Yama's Memorandum

LetsEncrypt SSL 証明書の更新(2025/11/03 実施)

November 3, 2025 – 5:13 pm

LetsEncrypt SSLの有効期限が１週間後に迫ってきたので、いつもの更新作業をした。

この証明書の更新作業は、基本的にはcronによる自動更新することも可能だが、私の場合ワイルドカード証明書の更新をするため、DNSレコードの書き換えを更新の都度行う必要があるため手動による作業をおこなっている。

以下、更新時のLogを転記しておく：

[root@Server01 ~]# certbot certonly --manual
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Please enter the domain name(s) you would like on your certificate (comma and/or
space separated) (Enter 'c' to cancel): *.yamasnet.com
Renewing an existing certificate for *.yamasnet.com

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Please deploy a DNS TXT record under the name:

_acme-challenge.yamasnet.com.

with the following value:

cLllrumdCEUWZzLPw0njhtR618gZRQ2aVS_g54cqmYQ

Before continuing, verify the TXT record has been deployed. Depending on the DNS
provider, this may take some time, from a few seconds to multiple minutes. You can
check if it has finished deploying with aid of online tools, such as the Google
Admin Toolbox: https://toolbox.googleapps.com/apps/dig/#TXT/_acme-challenge.yamasnet.com.
Look for one or more bolded line(s) below the line ';ANSWER'. It should show the
value(s) you've just added.

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Press Enter to Continue

Successfully received certificate.
Certificate is saved at: /etc/letsencrypt/live/yamasnet.com/fullchain.pem
Key is saved at:         /etc/letsencrypt/live/yamasnet.com/privkey.pem
This certificate expires on 2026-02-01.
These files will be updated when the certificate renews.

NEXT STEPS:
- This certificate will not be renewed automatically. Autorenewal of --manual certificates requires the use of an authentication hook script (--manual-auth-hook) but one was not provided. To renew this certificate, repeat this same certbot command before the certificate's expiry date.

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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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httpd を restartし、更新作業を反映：

[root@Server01 ~]# systemctl restart httpd

証明書が更新されたことを確認：

[root@Server01 ~]# certbot certificates
Saving debug log to /var/log/letsencrypt/letsencrypt.log

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Found the following certs:
  Certificate Name: yamasnet.com
    Serial Number: 5919adcacd2cf89f18c7b598af9894ba0fb
    Key Type: ECDSA
    Domains: *.yamasnet.com
    Expiry Date: 2026-02-01 06:50:36+00:00 (VALID: 89 days)
    Certificate Path: /etc/letsencrypt/live/yamasnet.com/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/yamasnet.com/privkey.pem
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