Connection refused error with AWS + Hashicorp Vault - amazon-web-services

I have configured a Hashicorp Vault server on a EC2 instance. When trying to use postman to test transit secret engine API I keep getting a error connection refused on postman, I went full ape mode and opened all ports on the security group inbound rule and it didn't work, I attached an elastic IP to the instance and didnt work either, im just trying with a simple GET and I just keep getting the same connectionrefused error.
When I use cUrl on the ssh connected session i have no issues though. The specified hosted adress is 127.0.0.1:8200, in postman I replaced that localhost with the public adress of the instance that i obviously censored in the screencap, in the headers theres the token needed to access vault, for simplicity I was just using the root token.
Postman screecap if it helps

#Emilio Marchant
I have faced similar issue (not with postman, but with telnet), Let's try to understand problem here.
The issue is with 127.0.0.1 IP. This is loopback IP and When you (or your computer) call an IP address, you are usually trying to contact another computer on the internet. However, if you call the IP address 127.0.0.1 then you are communicating with the localhost – in principle, with your own computer.
Reference link : https://www.ionos.com/digitalguide/server/know-how/localhost/
What you can try is below.
Start vault dev server with --dev-listen-address parameter.
Eg:
vault server -dev -dev-listen-address="123.456.789.1:8200"
in above command replace '123.456.789.1:8200' with '<your ec2 instance private IP : 8200'>
Next set VAULT_ADDR and VAULT_TOKEN parameter as below
export VAULT_ADDR='http://123.456.789.1:8200'
export VAULT_TOKEN='*****************'
Again replace 'http://123.456.789.1:8200' with 'http://[Your ec2 instance private IP]:8200'
For Vault_token : you should get a root token in console, when you start vault server , use that token
Now try to connect from postman or using curl command. It should work.
Reference question and solution :
How to connect to remote hashicorp vault server

The notable thing here is that the response is "connection refused". This error means that the connection is getting established and it found that there are no processes running on that port. This error means that there is no issue with firewall. A firewall will cause the connection to either drop (reject) or timeout (ignore), but won't give "Econnrefused".
The most likely issue is that the vault server process is not bound to the correct network interface. There must be a configuration in hashicorp-vault to setup the IP on which to bind. Most servers, by default, bind only on loopback address which is accessible only from 127.0.0.1. You need to bind it to "all" network interfaces by changing that to 0.0.0.0. I am not aware of the specific configuration option of hashicorp vault, but there has to be something to this effect.
Possible security issue:
Note that some servers expect you to run it behind a reverse proxy so that you can setup SSL (https) and other authentication if needed. Applications like vault servers should not be publicly accessible on http without SSL.

Related

Sending Requests from postman to AWS ec2 instance

I have my ec2 instance running a docker image and id like to test the functionality of my routes with postman, however whenever I ping the ec2 public dns, it says connection refused. I have the security group opened up for all traffic from my machine and am running the postman desktop app. The example route I'm trying to hit is
https://{IP address here}.compute-1.amazonaws.com:6000/register
and I'm sending a post request with some json in it. All of this works fine on my local machine. Please tell me what I'm missing?
You can't use https:. Instead you must use http: as default EC2 instance url does not support HTTPS. For valid https, the easiest way is to setup ALB or set it up on an instance directly.

Deploying a Go app in AWS ec2 got connection refused

I have a compiled Go project that I want to deploy to an AWS EC2 instance. I just simply upload the application and run ./application on the remote server.
In the terminal, the application is running and says he's listening to localhost:3000.
I've already added the 3000 port to the security group.
However, when I tried to access it in my browser using <public-ip>:3000, it always shows connection refused, whether I've run the application or not.
I tried to run the app locally, it does work.
So is it because I deploy it incorrectly?
It is a bit difficult to help you because of no code being shared.
Some reasons why you got connection refused:
Your application is listening only localhost:3000
EC2 security group does not expose port 3000
How to fix:
Most applications are defining the host address on a config file or env variables. If you have access to change it, change it from localhost:3000 to 0.0.0.0:3000 to accepts connection from all IP or to your_ec2_public_ip:3000
If host address is hardcoded and you have access to code, change the code per above
If you don't have access to config or code to change the host address, then add a reverse proxy to route the incoming call to localhost:3000. This is a good link about using Nginx as reverse proxy https://docs.nginx.com/nginx/admin-guide/web-server/reverse-proxy/
Ensure EC2 Security Group allowing inbound connection for the designated port, in this case, is 3000 if you manage to route the incoming to your_ip:3000

