path: root/recipes-containers/vcontainer/files/vxn-init.sh

#!/bin/sh
# SPDX-FileCopyrightText: Copyright (C) 2025 Bruce Ashfield
#
# SPDX-License-Identifier: GPL-2.0-only
#
# vxn-init.sh
# Init script for vxn: execute container entrypoint directly in Xen DomU
#
# This script runs on a real filesystem after switch_root from initramfs.
# Unlike vdkr-init.sh which starts Docker, this script directly mounts
# the container's rootfs and executes the entrypoint via chroot.
#
# The VM IS the container — no container runtime runs inside the guest.
#
# Drive layout:
#   /dev/xvda = rootfs.img (this script runs from here, mounted as /)
#   /dev/xvdb = container rootfs (OCI image, passed from host)
#
# Kernel parameters (reuses docker_ prefix for frontend compatibility):
#   docker_cmd=<base64>    Base64-encoded entrypoint command
#   docker_input=<type>    Input type: none, oci, rootfs (default: none)
#   docker_output=<type>   Output type: text (default: text)
#   docker_network=1       Enable networking
#   docker_interactive=1   Interactive mode (suppress boot messages)
#   docker_daemon=1        Daemon mode (command loop on hvc0 via serial PTY)
#   docker_exit_grace=<s>  Grace period (seconds) after entrypoint exits [default: 300]
#
# Version: 1.2.0

# Set runtime-specific parameters before sourcing common code
VCONTAINER_RUNTIME_NAME="vxn"
VCONTAINER_RUNTIME_CMD="chroot"
VCONTAINER_RUNTIME_PREFIX="docker"
VCONTAINER_STATE_DIR="/var/lib/vxn"
VCONTAINER_SHARE_NAME="vxn_share"
VCONTAINER_VERSION="1.2.0"

# Source common init functions
. /vcontainer-init-common.sh

# ============================================================================
# Container Rootfs Handling
# ============================================================================

# Find the container rootfs directory from the input disk.
# Sets CONTAINER_ROOT to the path of the extracted rootfs.
find_container_rootfs() {
    CONTAINER_ROOT=""

    if [ ! -d /mnt/input ] || [ -z "$(ls -A /mnt/input 2>/dev/null)" ]; then
        log "WARNING: No container rootfs found on input disk"
        return 1
    fi

    # Check if the input disk IS the rootfs (has typical Linux dirs)
    if [ -d /mnt/input/bin ] || [ -d /mnt/input/usr ]; then
        CONTAINER_ROOT="/mnt/input"
        log "Container rootfs: direct mount (/mnt/input)"
        return 0
    fi

    # Check for OCI layout (index.json + blobs/)
    if [ -f /mnt/input/index.json ] || [ -f /mnt/input/oci-layout ]; then
        log "Found OCI layout on input disk, extracting layers..."
        extract_oci_rootfs /mnt/input /mnt/container
        CONTAINER_ROOT="/mnt/container"
        return 0
    fi

    # Check for rootfs/ subdirectory
    if [ -d /mnt/input/rootfs ]; then
        CONTAINER_ROOT="/mnt/input/rootfs"
        log "Container rootfs: /mnt/input/rootfs"
        return 0
    fi

    log "WARNING: Could not determine rootfs layout in /mnt/input"
    [ "$QUIET_BOOT" = "0" ] && ls -la /mnt/input/
    return 1
}

# Extract OCI image layers into a flat rootfs.
# Usage: extract_oci_rootfs <oci_dir> <target_dir>
extract_oci_rootfs() {
    local oci_dir="$1"
    local target_dir="$2"

    mkdir -p "$target_dir"

    if [ ! -f "$oci_dir/index.json" ]; then
        log "ERROR: No index.json in OCI layout"
        return 1
    fi

    if command -v jq >/dev/null 2>&1; then
        local manifest_digest=$(jq -r '.manifests[0].digest' "$oci_dir/index.json")
        local manifest_file="$oci_dir/blobs/${manifest_digest/://}"

