Mystery failure accessing local server web pages

[scripting]

I'm having a problem accessing services on the same server.

When making a request from a Node.js process of a process running on the same server, I get an ECONNREFUSED. This has happened on two servers. The code used to work. It's part of my serverMontir app.

Then I tried accessing the server through the CURL command line utility and it also failed.

Yet if I access the same address from another computer, it works.

WTF is going on?

[tedchoward]

Can you share some sample code?

[scripting]

Ted in this case I think the problem has more to do with the system, rather than language, because CURL showed the same behavior as the node app.

Here's a screen shot of a terminal session where I show the source of the test app, the result of running it, and the curl call.

[scripting]

The server is on http://digitalocean.com

[theboxfactory]

Dave I think your correct it's configuration issue, not code.

What does a 'ping likes.scripting.com' on the server command line return?

Do you have an entry for 'likes.scripting.com' in your server hosts file?

[scripting]

[scripting]

I don't modify my server hosts file.

Also that's just one example, all the other sites on the same server return ECONNREFUSED.

And when I run it on another server, it fails to connect with servers running on that server, and works fine with the apps running on this server.

[tedchoward]

This is a tough one. I have a digital ocean server, where I run river5.

As you see, I can curl that server from that server.

So, what is different between our two environments?

[tedchoward]

How do you run your node apps on digital ocean? Are they running as a daemon? Do you use a process manager?

[tedchoward]

I'm using pm2 to run river5 as a background process.

ted@river5 in ted/
› pm2 list
┌────────┬────┬────────┬────────┬────────┬─────┬────────┬───────────┐
│ Name   │ id │ mode   │ status │ ↺      │ cpu │ memory │
├────────┼────┼────────┼────────┼────────┼─────┼────────┼───────────┤
│ river5 │ 0  │ 0.5.15 │ fork   │ online │ 1   │ 0.3%   │ 72.0 MB   │
└────────┴────┴────────┴────────┴────────┴─────┴────────┴───────────┘
 Use `pm2 show <id|name>` to get more details about an app

[scripting]

I use forever.

…

On Wed, Feb 27, 2019 at 5:04 PM Ted Howard ***@***.***> wrote: I'm using pm2 <https://github.com/Unitech/pm2> to run river5 as a background process. ***@***.*** in ted/ › pm2 list ┌────────┬────┬────────┬────────┬────────┬─────┬────────┬───────────┐ │ Name │ id │ mode │ status │ ↺ │ cpu │ memory │ ├────────┼────┼────────┼────────┼────────┼─────┼────────┼───────────┤ │ river5 │ 0 │ 0.5.15 │ fork │ online │ 1 │ 0.3% │ 72.0 MB │ └────────┴────┴────────┴────────┴────────┴─────┴────────┴───────────┘ Use `pm2 show <id|name>` to get more details about an app — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#110 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABm9O7WouEw91Ei2N0tYqH8eAGh5m3Gaks5vRwDRgaJpZM4bVACp> .

[brentashley]

if you do
netstat -an | grep LISTEN
you will see what address(es) your http(s) ports are bound to. If they are bound to the external address only, they will not be listening on localhost (127.0.0.1), but if they are bound to 0.0.0.0 they are listening on all interfaces.

also, using ping, dig and nslookup can give you an idea whether different machines see themselves and other machines by different addresses.

[scripting]

I'm not calling them over localhost or 127.0.0.1 -- I'm using their external name.

…

On Thu, Feb 28, 2019 at 8:47 AM Brent Ashley ***@***.***> wrote: if you do netstat -an | grep LISTEN you will see what address(es) your http(s) ports are bound to. If they are bound to the external address only, they will not be listening on localhost (127.0.0.1), but if they are bound to 0.0.0.0 they are listening on all interfaces. also, using ping, dig and nslookup can give you an idea whether different machines see themselves and other machines by different addresses. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#110 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABm9O9d3y1G2-GVnmeQ1H8tTTJUfq45-ks5vR93ygaJpZM4bVACp> .

[brentashley]

If the machines use different DNS servers or have host entries, the external name could resolve differently. That is, if the machines hosts file has the name mapped to 127.0.0.1, that is what it will use rather than the external interface.

I'm wondering if this is a firewall issue on the host. Maybe its blocking a request originating from the localhost to port 80?