idtools

Documentation

Index

• func AddNamespaceRangesUser(name string) (int, int, error)
• func CreateIDMappings(username, groupname string) ([]IDMap, []IDMap, error)
• func GetRootUIDGID(uidMap, gidMap []IDMap) (int, int, error)
• func MkdirAllAs(path string, mode os.FileMode, ownerUID, ownerGID int) error
• func MkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int) error
• func ToContainer(hostID int, idMap []IDMap) (int, error)
• func ToHost(contID int, idMap []IDMap) (int, error)
• type IDMap

Functions

func AddNamespaceRangesUser

func AddNamespaceRangesUser(name string) (int, int, error)

AddNamespaceRangesUser takes a name and finds an unused uid, gid pair and calls the appropriate helper function to add the group and then the user to the group in /etc/group and /etc/passwd respectively. This new user's /etc/sub{uid,gid} ranges will be used for user namespace mapping ranges in containers.

func CreateIDMappings

func CreateIDMappings(username, groupname string) ([]IDMap, []IDMap, error)

CreateIDMappings takes a requested user and group name and using the data from /etc/sub{uid,gid} ranges, creates the proper uid and gid remapping ranges for that user/group pair

func GetRootUIDGID

func GetRootUIDGID(uidMap, gidMap []IDMap) (int, int, error)

GetRootUIDGID retrieves the remapped root uid/gid pair from the set of maps. If the maps are empty, then the root uid/gid will default to "real" 0/0

func MkdirAllAs

func MkdirAllAs(path string, mode os.FileMode, ownerUID, ownerGID int) error

MkdirAllAs creates a directory (include any along the path) and then modifies ownership to the requested uid/gid. If the directory already exists, this function will still change ownership to the requested uid/gid pair.

func MkdirAs

func MkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int) error

MkdirAs creates a directory and then modifies ownership to the requested uid/gid. If the directory already exists, this function still changes ownership

func ToContainer

func ToContainer(hostID int, idMap []IDMap) (int, error)

ToContainer takes an id mapping, and uses it to translate a host ID to the remapped ID. If no map is provided, then the translation assumes a 1-to-1 mapping and returns the passed in id

func ToHost

func ToHost(contID int, idMap []IDMap) (int, error)

ToHost takes an id mapping and a remapped ID, and translates the ID to the mapped host ID. If no map is provided, then the translation assumes a 1-to-1 mapping and returns the passed in id #

Types

type IDMap

type IDMap struct {
	ContainerID int `json:"container_id"`
	HostID      int `json:"host_id"`
	Size        int `json:"size"`
}

IDMap contains a single entry for user namespace range remapping. An array of IDMap entries represents the structure that will be provided to the Linux kernel for creating a user namespace.