[CI:DOCS]addition of specgen package

warning: the naming of this might change as well as the location.

this is a build on a PR from mheon from last year that proposes a shift from our current approach of creating containers based on the arbitrarily made createconfig.  the new approach would be to have a specification that is detached from the podman cli.  the spec could then be generated and used to make a container.  this theoretically is the beginning of a long-needed refactor involving how we get from the cli -> libpod | apiv2 -> libpod with code re-use and less duplication.

the intent is to build the apiv2 container creation based on this approach only.  wiring to the podman cli will happen after the fact.

Signed-off-by: Brent Baude <bbaude@redhat.com>

pkg/specgen/specgen.go

@@ -3,12 +3,23 @@ package specgen
 import (
 	"net"
 
+	"github.com/containers/image/v5/manifest"
 	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/libpod/define"
+	"github.com/containers/storage"
+	"github.com/cri-o/ocicni/pkg/ocicni"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
 )
 
 // TODO
+// mheon provided this an off the cuff suggestion. Adding it here to retain
+// for history as we implement it.  When this struct is implemented, we need
+// to remove the nolints.
 type Namespace struct {
+	isHost      bool   //nolint
+	isPath      string //nolint
+	isContainer string //nolint
+	isPod       bool   //nolint
 }
 
 // ContainerBasicConfig contains the basic parts of a container.
@@ -16,76 +27,76 @@ type ContainerBasicConfig struct {
 	// Name is the name the container will be given.
 	// If no name is provided, one will be randomly generated.
 	// Optional.
-	Name string
+	Name string `json:"name,omitempty"`
 	// Pod is the ID of the pod the container will join.
 	// Optional.
-	Pod string
+	Pod string `json:"pod,omitempty"`
 	// Entrypoint is the container's entrypoint.
 	// If not given and Image is specified, this will be populated by the
 	// image's configuration.
 	// Optional.
-	Entrypoint []string
+	Entrypoint []string `json:"entrypoint,omitempty"`
 	// Command is the container's command.
 	// If not given and Image is specified, this will be populated by the
 	// image's configuration.
 	// Optional.
-	Command []string
+	Command []string `json:"command,omitempty"`
 	// Env is a set of environment variables that will be set in the
 	// container.
 	// Optional.
-	Env map[string]string
+	Env map[string]string `json:"env,omitempty"`
 	// Terminal is whether the container will create a PTY.
-	Terminal bool
+	Terminal bool `json:"terminal,omitempty"`
 	// Stdin is whether the container will keep its STDIN open.
-	Stdin bool
+	Stdin bool `json:"stdin,omitempty"`
 	// Labels are key-valid labels that are used to add metadata to
 	// containers.
 	// Optional.
-	Labels map[string]string
+	Labels map[string]string `json:"labels,omitempty"`
 	// Annotations are key-value options passed into the container runtime
 	// that can be used to trigger special behavior.
 	// Optional.
-	Annotations map[string]string
+	Annotations map[string]string `json:"annotations,omitempty"`
 	// StopSignal is the signal that will be used to stop the container.
 	// Must be a non-zero integer below SIGRTMAX.
 	// If not provided, the default, SIGTERM, will be used.
 	// Will conflict with Systemd if Systemd is set to "true" or "always".
 	// Optional.
-	StopSignal *uint
+	StopSignal *uint `json:"stop_signal,omitempty"`
 	// StopTimeout is a timeout between the container's stop signal being
 	// sent and SIGKILL being sent.
 	// If not provided, the default will be used.
 	// If 0 is used, stop signal will not be sent, and SIGKILL will be sent
 	// instead.
 	// Optional.
-	StopTimeout *uint
+	StopTimeout *uint `json:"stop_timeout,omitempty"`
 	// LogDriver is the container's log driver.
 	// Optional.
-	LogDriver string
+	LogDriver string `json:"log_driver,omitempty"`
 	// LogPath is the path the container's logs will be stored at.
 	// Only available if LogDriver is set to "json-file" or "k8s-file".
 	// Optional.
-	LogPath string
+	LogPath string `json:"log_path,omitempty"`
 	// ConmonPidFile is a path at which a PID file for Conmon will be
 	// placed.
 	// If not given, a default location will be used.
 	// Optional.
-	ConmonPidFile string
+	ConmonPidFile string `json:"conmon_pid_file,omitempty"`
 	// RestartPolicy is the container's restart policy - an action which
 	// will be taken when the container exits.
 	// If not given, the default policy, which does nothing, will be used.
 	// Optional.
-	RestartPolicy string
+	RestartPolicy string `json:"restart_policy,omitempty"`
 	// RestartRetries is the number of attempts that will be made to restart
 	// the container.
 	// Only available when RestartPolicy is set to "on-failure".
 	// Optional.
-	RestartRetries *uint
+	RestartRetries *uint `json:"restart_tries,omitempty"`
 	// OCIRuntime is the name of the OCI runtime that will be used to create
 	// the container.
 	// If not specified, the default will be used.
 	// Optional.
-	OCIRuntime string
+	OCIRuntime string `json:"oci_runtime,omitempty"`
 	// Systemd is whether the container will be started in systemd mode.
 	// Valid options are "true", "false", and "always".
 	// "true" enables this mode only if the binary run in the container is
@@ -96,27 +107,27 @@ type ContainerBasicConfig struct {
 	// conflicts with StopSignal.
 	// If not specified, "false" will be assumed.
 	// Optional.
-	Systemd string
+	Systemd string `json:"systemd,omitempty"`
 	// Namespace is the libpod namespace the container will be placed in.
 	// Optional.
-	Namespace string
+	Namespace string `json:"namespace,omitempty"`
 
