CentOS7でLet's Encryptを使って、SSL/TLSサーバ証明書を作成

環境

$ cat /etc/redhat-release
CentOS Linux release 7.5.1804 (Core)

cartbotをインストール

$ yum install certbot

証明書の発行

証明書の発行をします、インストールはしません certonly

$ certbot certonly --standalone -d mail.tsmsogn.work -m root@tsmsogn.work --agree-tos
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer None
Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for mail.tsmsogn.work
Waiting for verification...
Cleaning up challenges

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/mail.tsmsogn.work/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/mail.tsmsogn.work/privkey.pem
   Your cert will expire on 2018-12-26. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot
   again. To non-interactively renew *all* of your certificates, run
   "certbot renew"
 - 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

Let's Encryptの証明書の期限は90日間なので、renewする

$ certbot renew -q --deploy-hook "echo YES"

ここでは --deploy-hook を使って、更新が成功したときだけ YES しています

このようなものを cron などで動かしてやれば、証明書の自動更新 && サービスの再起動をできると思います

https://media.readthedocs.org/pdf/letsencrypt/latest/letsencrypt.pdf

--pre-hook and --post-hook hooks run before and after every renewal attempt. If you want your hook to run only after a successful renewal, use --deploy-hook in a command like this.

トラブルシューティング

$ certbot certonly --standalone -d mail.tsmsogn.work -m root@tsmsogn.work --agree-tos
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer None
Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for mail.tsmsogn.work
Cleaning up challenges
Problem binding to port 80: Could not bind to IPv4 or IPv6.

standalone？モードだと 80ポートが空いてないと、ダメらしい

docker が動いていたので、一旦停止*1

*1:本番環境のサーバだとどうやって入れるのだろう