I'm trying to connect my reveal.js client and master presentations together using socket.io server.
I did all stuff, that Hakim Se describes on his github page, but socket.io still produces an error, while trying to connect to server.
GET http://0.0.7.156:8080/socket.io/1/?t=1393864538446 net::ERR_ADDRESS_UNREACHABLE
If change 0.0.7.156 to my local machine name, query succeds.
I think I has wrong settings of presentations, but could not understand how to fix them.
Client:
multiplex: {
secret: null,
id: 'a9e10bc1b02efafe',
url: 'localname:1948'
},
Master:
multiplex: {
secret: '13938623264068002486',
id: 'a9e10bc1b02efafe',
url: 'localname:1948'
},
My experience has been that if I use localhost:
url: 'localhost:1948',
Something inside of reveal.js breaks and transforms localhost internally to the "nonsense" address 0.0.7.156 (bonus points to whoever digs into the code and finds the reason for this, I sadly currently do not have the time). If I instead use 127.0.0.1:
url: '127.0.0.1:1948',
Everything works just fine, at least locally for testing.
You will need to change 127.0.0.1 to whatever host name you will use when deploying the slides later on though.
Hope this helps!
Related
So I made a react native app with nodeJS and in order to connect nodejs backend to react native frontend I had to create an endpoint like such:
app.post("/send_mail", cors(), async (req, res) => {
let {text} = req.body
var transport = nodemailer.createTransport({
host: "smtp.mailtrap.io",
port: 2525,
auth: {
user: "usertoken",
pass: "password"
}
})
await transport.sendMail({
from: "email#email.com",
to: "email2#email.com",
subject: "message",
html: `<p>${text}</p>`
})
})
and in react native frontend call function like that :
const handleSend = async() => {
try {
await axios.post("http://192.168.0.104:3333/send_mail", { //localhost
text: placeHolderLocationLatLon
})
} catch (error) {
setHandleSetError(error)
}}
and it works fine in the local environment. But in the google play store, this IP address doesn't work because it's my localhost ipv4. I tried to use localhost:3333, but that doesn't work too. I can't find anywhere described anything about what IP has to be used in the google play store. Does anyone know how I should make this endpoint? Thank you
You can't just host a service by yourself like that (typically your back-end). Well, you can but not with your knowledge level. It would be inefficient (as in you'd have to keep your computer up 24/7) and present security issues.
Does anyone know how I should make this endpoint?
Don't get me wrong, your endpoint is fine in itself. You're just lacking the networking part.
1) For testing purposes ONLY!
If this app is only for testing purposes on your end, and won't be part of a final product that'll be present on the Google Store, there's a way you can achieve this, called ngrok.
It takes your locally-running project and provides it a https URL anyone can use to access it. I'll let you read the docs to find out how it works.
2) A somewhat viable solution (be extremely careful)
Since ngrok will provide a new URL everytime you run it with your local project, it's not very reliable in the long term.
What you could do, if you have a static IP address, is registering a domain name and link it to your IP address, and do all the shenanigans behind it (figuring out how to proxy incoming traffic to your machine and project, and so on). But honestly, it's way too cumbersome and it implies that you have valuable knowledge when it comes to securing your own private network, which I doubt.
3) A long-lasting, viable solution
You could loan a preemptive machine on GCP and run your back-end service on it. Of course, you would still have to figure out some networking things and configs, but it's way more reliable than solution 2 and 1 if your whole app aims to be public.
Google gives you free credit (I think it's like 200 or 250€, can't recall exactly) to begin with their stuff, and running a preemptive machine is really cheap.
I'm trying to figure out how to set up my backend api (next.js/api) to the database (postgresql) that both are hosted by heroku.
Mediated by pg.pool, i set up with the following code.
const pool = new Pool(
{
connectionString: process.env.DATABASE_URL,
// ssl: {
// rejectUnauthorized: false,
// }
})
but returned by heroku with the following error:
sql_error_code = 28000 FATAL: no pg_hba.conf entry for host "122.180.247.11", user "u3idolso5k2v83", database "dc85788d13v9ej", SSL off
The error description is from:
https://help.heroku.com/DR0TTWWD/seeing-fatal-no-pg_hba-conf-entry-errors-in-postgres
EDIT: meant to post this link, Is it ok to be setting rejectUnauthorized to false in production PostgreSQL connections?