 	// PidNS is the container's PID namespace.
 	// It defaults to private.
 	// Mandatory.
-	PidNS Namespace
+	PidNS Namespace `json:"pidns,omitempty"`
 
 	// UtsNS is the container's UTS namespace.
 	// It defaults to private.
 	// Must be set to Private to set Hostname.
 	// Mandatory.
-	UtsNS Namespace
+	UtsNS Namespace `json:"utsns,omitempty"`
 	// Hostname is the container's hostname. If not set, the hostname will
 	// not be modified (if UtsNS is not private) or will be set to the
 	// container ID (if UtsNS is private).
 	// Conflicts with UtsNS if UtsNS is not set to private.
 	// Optional.
-	Hostname string
+	Hostname string `json:"hostname,omitempty"`
 }
 
 // ContainerStorageConfig contains information on the storage configuration of a
@@ -127,54 +138,54 @@ type ContainerStorageConfig struct {
 	// volumes, and other configuration will be applied to the container.
 	// Conflicts with Rootfs.
 	// At least one of Image or Rootfs must be specified.
-	Image string
+	Image string `json:"image"`
 	// Rootfs is the path to a directory that will be used as the
 	// container's root filesystem. No modification will be made to the
 	// directory, it will be directly mounted into the container as root.
 	// Conflicts with Image.
 	// At least one of Image or Rootfs must be specified.
-	Rootfs string
+	Rootfs string `json:"rootfs,omitempty"`
 	// ImageVolumeMode indicates how image volumes will be created.
 	// Supported modes are "ignore" (do not create), "tmpfs" (create as
 	// tmpfs), and "anonymous" (create as anonymous volumes).
 	// The default is anonymous.
 	// Optional.
-	ImageVolumeMode string
+	ImageVolumeMode string `json:"image_volume_mode,omitempty"`
 	// VolumesFrom is a list of containers whose volumes will be added to
 	// this container. Supported mount options may be added after the
 	// container name with a : and include "ro" and "rw".
 	// Optional.
-	VolumesFrom []string
+	VolumesFrom []string `json:"volumes_from,omitempty"`
 	// Mounts are mounts that will be added to the container.
 	// These will supersede Image Volumes and VolumesFrom volumes where
 	// there are conflicts.
 	// Optional.
-	Mounts []spec.Mount
+	Mounts []spec.Mount `json:"mounts,omitempty"`
 	// Volumes are named volumes that will be added to the container.
 	// These will supersede Image Volumes and VolumesFrom volumes where
 	// there are conflicts.
 	// Optional.
-	Volumes []*libpod.ContainerNamedVolume
+	Volumes []*libpod.ContainerNamedVolume `json:"volumes,omitempty"`
 	// Devices are devices that will be added to the container.
 	// Optional.
-	Devices []spec.LinuxDevice
+	Devices []spec.LinuxDevice `json:"devices,omitempty"`
 	// IpcNS is the container's IPC namespace.
 	// Default is private.
 	// Conflicts with ShmSize if not set to private.
 	// Mandatory.
-	IpcNS Namespace
+	IpcNS Namespace `json:"ipcns,omitempty"`
 	// ShmSize is the size of the tmpfs to mount in at /dev/shm, in bytes.
 	// Conflicts with ShmSize if ShmSize is not private.
 	// Optional.
-	ShmSize *int64
+	ShmSize *int64 `json:"shm_size,omitempty"`
 	// WorkDir is the container's working directory.
 	// If unset, the default, /, will be used.
 	// Optional.
-	WorkDir string
+	WorkDir string `json:"work_dir,omitempty"`
 	// RootfsPropagation is the rootfs propagation mode for the container.
