I have just recieve SSL certificate from Letsencrypt and I want to use it with GKE Ingress. I was using self-signed certificate before and I am a bit confused about file names of my certificates. Here is what i have in /etc/letsencrypt/live/DOMAIN_NAME folder (description from the README):

• privkey.pem : the private key for your certificate.
• fullchain.pem: the certificate file used in most server software.
• chain.pem : used for OCSP stapling in Nginx >=1.3.7.
• cert.pem : will break many server configurations

And here is what i had before, the keys was created with openssl command below:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ssl.key -out ./ssl.crt
openssl dhparam -out ./ssl.pem 2048

• ssl.crt
• ssl.key
• ssl.pem

My question is - which files from the letsencrypt folder should I use?

• ssl.crt -> ?
• ssl.key -> ?
• ssl.pem -> ?