From 5855b50dae9f0fbd939e4488fb7387054e59168a Mon Sep 17 00:00:00 2001
From: abhaygoudannavar <abhaysgoudnvr@gmail.com>
Date: Thu, 7 May 2026 20:04:01 +0000
Subject: [PATCH] feat: implement OCI runtime state command

Implement the state subcommand for urunc, following the runc reference
implementation. The command outputs container state as JSON to stdout,
conforming to the OCI runtime specification.

- Adds containerState struct matching OCI state schema
- Dynamically checks process liveness via syscall.Kill(pid, 0)
- Sets pid=0 and status=stopped if the process has exited
- Registers stateCommand in main.go

Signed-off-by: abhaygoudannavar <abhaysgoudnvr@gmail.com>
---
 cmd/urunc/main.go  |  2 +-
 cmd/urunc/state.go | 95 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 cmd/urunc/state.go

diff --git a/cmd/urunc/main.go b/cmd/urunc/main.go
index e4fc2ff0..aac8c15c 100644
--- a/cmd/urunc/main.go
+++ b/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") {
diff --git a/cmd/urunc/state.go b/cmd/urunc/state.go
new file mode 100644
index 00000000..9b54c4fb
--- /dev/null
+++ b/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
+	},
+}