Use an instance's console
Open a browser console on an instance's screen, even when its network is down, and read its hardware and recent tasks.
In the dashboard
The Console tab shows the instance's screen in your browser and sends it your keyboard and mouse, as a monitor and keyboard plugged into the machine would. It works while the instance has no network. Use it when SSH does not answer, for example after a firewall change locks you out, or to watch the instance boot.
Below the screen, the tab shows what the instance is using, what its guest agent reports, its virtual hardware and the tasks its host ran for it.
Before you begin
Section titled Before you begin- The instance is running. Start it from the header if it is stopped, as Start, stop and restart an instance describes.
- The instance is not suspended. The console does not connect to a suspended instance.
- To sign in at the screen, you need the password of the instance's user account. We do not show the password the instance was created with, so reset the password first if you do not have one. SSH keys do not work at the console.
Open the console
Section titled Open the console- In the dashboard, go to Cloud Compute and open the instance.
- The Console tab opens first. The Display panel connects on its own and shows the screen once its status reads Connected.
- Click the screen, then type. Your keys go to the instance.
Use the display toolbar
Section titled Use the display toolbar- Ctrl+Alt+Del
- Sends that key combination to the instance. Your own computer keeps it for itself when you press it, so use this button instead.
- View only
- Stops your keyboard and mouse reaching the instance, so you can watch the screen without typing into it by accident. Select it again to type.
- Reconnect
- Starts a new session and connects again. It reads New session while you are connected.
- Fullscreen
- Fills the browser window with the screen. Select Exit fullscreen, or press Esc, to go back.
Note
Some older instances still use a serial port as their display, and the console shows a note about it above the screen. Restart the instance once from the header, and the console shows its screen from then on. A reboot typed inside the instance does not change its display.
Read the rest of the tab
Section titled Read the rest of the tabThe four cards above the display show the instance's size and use:
- vCPU
- The number of cores, and the share of them in use.
- Memory
- The memory size, and the share in use.
- Disk
- The disk size, and the share the host reports as allocated.
- Bandwidth
- The traffic used this period against the plan's allowance, and the date it resets. How instance traffic is counted explains the figure.
The Guest card shows what the QEMU guest agent inside the instance reports: its operating system, kernel and the addresses it sees. The badge reads Agent running when the agent answers, and Agent offline when it does not. You need the agent to reset the password, and it lets the instance shut down cleanly when you select Stop.
The Configuration card shows the virtual hardware: CPU model, storage, host location, template, VM ID, boot order, each disk and network card, and the network settings and user account that cloud-init applies. The password and SSH keys never appear there.
The Recent tasks table lists the last eight tasks the host ran for the instance, such as power actions, backups, snapshots and console sessions. Status reads OK when a task finished, Running while it runs, or the error the host gave. Select the refresh button (Refresh tasks) to read the list again.
Result
Section titled ResultYou see the instance's screen, and you can sign in at it as you would at a physical machine.
Troubleshooting
Section titled TroubleshootingThe instance is powered off- The instance is stopped. Select Start in the header. The console connects once the instance is running.
Could not connect to the console- The session expired before it connected, or the host did not answer. Select Try again for a new session. If the message below it says
You are signed out. Sign in again to open the console., sign in to the dashboard again first. Disconnected- The session ended or the connection dropped. Select Try again for a new session.
The guest agent is not responding- The instance has no QEMU guest agent, or it is not running. Install it from the console or over SSH. On Ubuntu or Debian, run
sudo apt install qemu-guest-agent. On AlmaLinux, Rocky Linux or Fedora, runsudo dnf install qemu-guest-agent. Then runsudo systemctl start qemu-guest-agent. No public address- The instance has no public IP address, so you can reach it only through this console. Select Open Network and attach a floating IP, as Manage an instance's addresses and names describes.
Related
Section titled Related- Connect to an instance over SSH once it is on the network.
- Repair an instance in rescue mode when it does not boot at all.
- Manage an instance's password, SSH keys and hostname to reset the password or change the keys.
With the API
Section titled With the APIGET /api/v1/client/vps/{uuid}/console starts a console session on the instance's host.
curl https://api.coritan.com/api/v1/client/vps/$INSTANCE_UUID/console \
-H "Authorization: Bearer $CORITAN_TOKEN"
{
"vnc_ws": "/ws/vps/vnc/5b0c2f7e-8a31-4d2b-9f4e-2a7c1d9e6b10",
"vnc_session": "q3Vx…",
"vnc_password": "Zk2p…",
"expires_in": 120,
"display": "vga"
}
Within expires_in seconds, connect a VNC client that speaks WebSocket, such as noVNC, to the socket below. Pass your access token and the session in the query string, and answer the VNC password prompt with vnc_password.
wss://api.coritan.com/ws/vps/vnc/<instance uuid>?token=<access token>&session=<vnc_session>
Ask for a new session for every connection, as the dashboard does. display is serial while the instance still uses its serial port as its screen; restart it with the reboot power action to give it a graphics display. When the socket cannot connect, it closes with one of these codes:
4001- The token is not a valid access token.
4003- The instance is not on your account, or it is suspended or being moved.
4004- The session is missing or expired, or the host's console is not available. Ask for a new session.
4029- You already have too many consoles open. Close one and try again.
When the host cannot start a console, GET /console answers 400 with a message that starts Console unavailable.
GET /api/v1/client/vps/{uuid}/config returns the virtual machine's configuration with the password and SSH keys removed. config holds cores, memory (in MiB), name, ostype, boot, agent, disks and nics (keyed by device, such as scsi0 or net0), and cloud_init, the settings cloud-init applies, such as ipconfig0, ciuser and nameserver. The response also carries vmid, rescue_mode and rescue_iso.
GET /api/v1/client/vps/{uuid}/guest asks the guest agent. agent_online is true when it answered, and os_info and network_interfaces then hold what it reported. When a question fails, agent_error, os_error or network_error says why, such as VM is not running or qemu-guest-agent not responding.
GET /api/v1/client/vps/{uuid}/tasks returns the host's recent tasks for the instance. Send limit for how many: the default is 50 and the most is 100.
type- What the task did, such as
qmstart,qmshutdown,qmsnapshot,vzdumpfor a backup orvncproxyfor a console session. statusOKwhen the task finished cleanly, and the error when it failed. It is absent while the task runs.starttime,endtime- When the task started and finished, in Unix seconds.
upid- The host's ID for the task.
While we move the instance to another host, /config, /guest and /tasks answer 409 with Instance is migrating.
API operations on this page
| Method | Path | What it does |
|---|---|---|
GET | /api/v1/client/vps/{uuid}/console | Mint a VNC console session (WebSocket path + RFB password) |
GET | /api/v1/client/vps/{uuid}/config | Get instance config |
GET | /api/v1/client/vps/{uuid}/guest | Get guest info |
GET | /api/v1/client/vps/{uuid}/tasks | Get instance tasks |