Get a cloud server

This tutorial gives you a Linux virtual machine of your own, a Cloud Compute instance, and signs you in to it over SSH. You make an SSH key, order the instance with the key on it, connect from your computer, and take a snapshot to return to if a change goes wrong. Each section ends with something you can check before you go on.

It costs the plan you choose, by the month or by the hour, and the order page shows each price. One public IPv4 address comes with the instance at no charge while it stays attached as its primary address (How instances are billed). If virtual machines are new to you, read Cloud servers first.

• A Coritan account. Create an account if you have none, then sign in.
• Credit for the first invoice, or a card or PayPal to pay it when you order (Add credit to your balance). Hourly billing also needs a minimum total of deposits on your account (How hourly billing works).
• A terminal: on Linux or macOS, or PowerShell on Windows 10 and later.

Skip this section if you already have a key in ~/.ssh.

1. In your terminal, create a key pair:

   Shell

   ssh-keygen -t ed25519 -C "alex@example.com"
   

   Press Enter to keep the default file, and choose a passphrase when it asks.

2. Print the public key:

   Shell

   cat ~/.ssh/id_ed25519.pub
   

The terminal prints one line that starts with ssh-ed25519. Copy the whole line (Make an SSH key).

1. In the dashboard, go to Cloud Compute and select Order instance.
2. Under Plan, choose how often to pay, then a plan under Size. Each row shows its vCPUs, memory, disk and monthly traffic.
3. Under Operating system, choose a card under Distribution, such as Ubuntu. The line under the releases names the user you sign in as.
4. Under Location, choose the data centre closest to the people who will use the instance.
5. Under Settings, keep the suggested Hostname or type your own, such as web-1. Paste your public key under SSH keys, and leave the switch on the Public IPv4 address card on.
6. Check the summary under Your order, then select the button under it. It reads Deploy instance when your credit pays the first invoice, and Place order and pay when you pay on the next page.
7. If the order's page reads Order placed, payment due, pay under Pay invoice.

The order's page shows Setting up while Coritan builds the instance, and its title becomes Your order is ready. The instance appears on the Cloud Compute page with its address (Create an instance).

1. On the Cloud Compute page, select the instance's hostname to open it, then select Copy address in the header.

2. Select the Access tab. The User account card shows the user to sign in as under Username, such as ubuntu.

3. In your terminal, connect as that user, with the address you copied:

   Shell

   ssh ubuntu@203.0.113.10
   

4. The first time, SSH asks you to confirm the host's fingerprint. Type yes.

Your terminal shows the instance's shell prompt, and hostname prints the hostname you chose. Coritan also sets a password for the user, but no page shows it. To sign in with a password instead of your key, reset it on the Access tab first (Connect to an instance over SSH).

A snapshot saves the instance's disk as it is now, so you can return to this clean state after a change that goes wrong.

1. Open the instance's Snapshots tab and select Take snapshot….
2. Under Name, type a name such as clean-install. Start with a letter, use letters, digits, hyphens and underscores, and keep it to 37 characters.
3. Select Take snapshot.

The snapshot appears in the table with Disk under Contents. Roll back… in the menu at the end of its row returns the disk to it, and loses everything written since (Take and roll back instance snapshots).

Permission denied (publickey)

The instance does not hold the key you used, or you signed in as the wrong user. Check Username on the Access tab (Connect to an instance over SSH).

Connection timed out

The instance is stopped or has no public address. Start it with the power buttons in its header (Start, stop and restart an instance).

Each line must be one OpenSSH public key, e.g. "ssh-ed25519 AAAA… you@laptop".

A line under SSH keys is not a public key. Paste the contents of the .pub file, one key per line.

• Put a website online with the instance as the site's origin
• Back up and restore an instance, for a copy that survives a rebuild
• Manage an instance's addresses and names, such as its reverse DNS name