        if [ -f "$manifest_file" ]; then
            # Extract layer digests from manifest (in order, bottom to top)
            local layers=$(jq -r '.layers[].digest' "$manifest_file")
            for layer_digest in $layers; do
                local layer_file="$oci_dir/blobs/${layer_digest/://}"
                if [ -f "$layer_file" ]; then
                    log "Extracting layer: ${layer_digest#sha256:}"
                    tar -xf "$layer_file" -C "$target_dir" 2>/dev/null || true
                fi
            done
        fi
    else
        # Fallback: find and extract all blobs that look like tarballs
        log "No jq available, extracting all blob layers..."
        for blob in "$oci_dir"/blobs/sha256/*; do
            if [ -f "$blob" ]; then
                tar -xf "$blob" -C "$target_dir" 2>/dev/null || true
            fi
        done
    fi

    if [ -d "$target_dir/bin" ] || [ -d "$target_dir/usr" ] || [ -f "$target_dir/hello" ]; then
        log "OCI rootfs extracted to $target_dir"
        return 0
    else
        log "WARNING: Extracted OCI rootfs may be incomplete"
        [ "$QUIET_BOOT" = "0" ] && ls -la "$target_dir/"
        return 0
    fi
}

# Parse OCI config for environment, entrypoint, cmd, workdir.
# Sets: OCI_ENTRYPOINT, OCI_CMD, OCI_ENV, OCI_WORKDIR
parse_oci_config() {
    OCI_ENTRYPOINT=""
    OCI_CMD=""
    OCI_ENV=""
    OCI_WORKDIR=""

    local config_file=""

    # Look for config in OCI layout on input disk
    if [ -f /mnt/input/index.json ]; then
        config_file=$(oci_find_config_blob /mnt/input)
    fi

    # Check for standalone config.json
    [ -z "$config_file" ] && [ -f /mnt/input/config.json ] && config_file="/mnt/input/config.json"

    if [ -z "$config_file" ] || [ ! -f "$config_file" ]; then
        log "No OCI config found (using command from kernel cmdline)"
        return
    fi

    log "Parsing OCI config: $config_file"

    if command -v jq >/dev/null 2>&1; then
        OCI_ENTRYPOINT=$(jq -r '(.config.Entrypoint // []) | join(" ")' "$config_file" 2>/dev/null)
        OCI_CMD=$(jq -r '(.config.Cmd // []) | join(" ")' "$config_file" 2>/dev/null)
        OCI_WORKDIR=$(jq -r '.config.WorkingDir // ""' "$config_file" 2>/dev/null)
        OCI_ENV=$(jq -r '(.config.Env // []) | .[]' "$config_file" 2>/dev/null)
    else
        # Fallback: parse OCI config JSON with grep/sed (no jq in minimal rootfs)
        log "Using grep/sed fallback for OCI config parsing"
        OCI_ENTRYPOINT=$(oci_grep_json_array "Entrypoint" "$config_file")
        OCI_CMD=$(oci_grep_json_array "Cmd" "$config_file")
        OCI_WORKDIR=$(grep -o '"WorkingDir":"[^"]*"' "$config_file" 2>/dev/null | sed 's/"WorkingDir":"//;s/"$//')
        OCI_ENV=$(grep -o '"Env":\[[^]]*\]' "$config_file" 2>/dev/null | \
            sed 's/"Env":\[//;s/\]$//' | tr ',' '\n' | sed 's/^ *"//;s/"$//')
    fi

    log "OCI config: entrypoint='$OCI_ENTRYPOINT' cmd='$OCI_CMD' workdir='$OCI_WORKDIR'"
}

# Follow OCI index.json → manifest → config blob using grep/sed.
# Works with or without jq.
oci_find_config_blob() {
    local oci_dir="$1"
    local digest=""
    local blob_file=""