 	// If not set, the default of rslave will be used.
 	// Optional.
-	RootfsPropagation string
+	RootfsPropagation string `json:"rootfs_propagation,omitempty"`
 }
 
 // ContainerSecurityConfig is a container's security features, including
@@ -187,61 +198,61 @@ type ContainerSecurityConfig struct {
 	// - Disables Seccomp, SELinux, and Apparmor confinement.
 	// TODO: this conflicts with things.
 	// TODO: this does more.
-	Privileged bool
+	Privileged bool `json:"privileged,omitempty"`
 	// User is the user the container will be run as.
 	// Can be given as a UID or a username; if a username, it will be
 	// resolved within the container, using the container's /etc/passwd.
 	// If unset, the container will be run as root.
 	// Optional.
-	User string
+	User string `json:"user,omitempty"`
 	// Groups are a list of supplemental groups the container's user will
 	// be granted access to.
 	// Optional.
-	Groups []string
+	Groups []string `json:"groups,omitempty"`
 	// CapAdd are capabilities which will be added to the container.
 	// Conflicts with Privileged.
 	// Optional.
-	CapAdd []string
+	CapAdd []string `json:"cap_add,omitempty"`
 	// CapDrop are capabilities which will be removed from the container.
 	// Conflicts with Privileged.
 	// Optional.
-	CapDrop []string
+	CapDrop []string `json:"cap_drop,omitempty"`
 	// SelinuxProcessLabel is the process label the container will use.
 	// If SELinux is enabled and this is not specified, a label will be
 	// automatically generated if not specified.
 	// Optional.
-	SelinuxProcessLabel string
+	SelinuxProcessLabel string `json:"selinux_process_label,omitempty"`
 	// SelinuxMountLabel is the mount label the container will use.
 	// If SELinux is enabled and this is not specified, a label will be
 	// automatically generated if not specified.
 	// Optional.
-	SelinuxMountLabel string
+	SelinuxMountLabel string `json:"selinux_mount_label,omitempty"`
 	// SelinuxOpts are options for configuring SELinux.
 	// Optional.
-	SelinuxOpts []string
+	SelinuxOpts []string `json:"selinux_opts,omitempty"`
 	// ApparmorProfile is the name of the Apparmor profile the container
 	// will use.
 	// Optional.
-	ApparmorProfile string
+	ApparmorProfile string `json:"apparmor_profile,omitempty"`
 	// SeccompProfilePath is the path to a JSON file containing the
 	// container's Seccomp profile.
 	// If not specified, no Seccomp profile will be used.
 	// Optional.
-	SeccompProfilePath string
+	SeccompProfilePath string `json:"seccomp_profile_path,omitempty"`
 	// NoNewPrivileges is whether the container will set the no new
 	// privileges flag on create, which disables gaining additional
 	// privileges (e.g. via setuid) in the container.
-	NoNewPrivileges bool
+	NoNewPrivileges bool `json:"no_new_privileges,omitempty"`
 	// UserNS is the container's user namespace.
 	// It defaults to host, indicating that no user namespace will be
 	// created.
 	// If set to private, IDMappings must be set.
 	// Mandatory.
-	UserNS Namespace
+	UserNS Namespace `json:"userns,omitempty"`
 	// IDMappings are UID and GID mappings that will be used by user
 	// namespaces.
 	// Required if UserNS is private.
-	IDMappings storage.IDMappingOptions
+	IDMappings storage.IDMappingOptions `json:"idmappings,omitempty"`
 }
 
