pikvm/pages/api.md

API

This document describes the Pi-KVM 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 parameter to disable SSL certificate verification, since the self-signed certificateis used in the default installation.

Authorization: /api/auth

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/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 --user admin:admin https://pikvm/api/auth/check
  

Session-based cookie auth

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.

The main web socket: /api/ws

Most of the data during the user's work with pikvm is transmitted over a web socket. 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 a web socket, 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 a web socket. 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/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": {}}.

System info: /api/info

On GET this handle will return general information about the Pi-KVM device. If you specify the fields query parameter, only the requested category will be selected, like fields=system,hw. By default all categories will be displayed:

$ curl -k -H X-KVMD-User:admin -H X-KVMD-Passwd:admin http://localhost:8080/api/info

Example

{
    "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.

System log: /api/log

On GET this handle will display messages from all KVMD services as plain text. The follow=1 request parameter turns the request into an infinite one and you will receive new log messages in real time. The seek parameter runs the log for the specified time in seconds. For example, seek=3600 will show the log for the last hour. Both the seek and follow parameters can be used together.

Get ATX state: /api/atx

On GET it will show current ATX state.

Example

{
    "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 PSU state: /api/atx/power

On POST it will change ATX power supply state to desired. Parameters:

• action describes desired state:
  • on - turned on (do nothing in case PSU is already on);
  • off - turned off (aka soft-off), emulates short-press on the power button;
  • off_hard - emulates long (5+ seconds) press on the power button;
  • reset_hard emulates pressing reset button (hardware hot reset).
• wait - boolean. Says if call should return immediately or just after finishing operation.

Emulate pressing buttons on computer case: /api/atx/click

On POST send button press events to {front-}panel header (like you pressing buttins on your computer's case). Parameters:

• button specifies the desired computer case button you would like to press. Currently supported options are: power — for short press on power button, power_long — for pressing POWER button for 4+ seconds (force OFF), reset — to initiate cold-reset
• wait Boolean. Says if call should return immediately or just after finishing operation.

To be continued ===>

Unfortunately, the developer doesn't have enough time to fully describe the API. You can find all existing APIs in the KVMD source tree. We would appreciate your help with documentation.