    if command -v jq >/dev/null 2>&1; then
        digest=$(jq -r '.manifests[0].digest' "$oci_dir/index.json" 2>/dev/null)
        blob_file="$oci_dir/blobs/${digest/://}"
        [ -f "$blob_file" ] && digest=$(jq -r '.config.digest' "$blob_file" 2>/dev/null)
        blob_file="$oci_dir/blobs/${digest/://}"
    else
        # grep fallback: extract first digest from index.json
        digest=$(grep -o '"digest":"sha256:[a-f0-9]*"' "$oci_dir/index.json" 2>/dev/null | \
            head -n 1 | sed 's/"digest":"//;s/"$//')
        blob_file="$oci_dir/blobs/${digest/://}"
        if [ -f "$blob_file" ]; then
            # Extract config digest from manifest (mediaType contains "config")
            digest=$(grep -o '"config":{[^}]*}' "$blob_file" 2>/dev/null | \
                grep -o '"digest":"sha256:[a-f0-9]*"' | sed 's/"digest":"//;s/"$//')
            blob_file="$oci_dir/blobs/${digest/://}"
        fi
    fi

    [ -f "$blob_file" ] && echo "$blob_file"
}

# Extract a JSON array value as a space-separated string using grep/sed.
# Usage: oci_grep_json_array "Entrypoint" config_file
# Handles: "Entrypoint":["/hello"], "Cmd":["/bin/sh","-c","echo hi"]
oci_grep_json_array() {
    local key="$1"
    local file="$2"
    grep -o "\"$key\":\\[[^]]*\\]" "$file" 2>/dev/null | \
        sed "s/\"$key\":\\[//;s/\\]$//" | \
        tr ',' '\n' | sed 's/^ *"//;s/"$//' | tr '\n' ' ' | sed 's/ $//'
}

# ============================================================================
# Command Resolution
# ============================================================================

# Parse a "docker run" command to extract the container command (after image name).
# "docker run --rm hello-world" → "" (no cmd, use OCI defaults)
# "docker run --rm hello-world /bin/sh" → "/bin/sh"
parse_docker_run_cmd() {
    local full_cmd="$1"
    local found_image=false
    local container_cmd=""
    local skip_next=false

    # Strip "docker run" or "podman run" prefix
    local args=$(echo "$full_cmd" | sed 's/^[a-z]* run //')

    for arg in $args; do
        if [ "$found_image" = "true" ]; then
            container_cmd="$container_cmd $arg"
            continue
        fi

        if [ "$skip_next" = "true" ]; then
            skip_next=false
            continue
        fi

        case "$arg" in
            --rm|--detach|-d|-i|--interactive|-t|--tty|--privileged)
                ;;
            -p|--publish|-v|--volume|-e|--env|--name|--network|-w|--workdir|--entrypoint|-m|--memory|--cpus)
                skip_next=true
                ;;
            -p=*|--publish=*|-v=*|--volume=*|-e=*|--env=*|--name=*|--network=*|-w=*|--workdir=*|--entrypoint=*)
                ;;
            -*)
                ;;
            *)
                # First non-option argument is the image name — skip it
                found_image=true
                ;;
        esac
    done

    echo "$container_cmd" | sed 's/^ *//'
}

# Determine the command to execute inside the container.
# Priority: 1) explicit command from docker run args, 2) RUNTIME_CMD as raw command,
#           3) OCI entrypoint + cmd, 4) /bin/sh fallback
determine_exec_command() {
    local cmd=""

    if [ -n "$RUNTIME_CMD" ]; then
        # Check if this is a "docker run" wrapper command
        if echo "$RUNTIME_CMD" | grep -qE '^(docker|podman) run '; then
            cmd=$(parse_docker_run_cmd "$RUNTIME_CMD")
            # If no command after image name, fall through to OCI config
        else
            # Raw command — use as-is
            cmd="$RUNTIME_CMD"
        fi
    fi

    # If no explicit command, use OCI config
    if [ -z "$cmd" ]; then
        if [ -n "$OCI_ENTRYPOINT" ]; then
            cmd="$OCI_ENTRYPOINT"
            [ -n "$OCI_CMD" ] && cmd="$cmd $OCI_CMD"
        elif [ -n "$OCI_CMD" ]; then
            cmd="$OCI_CMD"
        fi
    fi

    # Final fallback
    if [ -z "$cmd" ]; then
        cmd="/bin/sh"
        log "No command specified, defaulting to /bin/sh"
    fi

    echo "$cmd"
}

# ============================================================================
# Container Execution
# ============================================================================

