Move the Config portion of Inspect into libpod

While we're at it, rewrite how we populate it. There were several
potential segfaults in the optional spec.Process block, and a few
fields not being populated correctly versus 'docker inspect'.

Signed-off-by: Matthew Heon <mheon@redhat.com>

cmd/podman/shared/container_inspect.go

@@ -1,9 +1,6 @@
 package shared
 
 import (
-	"strings"
-
-	"github.com/containers/image/manifest"
 	"github.com/containers/libpod/libpod"
 	cc "github.com/containers/libpod/pkg/spec"
 	"github.com/docker/go-connections/nat"
@@ -17,7 +14,6 @@ import (
 type InspectContainer struct {
 	*libpod.InspectContainerData
 	HostConfig *InspectContainerHostConfig `json:"HostConfig"`
-	Config     *InspectContainerConfig     `json:"Config"`
 }
 
 // InspectContainerHostConfig holds Container configuration that is not specific
@@ -82,31 +78,6 @@ type InspectContainerHostConfig struct {
 	Tmpfs                []string                    `json:"Tmpfs"`
 }
 
-// InspectContainerConfig holds further data about a container, again mostly
-// not directly stored in Libpod. This struct is matched to the output of
-// `docker inspect`.
-type InspectContainerConfig struct {
-	Hostname     string                        `json:"Hostname"`
-	DomainName   string                        `json:"Domainname"` //TODO
-	User         specs.User                    `json:"User"`
-	AttachStdin  bool                          `json:"AttachStdin"`  //TODO
-	AttachStdout bool                          `json:"AttachStdout"` //TODO
-	AttachStderr bool                          `json:"AttachStderr"` //TODO
-	Tty          bool                          `json:"Tty"`
-	OpenStdin    bool                          `json:"OpenStdin"`
-	StdinOnce    bool                          `json:"StdinOnce"` //TODO
-	Env          []string                      `json:"Env"`
-	Cmd          []string                      `json:"Cmd"`
-	Image        string                        `json:"Image"`
-	Volumes      map[string]struct{}           `json:"Volumes"`
-	WorkingDir   string                        `json:"WorkingDir"`
-	Entrypoint   string                        `json:"Entrypoint"`
-	Labels       map[string]string             `json:"Labels"`
-	Annotations  map[string]string             `json:"Annotations"`
-	StopSignal   uint                          `json:"StopSignal"`
-	Healthcheck  *manifest.Schema2HealthConfig `json:"Healthcheck,omitempty"`
-}
-
 // InspectLogConfig holds information about a container's configured log driver
 // and is presently unused. It is retained for Docker compatability.
 type InspectLogConfig struct {
@@ -181,21 +152,6 @@ func GetCtrInspectInfo(config *libpod.ContainerConfig, ctrInspectData *libpod.In
 			SecurityOpt:          createArtifact.SecurityOpts,
 			Tmpfs:                createArtifact.Tmpfs,
 		},
-		&InspectContainerConfig{
-			Hostname:    spec.Hostname,
-			User:        spec.Process.User,
-			Env:         spec.Process.Env,
-			Image:       config.RootfsImageName,
-			WorkingDir:  spec.Process.Cwd,
-			Labels:      config.Labels,
-			Annotations: spec.Annotations,
-			Tty:         spec.Process.Terminal,
-			OpenStdin:   config.Stdin,
-			StopSignal:  config.StopSignal,
-			Cmd:         config.Spec.Process.Args,
-			Entrypoint:  strings.Join(createArtifact.Entrypoint, " "),
-			Healthcheck: config.HealthCheckConfig,
-		},
 	}
 	return data, nil
 }

libpod/container_inspect.go

@@ -1,8 +1,10 @@
 package libpod
 
 import (
+	"strings"
 	"time"
 
