Please read the comments which have some updates regarding email config. You can find me on https://noc.social/web/@marc

Some people are really not too happy with Silicon Valley’s monopoly on social media. There are some serious privacy concerns, and we’ve seen a massive migration from Whatsapp to Signal, and whatever you may think of the accusations against Parler, the alacrity shown in it’s thorough deplatforming by it’s competitors, many are shocked.

I have advocated for decentralized social networks for many years, and some who I have preached to have come to me asking for assistance. I won’t go into my reasoning in this post, it’s been a tough one I have been putting together for a while now.

There are many ways of getting involved with decentralized social networks.

For a start there are a few options besides Mastodon. Secondly there are many ways of getting an account on a Mastodon server, there is a huge list of servers offering free accounts in many cases. You can rent a preconfigured server instance which would be fine maybe for a small family (they have strict ToS, which you should check). For a large busy instance you would want to build something scalable you may want to use Docker or Kubernetes using this sort of method, or follow the official guide here.

But here below, as I have not found a nice simple guide I am going to describe how you can setup a simple, and scalable Mastodon instance at DigitalOcean, with a built in mail server hosting images locally, along with a simple firewall setup.

First you will need a Domain name, or a subdomain of an existing domain name, there are many vendors to choose from, I’m lucky my last name is pretty unique.

Next you will need an account at DigitalOcean, if you sign up using this link, you will get a $100 hosting credit, and I get a $25 gift for the referral, here it is again, if you missed it.

(Edited 04/11/22: You can not use SMTP on a new DigitalOcean account now, you would need to use a “mature” account, or use a 3rd party mailing service. https://www.digitalocean.com/blog/smtp-restricted-by-default)

Start by clicking Create, Marketplace, type Mastodon, and select it, select a server size, $15 instance seems a minimum for a reasonably busy, powerful server with a fair bit of storage.

Next choose a Datacenter near you, ideally you should use an SSH key pair and apply that here instead, but I know you won’t, so just make sure to use a really strong unique password, and keep it safe. Where you see Choose a hostname, enter the domain name or subdomain you are going to use, for the purpose of this walkthrough, I’ll be using pod.domain.com. I would also strongly recommend having backups which you can accept on this page, DigitalOcean charge 20% on server cost for a once a week backup, you can do far better, but this is simple, (I would also recommend before you make any potentially damaging changes, making a Snapshot of your server, as these are very easy to roll back to if needed, just remember to delete them when you are done.) Scroll to the bottom and click create.

Once it’s completed, normally 60 seconds, copy the IP address it has provisioned your server with.

Head over to your where your domain is registered and add an A record in their DNS management, something like this, all domain management tools tend to be similar, and would have good guides on creating or editing DNS A records.

While we are here, I’ll also add a TXT SPF record which should make your email less likely to hit spam folders, new servers take a little time to be recognized as legitimate, this record will help. Add this DNS TXT record, changing the IP to match yours:

v=spf1 ip4:104.248.9.10 -all

Now to log into your server, this can be using any shell, Terminal on a Mac or Linux, or Putty on a Windows machine. Here I’m using my Macbook, login with the domain name or IP as root:

ssh root@pod.domain.com

enter your password (or don’t if your using an ssh key pair), accept the ECDSA key by typing yes..

$ ssh root@104.248.9.10
The authenticity of host '104.248.9.10 (104.248.9.10)' can't be established.
ECDSA key fingerprint is SHA256:Wsv74TT7SBLN0Al4R6NrecifEclL35BPBxiQgEtShv0.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '104.248.9.10' (ECDSA) to the list of known hosts.
root@104.248.9.10's password: 
Welcome to Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0-91-generic x86_64)
---snip---
Booting Mastodon's first-time setup wizard...
Welcome to the Mastodon first-time setup!

Next, lets configure the Mastodon instance, enter the domain name, choose No for storing images in the cloud, (if your server is successful, you can host images with AWS or any other cloud provider very cheaply later.) For SMTP server, type localhost, for the next 4 questions, port, username, password and authentication, hit return to select the default values. for verify mode, select none. Accept the email address provided to send emails from, do not send a test email yet, it will fail. Choose your username and enter your real email for the Mastodon admin account, enter the email address again when Let’s Encrypt asks for it. So you should have something like this.

Welcome to the Mastodon first-time setup!
Domain name: pod.domain.com
Do you want to store user-uploaded files on the cloud? No
SMTP server: localhost
SMTP port: 587
SMTP username: 
SMTP password: 
SMTP authentication: plain
SMTP OpenSSL verify mode: none
E-mail address to send e-mails "from": Mastodon <notifications@pod.domain.com>
Send a test e-mail with this configuration right now? no
Great! Saving this configuration...
Booting up Mastodon...
It is time to create an admin account that you'll be able to use from the browser!
Username: admin
E-mail: admin@domain.com
You can login with the password: YOUR-PASSWORD-WILL-BE-HERE
The web interface should be momentarily accessible via https://pod.domain.com/
Launching Let's Encrypt utility to obtain SSL certificate...
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
Enter email address (used for urgent renewal and security notices) (Enter 'c' to cancel): admin@domain.com

Update certificates:

sudo apt install ca-certificates

Notice you were provided with the Admin Password above, keep it safe. Now to setup the local mail server, start by installing SendMail with:

sudo apt-get install sendmail

You can send yourself a test email if you like now using:

echo "Subject: sendmail test" | sendmail -v admin@domain.com

Configure Mastodon to use SendMail, open the Mastodon config file with:

nano /home/mastodon/live/.env.production

Navigate with your curser keys and add this line to the bottom:

SMTP_DELIVERY_METHOD=sendmail

Crtl+o to save, Crtl+x to exit nano, then correct the localhost configuration for SendMail, again with nano.

sudo nano /etc/hosts

Add your domain name so the 127.0.0.1 line looks like:

127.0.0.1 localhost pod.hostname.com

Again Crtl+o to save, Crtl+x to exit nano, now lets get some better stats on your DigitalOcean control panel:

curl -sSL https://repos.insights.digitalocean.com/install.sh | sudo bash

And finally, get a simple firewall enabled to block unused ports:

ufw allow ssh
ufw allow http
ufw allow https
ufw allow 25/udp
ufw enable

Thats it, your Mastodon server is up and running, and you can now login, you’ll first want to head over to https://pod.yourdomain.com/admin/invites to generate an invite link to send to friends and family. for the first few days, email will go to the spam folder, this is expected.

Tons of resources here: https://project-awesome.org/tleb/awesome-mastodon

There is far more that can and should ideally be done, DigitalOcean have a very robust firewall that works at a network level, there are better backup and image hosting solutions. And the mastodon instance itself can be personalized. make something nice, and please ping me your address so I can check it out.

Added Nov 6 2021,
It is important to prune media and preview cards, this can be done ad hock, logged in as masterdon user with something like:

RAILS_ENV=production /home/mastodon/live/bin/tootctl media remove
RAILS_ENV=production /home/mastodon/live/bin/tootctl preview_cards remove

Or adding as a cron (using crontab -e, then crontab -l to test) adding:

@weekly RAILS_ENV=production /home/mastodon/live/bin/tootctl media remove
@weekly RAILS_ENV=production /home/mastodon/live/bin/tootctl preview_cards remove

If you get ruby errors, “Could not locate Gemfile” you may need to install

git clone https://github.com/rtomayko/posix-spawn.git
cd posix-spawn/
gem build posix-spawn.gemspec
gem install posix-spawn*.gem