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API

This document describes the PiKVM API. Since the system consists of microservices, here is a common API with a common entry point provided by Nginx. The examples above use curl and websocat with the -k option to disable SSL certificate verification, since the self-signed certificateis used in the default installation.


Authorization

All APIs are restricted to authorization. To make requests, you either need to authorize each request individually, or get a token and pass it as a cookie with each request.

Single request auth

There are two options here:

  • Using X-headers. Just pass X-KVMD-User and X-KVMD-Passwd with the request:

    $ curl -k -H X-KVMD-User:admin -H X-KVMD-Passwd:admin https://<pikvm-ip>/api/auth/check
    
  • Using HTTP Basic Auth. Please note: contrary to the standard, this method DOES NOT use the WWW-Authenticate header. HTTP Basic Auth in this implementation is intended only for compatibility with other systems, such as Prometheus.

    $ curl -k -u admin:admin https://<pikvm-ip>/api/auth/check
    
  1. Authorize and get token for the user using POST /api/auth/login:

    $ curl -k -v -X POST --data user=admin --data passwd=admin https://pikvm/api/auth/login
    ...
    < Set-Cookie: auth_token=796cb83b11de4fcb749bc1bad14a91fb06dede84672b2f847fef1e988e6900de; Path=/
    ...
    

    On success the cookie auth_token will be received with 200 OK. On invalid user or password you will get 403 Forbidden.

  2. The handle GET /api/auth/check can be used for check the auth status. Return of 200 OK will signal that user is authenticated. If the token or any of the single-request auth methods are missing, 401 Unauthorized will be returned. In case of incorrect credentials or token, 403 Forbidden will be returned.

  3. The handle POST /api/auth/logout can be used to invalidate session token. The response codes will be similar to the previous handle.


WebSocket events

Most of the data during the user's work with pikvm is transmitted over WebSocket. This includes mouse events, keyboard input, change the state of the various subsystems (such as ATX and Mass Storage Drive). Each event type will be described in the corresponding paragraph for its component. When connecting via WebSocket, the client receives current states as separate events. Then, as the states change, it will receive new events.

In a normal situation, opening a socket session triggers the video streamer to start. The streamer works as long as there is at least one client connected via WebSocket. After the last connection is closed and the client timeout expires, the streamer will also be terminated.

It is possible create a session that will not start the streamer and will not be counted when counting clients to stop the streamer. To do this, use the URL parameter stream=0:

