This PR allows 'minio update' to not only shows update banner
but also allows for in-place upgrades.
Updates are done safely by validating the downloaded
sha256 of the binary.
Fixes#4781
- Add release-time conversion helpers
- Split GetCurrentReleaseTime() into two simpler functions.
- Avoid appending strings when assembling user-agent string.
- Reorder release info URLs to check the newer URLs earlier.
- Remove trivial low-level functions created solely for the purpose of
writing tests.
- Remove some unnecessary tests.
isDocker was currently reading from `/proc/cgroup` file. But
this file alone is rather not conclusive evidence. Docker
internally has `.dockerenv` as a special file which we should
use instead.
Fixes#4456
This change adopts the upstream fix in this regard at
https://go-review.googlesource.com/#/c/41834/ for Minio's
purposes.
Go's current os.Stat() lacks support for lot of strange
windows files such as
- share symlinks on SMB2
- symlinks on docker nanoserver
- de-duplicated files on NTFS de-duplicated volume.
This PR attempts to incorporate the change mentioned here
https://blogs.msdn.microsoft.com/oldnewthing/20100212-00/?p=14963/
The article suggests to use Windows I/O manager to
dereference the symbolic link.
Fixes#4122
