How to reach a webserver via fargate? - amazon-web-services

I have created a webpage with clojure and it works perfectly on ec2 on port 8555 with ssl. It also works in the docker container in the same ec2 machine.
It does not work in a fargate container in front of an nlb. I have my dns on the load balancer. The private ip of the running container is also healthy and the security group has an inbound rule for 8555
If i invoke the site: https://www.doppelkopf.me:8555
Secure Connection Failed
An error occurred during a connection to www.doppelkopf.me:8555. SSL peer was unable to negotiate an acceptable set of security parameters.
Error code: SSL_ERROR_HANDSHAKE_FAILURE_ALERT
The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.
If i invoke without ssl, i get at least an encrypted hello world:
http://www.doppelkopf.me:8555
Does ssl need to initiate a connection as well? Do i maybe need nat-gateway? My certicate is in my container.

I do not know why, but this suddenly worked, when i changed the port from 8555 to 443 with ssl.

Related

amqplib & AWS MQ: Socket closed abruptly during opening handshake

So the current issue I have is that before I was able to connect properly to my rabbitMQ cluster that was hosted on AWS MQ. After I changed its IP visibility to private I had to create some configuration to access the cluster from outside the VPC.
Current example of how the cluster is accessed:
mq.example.com -> Load balancer (w/target group to cluster host IP & TLS port 5671) in public VPC -> Cluster in private VPC.
I've done the same thing for the web console. Now the web console works perfectly, so the issue isn't necessarily with the load balancing or a certificate issue. I then checked out if the issue could be with the code I wrote, but that is also not the case since sometimes from inside the services it connects, but sometimes it then doesn't. It throws the error: "Socket closed abruptly during opening handshake".
I think I believe where the issue may arise from, however I don't really have a proper view on how to solve it. I believe the issue has to do with the fact that the service has go through the load balancer first before it can connect to the rabbit cluster. I just don't know what to do about it and most documentation on amqplib is obscure as it is. I haven't found any (documented) similar issue with AWS MQ & a load balancer.
So my question, specifically is: How would I be able to resolve the fact that sometimes my services connect and don't connect to the cluster when they go through the load balancer?
Good to know: I use AWS MQ for rabbit, amqplib for the client connection, amqps as the protocol, web console works with the same setup but services don't.
For people who run into this issue later on I have found a solution:
When creating a Network Load Balancer to route traffic to your cluster you have to assign it a target group. Make sure to NOT DO THIS: Do not register both port 5671 (amqps) and 443 (web console) to the same target group. During routing issues will arise like this.
Instead do the following:
Create two target groups on aws EC2:
TG1: Register: TLS - 443 (web console)
TG2: Register: TLS - 5671 (amqps)
Your NLB that is configured to simple routing & alias for IPV4 connections then needs the following listeners:
Listener 1: TLS - 443 and assign it to TG1
Listener 2: TLS - 5671 and assign it to TG2
This should then make sure whenever you connect there is no confusion for the microservice you're trying to connect to the cluster.
You can then connect to your web console with your subdomain:
eg. webconsole.example.com
and to your services: eg. amqps://cluster.example.com:5671 as host (how your host is formatted depends on the library you're using for the clientside)

Connection refused error with AWS + Hashicorp Vault

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.

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

Curl the webpage hosted on the same EC2 instance not working

I have the web application hosted on EC2 instance and created the DNS for it. The web page works fine when I hit the URL in browser. However, when I curl the URL from EC2 instance, there is no response or rather getting connection error.
curl: (7) Failed connect to dnsurl.com:80; Operation now in progress
Also, in my web application, I am calling a servlet inside another servlet using Apache Post method. This is not working as well. The same code works fine on non-EC2 servers.
Not working:-
curl dnsurl.com
curl elburl.com
Working:-
Curl to other http urls are working fine from EC2 instance
curl http://www.w3schools.com/Tags/ref_urlencode.asp
Your URLs are resolved to the public IP addresses. So the request goes outside your EC2 instance. For that to work you need the following:
Your security group should allow outbound traffic on port 80.
Your network ACL should allow outbound traffic on port 80.
Opening the ALB (Application Load Balancer) to allow inbound traffic from the EC2 instance on port 80 has resolved the issue.

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