Setting Up a Golang Web Server on EC2 with a Free SSL Cert and No Load Balancer

EC2 Instance Setup

Create a new EC2 instance. This example was done on amazon-linux but I think it would probably be better to use ubuntu next time.

If you do use ubuntu note that you’ll need to use apt instead of yum and will likely have to open ports 80 and 443 on the instance.

All instance types will need to have ports 443 and 80 opened via your linked security group.

Creating the backend domain

I have purchased a domain name from namecheap (~$1.50/yr). To get it this cheap it needs to be 6-10 numbers only with the xyz extension.

To manage dns via route53 we create a new hosted zone and then add the following nameservers on namecheap’s dns manager:

ns-596.awsdns-10.net.
ns-348.awsdns-43.com.
ns-1820.awsdns-35.co.uk.
ns-1429.awsdns-50.org.

We then create a subdomain called mysite1.1234567892.xyz and point it to the EC2 instance’s public IP in route53 19.100.124.17 (as an A record). This will be used for the certificate as well.

Nginx

Installation, note that if using the ubuntu you will need to use apt instead of yum.

sudo yum update
sudo yum install nginx

Verify that its running with systemctl status nginx

Create the configuration:

  • Create a new directory called sites-enabled: sudo mkdir /etc/nginx/sites-enabled
  • Edit the http block using sudo nano /etc/nginx/nginx.conf and add this line: include /etc/nginx/sites-enabled/*;
  • Create the configuration file: sudo nano /etc/nginx/sites-enabled/1234567892

Add the following values to the config file:

server {
  listen 80;
  server_name mysite1.1234567892.xyz;
  location / {
    proxy_set_header  X-Real-IP  $remote_addr;
    proxy_set_header  Host       $http_host;
    proxy_pass        http://127.0.0.1:4800;
  }
}

server {
  listen 80;
  server_name mysite2.1234567892.xyz;
  location / {
    proxy_set_header  X-Real-IP  $remote_addr;
    proxy_set_header  Host       $http_host;
    proxy_pass        http://127.0.0.1:4500;
  }
}

Restart nginx with sudo systemctl restart nginx. Check status again with: systemctl status nginx. To test, go to http://19.100.124.17/ and be sure that it showing as http, not https. Accessing the full http url http://mysite1.1234567892.xyz/ will give a bad gateway error until the application is deployed.

Setup Golang

Here are the steps to install GoLang on an Amazon Linux EC2 instance:

  1. First, connect to your EC2 instance using SSH.
  2. Once connected, update the package lists for upgrades and new package installations: sudo yum update -y
  3. Download the GoLang package. You can find the URL of the latest version on the official website: wget https://golang.org/dl/go1.22.3.linux-amd64.tar.gz
  4. Extract it: sudo tar -C /usr/local -xzf go1.22.3.linux-amd64.tar.gz
  5. Set the Go environment variables. Add these lines to the /etc/profile file (or to the specific user’s profile, like ~/.bash_profile or ~/.bashrc):
    export PATH=$PATH:/usr/local/go/bin
    export GOPATH=$HOME/go
    export PATH=$PATH:$GOPATH/bin
  6. Source the profile: source /etc/profile
  7. Check it installed correctly: go version

Add and then run the following go script on your EC2 instance:

package main

import (
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
)

func getRoot(w http.ResponseWriter, r *http.Request) {
	fmt.Printf("/ request\n")
	io.WriteString(w, "Website #1!\n")
}
func getPing(w http.ResponseWriter, r *http.Request) {
	fmt.Printf("got /ping request\n")
	io.WriteString(w, "pong HTTP!\n")
}

func main() {
	http.HandleFunc("/", getRoot)
	http.HandleFunc("/ping", getPing)

	err := http.ListenAndServe(":4800", nil)
	if errors.Is(err, http.ErrServerClosed) {
		fmt.Printf("server closed\n")
	} else if err != nil {
		fmt.Printf("error starting server: %s\n", err)
		os.Exit(1)
	}
}

You should then be able to see your application by visit your domain, for example http://mysite1.1234567892.xyz/. We haven’t setup ssl yet so make sure you’ve got http for the protocol.

