I want to create a custom tor circuit. I can get the list of relay nodes using get_network_statuses() of stem library, but I am not sure how whether a specific node can be used as guard node, middle node or exit node. Is there any way to identify that? If so, then how to do it.
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I am building custom node for my flow. The custom node is working properly and sending message/result to next node using node.send(msg); where node=this. It's working properly when I use this node only once. Incase if i use the same node in multiple places in same flow. it sends the message always to one(last) node. I think the script lost context of nodes. i.e., where to send the message. So, I want to replace node.sent(msg) to getnode(node_id).send(msg) so that it will always send the message to proper node. I am new to node red.So, please pardon if I failed to explain the problem. If you need more details, please let me know, i will add. Any hint would be appreciable.
That indicates a problem with how you have created your node.
The only way your node should be sending messages is by calling this.send(...).
In VS code there are two ways to launch the debug console for Node. One is “launch” which executes node and passes in your script. The script executes and node exits which i don’t want to happen. The other way is “attach”, this way you launch node yourself using --inspect then attach VS code to the debugger. Then I have to go to the node console and type “.load myscript”. This will keep the node console open after the script has finished.
What I want is to have ease of use of the “launch” method but keep the node console open at the end like the “attach” approach so I can then type further commands or view the contents of variables. There must be a way to do this but I can’t find out how. Can anyone advise how I could achieve this? I am even happy to only use the “launch” method if I could someone add a breakpoint at the end of code so that it would keep node open.
A node.js process will not exit as long as there are events pending. A simple way to do that at the end of your script is to start a server that does nothing:
net.createServer(()=>{}).listen(0)
Setting the port to 0 will cause the OS to give you a random available port so you don't need to think about what port to use.
This is generally safe if you are on a local network. However, if you are worried about other software connecting to your bogus server you can simply close all incoming connections upon receiving them:
net.createServer(x=>x.end()).listen(0)
I'm working on enabling cluster support in a project I'm working on. This question comes directly from a statement in the Nodejs docs on the cluster module:
from: https://nodejs.org/api/cluster.html#cluster_cluster
Please note that, on Windows, it is not yet possible to set up a named pipe server in a worker.
What exactly does this mean?
What are the implications of this?
From the docs, and other research I've done, the actual practical consequences to this limitation are not clear to me.
A process can expose a named pipe as a way to communicate with other interested parties - ie. an nginx server could expose a named pipe where all incoming requests would be sent (just an idea - I am not sure if nginx can even do that).
From Node.js process (not a cluster worker, though), you could then start an http server (or even a plain TCP server, for that matter) which listens for messages sent to this named pipe:
http.createServer().listen('\\.\pipe\nginx')
Docs for the .listen() method's signature are here, specifically this part is of interest:
Start a server listening for connections on a given handle that has already been bound to a port, a UNIX domain socket, or a Windows named pipe
However, as per the warning, this functionality is not available from a cluster worker, for reasons beyond my understanding.
Here is a relevant commit in Node.js which hints at this limitation. You can find it by opening the Markdown document for cluster, look at git blame and go further into history a bit until you arrive at the commit which introduces this note.
Normal interprocess communication is not affected by this limitation, so a cluster works just the same on Win32 as it does on Unix systems.
Note: Upon further thought, that nginx example is a bit misleading since a named pipe, to my understanding, cannot be used for stateful bidirectional communication. It's just one-way, ie. source->listener. But I do hope I conveyed the general idea behind the limitation.
Say I have a rest end point which when called starts a long running process server side e.g.
http://host/api/program/start
and I want to push any updates / output from that process from the server side to a client.
I'm thinking the rest call would return some sort of unique id which the client could then use when connecting to the websocket to only receive updates about that particular process.
I'd have to think about buffering the output / updates from the process to send to the client if they didn't connect before the first output from the process but irrespective of that, what would be the best way of achieving the socket data handling for this? Could I make use of the socket.io rooms / namespaces in some way?
If you really want to do it this way, I would suggest generating the ID via the initial start call, then passing that to the long running process as an argument. Then that process publishes all messages to that ID (which appropriate clients are listening to as well).
However, I would discourage you from going from this approach. There are plenty of ways to go about handling a child process in Node, so you might want to look into these options a little more so you don't end up dealing with zombie processes all over the place.
The first that comes to mind is ChildProcess. Another option would be something like WebWorker Threads. Either of these would be right in the vein of what (I think) you're trying to do, but allow you to maintain much more control over the child processes.
I'm developing a sort of Flash Operator Pannel for Asterisk but, with Node.js and Socket.io instead of depending of Flash.
I've polished the node server and the front end BUT I don't know how could I send events from Asterisk to node server and do things that will be sended over the socket.
Given the fact that we have a heavily tuned Asterisk to suit our company needs, connecting to the AMI nor the Asterisk socket will solve my problem because we aren't working with real extensions.
So, despite the Asterisk part, I want to know how could I send info to node through bash or curls or whatever
I thought about using curls to the server but this could cause that someone who knows the commands (pretty unlikely) could alter the application flow with unreal data.
EDIT: Rethinking about it, I would just want to be able to receive requests through the socket/server ??? and then be able to perform actions that will be emited through socket.io.
Is that even possible?
The answer really depends upon what specific data you are trying to get from Asterisk to Node. You're trying to replace the Flash Operator Panel, yet you don't have real extensions. I'm guessing that you are using Asterisk as an SBC/proxy of sorts.
If you truly want an event-driven approach, I suggest modifying your dialplan to reach out to Node whenever needed, with whatever data you want. This would most easily be achieved by calling an AGI script with some number of arguments (written in whatever language) that then connects to Node via an HTTP POST, socket, or other.
If you want a more passive approach, you could have Node stream-read the asterisk log files for data, or, as already suggested, connect to the Asterisk Manager Interface (AMI) and stream from there. Contrary to what has been stated previously, I don't consider this to be a very daunting task.
You want to open a socket from Node to Asterisk's AMI (asterisk manager interface). I never used Node, but I would imagine the code would look roughly like this:
var astman = new net.socket().connect(5038);//connect to port 5039 on localhost
astman.on('data', function(data) {
//do something with received data
});
One of the most well maintained ami libraries are FreePBX's php-astmanager. While it's written in php, it should give you a pretty good idea of what your need to do.
You could certainly set up your node.js program to listen on a socket for messages from Asterisk. But you'd have to roll your own connection management scheme, authentication scheme, message durability (possibly), etc.
Alternatively -- and especially if there is the node server and asterisk server are not on the same machine -- you could use a message queue program like RabbitMQ. That takes care of a lot of the important details involved in interprocess communications. It's pretty easy, too. On the node side, check out https://github.com/postwait/node-amqp
I've never used Asterisk but running command line programs can be done with the child_process module.
http://nodejs.org/docs/latest/api/child_processes.html