fix(kasmvnc): optimize KasmVNC deployment script (#329)

Co-authored-by: Mathias Fredriksson <[email protected]>

Author: djarbz

kasmvnc/README.md

@@ -14,7 +14,7 @@ Automatically install [KasmVNC](https://kasmweb.com/kasmvnc) in a workspace, and
 ```tf
 module "kasmvnc" {
   source              = "registry.coder.com/modules/kasmvnc/coder"
-  version             = "1.0.22"
+  version             = "1.0.23"
   agent_id            = coder_agent.example.id
   desktop_environment = "xfce"
 }

kasmvnc/main.tf

@@ -42,7 +42,7 @@ resource "coder_script" "kasm_vnc" {
   script = templatefile("${path.module}/run.sh", {
     PORT : var.port,
     DESKTOP_ENVIRONMENT : var.desktop_environment,
-    VERSION : var.kasm_version
+    KASM_VERSION : var.kasm_version
   })
   run_on_start = true
 }

kasmvnc/run.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 
-#!/bin/bash
+# Exit on error, undefined variables, and pipe failures
+set -euo pipefail
 
 # Function to check if vncserver is already installed
 check_installed() {
@@ -14,166 +15,221 @@ check_installed() {
 
 # Function to download a file using wget, curl, or busybox as a fallback
 download_file() {
-  local url=$1
-  local output=$2
-  if command -v wget &> /dev/null; then
-    wget $url -O $output
-  elif command -v curl &> /dev/null; then
-    curl -fsSL $url -o $output
+  local url="$1"
+  local output="$2"
+  local download_tool
+
+  if command -v curl &> /dev/null; then
+    # shellcheck disable=SC2034
+    download_tool=(curl -fsSL)
+  elif command -v wget &> /dev/null; then
+    # shellcheck disable=SC2034
+    download_tool=(wget -q -O-)
   elif command -v busybox &> /dev/null; then
-    busybox wget -O $output $url
+    # shellcheck disable=SC2034
+    download_tool=(busybox wget -O-)
   else
-    echo "Neither wget, curl, nor busybox is installed. Please install one of them to proceed."
+    echo "ERROR: No download tool available (curl, wget, or busybox required)"
     exit 1
   fi
+
+  # shellcheck disable=SC2288
+  "$${download_tool[@]}" "$url" > "$output" || {
+    echo "ERROR: Failed to download $url"
+    exit 1
+  }
 }
 
 # Function to install kasmvncserver for debian-based distros
 install_deb() {
   local url=$1
-  download_file $url /tmp/kasmvncserver.deb
-  sudo apt-get update
-  DEBIAN_FRONTEND=noninteractive sudo apt-get install --yes -qq --no-install-recommends --no-install-suggests /tmp/kasmvncserver.deb
-  sudo adduser $USER ssl-cert
-  rm /tmp/kasmvncserver.deb
-}
+  local kasmdeb="/tmp/kasmvncserver.deb"
 
-# Function to install kasmvncserver for Oracle 8
-install_rpm_oracle8() {
-  local url=$1
-  download_file $url /tmp/kasmvncserver.rpm
-  sudo dnf config-manager --set-enabled ol8_codeready_builder
-  sudo dnf install oracle-epel-release-el8 -y
-  sudo dnf localinstall /tmp/kasmvncserver.rpm -y
-  sudo usermod -aG kasmvnc-cert $USER
-  rm /tmp/kasmvncserver.rpm
-}
+  download_file "$url" "$kasmdeb"
 
-# Function to install kasmvncserver for CentOS 7
-install_rpm_centos7() {
-  local url=$1
-  download_file $url /tmp/kasmvncserver.rpm
-  sudo yum install epel-release -y
-  sudo yum install /tmp/kasmvncserver.rpm -y
