# 202105

## [離散数学入門#0: グラフ理論へのイントロダクション，授業ガイダンス・基本的な用語の準備 - YouTube](https://www.youtube.com/watch?v=d0KPWURyFIs)

## [東大が無料公開している超良質なPython/Data Science/Cloud教材まとめ (随時更新) - Digital, digital and digital](https://digitaldigital.hatenablog.com/entry/2020/07/21/104040)

## [The Missing Semester of Your CS Education (日本語版) · the missing semester of your cs education](https://missing-semester-jp.github.io/)

## certbot x cloudflare de wildcard cert.
```
testuser@lab01:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.5 LTS"
testuser@lab01:~$ uname -a
Linux lab01 4.15.0-142-generic #146-Ubuntu SMP Tue Apr 13 01:11:19 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
testuser@lab01:~$
testuser@lab01:~/certbot-cloudflare$ mkdir certbot-cloudflare
testuser@lab01:~/certbot-cloudflare$ cd certbot-cloudflare
testuser@lab01:~/certbot-cloudflare$ mkdir data
testuser@lab01:~/certbot-cloudflare$ cd data
testuser@lab01:~/certbot-cloudflare/data$ echo "dns_cloudflare_email=<cloudflare_account_email>" > credentials
testuser@lab01:~/certbot-cloudflare/data$ echo "dns_cloudflare_api_key=<cloudflare_global_apikey>" >> credentials
testuser@lab01:~/certbot-cloudflare/data$ chmod 600 /root/.cloudflare/credentials
testuser@lab01:~/certbot-cloudflare/data$ cd ..
testuser@lab01:~/certbot-cloudflare$ docker run -it --rm --name certbot-cloudflare \
>             -v $PWD/data/etc:/etc/letsencrypt \
>             -v $PWD/data/var/lib:/var/lib/letsencrypt \
>             -v $PWD/data/credentials:/root/cloudflare.credentials \
>             certbot/dns-cloudflare certonly \
>             --dns-cloudflare \
>             --dns-cloudflare-credentials /root/cloudflare.credentials \
>             --dns-cloudflare-propagation-seconds 60 \
>             --email jp7fkf@gmail.com \
>             --server https://acme-v02.api.letsencrypt.org/directory \
>             -d *.jp7fkf.dev
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator dns-cloudflare, Installer None

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must
agree in order to register with the ACME server. Do you agree?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: Y

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Would you be willing, once your first certificate is successfully issued, to
share your email address with the Electronic Frontier Foundation, a founding
partner of the Let's Encrypt project and the non-profit organization that
develops Certbot? We'd like to send you email about our work encrypting the web,
EFF news, campaigns, and ways to support digital freedom.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: Y
Account registered.
Requesting a certificate for *.jp7fkf.dev
Performing the following challenges:
dns-01 challenge for jp7fkf.dev
Waiting 60 seconds for DNS changes to propagate
Waiting for verification...
Cleaning up challenges
Subscribe to the EFF mailing list (email: jp7fkf@gmail.com).

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/jp7fkf.dev/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/jp7fkf.dev/privkey.pem
   Your certificate will expire on 2021-08-15. 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
```
- renew
```
docker run -it --rm --name certbot-cloudflare \
            -v $PWD/data/etc:/etc/letsencrypt \
            -v $PWD/data/var/lib:/var/lib/letsencrypt \
            -v $PWD/data/credentials:/root/cloudflare.credentials \
            certbot/dns-cloudflare renew --dry-run
```

### References
- [Get Certbot — Certbot 1.15.0.dev0 documentation](https://certbot.eff.org/docs/install.html#running-with-docker)
- [Docker Hub](https://hub.docker.com/r/certbot/dns-cloudflare)
- [certbot+certbot-dns-cloudflare でワイルドカード証明書を取得&自動更新する - Qiita](https://qiita.com/ooxif/items/99ad3c93d4d6862d45f0)