# Set up environment variables for the container
setup_container_env() {
    # Apply OCI environment variables
    if [ -n "$OCI_ENV" ]; then
        echo "$OCI_ENV" | while IFS= read -r env_line; do
            [ -n "$env_line" ] && export "$env_line" 2>/dev/null || true
        done
    fi

    # Ensure basic environment
    export PATH="${PATH:-/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin}"
    export HOME="${HOME:-/root}"
    export TERM="${TERM:-linux}"
}

# Execute a command inside the container rootfs via chroot.
# Mounts /proc, /sys, /dev inside the container and copies DNS config.
exec_in_container() {
    local rootfs="$1"
    local cmd="$2"
    local workdir="${OCI_WORKDIR:-/}"

    # Mount essential filesystems inside the container rootfs
    mkdir -p "$rootfs/proc" "$rootfs/sys" "$rootfs/dev" "$rootfs/tmp" 2>/dev/null || true
    mount -t proc proc "$rootfs/proc" 2>/dev/null || true
    mount -t sysfs sysfs "$rootfs/sys" 2>/dev/null || true
    mount --bind /dev "$rootfs/dev" 2>/dev/null || true

    # Copy resolv.conf for DNS
    if [ -f /etc/resolv.conf ]; then
        mkdir -p "$rootfs/etc" 2>/dev/null || true
        cp /etc/resolv.conf "$rootfs/etc/resolv.conf" 2>/dev/null || true
    fi

    log "Executing in container: $cmd"
    log "Working directory: $workdir"

    # Determine how to exec: use /bin/sh if available, otherwise direct exec
    local use_sh=true
    if [ ! -x "$rootfs/bin/sh" ]; then
        use_sh=false
        log "No /bin/sh in container, using direct exec"
    fi

    if [ "$RUNTIME_INTERACTIVE" = "1" ]; then
        # Interactive mode: establish a controlling terminal for job control.
        # PID 1 is already a session leader, so setsid() would fork — run in
        # a subshell (not session leader) where setsid() succeeds directly.
        # The -c flag does ioctl(TIOCSCTTY) on stdin to set the controlling tty.
        export TERM=linux
        dmesg -n 1 2>/dev/null || true
        if [ "$use_sh" = "true" ]; then
            (exec setsid -c chroot "$rootfs" /bin/sh -c "cd '$workdir' 2>/dev/null; exec $cmd")
        else
            (exec setsid -c chroot "$rootfs" $cmd)
        fi
        EXEC_EXIT_CODE=$?
    else
        # Non-interactive: capture output
        EXEC_OUTPUT="/tmp/container_output.txt"
        EXEC_EXIT_CODE=0
        if [ "$use_sh" = "true" ]; then
            chroot "$rootfs" /bin/sh -c "cd '$workdir' 2>/dev/null; $cmd" \
                > "$EXEC_OUTPUT" 2>&1 || EXEC_EXIT_CODE=$?
        else
            chroot "$rootfs" $cmd \
                > "$EXEC_OUTPUT" 2>&1 || EXEC_EXIT_CODE=$?
        fi

        log "Exit code: $EXEC_EXIT_CODE"

        echo "===OUTPUT_START==="
        cat "$EXEC_OUTPUT"
        echo "===OUTPUT_END==="
        echo "===EXIT_CODE=$EXEC_EXIT_CODE==="
    fi

    # Cleanup mounts inside container
    umount "$rootfs/proc" 2>/dev/null || true
    umount "$rootfs/sys" 2>/dev/null || true
    umount "$rootfs/dev" 2>/dev/null || true
}

# Execute a command inside the container rootfs in the background.
# Used by detached mode: start entrypoint, then enter daemon loop.
exec_in_container_background() {
    local rootfs="$1"
    local cmd="$2"
    local workdir="${OCI_WORKDIR:-/}"

    # Mount essential filesystems inside the container rootfs
    mkdir -p "$rootfs/proc" "$rootfs/sys" "$rootfs/dev" "$rootfs/tmp" 2>/dev/null || true
    mount -t proc proc "$rootfs/proc" 2>/dev/null || true
    mount -t sysfs sysfs "$rootfs/sys" 2>/dev/null || true
    mount --bind /dev "$rootfs/dev" 2>/dev/null || true

