lab/labsim/labsim-up.sh

#!/bin/bash
# Bring up the lab network simulation: one isolated libvirt network per VLAN,
# each with a single tiny Alpine VM offering SSH + a hello-world HTTP page.
#
# Idempotent: re-running only creates what is missing. Safe to run repeatedly.
#
# Usage: ./labsim-up.sh [vlan-id ...]      (default: every VLAN in vlans.conf)
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
source "$SCRIPT_DIR/lib.sh"
source "$SCRIPT_DIR/ovs.sh"

require_tools
[ -f "$BASE_IMAGE" ] || die "base image missing: $BASE_IMAGE (see README)"

SSH_PUB="$(find_ssh_pubkey)"
log "Using SSH key: ${SSH_PUB%% *} ...${SSH_PUB##* }"

selected_vlans "$@"

# --- switch fabric ------------------------------------------------------
log "bringing up OVS fabric ($OVS_BR) with host legs per VLAN"
ovs_up

# --- VMs ------------------------------------------------------------------
for entry in "${SELECTED[@]}"; do
  parse_vlan_entry "$entry"
  vid="$V_VID"; name="$V_NAME"; prefix="$V_PREFIX"; real="$V_REAL"
  vm="$(vm_name "$vid" "$name")"
  ip="${prefix}.10"

  if virsh_q dominfo "$vm" >/dev/null 2>&1; then
    state="$(virsh_q domstate "$vm" 2>/dev/null | head -1 | tr -d '\n')"
    if [ "$state" = "running" ]; then
      log "VM $vm already running ($ip)"
      continue
    fi
    log "VM $vm exists but is $state — starting"
    virsh_q start "$vm" >/dev/null
    continue
  fi

  log "creating VM $vm  ($ip on vlan $vid/$name)"

  disk="$IMG_DIR/${vm}.qcow2"
  seed="$IMG_DIR/${vm}-seed.iso"

  # Copy-on-write overlay: each VM costs a few MB, not 176.
  sudo qemu-img create -q -f qcow2 -F qcow2 -b "$BASE_IMAGE" "$disk" "$VM_DISK" >/dev/null

  build_seed "$seed" "$vm" "$vid" "$name" "$prefix" "$ip" "$real" "$SSH_PUB" "$V_MASK"

  sudo virt-install \
    --connect "$LIBVIRT_URI" \
    --name "$vm" \
    --memory "$VM_MEM" --vcpus "$VM_CPUS" \
    --disk "path=$disk,format=qcow2,bus=virtio" \
    --disk "path=$seed,device=cdrom,readonly=on" \
    --network "network=$OVS_NET,portgroup=vlan${vid},model=virtio" \
    --os-variant alpinelinux3.18 \
    --graphics none --noautoconsole --import >/dev/null
done

echo
log "waiting for VMs to answer on SSH + HTTP..."
wait_ready
echo
status_table
echo
log "environment is UP. Tear down with: $SCRIPT_DIR/labsim-down.sh"