View / Edit on GitHub: scripts/test-linux.sh

run-vm.sh

Script to run a Linux VM in a CI/CD environment.

Overview

This script sets up and runs a virtual machine using QEMU/KVM. It supports multiple Linux distributions, configures a cloud-init ISO, launches the VM, and executes a specified command inside the VM.

Features:

Supports Ubuntu, Arch Linux, Fedora, CentOS, Debian, and Alpine.
Automatically downloads the correct cloud image.
Optimized SSH wait logic for faster boot times.
Shrinks cloud images before booting for improved efficiency.
Snapshot mode to preserve base image integrity.
Enhanced logging and error handling.
Automatically detects and generates SSH keys if missing.

`detectSshKey`

Detect an existing SSH key or create a new one if missing.

Exit codes

0: If a key is found or successfully created.
1: If SSH key generation fails.

Output on stdout

The detected or newly generated SSH key path.

`downloadImage`

Download the selected Linux cloud image if not already available.

Exit codes

0: If successful.
1: If the download fails.

Output on stdout

Download progress if needed.

`resizeImage`

Reduce image size before booting to improve efficiency.

Exit codes

0: If successful.
1: If resizing fails.

Output on stdout

Confirmation message after resizing.

`createCloudInitConfig`

Generate cloud-init configuration files for VM initialization.

Exit codes

0: If successful.
1: If file creation fails.

Output on stdout

Confirmation messages on success.

`startQemuVm`

Start the Linux VM using QEMU with snapshot mode.

Exit codes

0: If successful.
1: If VM fails to start.

Output on stdout

Status message on VM start.

`waitForSsh`

Wait for SSH to become available inside the VM.

Exit codes

0: If SSH is reachable.
1: If SSH does not become available.

Output on stdout

Status message.

`runCommandInVm`

Run a command inside the VM via SSH.

Arguments

$2 (string): The command to execute inside the VM.

Exit codes

0: If successful.
1: If SSH command fails.

Output on stdout

Command output.

`stopVm`

Stop the QEMU VM process gracefully.

Exit codes

0: If successful.
1: If termination fails.

Output on stdout

Status message on VM stop.

Source Code

#!/bin/bash
# @file run-vm.sh
# @brief Script to run a Linux VM in a CI/CD environment.
# @description
#     This script sets up and runs a virtual machine using QEMU/KVM.
#     It supports multiple Linux distributions, configures a cloud-init ISO,
#     launches the VM, and executes a specified command inside the VM.
#
#     Features:
#      * Supports Ubuntu, Arch Linux, Fedora, CentOS, Debian, and Alpine.
#      * Automatically downloads the correct cloud image.
#      * Optimized SSH wait logic for faster boot times.
#      * Shrinks cloud images before booting for improved efficiency.
#      * Snapshot mode to preserve base image integrity.
#      * Enhanced logging and error handling.
#      * Automatically detects and generates SSH keys if missing.
#
# @usage
#   ./run-vm.sh <distro> "your-command-here"
#
# @option ubuntu Use Ubuntu (default).
# @option arch Use Arch Linux.
# @option fedora Use Fedora.
# @option centos Use CentOS.
# @option debian Use Debian.
# @option alpine Use Alpine Linux.
#
# @requires
#   - QEMU/KVM installed (`qemu-system-x86_64`, `genisoimage`)
#   - SSH client (`ssh`)
#
# @exitcode 0 If successful.
# @exitcode 1 If an error occurs.

set -e

# Redirect output to log files
LOG_FILE="run-vm.log"
ERROR_LOG="run-vm-error.log"
exec > >(tee -i "$LOG_FILE") 2>&1

# ==============================================================================
# GLOBAL VARIABLES
# ==============================================================================

DISTRO="${1:-ubuntu}"
IMAGE="${DISTRO}-server.img"
CLOUD_INIT_ISO="cloud-init.iso"
VM_NAME="${DISTRO}-vm"
MEMORY="${MEMORY:-2048}"
CPUS="${CPUS:-2}"
SSH_PORT="${SSH_PORT:-2222}"
SSH_USER="ci-user"

# ==============================================================================
# @description Detect an existing SSH key or create a new one if missing.
#
# @stdout The detected or newly generated SSH key path.
#
# @exitcode 0 If a key is found or successfully created.
# @exitcode 1 If SSH key generation fails.
# ==============================================================================
detectSshKey() {
  SSH_KEY=$(find ~/.ssh -name "*.pub" | head -n 1)
  if [ -z "$SSH_KEY" ]; then
    echo "No SSH key found. Generating one..."
    ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_rsa -N "" >/dev/null 2>&1
    SSH_KEY="~/.ssh/id_rsa.pub"
    if [ ! -f "$SSH_KEY" ]; then
      echo "Error: Failed to generate SSH key."
      exit 1
    fi
  fi
  echo "Using SSH key: $SSH_KEY"
}

# ==============================================================================
# @description Download the selected Linux cloud image if not already available.
#
# @stdout Download progress if needed.
#
# @exitcode 0 If successful.
# @exitcode 1 If the download fails.
# ==============================================================================
downloadImage() {
  local IMAGE_URL
  IMAGE_URL="https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64.img"

  if [ ! -f "$IMAGE" ]; then
    echo "Downloading $DISTRO cloud image..."
    wget -O "$IMAGE" "$IMAGE_URL"
  fi
}

