Add Go types for specification

This adds Go types implementing the configuration specification.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

spec.go

@@ -0,0 +1,63 @@
+package specs
+
+// Spec is the base configuration for the container.  It specifies platform
+// independent configuration.
+type Spec struct {
+	// Version is the version of the specification that is supported.
+	Version string `json:"version"`
+	// Platform is the host information for OS and Arch.
+	Platform Platform `json:"platform"`
+	// Process is the container's main process.
+	Process Process `json:"process"`
+	// Root is the root information for the container's filesystem.
+	Root Root `json:"root"`
+	// Hostname is the containers host name.
+	Hostname string `json:"hostname"`
+	// Mounts profile configuration for adding mounts to the container's filesystem.
+	Mounts []Mount `json:"mounts"`
+}
+
+// Mount specifies a mount for a container.
+type Mount struct {
+	// Type specifies the mount kind.
+	Type string `json:"type"`
+	// Source specifies the source path of the mount.  In the case of bind mounts on
+	// linux based systems this would be the file on the host.
+	Source string `json:"source"`
+	// Destination is the path where the mount will be placed relative to the container's root.
+	Destination string `json:"destination"`
+	// Options are fstab style mount options.
+	Options string `json:"options"`
+}
+
+// Process contains information to start a specific application inside the container.
+type Process struct {
+	// Terminal creates an interactive terminal for the container.
+	Terminal bool `json:"terminal"`
+	// User specifies user information for the process.
+	User User `json:"user"`
+	// Args specifies the binary and arguments for the application to execute.
+	Args []string `json:"args"`
+	// Env populates the process environment for the process.
+	Env []string `json:"env"`
+	// Cwd is the current working directory for the process and must be
+	// relative to the container's root.
+	Cwd string `json:"cwd"`
+}
+
+// Root contains information about the container's root filesystem on the host.
+type Root struct {
+	// Path is the absolute path to the container's root filesystem.
+	Path string `json:"path"`
+	// Readonly makes the root filesystem for the container readonly before the process is executed.
+	Readonly bool `json:"readonly"`
+}
+
+// Platform specifies OS and arch information for the host system that the container
+// is created for.
+type Platform struct {
+	// OS is the operating system.
+	OS string `json:"os"`
+	// Arch is the architecture
+	Arch string `json:"arch"`
+}

