Notes on running a personal Mastodon instance

mastodon-notes.md

Personal Mastodon instance

Effective total cost: $3–5/mo

Setup

Decide on an EC2 instance type:

1. At AWS Console → EC2 → Instance Types, filter for ≥1 GB RAM and sort by price.
   • t4g.micro is lowest.
2. Look up what t4g.micro means:
   • t: general-purpose with a burstable CPU quota
   • 4: the current generation
   • g: ARM architecture
   • micro: the second lowest configuration
3. Calculate cost:
   • $6.15/mo when paying hourly
   • $3.59mo when paying annually
   • $2.31/mo when paying every 3 years

Prepare your AWS account:

• Set up an alarm for your estimated monthly bill so you're notified early of any unanticipated expenses.
• Import your SSH public key. (EC2 → us-west-2 → Key pairs)

Have ready:

• a domain name and DNS host
• an outgoing mail server
  • I use AWS SES since it's easy (decent reputation, automatic DKIM, etc.) and inexpensive ($0.01/mo), but any SMTP provider will do, and you could also set up a traditional mail server on the EC2 instance.
• static file storage/hosting
  • I use AWS S3 ($1/mo), but a variety of providers offer "S3-compatible" service, and you could also just use the filesystem on the EC2 instance.

Start an EC2 instance:

1. Launch an instance (EC2 → us-west-2 → Instances) with:
   • Name: Mastodon
   • Image: Ubuntu Server 22.04 LTS (HVM), SSD Volume Type (64-bit ARM)
   • Type: t4g.micro
   • Auto-assign public IP: Disable
   • Security Group:
     • Name: Mastodon
     • SSH from anywhere
     • HTTP from anywhere
     • HTTPS from anywhere
   • Storage: 8 GiB standard (HDD, $0.40/mo)
   • Termination protection: Enable
   • Credit specification: Standard
2. At EC2 → us-west-2 → Elastic IPs, allocate and associate a static IP address.
3. Publish an A record at your preferred DNS host.

Prepare the host:

1. SSH in as ubuntu.
2. Add 1 GB of swap:
   1. Make a swap file at /swapfile.
   2. Add a swap entry in /etc/fstab.
3. Add swap on compressed RAM:
   1. Install package systemd-zram-generator.
   2. Set zram-fraction = 1 and compression-algorithm = zstd in /etc/systemd/zram-generator.conf.
4. Configure unattended upgrades:
   1. Enable Automatic-Reboot in /etc/apt/apt.conf.d/50unattended-upgrades.
5. Update and upgrade packages.
6. Reboot.

Install Mastodon:

1. Follow Mastodon's instructions.
   • To tune PostgreSQL, set:
     • effective_cache_size = 256MB
   • Tune Node.js to use enough memory:
     • Set export NODE_OPTIONS='--max-old-space-size=1024' in ~mastodon/.bashrc.
   • When editing .env.production, pay particular attention to:
     • LOCAL_DOMAIN
     • SINGLE_USER_MODE
     • SMTP…
     • S3… and AWS…
   • When registering services, set:
     • mastodon-sidekiq: --concurrency 1
     • mastodon-web: MAX_THREADS=2 and WEB_CONCURRENCY=1
2. Schedule the recommended periodic cleanup tasks.
   • Set --concurrency 1 on both tasks.
3. Reboot.
4. Sign in to the web interface and review/configure admin settings.

Try out the setup for a few days/weeks, then commit to a longer payment term:

1. At EC2 → Reserved Instances → Purchase, filter for t4g.micro, sort by effective rate, and purchase a reservation.
2. Wait a few hours for payment processing to complete.
3. At EC2 → Reserved Instances, confirm that the reservation is active.

Very helpful, thank you! The only things I had to do differently were:

* setup certbot before symlinking the mastodon nginx configuration. [mastodon/documentation#940](https://github.com/mastodon/documentation/issues/940)

* All requests were 404ing until I ran `chmod +x /home/mastodon`

yes precisely. on both debian 10/11 & ubuntu 20.04 uand 22.04. I think even the official instructions are a bit off.

Thanks everybody; it would be great if those of you who aren't using oracle's free tier are about to come back in a few months with some details on egress and s3 use (the uncertain parts of billing).

I will report back later, but the results seem promising. And as for email, since the emails are only sent back to ME, I'm using SES and I didn't bother leaving the sandbox mode. Works pretty well.

Hello, how's everybody getting on — expenses reasonable?

AWS has announced an approximate doubling of the price, making small-scale usage like this untenable for the foreseeable future.

I haven’t yet gotten a straight answer to whether they’re planning to apply the new pricing model to the three years I committed to under different terms.