FIX - implement OCI runtime state command [Enhancement]

cmd/urunc/main.go

@@ -115,7 +115,7 @@ func main() {
 			runCommand,
 			// specCommand,
 			startCommand,
-			// stateCommand,
+			stateCommand,
 		},
 		Before: func(_ context.Context, cmd *cli.Command) (context.Context, error) {
 			if !cmd.IsSet("root") {

cmd/urunc/state.go

@@ -0,0 +1,95 @@
+// Copyright (c) 2023-2026, Nubificus LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"syscall"
+
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v3"
+)
+
+// containerState represents the platform agnostic pieces relating to a
+// running container's status and state, matching the runc implementation.
+type containerState struct {
+	Version     string            `json:"ociVersion"`
+	ID          string            `json:"id"`
+	Pid         int               `json:"pid"`
+	Status      string            `json:"status"`
+	Bundle      string            `json:"bundle"`
+	Annotations map[string]string `json:"annotations,omitempty"`
+}
+
+var stateCommand = &cli.Command{
+	Name:  "state",
+	Usage: "output the state of a container",
+	ArgsUsage: `<container-id>
+
+Where "<container-id>" is the name for the instance of the container.
+
+EXAMPLE:
+For example, if the container id is "ubuntu01" the following will output the
+state of "ubuntu01":
+
+	# urunc state ubuntu01`,
+	Description: `The state command outputs current state information for the
+container instance, conforming to the OCI runtime specification.`,
+	Action: func(_ context.Context, cmd *cli.Command) error {
+		logrus.WithField("command", "STATE").WithField("args", os.Args).Debug("urunc INVOKED")
+		if err := checkArgs(cmd, 1, exactArgs); err != nil {
+			return err
+		}
+
+		// get Unikontainer data from state.json
+		unikontainer, err := getUnikontainer(cmd)
+		if err != nil {
+			return err
+		}
+
+		status := unikontainer.State.Status
+		pid := unikontainer.State.Pid
+
+		// Dynamically check if the process is still running.
+		// If it has died, OCI spec requires pid to be 0 and status to be stopped.
+		if pid > 0 {
+			if err := syscall.Kill(pid, 0); err != nil {
+				status = "stopped"
+				pid = 0
+			}
+		}
+
+		cs := containerState{
+			Version:     unikontainer.State.Version,
+			ID:          unikontainer.State.ID,
+			Pid:         pid,
+			Status:      status,
+			Bundle:      unikontainer.State.Bundle,
+			Annotations: unikontainer.State.Annotations,
+		}
+
+		stateData, err := json.MarshalIndent(cs, "", "  ")
+		if err != nil {
+			return fmt.Errorf("failed to marshal container state: %w", err)
+		}
+
+		// OCI runtime spec requires state to be printed to stdout
+		_, err = fmt.Fprintln(os.Stdout, string(stateData))
+		return err
+	},
+}