$ websocat -k wss://<pikvm-ip>/api/ws?stream=0 -H X-KVMD-User:admin -H X-KVMD-Passwd:admin
Output with initial events
{"event_type": "gpio_model_state", "event": {"scheme": {"inputs": {"led1": {"hw": {"driver": "__gpio__", "pin": 19}}, "led2": {"hw": {"driver": "__gpio__", "pin": 16}}}, "outputs": {"button1": {"switch": false, "pulse": {"delay": 0.1, "min_delay": 0.1, "max_delay": 0.1}, "hw": {"driver": "__gpio__", "pin": 26}}, "button2": {"switch": false, "pulse": {"delay": 0.1, "min_delay": 0.1, "max_delay": 0.1}, "hw": {"driver": "__gpio__", "pin": 20}}, "relay1": {"switch": true, "pulse": {"delay": 0.1, "min_delay": 0.1, "max_delay": 0.1}, "hw": {"driver": "relay", "pin": 0}}, "relay2": {"switch": true, "pulse": {"delay": 2.0, "min_delay": 0.1, "max_delay": 5.0}, "hw": {"driver": "relay", "pin": 1}}}}, "view": {"header": {"title": "Switches"}, "table": [[{"type": "label", "text": "Generic GPIO leds"}], null, [{"type": "label", "text": "Test 1:"}, {"type": "input", "channel": "led1", "color": "green"}, {"type": "output", "channel": "button1", "text": "Click"}], [{"type": "label", "text": "Test 2:"}, {"type": "input", "channel": "led2", "color": "green"}, {"type": "output", "channel": "button2", "text": "Click"}], null, [{"type": "label", "text": "HID Relays /dev/hidraw0"}], null, [{"type": "label", "text": "Relay #1:"}, {"type": "output", "channel": "relay1", "text": "Boop 0.1"}], [{"type": "label", "text": "Relay #2:"}, {"type": "output", "channel": "relay2", "text": "Boop 2.0"}]]}}}
{"event_type": "info_extras_state", "event": {"vnc": {"name": "VNC", "description": "Show VNC information", "icon": "share/svg/vnc.svg", "path": "vnc", "keyboard_cap": false, "daemon": "kvmd-vnc", "port": 5900, "place": 20, "enabled": true}, "ipmi": {"name": "IPMI", "description": "Show IPMI information", "icon": "share/svg/ipmi.svg", "path": "ipmi", "keyboard_cap": false, "daemon": "kvmd-ipmi", "port": 623, "place": 21, "enabled": true}}}
{"event_type": "info_hw_state", "event": {"platform": {"type": "rpi", "base": "Virtual Raspberry Pi"}, "health": {"temp": {"cpu": 36.511, "gpu": 35.0}, "throttling": {"raw_flags": 0, "parsed_flags": {"undervoltage": {"now": false, "past": false}, "freq_capped": {"now": false, "past": false}, "throttled": {"now": false, "past": false}}}}}}
{"event_type": "info_meta_state", "event": {"server": {"host": "localhost.localdomain"}, "kvm": {}}}
{"event_type": "info_system_state", "event": {"kvmd": {"version": "1.102"}, "streamer": {"app": "ustreamer", "version": "1.25", "features": {"WITH_OMX": false, "WITH_GPIO": false, "WITH_PTHREAD_NP": true, "WITH_SETPROCTITLE": true, "HAS_PDEATHSIG": true}}, "kernel": {"system": "Linux", "release": "5.8.10-arch1-1", "version": "#1 SMP PREEMPT Thu, 17 Sep 2020 18:01:06 +0000", "machine": "x86_64"}}}
{"event_type": "wol_state", "event": {"enabled": false, "target": {"ip": "255.255.255.255", "port": 9, "mac": ""}}}
{"event_type": "gpio_state", "event": {"inputs": {"led1": {"online": true, "state": false}, "led2": {"online": true, "state": false}}, "outputs": {"button1": {"online": true, "state": false, "busy": false}, "button2": {"online": true, "state": false, "busy": false}, "relay1": {"online": false, "state": false, "busy": false}, "relay2": {"online": false, "state": false, "busy": false}}}}
{"event_type": "hid_state", "event": {"online": true, "keyboard": {"online": true, "leds": {"caps": false, "scroll": false, "num": false}}, "mouse": {"online": true}}}
{"event_type": "atx_state", "event": {"enabled": true, "busy": false, "leds": {"power": false, "hdd": false}}}
{"event_type": "msd_state", "event": {"enabled": true, "online": true, "busy": false, "storage": {"size": 234950152192, "free": 23514271744, "images": {}, "uploading": false}, "drive": {"image": null, "connected": false, "cdrom": true}, "features": {"multi": true, "cdrom": true}}}
{"event_type": "streamer_state", "event": {"limits": {"max_fps": 40}, "params": {"desired_fps": 30, "quality": 80}, "snapshot": {"saved": null}, "streamer": null, "features": {"quality": true, "resolution": false}}}
{"event_type": "loop", "event": {}}

After connecting the client receives a bundle of states of all KVMD subsystems. After the batch is completed, it sends a loop event, which means that the websocket has entered event loop mode. Now it will send new states and respond to client's requests.

Another type of event is ping, which can be sent by the client: {"event_type": "ping", "event": {}}. If the server is running, it will respond with pong: {"event_type": "pong", "event": {}}.

Sending key events using Python

For keypresses, set event_type to key and fill in the event structure with key and state, where key is the key from mapping and state is boolean that determines if the key is pressed or released:

# python, install websocket-client
import websocket
uri = "wss://10.0.0.7/api/ws?stream=0"
headers = {"X-KVMD-User": "admin", "X-KVMD-Passwd": "admin"}
ws = websocket.WebSocket(sslopt={"cert_reqs": ssl.CERT_NONE})
ws.connect(uri, header=headers)
ws.send('{"event_type": "key", "event": {"key": "Enter", "state": true}}')
time.sleep(0.05)
ws.send('{"event_type": "key", "event": {"key": "Enter", "state": false}}')
ws.close()

System functions

Get system info

The GET /api/info handle returns the general information about the PiKVM device.