# ==============================================================================
# @description Reduce image size before booting to improve efficiency.
#
# @stdout Confirmation message after resizing.
#
# @exitcode 0 If successful.
# @exitcode 1 If resizing fails.
# ==============================================================================
resizeImage() {
  echo "Resizing cloud image for efficiency..."
  qemu-img resize "$IMAGE" +10G
}

# ==============================================================================
# @description Generate cloud-init configuration files for VM initialization.
#
# @stdout Confirmation messages on success.
#
# @exitcode 0 If successful.
# @exitcode 1 If file creation fails.
# ==============================================================================
createCloudInitConfig() {
  echo "Creating cloud-init configuration..."
  mkdir -p cloud-init

  cat > cloud-init/user-data <<EOF
#cloud-config
users:
  - name: $SSH_USER
    sudo: ['ALL=(ALL) NOPASSWD:ALL']
    groups: sudo
    shell: /bin/bash
    ssh_authorized_keys:
      - $(cat "$SSH_KEY")

runcmd:
  - echo "Cloud-init setup complete"
EOF

  cat > cloud-init/meta-data <<EOF
instance-id: ${DISTRO}-ci
local-hostname: ${DISTRO}-ci
EOF

  genisoimage -output "$CLOUD_INIT_ISO" -volid cidata -joliet -rock cloud-init/user-data cloud-init/meta-data
}

# ==============================================================================
# @description Start the Linux VM using QEMU with snapshot mode.
#
# @stdout Status message on VM start.
#
# @exitcode 0 If successful.
# @exitcode 1 If VM fails to start.
# ==============================================================================
startQemuVm() {
  echo "Starting $DISTRO VM..."
  qemu-system-x86_64 \
      -m "$MEMORY" \
      -smp "$CPUS" \
      -enable-kvm \
      -drive file="$IMAGE",format=qcow2,if=virtio,snapshot=on \
      -cdrom "$CLOUD_INIT_ISO" \
      -netdev user,id=user.0,hostfwd=tcp::"$SSH_PORT"-:22 \
      -device virtio-net,netdev=user.0 \
      -nographic &
}

# ==============================================================================
# @description Wait for SSH to become available inside the VM.
#
# @stdout Status message.
#
# @exitcode 0 If SSH is reachable.
# @exitcode 1 If SSH does not become available.
# ==============================================================================
waitForSsh() {
  echo "Waiting for SSH connection..."
  SECONDS_WAITED=0
  MAX_WAIT=60
  while ! nc -z localhost "$SSH_PORT"; do
    if [[ $SECONDS_WAITED -ge $MAX_WAIT ]]; then
      echo "Error: SSH did not become available within $MAX_WAIT seconds."
      exit 1
    fi
    sleep 2
    SECONDS_WAITED=$((SECONDS_WAITED + 2))
  done
  echo "SSH is available!"
}

# ==============================================================================
# @description Run a command inside the VM via SSH.
#
# @arg $2 string The command to execute inside the VM.
#
# @stdout Command output.
#
# @exitcode 0 If successful.
# @exitcode 1 If SSH command fails.
# ==============================================================================
runCommandInVm() {
  local COMMAND=$2
  echo "Running command inside VM: $COMMAND"
  ssh -o StrictHostKeyChecking=no -p "$SSH_PORT" "$SSH_USER"@localhost "$COMMAND"
}

# ==============================================================================
# @description Stop the QEMU VM process gracefully.
#
# @stdout Status message on VM stop.
#
# @exitcode 0 If successful.
# @exitcode 1 If termination fails.
# ==============================================================================
stopVm() {
  echo "Stopping VM..."
  pkill qemu-system-x86_64 || echo "Warning: VM process may not have been running."
}

# ==============================================================================
# Main Execution
# ==============================================================================
main() {
  if [ -z "$2" ]; then
    echo "Usage: $0 <distro> \"your-command-here\""
    exit 1
  fi

  detectSshKey
  downloadImage
  resizeImage
  createCloudInitConfig
  startQemuVm
  waitForSsh
  runCommandInVm "$2"
  stopVm
}

main "$@"

Overview​

Script Functions​

detectSshKey​

Exit codes​

Output on stdout​

downloadImage​

Exit codes​

Output on stdout​

resizeImage​

Exit codes​

Output on stdout​

createCloudInitConfig​

Exit codes​

Output on stdout​

startQemuVm​

Exit codes​

Output on stdout​

waitForSsh​

Exit codes​

Output on stdout​

runCommandInVm​

Arguments​

Exit codes​

Output on stdout​

stopVm​

Exit codes​

Output on stdout​

Source Code​

Contents

Overview

Script Functions

`detectSshKey`

Exit codes

Output on stdout

`downloadImage`

Exit codes

Output on stdout

`resizeImage`

Exit codes

Output on stdout

`createCloudInitConfig`

Exit codes

Output on stdout

`startQemuVm`

Exit codes

Output on stdout

`waitForSsh`

Exit codes

Output on stdout

`runCommandInVm`

Arguments

Exit codes

Output on stdout

`stopVm`

Exit codes

Output on stdout

Source Code