How to Add Free SSL Certificate from LetsEncrypt via Certbot in your Java Tomcat / Tomee website?

Assumptions:

1. You are using Linux / Debian Server

2. You are using Compute Engine

3. You are using Google Domains

4. Set $JAVA_HOME=<path to your java base directory>

5. Set $CATALINA_BASE=<path to your Tomcat / Tomee base directory>

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Procedure:

1. Visit site https://certbot.eff.org/

2. In selection option, 

    a) My website running on <none of the above>

    b) Operating system using <as per your operating system>, <Debian 10 in my case>

3. Type command sudo apt-get install certbot

4. Type command sudo certbot certonly --standalone

5. Your certificate will be downloaded and installed in /etc/letsencrypt folder

6. Your certificate files are as follows:

/etc/letsencrypt/live/<your domain name>/cert.pem

/etc/letsencrypt/live/<your domain name>/chain.pem

/etc/letsencrypt/live/<your domain name>/fullchain.pem

/etc/letsencrypt/live/<your domain name>/privkey.pem

7. Change permissions of these file if needed as it have default root access only so that Tomcat/ Tomee user can acces them

8. Type command sudo nano $CATALINA_BASE/conf/server.xml

9. Provide following lines in server.xml

<Connector port="443" protocol="org.apache.coyote.http11.Http11NioProtocol"

               maxThreads="150" SSLEnabled="true" >

        <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />

        <SSLHostConfig>

            <Certificate certificateKeyFile="/etc/letsencrypt/live/<your domain name>/privkey.pem"

                         certificateFile="/etc/letsencrypt/live/<your domain name>/cert.pem"

                         certificateChainFile="/etc/letsencrypt/live/<your domain name>/chain.pem"

                         type="RSA" />

        </SSLHostConfig>

    </Connector>

10.  // restart tomc(at/ee) server

11. Check your working https:// website in your domain name

Work Done