moby/docs
Akihiro Suda 8493fb18ae
dockerd: fix rootless detection (alternative to #39024)
The `--rootless` flag had a couple of issues:
* #38702: euid=0, $USER="root" but no access to cgroup ("rootful" Docker in rootless Docker)
* #39009: euid=0 but $USER="docker" (rootful boot2docker)

To fix #38702, XDG dirs are ignored as in rootful Docker, unless the
dockerd is directly running under RootlessKit namespaces.

RootlessKit detection is implemented by checking whether `$ROOTLESSKIT_STATE_DIR` is set.

To fix #39009, the non-robust `$USER` check is now completely removed.

The entire logic can be illustrated as follows:

```
withRootlessKit := getenv("ROOTLESSKIT_STATE_DIR")
rootlessMode := withRootlessKit || cliFlag("--rootless")
honorXDG := withRootlessKit
useRootlessKitDockerProxy := withRootlessKit
removeCgroupSpec := rootlessMode
adjustOOMScoreAdj := rootlessMode
```

Close #39024
Fix #38702 #39009

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
(cherry picked from commit 3518383ed9)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2019-05-13 15:31:31 -07:00
..
api Merge pull request #38898 from tonistiigi/build-outputs 2019-03-19 14:00:16 -07:00
contributing change WindowsContainers.md to README.md 2019-04-09 16:11:54 +08:00
static_files Remove Docker logo 2017-10-11 13:17:59 +01:00
rootless.md dockerd: fix rootless detection (alternative to #39024) 2019-05-13 15:31:31 -07:00