DataPusher is unable to connect to CKAN 2.8

DataPusher is not working with my CKAN 2.8 install. I have DataPusher and CKAN on the same VPS (an Amazon EC2 instance). I cannot curl /api/3/action/resource_show from within the instance, but I can from outside it at the same IP address I can access the CKAN web gui from. I am using the default port settings/followed the official CKAN documentation for setting up CKAN and DataPusher/DataStore.
Upon checking the error logs (specifically datapusher.error.log in /var/log/apache2) the latest message is:
ConnectionError: HTTPConnectionPool(host='{ckan.site_url value, in this case the public IP of the instance}', port=80): Max retries exceeded with url: /api/3/action/resource_show (Caused by NewConnectionError('<requests.packages.urllib3.connection.HTTPConnection object at 0x7f3bb0151490>: Failed to establish a new connection: [Errno 110] Connection timed out',))
I had a similar issue but I used a different approach to solve it.
The system looks up DNS names in the /etc/hosts file before it goes to the external DNS server. I simply pointed my hostname (from the URL) to the local IP address like so:
172.16.22.2 ckan.installation.url
This way, the server connects to itself when it needs to reach ckan.installation.url and users connect to ckan.installation.url (public facing IP) when they need to access the site.
Ultimately the issue is that with an AWS EC2 VPS, your Ubuntu instance is not aware of its public-facing IP address, which is probably what you're using to reach the CKAN web gui hosted on said VPS.
Ideally the CKAN API can be hit internally but I have been unable to do so with localhost/127.0.0.1 in place of the VPS's external/public-facing IP address. The issue with setting the ckan site_url to localhost is that is what you will be directed to from the CKAN web gui when attempting to use DataPusher (e.g. manually initiating upload of a resource to the DataStore). Your computer obviously won't know localhost refers to the CKAN dev server... So in short, the ckan site_url value must be something accessible by both DataPusher and people/devices on the public Internet (assuming you want your CKAN instance to be publicly-accessible).
The solution here is to open port 80 to the public IP address of the AWS EC2 instance in the inbound rules of the instance's security group. In other words, you are letting the instance hit itself at port 80. Seem inefficient, but I don't have an alternative at the moment. It's better than nothing!

unable to access localhost URL of AWS from local machine

I have a AWS EC2 instance running and I am supposed to access the localhost URL of the instance. Whenever I try the localhost:port/index.html URL I get a server not responding error. I tried using the public IP of the instance instead, but that failed. I configured AWS by exposing the particular port number for the inbound traffic (IP : 0.0.0.0/0) that did not work either. How should I configure so that I can access the URL?
If a service is running at localhost:45984 on an EC2 instance, you cannot access that server from your browser on your local machine unless you employ port forwarding.
Here's a good article that explains the different concepts:
https://help.ubuntu.com/community/SSH/OpenSSH/PortForwarding
I believe what you want is local port forwarding, where you set up a tunnel so that you can access "localhost:45984" on your EC2 instance from some port you specify on your Mac.

Connection getting refused to socket.io server on Amazon EC2

I have set up a a micro EC2 instance on AWS. Currently, I am using the free tier in Oregon. There are two problems which I am facing.
When I try to SSH the instance using the public DNS, it says host does not exist but when I try conencting it using the public IP, it connects to it. What setting is needed to use the public DNS ?
I have opened the SSH client using the IP address. I want to set up my application which needs Node.js and MongoDB. I installed Node.js using this
Next I installed MongoDB using this
Then I connected to my instance using Filezilla and uploaded my code to it. I then start my node application which uses socket.io.
When I try to connect to socket.io server using web browser, I get a message which says connection refused "error 111". I have opened TCP port 80 in instance's security groups. In iptables, I have forwarded port 80 to 8080, but still it does not work. I have also checked that the firewall is disabled in ec2. Kindly help me to resolve this issue.
Did you check if all of the necessary ports are open on Amazon Security Policy?
What you can do is to allow all traffic on Amazon Security Policy for test and see if the connection goes well or not.
You might also check if you need access DB from outside. In that case, you also have to open the mongodb port and setup mongodb correctly as well.
Other tools that might useful to test firewall and connection issue will be tcpdump and syslog file
For the dns issue, did you try to nslookup on that name and see if the IP shown matches your server IP?
As Amazon gives a long DNS hostname for the server, I always use my own domain name. It's much easier.
example : ec2.domainname.com, which points to the Amazon IP address
Hope that help.
My problem is resolved now..
For the DNS issue, earlier I needed proxy to access internet, so I guess the DNS name was not getting resolved. When I tried using proxy free internet, I was able to ssh using public DNS.
And regarding connection to socket.io, I used port 8080 instead of 80 and used "sudo node main.js" to run my node file. Now I am able to connect to the socket.io server and MongoDB.
Another thing which I want to ask is that would running the node file with sudo rights create some security issue ?
Thanks for the answer! That also worked for me. I had the same problem trying to connect through sockets (http://myipaddress:3000) to a node.js server, i tried opening ports on the actual ec2 instance and disabling the firewall through SSH but nothing worked. Had to go to Security Groups on the ec2 console and open a new inbound tcp rule enabling that port