. Also check the firewall of the new machine: it is born with the default rules, not the old machine's, so reopen 443 and whatever else you used.
Delete the old machine when you are sure
Leave it stopped for a few days as a safety net. In Lightsail a stopped machine is still charged, so once you confirm everything is fine, take one last (cheap) snapshot of it and delete it. When deleting it, check that it does not leave an orphaned static IP behind.
What can go wrong
The website gives a certificate error after the change
The HTTPS certificate lives inside the machine, so it travelled with the snapshot and should work. If you were using Let's Encrypt with automatic renewal, check that the renewal task is still active on the new machine. If the certificate was managed by the Lightsail load balancer, you need to point the load balancer to the new machine.
The static IP does not appear for attaching
Static IPs are per region. If you created the new machine in another region, you will not see it. Create the machine in the IP's region, or create a new IP there and change the DNS.
I want a smaller plan, not a bigger one
Lightsail does not allow restoring a snapshot onto a plan with less disk. The only way is to set up the small machine from scratch and migrate the data by hand. Before doing so, check whether the current disk is really full: often there is spare CPU but not spare disk, and then no smaller plan is possible.
I have deleted the machine and the static IP is still on the bill
Static IPs are not deleted with the machine. Go to Networking and delete it, or attach it to another machine.
In Simplio
In Simplio you see each Lightsail machine's IP, whether it is static or not, its plan and its firewall on the same card, with the snapshot button next to it. Scheduled snapshots make sure there is always a recent copy from which to create the big machine when the time comes, and if a machine that should be running shows up stopped, it emails you.
The same task, in AWS and in Simplio
| In the AWS console | In Simplio | |
|---|---|---|
| See whether a machine has a static IP | Open each machine, Networking tab | On each machine's card, at a glance |
| Change plan | Snapshot, new machine, move IP, redo firewall, delete the old one: 6 steps, 25 minutes | Snapshot and new machine from the same screen, with the IP and the firewall to hand |
| Find out that something was left stopped or orphaned | Nothing warns you | Email alert |