Parameters:

  • fields=... (optional) - Only specified categories will be returned, for example fields=system,hw. By default all categories will be displayed.
$ curl -k -u admin:admin https://<pikvm-ip>/api/info
Click to expand
{
    "ok": true,
    "result": {
        "extras": { // Installed applications; null on internal error
            "ipmi": {
                "daemon": "kvmd-ipmi",
                "description": "Show IPMI information",
                "enabled": true,
                "icon": "share/svg/ipmi.svg",
                "keyboard_cap": false,
                "name": "IPMI",
                "path": "ipmi",
                "place": 21,
                "port": 623
            },
            "vnc": {
                "daemon": "kvmd-vnc",
                "description": "Show VNC information",
                "enabled": true,
                "icon": "share/svg/vnc.svg",
                "keyboard_cap": false,
                "name": "VNC",
                "path": "vnc",
                "place": 20,
                "port": 5900
            }
        },
        "hw": { // Hardware info
            "health": {
                "temp": {
                    "cpu": 36.511, // /sys/class/thermal/thermal_zone0/temp / 1000; null on error
                    "gpu": 35.0    // vcgencmd measure_temp; null on error
                },
                "throttling": { // vcgencmd get_throttled; null on error
                    "parsed_flags": {
                        "freq_capped": {
                            "now": false,
                            "past": false
                        },
                        "throttled": {
                            "now": false,
                            "past": false
                        },
                        "undervoltage": {
                            "now": false,
                            "past": false
                        }
                    },
                    "raw_flags": 0
                }
            },
            "platform": {
                "base": "Raspberry Pi 4 Model B Rev 1.1", // /proc/device-tree/model; null on error
                "type": "rpi"
            }
        },
        "meta": {  // /etc/kvmd/meta.yaml; null on error
            "kvm": {},
            "server": {
                "host": "localhost.localdomain"
            }
        },
        "system": {
            "kernel": {
                "machine": "x86_64",
                "release": "5.8.14-arch1-1",
                "system": "Linux",
                "version": "#1 SMP PREEMPT Wed, 07 Oct 2020 23:59:46 +0000"
            },
            "kvmd": {
                "version": "2.1"
            },
            "streamer": {
                "app": "ustreamer",
                "features": { // {} on error
                    "HAS_PDEATHSIG": true,
                    "WITH_GPIO": false,
                    "WITH_OMX": false,
                    "WITH_PTHREAD_NP": true,
                    "WITH_SETPROCTITLE": true
                },
                "version": "2.1" // "" on error
            }
        }
    }
}

Each category is represented by its own event in the websocket (info_hw_state, info_system_state, etc). The event content has the same format as the category content in API.

Get system log

The GET /api/log handle displays logs from all KVMD services as plain text.

Parameters:

  • follow=1 (optional) - Turns the request into long-polling mode and follow log messages in real time.
  • seek=N (optional) - Runs the log for the specified time in seconds, for example seek=3600 will show the log for the last hour.
$ curl -k -u admin:admin https://<pikvm-ip>/api/log

ATX power management

Get ATX state

The GET /api/atx handle shows the current ATX state.

$ curl -k -u admin:admin https://<pikvm-ip>/api/atx
Click to expand
{
    "ok": true,
    "result": {
        "busy": false, // True if ATX is busy performing an operation and does not accept commands
        "enabled": true,
        "leds": {
            "hdd": false,
            "power": false
        }
    }
}

Set ATX power

The POST /api/atx/power handle changes ATX power state to desired.

