AWS Elastic Beanstalk .ebextensions config for single instance free SSL using letsencrypt certbot and nginx. http://bluefletch.com/blog/domain-agnostic-letsencrypt-ssl-config-for-elastic-beanstalk-single-instances/

AWS_Single_LetsEncrypt.yaml

# Dont forget to set the env variable "certdomain", and either fill in your email below or use an env variable for that too.
# Also note that this config is using the LetsEncrypt staging server, remove the flag when ready!

Resources:
  sslSecurityGroupIngress: 
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      GroupId: {"Fn::GetAtt" : ["AWSEBSecurityGroup", "GroupId"]}
      IpProtocol: tcp
      ToPort: 443
      FromPort: 443
      CidrIp: 0.0.0.0/0

files:

  # The Nginx config forces https, and is meant as an example only. 
  /etc/nginx/conf.d/000_http_redirect_custom.conf:
    mode: "000644"
    owner: root
    group: root
    content: |
      server {
        listen 8080;
        return 301 https://$host$request_uri;
      }

  # The Nginx config forces https, and is meant as an example only. 
  /etc/nginx/conf.d/https_custom.pre:
    mode: "000644"
    owner: root
    group: root
    content: |
      # HTTPS server
      server {
        listen       443 default ssl;
        server_name  localhost;
        error_page  497 https://$host$request_uri;
        
        ssl_certificate      /etc/letsencrypt/live/ebcert/fullchain.pem;
        ssl_certificate_key  /etc/letsencrypt/live/ebcert/privkey.pem;

        ssl_session_timeout  5m;
        ssl_protocols  TLSv1.1 TLSv1.2;
        ssl_ciphers "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH";
        ssl_prefer_server_ciphers   on;

        if ($ssl_protocol = "") {
          rewrite ^ https://$host$request_uri? permanent;
        }

        location ~ ^/(lib/|img/) {
          root /var/app/current/public;
          access_log off;
        }

        location / {
            proxy_pass  http://nodejs;
            proxy_set_header   Connection "";
            proxy_http_version 1.1;
            proxy_set_header        Host            $host;
            proxy_set_header        X-Real-IP       $remote_addr;
            proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header        Upgrade         $http_upgrade;
            proxy_set_header        Connection      "upgrade";
        }
      }

packages: 
  yum:
    epel-release: [] 

container_commands:
  10_installcertbot:
    command: "wget https://dl.eff.org/certbot-auto;chmod a+x certbot-auto"
  20_getcert:
    command: "sudo ./certbot-auto certonly --debug --non-interactive --email [email protected] --agree-tos --standalone --domains ${certdomain} --keep-until-expiring --pre-hook \"service nginx stop\" --staging"
  30_link:
    command: "ln -sf /etc/letsencrypt/live/${certdomain} /etc/letsencrypt/live/ebcert"
  40_config:
    command: "mv /etc/nginx/conf.d/https_custom.pre /etc/nginx/conf.d/https_custom.conf"

If I'm not mistaken, this is all it takes now:

.ebextensions
|_ 00_epel.config
|_ 01_AWS_Single_LetsEncrypt.config

00_epel.config

commands:
  add_epel_repo:
    command: "sudo yum install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm"
    test: "[ ! -e /tmp/add_epel_repo_run_once ] && touch /tmp/add_epel_repo_run_once || exit 0"
    ignoreErrors: true

01_AWS_Single_LetsEncrypt.config

Resources:
  sslSecurityGroupIngress:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      GroupId: { "Fn::GetAtt": ["AWSEBSecurityGroup", "GroupId"] }
      IpProtocol: tcp
      ToPort: 443
      FromPort: 443
      CidrIp: 0.0.0.0/0

packages:
  yum:
    epel-release: []

container_commands:
  01_certbot_install:
    command: "sudo yum install certbot python-certbot-nginx"
  02_certbot_generate_certs:
    command: "sudo certbot --agree-tos --non-interactive --domains ${CERT_DOMAINS} --email ${CERT_EMAIL} --nginx"
  03_certbot_auto_renew:
    command: "sudo certbot renew --dry-run"

This will not work, because container_commands runs before Elastic Beanstalk deploys and runs your application and the proxy server. So, the /etc/nginx/nginx.conf will be overridden.
The structure that works for me is shown below:

|-- .platform
|   -- hooks
|       -- postdeploy
|           -- ssl_setup_certbot.sh
|-- .ebextensions
|   -- ssl.config

The content of ssl_setup_certbot.sh:

#!/usr/bin/env bash

echo "Installing CERTBOT.."
CERT_DOMAIN=`/opt/elasticbeanstalk/bin/get-config environment -k CERT_DOMAIN`
CERT_EMAIL=`/opt/elasticbeanstalk/bin/get-config environment -k CERT_EMAIL`
sudo yum -y install certbot python-certbot-nginx
sudo certbot --agree-tos --non-interactive --domains ${CERT_DOMAIN} --email ${CERT_EMAIL} --nginx
sudo certbot renew --dry-run
echo "CERTBOT installed!"

The content of ssl.config:

Resources:
  sslSecurityGroupIngress:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      GroupId: { "Fn::GetAtt": ["AWSEBSecurityGroup", "GroupId"] }
      IpProtocol: tcp
      ToPort: 443
      FromPort: 443
      CidrIp: 0.0.0.0/0

packages:
  yum:
    epel-release: []

files:
  "/etc/cron.d/certbot_renew":
    mode: "000644"
    owner: root
    group: root
    content: |
      0 */12 * * * root /usr/bin/certbot -q renew --nginx
 
commands:
  add_epel_repo:
    command: "sudo yum install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm"
    test: "[ ! -e /tmp/add_epel_repo_run_once ] && touch /tmp/add_epel_repo_run_once || exit 0"
    ignoreErrors: true
    
   

CERT_DOMAIN and CERT_EMAIL is environment variable included in the eb environment.

Thanks @lucas-coelho, I'll test that out
I pretty much got exhausted and switched to CodeDeploy 😅

Hi @lucas-coelho.
I'm trying this your config in code but not run https.
can you tell me what config am i missing?