Amazon | David's Blog

New site steps

Note this is for a new WordPress Multisite

Log into AWS Management Console
Lightsail → Create a new instance (Linux, WordPress Multisite)
Create a new static IP address
Assign the static IP address to the new instance.
Buy a new domain name (if I don’t have one available) – in this case, gerisch.org
Update DNS with the new static IP address
ssh – i path-to-pem-file-for-AWS-instances bitnami@gerisch.org
Make Ubuntu like OpenSUSE
Log out, and log back in (get the benefits of pageup for history search, and .. as the cd .. alias)
cd /opt/bitnami/apps/wordpress
sudo ./bnconfig --machine_hostname gerisch.org
sudo mv bnconfig bnconfig.disabled
sudo apt upgrade
sudo init 6
wait for reboot to finish
ssh – i path-to-pem-file-for-AWS-instances bitnami@gerisch.org
sudo /opt/bitnami/bncert-tool

At this point, I get a warning:

Warning: Custom redirections are not supported in the Bitnami WordPress Multisite Stack. This tool will not be able to enable/disable redirections.
Press [Enter] to continue:

An updated version is available. Would you like to download it? You would need to run it manually later. [Y/n]:

sudo /opt/bitnami/bncert-tool

Welcome to the Bitnami HTTPS Configuration tool.

Domains

Please provide a valid space-separated list of domains for which you wish to configure your web server.

Domain list []:

gerisch.org

The following domains were not included: www.gerisch.org. Do you want to add them? [Y/n]:

The interesting thing here is that (if I’m interpreting things correctly) that WordPress Multisite really does not want one of the subdomains to be www.gerisch.org – yet here, Bitnami, through the Let’s Encrypt really does want one of the domains to be www

I hit <Enter> which signifies yes

Changes to perform

The following changes will be performed to your Bitnami installation:

Stop web server
Configure web server to use a free Let’s Encrypt certificate for the domains:
gerisch.org www.gerisch.org
Configure a cron job to automatically renew the certificate each month
Configure web server name to: gerisch.org
Start web server once all changes have been performed

Do you agree to these changes? [Y/n]:

I hit <Enter> which signifies yes

Create a free HTTPS certificate with Let’s Encrypt

Please provide a valid e-mail address for which to associate your Let’s Encrypt certificate.

Domain list: gerisch.org www.gerisch.org

Server name: gerisch.org

E-mail address []:

I put in my personal email address

The Let’s Encrypt Subscriber Agreement can be found at:

https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf

Do you agree to the Let’s Encrypt Subscriber Agreement? [Y/n]:

I hit <Enter> which signifies yes

And after a bit of work, the configuration of my new web site to be SSL protected is complete.

How to use Lightsail snapshots to revert to a previous version

I have the new Bitnami WordPress multisite web server up and running. I’d like to make a backup of it, prior to mucking with it, so that I can revert back if needed.

Schrodinger’s Backups: The condition of any backup is unknown until a restore is attempted.

Murphy’s take on Schrodinger’s Backups: You’re fucked. The backup is dead.

Well, that is often the case when you just lost the computer, and you now need to restore from your “backups”.

Let’s see what it takes to successfully take a Lightsail snapshot and restore to it.

Technically, you spin up a new instance, move the IP address, and delete the old instance. So you will be incurring a little bit more extra charges with Lightsail, because for a little while, you had two instances. Snapshots cost money, too.

Step the first: shut down your instance.

In theory, this step should not be necessary. The snapshot process should work on the running image. It probably will.

In theory, there is no difference between theory and practice. In practice, there is.

Although it is a remote chance, there is a problem of database coherency. What if, at the exact moment you take a snapshot, some database transaction is only half-posted? What if one half of the transaction is written to disk, then the snapshot happens, then the other half of the transaction gets written to disk? When you restore, the database is going to no longer be coherent.

For some databases, there are a whole subset of features and work done to ensure atomic transactions that prevent any piece of the transaction of being committed until all of it can be verified to be done. That’s all nice and everything, but what’s wrong with just shutting down the server? If your server is so mission critical that you cannot have a minute or two of downtime, you should be working on clusters of machines that can announce themselves into the cluster, and announce themselves out of the cluster and gracefully transition between states.

Power down the server, and the server is quiescent with the world.

Step the second: take the snapshot.

A picture being worth a thousand words, here’s thirteen thousand words:

Go to the snapshot manager tab a click the Create snapshot button

Lightsail picked a name for you; click the Create button to launch the snapshot process

Once the snapshot is complete, you get the raindrops menu button

Step the third: the snapshot becomes the machine.

The raindrops menu has the option to create a new instance from the snapshot

See that big orange Create Instance button? Click it!

I may be a stockholder of Amazon.com stock, and will see revenue slightly rise as you invoke an additional charge on your account. Click it!

Now there are two instances; one pending, and the other stopped

Eventually, the new instance is running. But we still need to move off of the old instance.

The static IP address that DNS points to is connected to the server that crashed and is going away

The new instance, WordPress_Multisite-2, has a random IP address assigned during creation

After selecting the static IP from the list, click the green Checkmark button to assign it to the new instance

We now see the new instance in the wild, at the old IP address DNS points to

Delete the old instance, so as to not leave trash laying around

That’s pretty much it. The snapshot has been launched as a new instance, and is almost a verbatim copy of the old instance. Almost.

When the new instance was spun up, it got a new security certificate fingerprint.

Amazon Transcribe – mildly amusing transcription attempt

I’m using Amazon Transcribe, to do that, with MP3 files of a talk given by couple guys with thick southern accents (Arkansas / Louisiana). Machine translation is still pretty new. Even with superb AI, this audio would be tough. Still, the following was mildly amusing to me.

What the transcription came up with: “the moment after rescue from the shipwreck, when camaraderie, Georgian markets evade a vessel for misters to the captain’s table.”

What the actual audio is: “the moment after rescue from the shipwreck, when camaraderie, joyousness and democracy pervade the vessel from steerage to the captain’s table.”

Admittedly, evade versus pervade is very close; pervade isn’t exactly a common word. The difference between misters and steerage is pretty far. But what tickled my funny bone was that apparently, joyousness and democracy are what you get going to Georgian markets.

As one popular meme goes right now: Why not both?