Remove dependency from docker/pkg/systemd

Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com>
Merge pull request #159 from LK4D4/remove_docker_systemd_dep

Remove dependency from docker/pkg/systemd
Return NotFound error for cgroups abs paths

Signed-off-by: Michael Crosby <michael@docker.com>
Change not found error to be typed with cgroup subsystem

Signed-off-by: Michael Crosby <michael@docker.com>
Ignore not found erros in Paths

Signed-off-by: Michael Crosby <michael@docker.com>
Merge pull request #161 from crosbymichael/return-notfound-err

Return NotFound error for cgroups abs paths
user: refactor GetUser... and expose private functions

This patch refactors most of GetUserGroupSupplementaryHome and its
signature, to make using it much simpler. The private parsing functions
have also been exposed (parsePasswdFile, parseGroupFile) to allow custom
data source to be used (increasing the versatility of the user/ tools).

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
user: use struct values instead of pointers

This patch fixes the incorrect practice of using pointers to struct
values rather than using the struct values themselves when the struct
value memory is not intended to be shared.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
user: add unit tests for GetRunUser

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)