Overview

To install Discourse, there are five essential steps:

1. Setup the Mail Server.
2. Create a Droplet.
3. Setup the Swap File: If the VPS plan does not have sufficient RAM (less than 1G), it is required to setup a swap file.
4. Installation: Install Docker, install Discourse and launch the containers.
5. Configure Discourse.

Setup the Mail Server

It is required to have a mail server for Discourse. If you already have one, then just use it. If you don't have a mail server, then you can register one for free at SparkPost, which allows you to send 10k e-mails per month.

1. Visit SparkPost and click the TRY FOR FREE button on the top right corner.

2. Sign up for SparkPost.

   1. Fill in the e-mail and the password.
   2. Solve the CAPTCHA.
   3. Agree to the terms of use.
   4. Click the Sign Up button.

3. Verify your account by clicking the links in the confirmation e-mail.

   Note: If you didn't receive the confirmation e-mail, you can request a new e-mail by clicking "ACCOUNT -> SENDING DOMAINS" and click the link in the top bar.

4. Before we can send e-mails with SparkPost, we have to claim that we are the owner of a domain name. This will require us to configure the DNS records.

   1. Click "ACCOUNT -> SENDING DOMAINS".
   2. Click the NEW DOMAIN button.
   3. Fill in the domain name and click ADD DOMAIN.
   4. Update DNS records for SPF and DKIM. Click the Configure link for more details. In summary, you have to add two different TXT records.
   5. After updating the DNS TXT records, click the Test links for verification.

5. Create a new API key.

   1. Click "ACCOUNT -> API & SMTP".
   2. Click the "NEW API KEY" button.
   3. Fill in the API Key Name, e.g. "discourse".
   4. Select the Send via SMTP in the API Permissions section.
   5. Fill in the SparkPost password again.
   6. Copy the API key.

Create a Droplet

After logging into Digital Ocean, click on the Create Droplet button on the top right corner. In the new page, you have to fill in the following fields:

1. Droplet Hostname -- Choose a good name for your installation.
2. Select Size -- All plans are fine. I tried the cheapest $5/mo plan, and it works perfectly.
3. Select Region -- Choose a region for the data center. I chose New York data center. Pick one which is close to your visitors.
4. Select Image -- The default image, Ubuntu 14.04 x64, is suggested. It is recommended by the Discourse development team.
5. Add your SSH public key to the Add SSH Keys section.

Now, we can click on the Create Droplet button and wait for a while. After the droplet is created, then try to log in with ssh command.

Note: You can check the SSH server fingerprint by clicking the Console Access button in the Digital Ocean admin console.

Setup the Swap File

Discourse requires 1GB RAM to run without problems. If you are running with 500MB RAM, then you must enable the swap file. Otherwise, you will not be able to build the Discourse container.

Here are the instructions to setup the swap file:

# Create a new swap file.
$ sudo fallocate -l 4G /swapfile

# Change the file permission.
$ sudo chmod 600 /swapfile

# Format the swap file.
$ sudo mkswap /swapfile

# Enable the swap file.
$ sudo swapon /swapfile

# Check that the swap file has been enabled.
$ sudo swapon -s
Filenam    Type  Size     Used  Priority
/swapfile  file  4194300  0     -1

# Add the swap file to fstab
$ sudo bash -c "echo '/swapfile none swap sw 0 0' >> /etc/fstab"

# Reboot the machine now.
$ sudo reboot

You can further tweak the configuration by reading: How to Add Swap on Ubuntu 14.04.

Installation

In this section, we would like to install Discourse. There are three steps:

1. Harden Droplet - Make your Droplet much more secure.
2. Install Docker - Install Docker for Discourse.
3. Install Discourse - Install Discourse and modify the settings.

$ sudo dpkg-reconfigure -plow unattended-upgrades
# Choose <yes> to enable automatic upgrade.

# Create a new user.
$ sudo adduser [username]
Enter new UNIX password:
Retype new UNIX password:

# Grant sudo access to that user.
$ sudo visudo
# ... Add "[username] ALL=(ALL:ALL) ALL"

# Copy SSH keys.
$ sudo mkdir -p /home/[username]/.ssh
$ sudo cp /root/.ssh/authorized_keys /home/[username]/.ssh
$ sudo chown -R [username]:[username] /home/[username]/.ssh

# Logout.
$ exit

# Lock the root password.
$ sudo passwd -l root

# Disable the ssh root login.
$ sudo vi /etc/ssh/sshd_config
# ... Change "PermitRootLogin" to "no"

# Restart ssh server.
$ sudo service ssh restart

$ wget -qO- https://get.docker.com/ | sudo sh

# Switch to root user.
$ sudo -s

# Create a directory for Discourse.
> mkdir /var/discourse

# Clone the Discourse docker image.
> git clone https://github.com/discourse/discourse_docker.git \
            /var/discourse

# Change the directory to /var/discourse.
> cd /var/discourse

# Copy the sample configuration.
> cp samples/standalone.yml containers/app.yml

# Edit the configuration.
> vi containers/app.yml

./launcher bootstrap app

./launcher start app

# Rebuild the container.
./launcher rebuild app

Configure Discourse

As the last step of installation, we have to create an administrator account so that we can fill in several important settings and moderate the forum.

Summary

These are my notes to get a Discourse installation. We have covered:

1. Register a SparkPost account and create an API key.
2. Create a droplet and enable the swap file.
3. Install Discourse and fill in the necessary settings.

Hope you enjoy this. You can find more information in the Discourse GitHub repository.

Reference

• Discourse, Set up Discourse in the cloud in under 30 minutes
• Sam Saffron, Allowing SSL for your Discourse Docker setup
• Justin Ellingwood, How to Add Swap on Ubuntu 14.04