 // ContainerCgroupConfig contains configuration information about a container's
@@ -251,16 +262,16 @@ type ContainerCgroupConfig struct {
 	// It defaults to private.
 	// Conflicts with NoCgroups if not set to host.
 	// Mandatory.
-	CgroupNS Namespace
+	CgroupNS Namespace `json:"cgroupns,omitempty"`
 	// NoCgroups indicates that the container should not create CGroups.
 	// Conflicts with CgroupParent and CgroupNS if CgroupNS is not set to
 	// host.
-	NoCgroups bool
+	NoCgroups bool `json:"no_cgroups,omitempty"`
 	// CgroupParent is the container's CGroup parent.
 	// If not set, the default for the current cgroup driver will be used.
 	// Conflicts with NoCgroups.
 	// Optional.
-	CgroupParent string
+	CgroupParent string `json:"cgroup_parent,omitempty"`
 }
 
 // ContainerNetworkConfig contains information on a container's network
@@ -269,70 +280,70 @@ type ContainerNetworkConfig struct {
 	// NetNS is the configuration to use for the container's network
 	// namespace.
 	// Mandatory.
-	NetNS Namespace
+	NetNS Namespace `json:"netns,omitempty"`
 	// ConfigureNetNS is whether Libpod will configure the container's
 	// network namespace to send and receive traffic.
 	// Only available is NetNS is private - conflicts with other NetNS
 	// modes.
-	ConfigureNetNS bool
+	ConfigureNetNS bool `json:"configure_netns,omitempty"`
 	// StaticIP is the a IPv4 address of the container.
 	// Only available if ConfigureNetNS is true.
 	// Optional.
-	StaticIP *net.IP
+	StaticIP *net.IP `json:"static_ip,omitempty"`
 	// StaticIPv6 is a static IPv6 address to set in the container.
 	// Only available if ConfigureNetNS is true.
 	// Optional.
-	StaticIPv6 *net.IP
+	StaticIPv6 *net.IP `json:"static_ipv6,omitempty"`
 	// StaticMAC is a static MAC address to set in the container.
 	// Only available if ConfigureNetNS is true.
 	// Optional.
-	StaticMAC *net.HardwareAddr
+	StaticMAC *net.HardwareAddr `json:"static_mac,omitempty"`
 	// PortBindings is a set of ports to map into the container.
 	// Only available if ConfigureNetNS is true.
 	// Optional.
-	PortMappings []ocicni.PortMapping
+	PortMappings []ocicni.PortMapping `json:"portmappings,omitempty"`
 	// PublishImagePorts will publish ports specified in the image to random
 	// ports outside.
 	// Requires Image to be set.
-	PublishImagePorts bool
+	PublishImagePorts bool `json:"publish_image_ports,omitempty"`
 	// CNINetworks is a list of CNI networks to join the container to.
 	// If this list is empty, the default CNI network will be joined
 	// instead. If at least one entry is present, we will not join the
 	// default network (unless it is part of this list).
 	// Only available if ConfigureNetNS is true.
 	// Optional.
-	CNINetworks []string
+	CNINetworks []string `json:"cni_networks,omitempty"`
 	// UseImageResolvConf indicates that resolv.conf should not be managed
 	// by Podman, but instead sourced from the image.
 	// Conflicts with DNSServer, DNSSearch, DNSOption.
-	UseImageResolvConf bool
+	UseImageResolvConf bool `json:"use_image_resolve_conf,omitempty"`
 	// DNSServer is a set of DNS servers that will be used in the
 	// container's resolv.conf, replacing the host's DNS Servers which are
 	// used by default.
 	// Conflicts with UseImageResolvConf.
 	// Optional.
-	DNSServer []net.IP
+	DNSServer []net.IP `json:"dns_server,omitempty"`
 	// DNSSearch is a set of DNS search domains that will be used in the
 	// container's resolv.conf, replacing the host's DNS search domains
 	// which are used by default.
 	// Conflicts with UseImageResolvConf.
 	// Optional.
-	DNSSearch []string
+	DNSSearch []string `json:"dns_search,omitempty"`
 	// DNSOption is a set of DNS options that will be used in the
 	// container's resolv.conf, replacing the host's DNS options which are
 	// used by default.
 	// Conflicts with UseImageResolvConf.
 	// Optional.
-	DNSOption []string
+	DNSOption []string `json:"dns_option,omitempty"`
 	// UseImageHosts indicates that /etc/hosts should not be managed by
 	// Podman, and instead sourced from the image.
 	// Conflicts with HostAdd.
-	UseImageHosts bool
+	UseImageHosts bool `json:"use_image_hosts,omitempty"`
 	// HostAdd is a set of hosts which will be added to the container's
 	// /etc/hosts file.
 	// Conflicts with UseImageHosts.
 	// Optional.
-	HostAdd []string
+	HostAdd []string `json:"hostadd,omitempty"`
 }
 