    # Copy resolv.conf for DNS
    if [ -f /etc/resolv.conf ]; then
        mkdir -p "$rootfs/etc" 2>/dev/null || true
        cp /etc/resolv.conf "$rootfs/etc/resolv.conf" 2>/dev/null || true
    fi

    # Run in background, save PID
    # Note: no 'exec' — compound commands (&&, ||, ;) need the wrapper shell
    chroot "$rootfs" /bin/sh -c "cd '$workdir' 2>/dev/null; $cmd" > /tmp/entrypoint.log 2>&1 &
    ENTRYPOINT_PID=$!
    echo "$ENTRYPOINT_PID" > /tmp/entrypoint.pid
    log "Entrypoint PID: $ENTRYPOINT_PID"
}

# ============================================================================
# Memres: Run Container from Hot-Plugged Disk
# ============================================================================

# Run a container from a hot-plugged /dev/xvdb block device.
# Called by the daemon loop in response to ===RUN_CONTAINER=== command.
# Mounts the device, finds rootfs, executes entrypoint, unmounts.
# Output follows the daemon command protocol (===OUTPUT_START/END/EXIT_CODE/END===).
run_container_from_disk() {
    local user_cmd="$1"

    # Wait for hot-plugged block device
    log "Waiting for input device..."
    local found=false
    for i in $(seq 1 30); do
        if [ -b /dev/xvdb ]; then
            found=true
            break
        fi
        sleep 0.5
    done

    if [ "$found" != "true" ]; then
        echo "===ERROR==="
        echo "Input device /dev/xvdb not found after 15s"
        echo "===END==="
        return
    fi

    # Mount input disk
    mkdir -p /mnt/input
    if ! mount /dev/xvdb /mnt/input >/dev/null 2>&1; then
        echo "===ERROR==="
        echo "Failed to mount /dev/xvdb"
        echo "===END==="
        return
    fi
    log "Input disk mounted"

    # Find container rootfs
    if ! find_container_rootfs; then
        echo "===ERROR==="
        echo "No container rootfs found on input disk"
        echo "===END==="
        umount /mnt/input 2>/dev/null || true
        return
    fi

    # Parse OCI config for entrypoint/env/workdir
    parse_oci_config
    setup_container_env

    # Determine command: user-supplied takes priority, then OCI config
    if [ -n "$user_cmd" ]; then
        RUNTIME_CMD="$user_cmd"
    else
        RUNTIME_CMD=""
    fi
    local exec_cmd
    exec_cmd=$(determine_exec_command)

    log "Executing container: $exec_cmd"

    # Execute in container rootfs (blocking)
    local rootfs="$CONTAINER_ROOT"
    local workdir="${OCI_WORKDIR:-/}"
    local exit_code=0

    # Mount essential filesystems inside container
    mkdir -p "$rootfs/proc" "$rootfs/sys" "$rootfs/dev" "$rootfs/tmp" 2>/dev/null || true
    mount -t proc proc "$rootfs/proc" 2>/dev/null || true
    mount -t sysfs sysfs "$rootfs/sys" 2>/dev/null || true
    mount --bind /dev "$rootfs/dev" 2>/dev/null || true
    [ -f /etc/resolv.conf ] && {
        mkdir -p "$rootfs/etc" 2>/dev/null || true
        cp /etc/resolv.conf "$rootfs/etc/resolv.conf" 2>/dev/null || true
    }

    local output_file="/tmp/container_run_output.txt"
    if [ -x "$rootfs/bin/sh" ]; then
        chroot "$rootfs" /bin/sh -c "cd '$workdir' 2>/dev/null; $exec_cmd" \
            > "$output_file" 2>&1 || exit_code=$?
    else
        chroot "$rootfs" $exec_cmd \
            > "$output_file" 2>&1 || exit_code=$?
    fi

    echo "===OUTPUT_START==="
    cat "$output_file"
    echo "===OUTPUT_END==="
    echo "===EXIT_CODE=$exit_code==="