Setting up SSL

Firstly, we need to setup letsencryt/certbot:

  1. sudo dnf install python3 augeas-libs
  2. sudo python3 -m venv /opt/certbot
  3. sudo /opt/certbot/bin/pip install --upgrade pip
  4. sudo /opt/certbot/bin/pip install certbot certbot-nginx
  5. sudo ln -s /opt/certbot/bin/certbot /usr/bin/certbot

Create a certificate: sudo certbot -n -d mysite1.1234567892.xyz --nginx --agree-tos --email your-email+mysite1@gmail.com

This will also add entries to /etc/nginx/sites-enabled/1234567892. You can also setup auto-renew : https://eff-certbot.readthedocs.io/en/latest/using.html#setting-up-automated-renewal

Your sites should now be accessible via https, for example: https://mysite1.1234567892.xyz/

Thanks to the following links for the info:
https://eff-certbot.readthedocs.io/en/latest/using.html#setting-up-automated-renewal
https://gist.github.com/rschuetzler/793f478fa656cca57181261a266ec127
https://www.digitalocean.com/community/tutorials/how-to-configure-nginx-as-a-reverse-proxy-on-ubuntu-22-04

CREATE_IN_PROGRESS when creating a certificate with CloudFormation

Hi everyone,

I ran into a bit of an issue today while creating a certificate with CloudFormation. After kicking the stack off it ended up hanging on a step to create a domain verification entry in Route 53.

I had used this script multiple times for creating a certificate for a subdomain, but this time I included an apex domain as well. In order to narrow things down a little further I checked out the certificate via the console:

While the subdomain had passed the apex domain was still sitting in pending. Surprisingly, in Route53 the record DID exist. In order to get things moving again I manually deleted the record and then clicked “Create records in Route 53”.

This re-created the record I’d just deleted, and after a couple of minutes the domain validation passed and then the certificate was created:

This was a bit of a weird one that I have been unable to reproduce. I’m not certain why the DNS validation ended up hanging but retriggering the process seems to have resolved it.

Note that there are other legitimate reasons why your deployment might be hanging at this step:

When you use the AWS::CertificateManager::Certificate resource in a CloudFormation stack, domain validation is handled automatically if all three of the following are true: The certificate domain is hosted in Amazon Route 53, the domain resides in your AWS account, and you are using DNS validation.

However, if the certificate uses email validation, or if the domain is not hosted in Route 53, then the stack will remain in the CREATE_IN_PROGRESS state. Further stack operations are delayed until you validate the certificate request, either by acting upon the instructions in the validation email, or by adding a CNAME record to your DNS configuration. For more information, see Option 1: DNS Validation and Option 2: Email Validation.

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-certificatemanager-certificate.html

AWS IoT – error in discovery certificate_verify_failed

Hi everyone,

I ran into the following error while using the AWS IoT python SDK:

Error in discovery!
Type: 
Error message: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:720)

It turns out that this was because I was using the wrong root certificate. In the documentation there are five certificates listed:

  • RSA 2048 bit key: VeriSign Class 3 Public Primary G5 root CA certificate
  • RSA 2048 bit key: Amazon Root CA 1
  • RSA 4096 bit key: Amazon Root CA 2
  • ECC 256 bit key: Amazon Root CA 3
  • ECC 384 bit key: Amazon Root CA 4

If you’re using the console to create the certificate and have already downloaded your device cert, public cert and private key you can use Amazon Root CA 1: https://www.amazontrust.com/repository/AmazonRootCA1.pem

As soon as that was added the error was resolved and I was able to move onto the next one. I found most of the info on the AWS forums but let me know if you have any questions: https://forums.aws.amazon.com/thread.jspa?threadID=286871

OpenSSL::PKey::RSAError Neither PUB key nor PRIV key:: nested asn1 error – Adaptive Payments Gem

Hey everyone,

I’ve been mucking around with PayPal for a while and decided to try out the adaptive_payments gem by Tommy Chheng. Unfortunately I ran into the following error:

OpenSSL::PKey::RSAError

Neither PUB key nor PRIV key:: nested asn1 error

It turns out that I’d simply skipped an important part of the readme file. The api_cert_file in the paypal_adaptive.yaml file should point to a file containing BOTH your paypal_cert_pem.txt and whatever your private key happens to be. This took an embarrassingly long time for me to figure out, so hopefully this will help some of you!


UPDATE
It turns out I still had this wrong, I was using the wrong certs. After sorting out a few more errors that I ran into after the one mentioned above I finally started getting a response from Paypal, unfortunately it was another error message:

Authentication failed. API credentials are incorrect

It turns out I was using the wrong certs. If you’ve run into the same problem you’ll need to go to Profile > Request API Credentials > Option 2 (Request API credentials to create your own API username and password.). Then download the cert and point to this.


UPDATE
Hey everyone, just another update to this. If you happened to be following the railscast on PayPal before attempting to use the gem, you may not get the option to download the certs mentioned above. To get around this, simply remove your existing certificates (Profile > API Access > Option 2 > Remove > Remove). You should now see the ‘Request API Certificate Option’.

Sorry about the confusing post, but there’s a *slight* chance it might be able to help someone else who runs into the same problem.
Cheers