## [Free Video Conferencing Software for Web & Mobile | Jitsi](https://jitsi.org/)

## Linux network tuning
- [カーネルパラメータ net.core.[rw]mem_{default,max} の意味を考えてみた - ablog](https://yohei-a.hatenablog.jp/entry/20101117/1289970302)
- [カーネルパラメタの設定および確認をする](http://itdoc.hitachi.co.jp/manuals/3000/3000650120/HSYG0053.HTM)
- [Linuxカーネルパラメータのチューニング - Qiita](https://qiita.com/ryuichi1208/items/3bb7a270fe650b2f7260)
- [How to show dropped packets per interface on Linux - nixCraft](https://www.cyberciti.biz/faq/linux-show-dropped-packets-per-interface-command/)
- [パケットロスト、キュー/フレーム損失の改善 - suima8のメモ](https://suima8.hatenablog.com/entry/2020/12/21/110525)
- [第31章 ethtool オフロード機能の設定 Red Hat Enterprise Linux 8 | Red Hat Customer Portal](https://access.redhat.com/documentation/ja-jp/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/configuring-ethtool-offload-features_configuring-and-managing-networking)

## [Raima Database Manager - Wikipedia](https://en.wikipedia.org/wiki/Raima_Database_Manager)
- junosに入ってるDBM. [Smith Micro | Proven Solutions For A Mobile World](http://birdstep.com/)

## オーディオミュート回路
- [ねがてぃぶろぐ　逆さまトランジスタ2SC2878](http://gomisai.blog75.fc2.com/blog-entry-50.html)
- [ミュート用トランジスタって: new_western_elec](https://nw-electric.way-nifty.com/blog/2012/10/post-1600.html)
- [ミュート回路 - ligerarts ページ！](https://www.voltecher.com/2020/04/20/%E3%83%9F%E3%83%A5%E3%83%BC%E3%83%88%E5%9B%9E%E8%B7%AF/)

## [住友電線IVケーブルより線](https://www.monotaro.com/g/00348111/)
- KIV-LF-TAがアンテナワイヤとしてよい．
- [電気機器用ビニル絶縁電線 KIV | 日立金属（旧日立電線） | MISUMI-VONA【ミスミ】](https://jp.misumi-ec.com/vona2/detail/222005986396/)

## [５Ｖ出力昇圧ＤＣＤＣコンバーター: 組立キット 秋月電子通商-電子部品・ネット通販](https://akizukidenshi.com/catalog/g/gK-13065/)

## autossh on docker
```
version: '3'
services:
  ssh-to-docker-host:
    image: jnovack/autossh
    container_name: autossh-ssh-to-docker-host
    environment:
      - SSH_REMOTE_USER=remote_user
      - SSH_REMOTE_HOST=10.10.10.20
      - SSH_REMOTE_PORT=22
      - SSH_TARGET_HOST=10.10.10.10
      - SSH_TARGET_PORT=22
      - SSH_TUNNEL_PORT=12322
    restart: always
    volumes:
      - ~/.ssh/id_rsa:/id_rsa:ro
```
- 簡易バックドア的に使える

## [R8C/M12Aで鉛バッテリーパルス充電器を製作（サルフェーション除去）](https://kyoutan.jpn.org/uts/car/charger/)

## [GitHub で Squash merge されたブランチを削除する · ryym.log](https://ryym.tokyo/posts/delete-squash-merged-branch/)

## [Stoplight Studio の homebrew cask を作りました - TIM Labs](http://labs.timedia.co.jp/2019/10/stoplight-studio-homebrew-cask.html)
- [GitHub - not-an-aardvark/git-delete-squashed: Delete branches that have been squashed and merged into master](https://github.com/not-an-aardvark/git-delete-squashed)

## [MEF Reference Wiki - MEF Reference Wiki - MEF Wiki](https://wiki.mef.net/display/CESG/MEF+Reference+Wiki)

## [デュアル（ステレオ）２５０ｍＷオーディオ・パワーアンプＩＣ　ＬＭ４８８０: 半導体 秋月電子通商-電子部品・ネット通販](https://akizukidenshi.com/catalog/g/gI-10052/)

## [GitHub - monochromegane/go_design_pattern: Design patterns in Golang.](https://github.com/monochromegane/go_design_pattern)

