Failed to get value of parameter. Authorization failure.

[gargulakj]

I need help retrieving parameters using ax_parameter_get. It works only for application parameters.

When I try to get ImageSource.I0.Sensor.Exposure, I get the following error:
Authorization failure: client with UID=999 is not allowed to get parameter.

How can I access system parameters like this one?

Now I have:
AXIS OS: 12.4.59
ACAP SDK: 12.4.0

Thank you.

[losamtz]

Hi @gargulakj ,

We are looking into it but for now "ImageSource.I0.*" is not accessible through axparameter. A temporary workaround is to request, within your acap, the parameter through param.cgi, with curl.

http://127.0.0.12/axis-cgi/param.cgi?action=list&group=ImageSource.I0.Exposure

Please follow the instructions from the doc:
https://developer.axis.com/acap/develop/VAPIX-access-for-ACAP-applications/

Example:
https://github.com/AxisCommunications/acap-native-sdk-examples/tree/main/vapix

Note: The acap team is working right now on it to be accessed through axparameter, but if you are in a hurry you could use the workaround.

[vivekatoffice]

Hi @gargulakj ,
Looks like this is related to securityLevel. You can use the VAPIX API to get the securityLevel="7744" for ImageSource.I0.Sensor.Exposure.

https://{{device}}/axis-cgi/param.cgi?action=listdefinitions&listformat=xmlschema&group=ImageSource.I0.Sensor.Exposure

• create: 7 Root access. Internal parameters that can be changed by software applications or by root editing the configuration files directly.

• delete: 7 Root access. Internal parameters that can be changed by software applications or by root editing the configuration files directly.

• read: 4 Operator access

• write: 4 Operator access

As @losamtz mentioned, vapix example do works.

I tested a sample by changing the URL:

[vivekatoffice]

@Cacsjep Can we use the static user here? My Idea is to have an operator user created.

Image reference

[Cacsjep]

My latest knowledge is dynamic users should be used, also that would mean you would know the operator at compile time.

That's a bug that needs to fixed on acap team :)

[vivekatoffice]

Ya, looks like you are right 🫡 . I have asked the ACAP SDK experts. Will update here soon 😉

[vivekatoffice]

Hi @gargulakj ,
I found the following from the ACAP SDK experts to change in the manifest.json 😄

 "resources": {
        "linux": {
            "user":{
                    "groups":["operator"]
                }
        }
    }

My manifest.json :

{
    "schemaVersion": "1.7.3",
    "acapPackageConf": {
        "setup": {
            "friendlyName": "axparameter",
            "appName": "axparameter",
            "vendor": "Axis Communications",
            "embeddedSdkVersion": "3.0",
            "vendorUrl": "https://www.axis.com",
            "runMode": "never",
            "version": "1.0.0"
        },
        "configuration": {
            "paramConfig": [
                {
                    "name": "IsCustomized",
                    "default": "no",
                    "type": "bool:no,yes"
                },
                {
                    "name": "BackupValue",
                    "default": "restored from backup",
                    "type": "hidden:string"
                }
            ]
        }
    },
    "resources": {
        "linux": {
            "user":{
                    "groups":["operator"]
                }
        }
    }
}

// Parameters outside the application's group requires qualification.
    gchar* exposure_details;
    if (!ax_parameter_get(handle, "ImageSource.I0.Sensor.Exposure", &exposure_details, &error))
        panic("%s", error->message);
    syslog(LOG_INFO, "ImageSource.I0.Sensor.Exposure: '%s'", exposure_details);
    g_free(exposure_details);

Output:

[gargulakj]

Perfect, this works!

But it gives me warning:
Vegafied parameter used through libparhand (Client:./App Parameter:root.ImageSource.I0.Sensor.Exposure) Please use it through its DBus service

[Cacsjep]

Try remove the root. prefix

[gargulakj]

I tried both: with root. and without root prefix. Warning is still there.

[Cacsjep]

strange i do not get this warning, thats my manifest

{
    "schemaVersion": "1.7.0",
    "resources": {
        "linux": {
            "user": {
                "groups": [
                    "storage",
                    "operator" // <-- I also now using this 
                ]
            }
        },
        "dbus": {
            "requiredMethods": [
                "com.axis.Graphics2.*",
                "com.axis.Overlay2.*",
                "com.axis.HTTPConf1.VAPIXServiceAccounts1.GetCredentials"
            ]
        }
    },
    "acapPackageConf": {
        "setup": {
            "appName": "ax_msf",
            "embeddedSdkVersion": "3.5",
            "friendlyName": "Missing Features",
            "runMode": "respawn",
            "vendor": "Commend Österreich GmbH",
            "version": "1.0.93",
            "appId": "----"
        },
        "copyProtection": {
            "method": "axis"
        },
        "configuration": {
            "settingPage": "redirect.html",
            "reverseProxy": [
                {
                    "apiPath": "ax_msf",
                    "target": "http://localhost:2001",
                    "access": "admin"
                }
            ]
        }
    }
}