Parameters:

  • action=... - Describes desired state:
    • on - Turn on (do nothing in case PSU is already on).
    • off - Turn off (aka soft-off), emulates click on the power button.
    • off_hard - Perform long press on the power button (5+ seconds).
    • reset_hard - Emulates pressing reset button (hardware hot reset).
  • wait=1 (optional) - Says if call should return immediately or just after finishing operation.
$ curl -X POST -k -u admin:admin https://<pikvm-ip>/api/atx/power?action=on

Click ATX button

The POST /api/atx/click handle sends the ATX button press event.

Parameters:

  • button=... - Specifies the desired PC case button:
    • power - Short click on the power button.
    • power_long - Long press on the power button (5+ seconds).
    • reset - Short click on the reset button.
  • wait=1 (Optional) - Says if call should return immediately or just after finishing operation.
$ curl -X POST -k -u admin:admin https://<pikvm-ip>/api/atx/click?button=power

Mass Storage Drive

Get MSD state

The GET /api/msd handle shows the current MSD state.

$ curl -k -u admin:admin https://<pikvm-ip>/api/msd

Upload MSD image

The POST /api/msd/write uploads an image to MSD.

Parameters:

  • image=... - Specifies the name of the image.
  • Binary data should be passed to the POST body.
$ # create a test image
$ dd if=/dev/zero of=test.iso bs=1M count=1

$ # upload it to pikvm
$ curl -v -X POST --data-binary @test.iso -k -u admin:admin https://<pikvm-ip>/api/msd/write?image=test.iso

Upload MSD image by URL

The POST /api/msd/write_remote handle downloads an image from HTTP(S) URL to the MSD.

Parameters:

  • url=... - Image URL.
  • image=... (optional) - Image name.
  • timeout=N (optional) - Remote request timeout, 10 seconds by default.

Note

This is a long-polling request. Do not interrupt the request until the download is complete, otherwise the download will stop.

$ # create test image
$ dd if=/dev/zero of=test.iso bs=1M count=1

$ # upload it to pikvm
$ curl -v -X POST -k -u admin:admin https://<pikvm-ip>/api/msd/write_remote?url=http://example.com/test.iso

Set MSD parameters

The POST /api/msd/set_params handle changes the current image and/or set drive parameters

Parameters:

  • image=... (optional) - Change the current image.
  • cdrom=1|0 (optional) - Change the media type to the CD-ROM on 1, otherwise to the Flash.
$ curl -X POST -k -u admin:admin "https://<pikvm-ip>/api/msd/set_params?image=test.iso&cdrom=1"

Control MSD

The POST /api/msd/set_connected connects or disconnect the MSD to the host.

Parameters:

  • connected=1|0 - Change the state.
$ curl -X POST -k -u admin:admin https://<pikvm-ip>/api/msd/set_connected?connected=1

Remove MSD image

The POST /api/msd/remove handle removes the specified image.

Parameters:

  • image=... - The image name.
$ curl -X POST -k -u admin:admin https://<pikvm-ip>/api/msd/remove?image=test.iso

Reset MSD

The POST /api/msd/reset handle resets the drive.

$ curl -X POST -k -u admin:admin https://<pikvm-ip>/api/msd/reset

GPIO

Get GPIO state

The GET /api/gpio handle shows the current GPIO state.

$ curl -k -u admin:admin https://<pikvm-ip>/api/gpio

Switch GPIO channel

The POST /api/gpio/switch handle interacts with selected GPIO driver channel in switch mode.

Parameters:

  • channel=... - The GPIO driver channel.
  • state=1|0 - The new switch state.
  • wait=1 (optional) - Says if call should return immediately or just after finishing operation.

Pulse GPIO channel

The POST /api/gpio/pulse handle interacts with selected GPIO driver channel in pulse mode.

Parameters:

  • channel=... - The GPIO driver channel.
  • delay=N.N (optional) - The pulse time in seconds (float), 0 for default delay.
  • wait=1 (optional) - Says if call should return immediately or just after finishing operation.

Misc

Get Prometheus metrics

The GET /api/export/prometheus/metrics handle returns the Prometheus metrics. Also see here for details.

$ curl -k -u admin:admin https://<pikvm-ip>/api/export/prometheus/metrics

To be continued ===>

You can find all existing APIs in the KVMD source tree. We would appreciate your help with documentation.

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