Debian / Ubuntu Linux 安裝套件的下載暫存路徑

Debian / Ubuntu Linux 預設 APT 下載的暫存目錄 /var/cache/apt

但是若有被修改，可以使用 apt-config 來查詢：

1. eval $(apt-config shell CACHE Dir::Cache)
2. eval $(apt-config shell ARCHIVES Dir::Cache::archives)
3. echo /${CACHE}/${ARCHIVES} # 可以看到完整路徑

Debian / Ubuntu Linux 安裝套件的下載暫存路徑

查詢暫存目錄指令：

• apt-config shell Cache Dir::Cache
• apt-config shell Cache Dir::Cache::Archives

在 Docker 安裝套件，在 Cache 資料夾都找不到任何東西，是因為 Docker 有個 docker-clean 設定不存 Cache

• cat /etc/apt/apt.conf.d/docker-clean
  # Since for most Docker users, package installs happen in "docker build" steps,
  # they essentially become individual layers due to the way Docker handles
  # layering, especially using CoW filesystems. What this means for us is that
  # the caches that APT keeps end up just wasting space in those layers, making
  # our layers unnecessarily large (especially since we'll normally never use
  # these caches again and will instead just "docker build" again and make a brand
  # new image).

  # Ideally, these would just be invoking "apt-get clean", but in our testing,
  # that ended up being cyclic and we got stuck on APT's lock, so we get this fun
  # creation that's essentially just "apt-get clean".
  DPkg::Post-Invoke { "rm -f /var/cache/apt/archives/.deb /var/cache/apt/archives/partial/.deb /var/cache/apt/.bin || true"; };
  APT::Update::Post-Invoke { "rm -f /var/cache/apt/archives/.deb /var/cache/apt/archives/partial/.deb /var/cache/apt/.bin || true"; };

  Dir::Cache::pkgcache "";
  Dir::Cache::srcpkgcache "";

  # Note that we do realize this isn't the ideal way to do this, and are always
  # open to better suggestions (https://github.com/debuerreotype/debuerreotype/issues).

• 想要留套件資料，把這個檔案砍掉即可：rm /etc/apt/apt.conf.d/docker-clean