The authentication failed because the connection didn't use SSL encryption: (SSL off). All Heroku Postgres production databases require using SSL connections to ensure that communications between applications and the database remain secure. If your client is not using SSL to connect to your database, you would see these errors even if you're using the right credentials to connect to it.
I find this strange, since heroku do provide ssl already to my server hoested by them by default, so its unexpected for such an error to occur at all?
The side step solution I've come across online is uncomment the ssl property in the connection...which works, but i feel uneasy with this one.
const pool = new Pool(
{
connectionString: process.env.DATABASE_URL,
ssl: {
rejectUnauthorized: false,
}
})
As mentioned briefly it is not safe from here: https://security.stackexchange.com/questions/229282/is-it-safe-to-set-rejectunauthorized-to-false-when-using-herokus-postgres-datab
I don't understand why this error occur at all, and how can it be fixed with proper security.
It's pretty standard for SSL certificates for Postgres servers to not be valid. Even official postgres clients don't validate the certificates. The library you are using defaults to validating certificates, but is very much in the minority.
When setting this up for https://www.atdatabases.org/docs/pg-options I made it not validate certificates by default to match the standard behaviour for Postgres.
This lets you create a connection pool for heroku using simply:
import createConnectionPool from '#databases/pg';
createConnectionPool(process.env.DATABASE_URL);
As described in your linked-to answer, you can upgrade to one of Heroku's paid products which does support this. Or you can stop using Heroku. Or you can put up with the incredibly low risk that someone will MITM you.
I don't understand why this error occur at all,
What about it do you not understand? The explanation you linked to seems pretty clear. If you cannot formulate your uncertainty any more clearly than you have so far, how can anyone help you understand?
This is the extension of my last question here:
socket.io always has connection false
For now, I have two servers deployed in two different domain names. The first server works perfectly fine with socket.io, so I redeployed the server to the new domain name by simply pull the same branch from GitHub, install everything and run it. And then I found that all my socket.io connections failed and the symptom is exactly the same as last time: connection always 'false' and disconnection always 'true'.
This time I am pretty sure it is not related with cors, because I tried io.origins((origin, cb) => if (whitelist.includes(origin)) { cb(null, true) } else { cb('failed', false) ) and it shows the origin is allowed.
I also tried cors: { origin: '*' } and that also doesn't work.
Strangely, despite the fact that they are using the same code, connecting to the first domain name works perfectly fine. But the second one has the issue.
UPDATE:
I use this to track the error message.
this.socket.on('connect_error', function(err) {
console.log(`connect_error due to ${err.message}`);
});
And this is what is returned:
connect_error due to server error
In the mean time, on server side I can see nothing other than the new connections being created and being disconnected due to ping timeout.
Where can I find more information to help me debug?
Turns out I forgot to run npm i after deploying to a new domain name. The version of socket.io wasn't updated and caused that issue.
Everyone who sees this, just make sure you have updated the package before you give up on debugging.
OK this is very simple to anyone who's used websocket and nodejs.
I have created a websocket server named ws_server.js and put it in C:\Program Files (x86)\nodejs where I have installed the nodejs framework. I started the server and it is running and it says it's listening on port 8080. So far so good, I have the server running.
Now I simply want to connect to it from client code so that I can do all that lovely stuff about capturing events using event listeners etc. The problem is, embarassingly, I cannot figure out what URL to use to connect to my websocket server.
function init() {
testWebSocket();
}
function testWebSocket() {
websocket = new WebSocket("ws://localhost:8080/"); // WHAT URL SHOULD BE USED HERE?
websocket.onopen = function(evt) { alert("OPEN") };
websocket.onclose = function(evt) { alert("CLOSE") };
websocket.onmessage = function(evt) { alert("MESSAGE") };
websocket.onerror = function(evt) { alert("ERROR") };
}
function doSend(message) {
// this would be called by user pressing a button somewhere
websocket.send(message);
alert("SENT");
}
window.addEventListener("load", init, false);
When I use ws://localhost:8080 the only events that trigger are CLOSE and ERROR. I cannot get the client to connect. I must be missing something very simple. Do I need to set up my nodejs folder in IIS for example and then use that as the URL?