## [スイッチング電源用ＩＣ　ＴＬ４９４Ｌ−Ｄ１６−Ｔ: 半導体 秋月電子通商-電子部品・ネット通販](https://akizukidenshi.com/catalog/g/gI-14056/)

## [Go言語でLet's EncryptのACMEを理解する | Taichi Nakashima](https://deeeet.com/writing/2015/12/01/go-letsencrypt-acme/)

## [GitHub - letsencrypt/boulder: An ACME-based certificate authority, written in Go.](https://github.com/letsencrypt/boulder/)

## [Ceph で分散ストレージをやってみた | 自鯖](https://jisaba.life/2021/05/15/post-1675/)

## [GNU M4 1.4.18 macro processor](https://www.gnu.org/savannah-checkouts/gnu/m4/manual/m4-1.4.18/m4.html)

## aironetで `Previous authentication no longer valid` が出る
- `Deauthenticating Station xxxx.xxxx.xxxx Reason: Previous authentication no longer valid` と出る．
  - どうやらapでaironet extentionが有効になっていると起きるっぽい．
  - `(config-if)# no dot11 extention aironet` するとdisableできる．
  - 実行時radioがup/downするので注意
- [Previous authentication no longer valid on WiFi – Cisco Aironet 1240AG – HeelpBook](https://www.heelpbook.net/2017/previous-authentication-no-longer-valid-on-wifi-cisco/)
- [CCIE Wireless: dot11 extension aironet](http://cciew.blogspot.com/2011/02/dot11-extension-aironet.html)
- [Cisco AironetでPacket to client xxxx reached max retries, removing the clientやPrevious authentication no longer validが頻繁に出るときの対処 | mipsparcのメモ帳](https://mipsparc.wordpress.com/2017/03/27/cisco-aironet%E3%81%A7packet-to-client-xxxx-reached-max-retries-removing-the-client%E3%81%A8previous-authentication-no-longer-valid%E3%81%8C%E9%A0%BB%E7%B9%81%E3%81%AB%E5%87%BA%E3%82%8B%E3%81%A8/)

## [GitHub - telekom-security/tpotce: 🍯 T-Pot - The All In One Honeypot Platform 🐝](https://github.com/telekom-security/tpotce)
- honeypot

## コンテナセキュリティ
- [GitHub - aquasecurity/trivy: A Simple and Comprehensive Vulnerability Scanner for Container Images, Git Repositories and Filesystems. Suitable for CI](https://github.com/knqyf263/trivy)
- [GitHub - goodwithtech/dockle: Container Image Linter for Security, Helping build the Best-Practice Docker Image, Easy to start](https://github.com/goodwithtech/dockle)
- [Security Issues in Popular Containers](https://containers.goodwith.tech/)
   - [DockerHubで公開されているコンテナが安全か確かめてみた結果【人気のコンテナ上位800個】 - Qiita](https://qiita.com/tomoyamachi/items/e0e69da521505e73237b)

## [3D Printable Jet Engine by Catiav5ftw - Thingiverse](https://www.thingiverse.com/thing:1327093)

## [Tiny Exit Sign with LED Light by tonyyoungblood - Thingiverse](https://www.thingiverse.com/thing:683132)

## [On Air Sign by klein0r - Thingiverse](https://www.thingiverse.com/thing:2847029)

## [Mercurial SCM](https://www.mercurial-scm.org/)

## [italki:言語をオンラインで学習する](https://www.italki.com/home?hl=ja)

## [オンライン英会話のネイティブキャンプ | 英会話7日間無料トライアル開催中](https://nativecamp.net/)

## [.terraform.lock.hcl 完全に理解した / How to update .terraform.lock.hcl efficiently - Speaker Deck](https://speakerdeck.com/minamijoyo/how-to-update-terraform-dot-lock-dot-hcl-efficiently?slide=53)