Kotlang Services Deployment

This repository contains the deployment files for the Kotlang services. Below deployment lets us deploy any number of services and protocols (HTTP/2, HTTP/1.1, HTTPS) behind a single load balancer. Thus, we can deploy multiple services with their gRpc and web proxy version together.

Below deployment constitutes services and routing in a single node. We can deploy the services in multiple nodes by using a load balancer on top of nginx routing of single node.

File Details

• docker-compose.yml - The docker compose file for the services. This file is used to deploy the services on a single machine.

In docker-compose an independent network is created. One service can call another service by using the service name as the hostname. For example, the socialGo service can call the authGo service by using the hostname authGo. These calls happen over the internal network created by docker-compose and doesn't require any port mapping. This reduces the complexity of the deployment and number of hops required to make a call.

• nginx.conf - The nginx configuration file. This file is used to configure the nginx server. The nginx server is used to route the requests to the appropriate service. It uses sub-domain based routing. For example, the socialGo service is available at social.neptune.co.

Only ports of the nginx server are exposed to the outside world.

Deployment:

docker compose up -d

Stopping services:

docker compose down

LetsEncrypt and Certbot

LetsEncrypt provides free SSL certificates. Certbot is a tool to automate the process of getting and renewing the SSL certificates. Certbot is used to get the SSL certificates for the sub-domains. The certificates are stored in the certs directory. The certificates are renewed automatically by certbot.

nginx and certbot interact with each other through shared volumes.

Certbot command to get certificate:

root@kotlang-ubuntu:~/kotlang-cluster# docker compose run --rm  certbot certonly --webroot --webroot-path /var/www/certbot/ -d *.navachar.co
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Requesting a certificate for navachar.co

Successfully received certificate.
Certificate is saved at: /etc/letsencrypt/live/navachar.co/fullchain.pem
Key is saved at:         /etc/letsencrypt/live/navachar.co/privkey.pem
This certificate expires on 2023-03-16.
These files will be updated when the certificate renews.

NEXT STEPS:
- The certificate will need to be renewed before it expires. Certbot can automatically renew the certificate in the background, but you may need to take steps to enable that functionality. See https://certbot.org/renewal-setup for instructions.

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If you like Certbot, please consider supporting our work by:
 * Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
 * Donating to EFF:                    https://eff.org/donate-le
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docker compose run enables us to run individual commands in a service. The --rm flag removes the container after the command is executed.

Renew certificate using:

docker compose run --rm certbot renew