Just to reiterate, the websocket server is running fine, I just don't know what URL to use to connect to it from the client.
EDIT: The websocket server reports the following error.
Specified protocol was not requested by the client.
I think I have got it working by doing the following.
var websocket = new WebSocket("ws://localhost:8080/","echo-protocol");
The problem being that I needed to specify a protocol. At least now I get the onopen event. ...if nothing much else
I was seeing the same error, the entire web server goes down. Adding the protocol fixes it but leaves me wondering why it was implemented this way. I mean, one bad request should not bring down your server.
You definitely have to encase it a try/catch, but the example code provided here https://www.npmjs.com/package/websocket (2019-08-07) does not. This issue can be easily avoided.
I just wanted to share a crazy issue that I had. I was able to connect to a websocket of an old version of a 3rd party app in one computer, but not to a newer version of the app in another.
Moreever, even in new computer with the new version of the app, The app was able to connect to the websocket, but no matter what I did, when I tried to connect with my own code, I kept getting the error message that the websocket connection failed
Long story short, They changed an apache configuration that allowed connecting to the websocket via a proxy.
In the old version, apache config was:
ProxyPass /socket/ ws://localhost:33015/ retry=10
ProxyPass /socket ws://localhost:33015/ retry=10
In the new version, apache config was changed to:
ProxyPass /socket/ ws://localhost:33015/ retry=10
By bad luck, I was trying to connect to ws://localhost/socket and not to ws://localhost/socket/. As a result, proxy was not found, and connection returned an error.
Moral of the story: Make sure that you are trying to connect to a websocket url that exists.
For me, the solution was to change the URL from ws:// to wss://. This is because the server I was connecting to had updated its security, and now only accepted wss.
I'm currently at y-hack, hacking up an app. I've never deployed an app to a server before, but I've managed to create an AWS EC2 instance, I created ca certificates with startssl, and now I'm trying to retrieve information using the DropBox API.
My code works on my local machine just fine, but I keep getting a 400 Bad Request Error when I try to use the code on my server. Here's what my options look like:
var options = {
key: fs.readFileSync('./cred/ssl.key'),
cert: fs.readFileSync('./cred/ssl.crt'),
ca: [fs.readFileSync('./cred/sub.class1.server.ca.pem')]
}
And my server looks like:
https.createServer(options,app).listen(443, function(){
console.log('Express server listening on port ' + 443);
});
When I try authenticating I use the built-in dropbox javascript client and call:
var server = new Dropbox.AuthDriver.NodeServer(500);
All my ports are open and I'm able to access my website with HTTPS. I've verified that my SSL certificate is okay, but every time I make a request from my micro instance to DropBox, the page hangs. I tried:
curl https://www.dropbox.com/1/oauth2/authorize?client_id={client_id}&redirect_uri=https%3A%2F%2Fsimplestever.com%3A8912%2Foauth_callback/&response_type=code/&state={state}
And I get this as a response (forgive the formatting):
Error (400)
It seems the app you were using submitted a bad request. If you would like to report this error to the app's developer, include the information below.
More details for developers
Missing "response_type".
=====================
I'm very new to this all and only taught myself today. I never used curl before... If anyone has any idea why I'm having these issues with the request, it would be incredibly helpful! Cheers!
Edit: I curled with the escaped characters and it worked! ...which means the client may be broken? I'll replace it with a query and forget about the csrf variable for now to see if it works.
Edit2: I ended up writing the authentication request using the request module and it worked! Just in the nick of time. Cheers!
Edit3: I should give credit to the code I imitated. https://github.com/smarx/othw/blob/master/Node.js/app.js
I think the issue with your curl command is that it has unescaped ampersands. Try putting quotes around the whole URL.