Livebook cannot connect to the default runtime about livebook

[jonatanklosko]

Can you also try the nightly desktop build to make sure it's still present there?

[mat-hek]

Yes. With the nightly build, when I first clicked 'New notebook' from the Livebook icon menu, it shut down. After trying again, the app feels slow and the UI hangs, and the original problem persists.

[jonatanklosko]

Curious, is it the same if you run as escript or from source? It would be helpful to know if it is or isn't specific to the desktop app.

When I connect to a manually created runtime, everything works well.

You mean using the attached runtime, or something else?

[mat-hek]

Just installed via escript and it's the same.

You mean using the attached runtime, or something else?

The attached runtime

[jonatanklosko]

Ok, so it could be something with hostname resolution. And does it work if you start with LIVEBOOK_DISTRIBUTION=name [email protected]?

[mat-hek]

Yes, now it works 🎉

[jonatanklosko]

Interesting, people run into this several times due to unset or invalid host names and we even have a section on it here, but we check the resolution on boot, so I would expect an error. You can check if the host is set with scutil --get HostName.

[jonatanklosko]

It's particularly curious that it worked by attaching manually, if you want to debug more, you can check if this returns expected hostnames:

$ iex -S mix phx.server
iex> node()
:livebook_ly3srpox@chonker
iex> Livebook.Runtime.NodePool.get_name(node())
:"a34dmksi-livebook_ly3srpox@chonker"

[mat-hek]

scutil --get HostName
HostName: not set

Interactive Elixir (1.16.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(livebook_as2mazzi@Mateuszs-MacBook-Pro-2)1> node
:"livebook_as2mazzi@Mateuszs-MacBook-Pro-2"
iex(livebook_as2mazzi@Mateuszs-MacBook-Pro-2)2> Livebook.Runtime.NodePool.get_name node
:"vjqoxwku-livebook_as2mazzi@Mateuszs-MacBook-Pro-2"
iex(livebook_as2mazzi@Mateuszs-MacBook-Pro-2)3>

[jonatanklosko]

Ah, so it is actually the same issue, you want to set the host name as noted here.

@josevalim anything else we should be asserting in the hostname resolution check?

[mat-hek]

Hmm, it doesn't help 🤔 still the same behaviour

[jonatanklosko]

So there must be something else about the environment. I updated to Sonoma 14.4.1 and tried Desktop nightly to ensure the same versions, but couldn't reproduce :<

[josevalim]

Yeah, this is a new issue, not sure how to spot it. :( probably better to wait for more cases to see how prevalent it is

[mat-hek]

Ok, I can help debugging further if you need ;) For now, is it possible to set LIVEBOOK_NODE and LIVEBOOK_DISTRIBUTION vars in the Livebook desktop?

[hugobarauna]

Ok, I can help debugging further if you need ;) For now, is it possible to set LIVEBOOK_NODE and LIVEBOOK_DISTRIBUTION vars in the Livebook desktop?

Yes, you can use the ~/.livebookdesktop.sh file to set env vars. More about that here: https://github.com/livebook-dev/livebook?tab=readme-ov-file#livebook-desktop

[mat-hek]

eh, when I set

export LIVEBOOK_DISTRIBUTION=name
export [email protected]

in ~/.livebookdesktop.sh, the application crashes on startup and this is logged:

