From 50c851cf0772b42c5a0a90111cfdd25e22875497 Mon Sep 17 00:00:00 2001
From: Thales Maciel <thales@thalesmaciel.com>
Date: Wed, 21 Jan 2026 18:45:45 -0300
Subject: [PATCH] init

---
 run.sh | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100755 run.sh

diff --git a/run.sh b/run.sh
new file mode 100755
index 0000000..bd67534
--- /dev/null
+++ b/run.sh
@@ -0,0 +1,136 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+log() {
+  printf '[spawn] %s\n' "$*"
+}
+
+log "starting"
+
+DIR="$(pwd)"
+STATE="$DIR/state"
+mkdir -p "$STATE"
+
+FC_BIN="$DIR/firecracker"
+KERNEL="$DIR/vmlinux"
+ROOTFS="$DIR/rootfs.ext4"
+SSH_KEY="$DIR/id_ed25519"
+
+BR_DEV="br-fc"
+BR_IP="172.16.0.1"
+CIDR="24"
+
+VM_ID="$(date +%s)-$$"
+VM_DIR="$STATE/vm-$VM_ID"
+mkdir -p "$VM_DIR"
+
+API_SOCK="$VM_DIR/firecracker.sock"
+LOG_FILE="$VM_DIR/firecracker.log"
+TAP_DEV="tap-fc-$VM_ID"
+
+# Allocate guest IP
+NEXT_IP_FILE="$STATE/next_ip"
+NEXT_IP="$(cat "$NEXT_IP_FILE" 2>/dev/null || echo 2)"
+GUEST_IP="172.16.0.$NEXT_IP"
+echo "$((NEXT_IP + 1))" > "$NEXT_IP_FILE"
+
+log "vm id: $VM_ID"
+log "allocated guest ip: $GUEST_IP"
+
+sudo -v
+
+# Host bridge
+if ! ip link show "$BR_DEV" >/dev/null 2>&1; then
+  log "creating host bridge $BR_DEV ($BR_IP/$CIDR)"
+  sudo ip link add name "$BR_DEV" type bridge
+  sudo ip addr add "${BR_IP}/${CIDR}" dev "$BR_DEV"
+  sudo ip link set "$BR_DEV" up
+else
+  log "host bridge $BR_DEV already exists"
+fi
+
+# Per-VM TAP
+log "creating tap device $TAP_DEV"
+sudo ip tuntap add dev "$TAP_DEV" mode tap
+sudo ip link set "$TAP_DEV" master "$BR_DEV"
+sudo ip link set "$TAP_DEV" up
+
+# Start Firecracker
+log "starting firecracker process"
+rm -f "$API_SOCK"
+nohup "$FC_BIN" --api-sock "$API_SOCK" >"$LOG_FILE" 2>&1 &
+FC_PID="$!"
+echo "$FC_PID" > "$VM_DIR/pid"
+log "firecracker pid: $FC_PID"
+
+# Wait for API socket
+log "waiting for firecracker api socket"
+for _ in $(seq 1 200); do
+  [[ -S "$API_SOCK" ]] && break
+  sleep 0.02
+done
+[[ -S "$API_SOCK" ]] || { log "firecracker api socket not ready"; exit 1; }
+log "api socket ready"
+
+# Machine config
+log "configuring machine"
+curl --unix-socket "$API_SOCK" -X PUT http://localhost/machine-config \
+  -H "Content-Type: application/json" \
+  -d '{
+    "vcpu_count": 2,
+    "mem_size_mib": 1024,
+    "smt": false
+  }' >/dev/null
+
+# Boot source
+log "configuring boot source"
+KCMD="console=ttyS0 reboot=k panic=1 pci=off root=/dev/vda rw ip=${GUEST_IP}::${BR_IP}:255.255.255.0::eth0:off"
+
+curl --unix-socket "$API_SOCK" -X PUT http://localhost/boot-source \
+  -H "Content-Type: application/json" \
+  -d "{
+    \"kernel_image_path\": \"$KERNEL\",
+    \"boot_args\": \"$KCMD\"
+  }" >/dev/null
+
+# Root filesystem
+log "attaching root filesystem"
+curl --unix-socket "$API_SOCK" -X PUT http://localhost/drives/rootfs \
+  -H "Content-Type: application/json" \
+  -d "{
+    \"drive_id\": \"rootfs\",
+    \"path_on_host\": \"$ROOTFS\",
+    \"is_root_device\": true,
+    \"is_read_only\": false
+  }" >/dev/null
+
+# Network interface
+log "configuring network interface"
+curl --unix-socket "$API_SOCK" -X PUT http://localhost/network-interfaces/eth0 \
+  -H "Content-Type: application/json" \
+  -d "{
+    \"iface_id\": \"eth0\",
+    \"host_dev_name\": \"$TAP_DEV\"
+  }" >/dev/null
+
+# Start VM
+log "starting virtual machine"
+curl --unix-socket "$API_SOCK" -X PUT http://localhost/actions \
+  -H "Content-Type: application/json" \
+  -d '{ "action_type": "InstanceStart" }' >/dev/null
+
+cat > "$VM_DIR/info" <<EOF
+vm_id=$VM_ID
+pid=$FC_PID
+guest_ip=$GUEST_IP
+tap=$TAP_DEV
+api_sock=$API_SOCK
+log=$LOG_FILE
+EOF
+
+log "vm started successfully"
+log "guest ip: $GUEST_IP"
+log "ssh: ssh -i \"$SSH_KEY\" root@$GUEST_IP"
+log "logs: $LOG_FILE"
+log "done"
+