spec_linux.go

@@ -0,0 +1,148 @@
+// +build linux
+
+package specs
+
+// LinuxSpec is the full specification for linux containers.
+type LinuxSpec struct {
+	Spec
+	// Linux is platform specific configuration for linux based containers.
+	Linux Linux `json:"linux"`
+}
+
+// Linux contains platform specific configuration for linux based containers.
+type Linux struct {
+	// UidMapping specifies user mappings for supporting user namespaces on linux.
+	UidMappings []IDMapping `json:"uidMappings"`
+	// UidMapping specifies group mappings for supporting user namespaces on linux.
+	GidMappings []IDMapping `json:"gidMappings"`
+	// Rlimits specifies rlimit options to apply to the container's process.
+	Rlimits []Rlimit `json:"rlimits"`
+	// SystemProperties are a set of key value pairs that are set for the container on start.
+	SystemProperties map[string]string `json:"systemProperties"`
+	// Resources contain cgroup information for handling resource constraints
+	// for the container.
+	Resources Resources `json:"resources"`
+	// Namespaces contains the namespaces that are created and/or joined by the container.
+	Namespaces []Namespace `json:"namespaces"`
+	// Capabilities are linux capabilities that are kept for the container.
+	Capabilities []string `json:"capabilities"`
+	// Devices are a list of device nodes that are created and enabled for the container.
+	Devices []string `json:"devices"`
+}
+
+// User specifies linux specific user and group information for the container's
+// main process.
+type User struct {
+	// Uid is the user id.
+	Uid int32 `json:"uid"`
+	// Gid is the group id.
+	Gid int32 `json:"gid"`
+	// AdditionalGids are additional group ids set the the container's process.
+	AdditionalGids []int32 `json:"additionalGids"`
+}
+
+// Namespace is the configuration for a linux namespace.
+type Namespace struct {
+	// Type is the type of linux namespace.
+	Type string `json:"type"`
+	// Path is a path to an existing namespace persisted on disk that can be joined
+	// and is of the same type.
+	Path string `json:"path"`
+}
+
+// IDMapping specifies uid/gid mappings.
+type IDMapping struct {
+	// From is the uid/gid of the host user or group.
+	From int32 `json:"from"`
+	// To is the uid/gid of the container's user or group.
+	To int32 `json:"to"`
+	// Count is how many uid/gids to map after To.
+	Count int32 `json:"count"`
+}
+
+// Rlimit type and restrictions.
+type Rlimit struct {
+	// Type of the rlimit to set.
+	Type int `json:"type"`
+	// Hard is the hard limit for the specified type.
+	Hard uint64 `json:"hard"`
+	// Soft is the soft limit for the specified type.
+	Soft uint64 `json:"soft"`
+}
+
+type HugepageLimit struct {
+	Pagesize string `json:"pageSize"`
+	Limit    int    `json:"limit"`
+}
+
+type InterfacePriority struct {
+	// Name is the name of the network interface.
+	Name string `json:"name"`
+	// Priority for the interface.
+	Priority int64 `json:"priority"`
+}
+
+type BlockIO struct {
+	// Specifies per cgroup weight, range is from 10 to 1000.
+	Weight int64 `json:"blkioWeight"`
+	// Weight per cgroup per device, can override BlkioWeight.
+	WeightDevice string `json:"blkioWeightDevice"`
+	// IO read rate limit per cgroup per device, bytes per second.
+	ThrottleReadBpsDevice string `json:"blkioThrottleReadBpsDevice"`
+	// IO write rate limit per cgroup per divice, bytes per second.
+	ThrottleWriteBpsDevice string `json:"blkioThrottleWriteBpsDevice"`
+	// IO read rate limit per cgroup per device, IO per second.
+	ThrottleReadIOpsDevice string `json:"blkioThrottleReadIopsDevice"`
+	// IO write rate limit per cgroup per device, IO per second.
+	ThrottleWriteIOpsDevice string `json:"blkioThrottleWriteIopsDevice"`
+}
+
+type Memory struct {
+	// Memory limit (in bytes)
+	Limit int64 `json:"limit"`
+	// Memory reservation or soft_limit (in bytes)
+	Reservation int64 `json:"reservation"`
+	// Total memory usage (memory + swap); set `-1' to disable swap
+	Swap int64 `json:"swap"`
+	// Kernel memory limit (in bytes)
+	Kernel int64 `json:"kernel"`
+}
+
+type CPU struct {
+	// CPU shares (relative weight vs. other cgroups with cpu shares).
+	Shares int64 `json:"shares"`
+	// CPU hardcap limit (in usecs). Allowed cpu time in a given period.
+	Quota int64 `json:"quota"`
+	// CPU period to be used for hardcapping (in usecs). 0 to use system default.
+	Period int64 `json:"period"`
+	// How many time CPU will use in realtime scheduling (in usecs).
+	RealtimeRuntime int64 `json:"realtimeRuntime"`
+	// CPU period to be used for realtime scheduling (in usecs).
+	RealtimePeriod int64 `json:"realtimePeriod"`
+	// CPU to use within the cpuset.
+	Cpus string `json:"cpus"`
+	// MEM to use within the cpuset.
+	Mems string `json:"mems"`
+}
+
+type Network struct {
+	// Set class identifier for container's network packets.
+	ClassID string `json:"classId"`
+	// Set priority of network traffic for container.
+	Priorities []InterfacePriority `json:"priorities"`
+}
+
+type Resources struct {
+	// DisableOOMKiller disables the OOM killer for out of memory conditions.
+	DisableOOMKiller bool `json:"disableOOMKiller"`
+	// Memory restriction configuration.
+	Memory Memory `json:"memory"`
+	// CPU resource restriction configuration.
+	CPU CPU `json:"cpu"`
+	// BlockIO restriction configuration.
+	BlockIO BlockIO `json:"blockIO"`
+	// Hugetlb limit (in bytes)
+	HugepageLimits []HugepageLimit `json:"hugepageLimits"`
+	// Network restriction configuration.
+	Network Network `json:"network"`
+}

version.go

@@ -0,0 +1,4 @@
+package specs
+
+// Version is the specification version that the package types support.
+const Version = "pre-draft"