Add initial QVM CLI, Nix flake, scripts and README

lib/common.sh

@@ -0,0 +1,169 @@
+#!/usr/bin/env bash
+#
+# common.sh - Shared functions and configuration for QVM CLI tool
+#
+# This file defines XDG-compliant directory paths, constants, and utility
+# functions used across all qvm-* commands. It should be sourced by each
+# command script via: source "${QVM_LIB_DIR}/common.sh"
+#
+
+set -euo pipefail
+
+# XDG-compliant directory paths
+readonly QVM_DATA_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/qvm"
+readonly QVM_STATE_DIR="${XDG_STATE_HOME:-$HOME/.local/state}/qvm"
+readonly QVM_CACHE_DIR="${XDG_CACHE_HOME:-$HOME/.cache}/qvm"
+readonly QVM_CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/qvm"
+
+# Path constants for VM artifacts
+readonly QVM_BASE_IMAGE="$QVM_DATA_DIR/base.qcow2"
+readonly QVM_OVERLAY="$QVM_STATE_DIR/overlay.qcow2"
+readonly QVM_PID_FILE="$QVM_STATE_DIR/vm.pid"
+readonly QVM_SSH_PORT_FILE="$QVM_STATE_DIR/ssh.port"
+readonly QVM_SERIAL_LOG="$QVM_STATE_DIR/serial.log"
+readonly QVM_WORKSPACES_FILE="$QVM_STATE_DIR/workspaces.json"
+readonly QVM_USER_FLAKE="$QVM_CONFIG_DIR/flake"
+
+# Cache directories for 9p mounts (shared between host and VM)
+readonly QVM_CARGO_HOME="$QVM_CACHE_DIR/cargo-home"
+readonly QVM_CARGO_TARGET="$QVM_CACHE_DIR/cargo-target"
+readonly QVM_PNPM_STORE="$QVM_CACHE_DIR/pnpm-store"
+readonly QVM_SCCACHE="$QVM_CACHE_DIR/sccache"
+
+# Color codes (only used if stdout is a TTY)
+if [[ -t 1 ]]; then
+    readonly COLOR_INFO='\033[0;36m'    # Cyan
+    readonly COLOR_WARN='\033[0;33m'    # Yellow
+    readonly COLOR_ERROR='\033[0;31m'   # Red
+    readonly COLOR_RESET='\033[0m'      # Reset
+else
+    readonly COLOR_INFO=''
+    readonly COLOR_WARN=''
+    readonly COLOR_ERROR=''
+    readonly COLOR_RESET=''
+fi
+
+#
+# log_info - Print informational message in cyan
+# Usage: log_info "message"
+#
+log_info() {
+    echo -e "${COLOR_INFO}[INFO]${COLOR_RESET} $*" >&2
+}
+
+#
+# log_warn - Print warning message in yellow
+# Usage: log_warn "message"
+#
+log_warn() {
+    echo -e "${COLOR_WARN}[WARN]${COLOR_RESET} $*" >&2
+}
+
+#
+# log_error - Print error message in red
+# Usage: log_error "message"
+#
+log_error() {
+    echo -e "${COLOR_ERROR}[ERROR]${COLOR_RESET} $*" >&2
+}
+
+#
+# die - Print error message and exit with status 1
+# Usage: die "error message"
+#
+die() {
+    log_error "$@"
+    exit 1
+}
+
+#
+# ensure_dirs - Create all required QVM directories
+# Usage: ensure_dirs
+#
+ensure_dirs() {
+    mkdir -p "$QVM_DATA_DIR" \
+             "$QVM_STATE_DIR" \
+             "$QVM_CACHE_DIR" \
+             "$QVM_CONFIG_DIR" \
+             "$QVM_CARGO_HOME" \
+             "$QVM_CARGO_TARGET" \
+             "$QVM_PNPM_STORE" \
+             "$QVM_SCCACHE"
+}
+
+#
+# is_vm_running - Check if VM process is running
+# Returns: 0 if running, 1 if not
+# Usage: if is_vm_running; then ... fi
+#
+is_vm_running() {
+    if [[ ! -f "$QVM_PID_FILE" ]]; then
+        return 1
+    fi
+    
+    local pid
+    pid=$(cat "$QVM_PID_FILE")
+    
+    # Check if process exists and is a QEMU process
+    if kill -0 "$pid" 2>/dev/null; then
+        return 0
+    else
+        # Stale PID file, remove it
+        rm -f "$QVM_PID_FILE"
+        return 1
+    fi
+}
+
+#
+# get_ssh_port - Read SSH port from state file
+# Returns: SSH port number on stdout
+# Usage: port=$(get_ssh_port)
+#
+get_ssh_port() {
+    if [[ ! -f "$QVM_SSH_PORT_FILE" ]]; then
+        die "SSH port file not found. Is the VM running?"
+    fi
+    cat "$QVM_SSH_PORT_FILE"
+}
+
+#
+# workspace_hash - Generate short hash from absolute path
+# Args: $1 - absolute path to workspace
+# Returns: 8-character hash on stdout
+# Usage: hash=$(workspace_hash "/path/to/workspace")
+#
+workspace_hash() {
+    local path="$1"
+    echo -n "$path" | sha256sum | cut -c1-8
+}
+
+#
+# wait_for_ssh - Wait for SSH to become available on VM
+# Args: $1 - SSH port number
+#       $2 - timeout in seconds (default: 60)
+# Returns: 0 if SSH is available, 1 on timeout
+# Usage: wait_for_ssh "$port" 30
+#
+wait_for_ssh() {
+    local port="${1:-}"
+    local timeout="${2:-60}"
+    local elapsed=0
+    
+    if [[ -z "$port" ]]; then
+        die "wait_for_ssh requires port argument"
+    fi
+    
+    log_info "Waiting for SSH on port $port (timeout: ${timeout}s)..."
+    
+    while (( elapsed < timeout )); do
+        if nc -z -w 1 localhost "$port" 2>/dev/null; then
+            log_info "SSH is ready"
+            return 0
+        fi
+        sleep 1
+        (( elapsed++ ))
+    done
+    
+    log_error "SSH did not become available within ${timeout}s"
+    return 1
+}