    # Clean up container mounts
    umount "$rootfs/proc" 2>/dev/null || true
    umount "$rootfs/sys" 2>/dev/null || true
    umount "$rootfs/dev" 2>/dev/null || true
    umount /mnt/input 2>/dev/null || true
    rm -f "$output_file"

    # Reset container state for next run
    CONTAINER_ROOT=""
    OCI_ENTRYPOINT=""
    OCI_CMD=""
    OCI_ENV=""
    OCI_WORKDIR=""
    RUNTIME_CMD=""
    # Clean up extracted OCI rootfs (if any)
    rm -rf /mnt/container 2>/dev/null || true

    echo "===END==="
    log "Container finished (exit code: $exit_code)"
}

# ============================================================================
# Daemon Mode (vxn-specific)
# ============================================================================

# Daemon mode: command loop on hvc0 (stdin/stdout).
# The host bridges the domain's console PTY to a Unix socket via socat.
# Commands arrive as base64-encoded lines on stdin, responses go to stdout.
# This is the same model runx used (serial='pty' + serial_start).
run_vxn_daemon_mode() {
    log "=== vxn Daemon Mode ==="
    log "Container rootfs: ${CONTAINER_ROOT:-(none)}"
    log "Idle timeout: ${RUNTIME_IDLE_TIMEOUT}s"

    ACTIVITY_FILE="/tmp/.daemon_activity"
    touch "$ACTIVITY_FILE"
    DAEMON_PID=$$

    trap 'log "Shutdown signal"; sync; reboot -f' TERM
    trap 'rm -f "$ACTIVITY_FILE"; exit' INT

    log "Using hvc0 console for daemon IPC"
    log "Daemon ready, waiting for commands..."

    # Emit readiness marker so the host can detect daemon is ready
    # without needing to send PING first (host reads PTY for this)
    echo "===PONG==="

    # Command loop: read from stdin (hvc0), write to stdout (hvc0)
    while true; do
        CMD_B64=""
        read -r CMD_B64
        READ_EXIT=$?

        if [ $READ_EXIT -eq 0 ] && [ -n "$CMD_B64" ]; then
            touch "$ACTIVITY_FILE"

            case "$CMD_B64" in
                "===PING===")
                    echo "===PONG==="
                    continue
                    ;;
                "===STATUS===")
                    if [ -f /tmp/entrypoint.exit_code ]; then
                        echo "===EXITED=$(cat /tmp/entrypoint.exit_code)==="
                    else
                        echo "===RUNNING==="
                    fi
                    continue
                    ;;
                "===SHUTDOWN===")
                    log "Received shutdown command"
                    echo "===SHUTTING_DOWN==="
                    break
                    ;;
                "===RUN_CONTAINER==="*)
                    # Memres: run a container from a hot-plugged disk
                    _rc_cmd_b64="${CMD_B64#===RUN_CONTAINER===}"
                    _rc_cmd=""
                    if [ -n "$_rc_cmd_b64" ]; then
                        _rc_cmd=$(echo "$_rc_cmd_b64" | base64 -d 2>/dev/null)
                    fi
                    log "RUN_CONTAINER: cmd='$_rc_cmd'"
                    run_container_from_disk "$_rc_cmd"
                    continue
                    ;;
            esac

            # Decode command
            CMD=$(echo "$CMD_B64" | base64 -d 2>/dev/null)
            if [ -z "$CMD" ]; then
                echo "===ERROR==="
                echo "Failed to decode command"
                echo "===END==="
                continue
            fi

            log "Executing: $CMD"

            # Execute command in container rootfs (or host rootfs if no container)
            EXEC_OUTPUT="/tmp/daemon_output.txt"
            EXEC_EXIT_CODE=0
            if [ -n "$CONTAINER_ROOT" ]; then
                chroot "$CONTAINER_ROOT" /bin/sh -c "$CMD" \
                    > "$EXEC_OUTPUT" 2>&1 || EXEC_EXIT_CODE=$?
            else
                eval "$CMD" > "$EXEC_OUTPUT" 2>&1 || EXEC_EXIT_CODE=$?
            fi

            echo "===OUTPUT_START==="
            cat "$EXEC_OUTPUT"
            echo "===OUTPUT_END==="
            echo "===EXIT_CODE=$EXEC_EXIT_CODE==="
            echo "===END==="

            log "Command completed (exit code: $EXEC_EXIT_CODE)"
        else
            sleep 0.1
        fi
    done

    log "Daemon shutting down..."
}

# ============================================================================
# Main
# ============================================================================

