Interface not found error on the generated bindings

[GaikwadPratik]

@amenzhinsky ,

I am currently using the library to generate server bindings with example mentioned in client-server example with following command: dbus-codegen-go -package=main -output=dbusserver/server.go -server-only dbusserver/service.xml

When I start dbus server that, I get error on the client side when I invoke generator interface:

DBusError: Object does not implement the interface

However if I hard-code the xml inside the code as mentioned in the dbus-server example, it works just fine.

Same client is being used for calling the server code

I've created a sample project which I uploaded to my github for easiness.

I updated the my github example to include goclient using this library as well and I get same error but this time for hardcoded method.

Also in the client code, I get below errors:

Can you point me what am I doing wrong?

P.S. Awesome library

[amenzhinsky]

Hi @GaikwadPratik ,

It seems you've made a typo with extra 1 at the end of the interface name here you could use InterfaceCom_Hiveio_Vm_Manager constant to avoid this.

[amenzhinsky]

Also fixed the error with unused imports, can you try the latest version?

[GaikwadPratik]

Hi @amenzhinsky,

1. 1 in here is to provide you with two different services. I couldn't think of better name at the time so I added 1. I could very well use hardcoded instead of 1
2. Do you need to release a new version of the pkg, because even using go get -u github.com/amenzhinsky/dbus-codegen-go@latest gives me v0.2.0

[amenzhinsky]

1. You're registering service that implements com.hiveio.vm.Manager1, but client is calling com.hiveio.vm.Manager without 1, that's why you're getting the error.
2. I haven't added a new tag yet, you may try @master

[GaikwadPratik]

Hi @amenzhinsky ,

I updated my source code to include name hardcoded instead of 1 to avoid confusion. There are two different services. I'm invoking each one of them in both. golang

1. hardcoded
2. generated

javascript

1. hradcoded
2. generated

here is the out put that I get

root@hive1:~# ./goclient 
{"level":"error","error":"Object does not implement the interface","time":"2021-06-24T12:06:54Z","message":"While checking host for migration in hardcoded call"}
{"level":"debug","val":true,"time":"2021-06-24T12:06:54Z","message":"Recived response in generator call"}
^C{"level":"warn","time":"2021-06-24T12:07:01Z","message":"Adios!"}
root@hive1:~# node client/index.js 
hardcoded worked
{ DBusError: Object does not implement the interface
    at _methodReturnHandlers.(anonymous function) (/root/client/node_modules/dbus-next/lib/bus.js:343:27)
    at handleMessage (/root/client/node_modules/dbus-next/lib/bus.js:101:11)
    at EventEmitter.MessageBus.conn.on (/root/client/node_modules/dbus-next/lib/bus.js:151:9)
    at EventEmitter.emit (events.js:198:13)
    at /root/client/node_modules/dbus-next/lib/connection.js:116:14
    at Socket.<anonymous> (/root/client/node_modules/dbus-next/lib/message.js:63:9)
    at Socket.emit (events.js:198:13)
    at emitReadable_ (_stream_readable.js:555:12)
    at process._tickCallback (internal/process/next_tick.js:63:19)
  name: 'DBusError',
  type: 'org.freedesktop.DBus.Error.UnknownInterface',
  text: 'Object does not implement the interface',
  reply:
   Message {
     type: 3,
     _sent: false,
     _serial: 7,
     path: undefined,
     interface: undefined,
     member: undefined,
     errorName: 'org.freedesktop.DBus.Error.UnknownInterface',
     replySerial: 2,
     destination: ':1.45',
     sender: ':1.41',
     signature: 's',
     body: [ 'Object does not implement the interface' ],
     flags: 0 } } 'Inside generator'

I think I understand what you are saying here for invoking hardcoded service from generated goclient. But I am more concerned about javascript part

[amenzhinsky]

You did the same mistake, generated client is calling exactly com.hiveio.vm.Manager, not *1, not *hardcoded

https://github.com/GaikwadPratik/dbus-local-test/blob/master/server/goclient/client.go#L11 https://github.com/GaikwadPratik/dbus-local-test/blob/master/server/goclient/client.go#L27

So server MUST export the same interface here: https://github.com/GaikwadPratik/dbus-local-test/blob/master/server/goserver/main.go#L51

[GaikwadPratik]

I think I understand what you are saying here for invoking hardcoded service from generated goclient. But I am more concerned about javascript part

JS does call both of them: https://github.com/GaikwadPratik/dbus-local-test/blob/master/client/index.js#L5-L7 https://github.com/GaikwadPratik/dbus-local-test/blob/master/client/index.js#L19-L21

[GaikwadPratik]

@amenzhinsky ,

I'm not sure if this helps or not but I get this with qdbus

for the bindings using generator

root@hive1:~# qdbus --system com.hiveio.vmmanager /com/hiveio/vmmanager
Error: org.freedesktop.DBus.Error.UnknownInterface
Object does not implement the interface

for the inline hardcoded service

root@hive1:~# qdbus --system com.hiveio.vmmanagerhardcoded /com/hiveio/vmmanagerhardcoded
method bool com.hiveio.vm.Managerhardcoded.CheckHostForMigration(QString, QString)
method void com.hiveio.vm.Managerhardcoded.RecoverGuest(QString, QString)
method void com.hiveio.vm.Managerhardcoded.RecoverUservolume(QString guestName, QString username)
method QString org.freedesktop.DBus.Introspectable.Introspect()
root@hive1:~

[GaikwadPratik]

@amenzhinsky ,

When I'm exposing service using godbus/dbus server example, I noticed it added a Introspectable interface and exported both custom interface and introspectable interface on the bus to object path defined. But the server generated using dbus-codegen-go doesn't add that. Even if I add the introspectable interface manually in the xml, it is still not exported.

My observation is based on qdbus as well deus-send

root@hive1:~# dbus-send --system --dest=com.hiveio.vmmanager --type=method_call --print-reply /com/hiveio/vmmanager org.freedesktop.DBus.Introspectable.Introspect
Error org.freedesktop.DBus.Error.UnknownInterface: Object does not implement the interface

root@hive1:~# dbus-send --system --dest=com.hiveio.vmmanagerhardcoded --type=method_call --print-reply /com/hiveio/vmmanagerhardcoded org.freedesktop.DBus.Introspectable.Introspect
method return time=1624681884.126838 sender=:1.389 -> destination=:1.397 serial=5 reply_serial=2
   string "
<node>
    <interface name="com.hiveio.vmmanagerhardcoded">
        <method name="CheckHostForMigration">
        <arg name="guestName" direction="in" type="s"/>
        <arg name="cpuxml" direction="in" type="s"/>
        <arg name="result" direction="out" type="b"/>
    </method>
    <method name="RecoverGuest">
        <arg name="guestName" direction="in" type="s"/>
        <arg name="reason" direction="in" type="s"/>
    </method>
    <method name="RecoverUservolume">
        <arg name="guestName" direction="in" type="s"/>
        <arg name="username" direction="in" type="s"/>
    </method>
</interface>
    <interface name="org.freedesktop.DBus.Introspectable">
        <method name="Introspect">
            <arg name="out" direction="out" type="s"/>
        </method>
    </interface>
</node> "

In both the cases, I'm not using any client. So no mistake of using incorrect interface name or something like that

can you please help? If its something beyond the scope of the library, please do let me know so I'll just continue to maintain inline xml

[GaikwadPratik]

Seems like this library implements and calls UnexportOrgFreedesktopDBusIntrospectable so regular Introspectable interface will not be available.