2024-04-15 15:27:13.111801 
    args: []
    label: {error_logger,info_msg}
    format: "Can't set short node name!\nPlease check your configuration\n"
2024-04-15 15:27:13.111840 crash_report        
    initial_call: {net_kernel,init,['Argument__1']}
    pid: <0.64.0>
    registered_name: []
    error_info: {exit,{error,badarg},[{gen_server,init_it,6,[{file,"gen_server.erl"},{line,961}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,241}]}]}
    ancestors: [net_sup,kernel_sup,<0.47.0>]
    message_queue_len: 0
    messages: []
    links: [<0.61.0>]
    dictionary: [{longnames,false}]
    trap_exit: true
    status: running
    heap_size: 610
    stack_size: 28
    reductions: 348
2024-04-15 15:27:13.111851 supervisor_report   
    supervisor: {local,net_sup}
    errorContext: start_error
    reason: {'EXIT',nodistribution}
    offender: [{pid,undefined},{id,net_kernel},{mfargs,{net_kernel,start_link,[#{name=>'[email protected]',supervisor=>net_sup,name_domain=>shortnames,clean_halt=>true}]}},{restart_type,permanent},{significant,false},{shutdown,2000},{child_type,worker}]
2024-04-15 15:27:13.111874 supervisor_report   
    supervisor: {local,kernel_sup}
    errorContext: start_error
    reason: {shutdown,{failed_to_start_child,net_kernel,{'EXIT',nodistribution}}}
    offender: [{pid,undefined},{id,net_sup},{mfargs,{erl_distribution,start_link,[]}},{restart_type,permanent},{significant,false},{shutdown,infinity},{child_type,supervisor}]
2024-04-15 15:27:13.112463 crash_report        
    initial_call: {application_master,init,['Argument__1','Argument__2','Argument__3','Argument__4']}
    pid: <0.46.0>
    registered_name: []
    error_info: {exit,{{shutdown,{failed_to_start_child,net_sup,{shutdown,{failed_to_start_child,net_kernel,{'EXIT',nodistribution}}}}},{kernel,start,[normal,[]]}},[{application_master,init,4,[{file,"application_master.erl"},{line,142}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,241}]}]}
    ancestors: [<0.45.0>]
    message_queue_len: 1
    messages: [{'EXIT',<0.47.0>,normal}]
    links: [<0.45.0>,<0.44.0>]
    dictionary: []
    trap_exit: true
    status: running
    heap_size: 233
    stack_size: 28
    reductions: 167
2024-04-15 15:27:13.112438 Error in process ~p with exit value:~n~p~n
	<0.65.0>
	{badarg,[{erlang,send,[code_server,{code_call,<0.65.0>,{load_module,#Ref<0.1242819413.1615724547.207451>,logger_formatter,"/Applications/Livebook.app/Contents/Resources/rel/vendor/otp/lib/kernel-9.2/ebin/logger_formatter.beam",false,#Ref<0.1242819413.1615593475.207450>}}],[{error_info,#{module=>erl_erts_errors}}]},{code_server,call,1,[{file,"code_server.erl"},{line,150}]},{error_handler,undefined_function,3,[{file,"error_handler.erl"},{line,40}]},{logger_simple_h,'-do_log/2-fun-0-',1,[{file,"logger_simple_h.erl"},{line,154}]}]}
2024-04-15 15:27:13.112523 std_info            
    application: kernel
    exited: {{shutdown,{failed_to_start_child,net_sup,{shutdown,{failed_to_start_child,net_kernel,{'EXIT',nodistribution}}}}},{kernel,start,[normal,[]]}}
    type: permanent
Kernel pid terminated (application_controller) ("{application_start_failure,kernel,{{shutdown,{failed_to_start_child,net_sup,{shutdown,{failed_to_start_child,net_kernel,{'EXIT',nodistribution}}}}},{kernel,start,[normal,[]]}}}")

Crash dump is being written to: erl_crash.dump...done

LIVEBOOK_DISTRIBUTION=name [email protected] livebook server works

[jonatanklosko]

@mat-hek try RELEASE_DISTRIBUTION=name instead. We should be setting it based on LIVEBOOK_DISTRIBUTION, but looks like the app env.sh doesn't.

[mat-hek]

Now the app starts, but the original problem persists

[jonatanklosko]

@mat-hek please try nightly desktop with LIVEBOOK_DISTRIBUTION=name [email protected], I've just rebuilt it to include the fix from #2570.

[mat-hek]

Works now! Thanks ;)