# Initialize base environment
setup_base_environment
mount_base_filesystems

# Check for quiet boot mode
check_quiet_boot

# Interactive mode: suppress guest kernel console messages early
if [ "$QUIET_BOOT" = "1" ]; then
    dmesg -n 1 2>/dev/null || true
fi

log "=== vxn Init ==="
log "Version: $VCONTAINER_VERSION"

# Mount tmpfs directories and cgroups
mount_tmpfs_dirs
setup_cgroups

# Parse kernel command line
parse_cmdline

# Parse vxn-specific kernel parameters
ENTRYPOINT_GRACE_PERIOD="300"
for param in $(cat /proc/cmdline); do
    case "$param" in
        docker_exit_grace=*) ENTRYPOINT_GRACE_PERIOD="${param#docker_exit_grace=}" ;;
    esac
done
log "Entrypoint grace period: ${ENTRYPOINT_GRACE_PERIOD}s"

# Detect and configure disks
detect_disks

# Mount input disk (container rootfs from host)
mount_input_disk

# Configure networking
configure_networking

# Find the container rootfs on the input disk
if ! find_container_rootfs; then
    if [ "$RUNTIME_DAEMON" = "1" ]; then
        log "No container rootfs, daemon mode will execute on host rootfs"
        CONTAINER_ROOT=""
    else
        echo "===ERROR==="
        echo "No container rootfs found on input disk"
        echo "Contents of /mnt/input:"
        ls -la /mnt/input/ 2>/dev/null || echo "(empty)"
        sleep 2
        reboot -f
    fi
fi

# Parse OCI config for entrypoint/env/workdir
parse_oci_config

# Set up container environment
setup_container_env

if [ "$RUNTIME_DAEMON" = "1" ]; then
    # If we also have a command, run it in background first (detached container)
    if [ -n "$RUNTIME_CMD" ] && [ "$RUNTIME_CMD" != "1" ]; then
        EXEC_CMD=$(determine_exec_command)
        if [ -n "$EXEC_CMD" ] && [ -n "$CONTAINER_ROOT" ]; then
            log "Starting entrypoint in background: $EXEC_CMD"
            exec_in_container_background "$CONTAINER_ROOT" "$EXEC_CMD"

            # Monitor entrypoint: when it exits, record exit code and
            # schedule DomU shutdown after grace period.
            # During the grace period, exec and logs still work.
            if [ -n "$ENTRYPOINT_PID" ]; then
                (
                    wait $ENTRYPOINT_PID 2>/dev/null
                    EP_EXIT=$?
                    echo "$EP_EXIT" > /tmp/entrypoint.exit_code
                    log "Entrypoint exited (code: $EP_EXIT), grace period: ${ENTRYPOINT_GRACE_PERIOD}s"
                    if [ "$ENTRYPOINT_GRACE_PERIOD" -gt 0 ] 2>/dev/null; then
                        sleep "$ENTRYPOINT_GRACE_PERIOD"
                    fi
                    log "Grace period expired, shutting down"
                    reboot -f
                ) &
                ENTRYPOINT_MONITOR_PID=$!
                log "Entrypoint monitor started (PID: $ENTRYPOINT_MONITOR_PID)"
            fi
        fi
    fi
    run_vxn_daemon_mode
else
    # Determine command to execute
    EXEC_CMD=$(determine_exec_command)

    if [ -z "$EXEC_CMD" ]; then
        echo "===ERROR==="
        echo "No command to execute"
        sleep 2
        reboot -f
    fi

    # Execute in container rootfs
    exec_in_container "$CONTAINER_ROOT" "$EXEC_CMD"
fi

# Graceful shutdown
graceful_shutdown