 // ContainerResourceConfig contains information on container resource limits.
@@ -341,14 +352,20 @@ type ContainerResourceConfig struct {
 	// Can only be set as root on cgroups v1 systems, but can be set as
 	// rootless as well for cgroups v2.
 	// Optional.
-	ResourceLimits *spec.LinuxResources
+	ResourceLimits *spec.LinuxResources `json:"resource_limits,omitempty"`
 	// Rlimits are POSIX rlimits to apply to the container.
 	// Optional.
-	Rlimits []spec.POSIXRlimit
+	Rlimits []spec.POSIXRlimit `json:"r_limits,omitempty"`
 	// OOMScoreAdj adjusts the score used by the OOM killer to determine
 	// processes to kill for the container's process.
 	// Optional.
-	OOMScoreAdj *int
+	OOMScoreAdj *int `json:"oom_score_adj,omitempty"`
+}
+
+// ContainerHealthCheckConfig describes a container healthcheck with attributes
+// like command, retries, interval, start period, and timeout.
+type ContainerHealthCheckConfig struct {
+	HealthConfig manifest.Schema2HealthConfig `json:"healthconfig,omitempty"`
 }
 
 // SpecGenerator creates an OCI spec and Libpod configuration options to create
@@ -360,4 +377,23 @@ type SpecGenerator struct {
 	ContainerCgroupConfig
 	ContainerNetworkConfig
 	ContainerResourceConfig
+	ContainerHealthCheckConfig
+}
+
+// NewSpecGenerator returns a SpecGenerator struct given one of two mandatory inputs
+func NewSpecGenerator(image, rootfs *string) (*SpecGenerator, error) {
+	_ = image
+	_ = rootfs
+	return &SpecGenerator{}, define.ErrNotImplemented
+}
+
+// Validate verifies that the given SpecGenerator is valid and satisfies required
+// input for creating a container.
+func (s *SpecGenerator) Validate() error {
+	return define.ErrNotImplemented
+}
+
+// MakeContainer creates a container based on the SpecGenerator
+func (s *SpecGenerator) MakeContainer() (*libpod.Container, error) {
+	return nil, define.ErrNotImplemented
 }