+	"github.com/containers/image/manifest"
 	"github.com/containers/libpod/libpod/driver"
 	"github.com/cri-o/ocicni/pkg/ocicni"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
@@ -49,6 +51,53 @@ type InspectContainerData struct {
 	ExitCommand     []string                `json:"ExitCommand"`
 	Namespace       string                  `json:"Namespace"`
 	IsInfra         bool                    `json:"IsInfra"`
+	Config          *InspectContainerConfig `json:"Config"`
+}
+
+// InspectContainerConfig holds further data about how a container was initially
+// configured.
+type InspectContainerConfig struct {
+	// Container hostname
+	Hostname string `json:"Hostname"`
+	// Container domain name - unused at present
+	DomainName string `json:"Domainname"`
+	// User the container was launched with
+	User string `json:"User"`
+	// Unused, at present
+	AttachStdin bool `json:"AttachStdin"`
+	// Unused, at present
+	AttachStdout bool `json:"AttachStdout"`
+	// Unused, at present
+	AttachStderr bool `json:"AttachStderr"`
+	// Whether the container creates a TTY
+	Tty bool `json:"Tty"`
+	// Whether the container leaves STDIN open
+	OpenStdin bool `json:"OpenStdin"`
+	// Whether STDIN is only left open once.
+	// Presently not supported by Podman, unused.
+	StdinOnce bool `json:"StdinOnce"`
+	// Container environment variables
+	Env []string `json:"Env"`
+	// Container command
+	Cmd []string `json:"Cmd"`
+	// Container image
+	Image string `json:"Image"`
+	// Unused, at present. I've never seen this field populated.
+	Volumes map[string]struct{} `json:"Volumes"`
+	// Container working directory
+	WorkingDir string `json:"WorkingDir"`
+	// Container entrypoint
+	Entrypoint string `json:"Entrypoint"`
+	// On-build arguments - presently unused. More of Buildah's domain.
+	OnBuild *string `json:"OnBuild"`
+	// Container labels
+	Labels map[string]string `json:"Labels"`
+	// Container annotations
+	Annotations map[string]string `json:"Annotations"`
+	// Container stop signal
+	StopSignal uint `json:"StopSignal"`
+	// Configured healthcheck for the container
+	Healthcheck *manifest.Schema2HealthConfig `json:"Healthcheck,omitempty"`
 }
 
 // InspectMount provides a record of a single mount in a container. It contains
@@ -284,6 +333,12 @@ func (c *Container) getContainerInspectData(size bool, driverData *driver.Data)
 	// Get information on the container's network namespace (if present)
 	data = c.getContainerNetworkInfo(data)
 
+	inspectConfig, err := c.generateInspectContainerConfig(spec)
+	if err != nil {
+		return nil, err
+	}
+	data.Config = inspectConfig
+
 	if size {
 		rootFsSize, err := c.rootFsSize()
 		if err != nil {
@@ -401,3 +456,56 @@ func parseMountOptionsForInspect(options []string, mount *InspectMount) {
 	mount.Mode = zZ
 	mount.Options = otherOpts
 }
+
+// Generate the InspectContainerConfig struct for the Config field of Inspect.
+func (c *Container) generateInspectContainerConfig(spec *spec.Spec) (*InspectContainerConfig, error) {
+	ctrConfig := new(InspectContainerConfig)
+
+	ctrConfig.Hostname = c.Hostname()
+	ctrConfig.User = c.config.User
+	if spec.Process != nil {
+		ctrConfig.Tty = spec.Process.Terminal
+		ctrConfig.Env = []string{}
+		for _, val := range spec.Process.Env {
+			ctrConfig.Env = append(ctrConfig.Env, val)
+		}
+		ctrConfig.WorkingDir = spec.Process.Cwd
+	}
+
+	ctrConfig.OpenStdin = c.config.Stdin
+	ctrConfig.Image = c.config.RootfsImageName
+
+	// Leave empty is not explicitly overwritten by user
+	if len(c.config.Command) != 0 {
+		ctrConfig.Cmd = []string{}
+		for _, val := range c.config.Command {
+			ctrConfig.Cmd = append(ctrConfig.Cmd, val)
+		}
+	}
+
+	// Leave empty if not explicitly overwritten by user
+	if len(c.config.Entrypoint) != 0 {
+		ctrConfig.Entrypoint = strings.Join(c.config.Entrypoint, " ")
+	}
+
+	if len(c.config.Labels) != 0 {
+		ctrConfig.Labels = make(map[string]string)
+		for k, v := range c.config.Labels {
+			ctrConfig.Labels[k] = v
+		}
+	}
+
+	if len(spec.Annotations) != 0 {
+		ctrConfig.Annotations = make(map[string]string)
+		for k, v := range spec.Annotations {
+			ctrConfig.Annotations[k] = v
+		}
+	}
+
+	ctrConfig.StopSignal = c.config.StopSignal
+	// TODO: should JSON deep copy this to ensure internal pointers don't
+	// leak.
+	ctrConfig.Healthcheck = c.config.HealthCheckConfig
+
+	return ctrConfig, nil
+}