-  sudo usermod -aG kasmvnc-cert $USER
-  rm /tmp/kasmvncserver.rpm
+  CACHE_DIR="/var/lib/apt/lists/partial"
+  # Check if the directory exists and was modified in the last 60 minutes
+  if [[ ! -d "$CACHE_DIR" ]] || ! find "$CACHE_DIR" -mmin -60 -print -quit &> /dev/null; then
+    echo "Stale package cache, updating..."
+    # Update package cache with a 300-second timeout for dpkg lock
+    sudo apt-get -o DPkg::Lock::Timeout=300 -qq update
+  fi
+
+  DEBIAN_FRONTEND=noninteractive sudo apt-get -o DPkg::Lock::Timeout=300 install --yes -qq --no-install-recommends --no-install-suggests "$kasmdeb"
+  rm "$kasmdeb"
 }
 
 # Function to install kasmvncserver for rpm-based distros
 install_rpm() {
   local url=$1
-  download_file $url /tmp/kasmvncserver.rpm
-  sudo rpm -i /tmp/kasmvncserver.rpm
-  rm /tmp/kasmvncserver.rpm
+  local kasmrpm="/tmp/kasmvncserver.rpm"
+  local package_manager
+
+  if command -v dnf &> /dev/null; then
+    # shellcheck disable=SC2034
+    package_manager=(dnf localinstall -y)
+  elif command -v zypper &> /dev/null; then
+    # shellcheck disable=SC2034
+    package_manager=(zypper install -y)
+  elif command -v yum &> /dev/null; then
+    # shellcheck disable=SC2034
+    package_manager=(yum localinstall -y)
+  elif command -v rpm &> /dev/null; then
+    # Do we need to manually handle missing dependencies?
+    # shellcheck disable=SC2034
+    package_manager=(rpm -i)
+  else
+    echo "ERROR: No supported package manager available (dnf, zypper, yum, or rpm required)"
+    exit 1
+  fi
+
+  download_file "$url" "$kasmrpm"
+
+  # shellcheck disable=SC2288
+  sudo "$${package_manager[@]}" "$kasmrpm" || {
+    echo "ERROR: Failed to install $kasmrpm"
+    exit 1
+  }
+
+  rm "$kasmrpm"
 }
 
 # Function to install kasmvncserver for Alpine Linux
 install_alpine() {
   local url=$1
-  download_file $url /tmp/kasmvncserver.tgz
-  tar -xzf /tmp/kasmvncserver.tgz -C /usr/local/bin/
-  rm /tmp/kasmvncserver.tgz
+  local kasmtgz="/tmp/kasmvncserver.tgz"
+
+  download_file "$url" "$kasmtgz"
+
+  tar -xzf "$kasmtgz" -C /usr/local/bin/
+  rm "$kasmtgz"
 }
 
 # Detect system information
-distro=$(grep "^ID=" /etc/os-release | awk -F= '{print $2}')
-version=$(grep "^VERSION_ID=" /etc/os-release | awk -F= '{print $2}' | tr -d '"')
-arch=$(uname -m)
+if [[ ! -f /etc/os-release ]]; then
+  echo "ERROR: Cannot detect OS: /etc/os-release not found"
+  exit 1
+fi
+
+# shellcheck disable=SC1091
+source /etc/os-release
+distro="$ID"
+distro_version="$VERSION_ID"
+codename="$VERSION_CODENAME"
+arch="$(uname -m)"
+if [[ "$ID" == "ol" ]]; then
+  distro="oracle"
+  distro_version="$${distro_version%%.*}"
+elif [[ "$ID" == "fedora" ]]; then
+  distro_version="$(grep -oP '\(\K[\w ]+' /etc/fedora-release | tr '[:upper:]' '[:lower:]' | tr -d ' ')"
+fi
 
 echo "Detected Distribution: $distro"
-echo "Detected Version: $version"
+echo "Detected Version: $distro_version"
+echo "Detected Codename: $codename"
 echo "Detected Architecture: $arch"
 
 # Map arch to package arch
-if [[ "$arch" == "x86_64" ]]; then
-  if [[ "$distro" == "ubuntu" || "$distro" == "debian" || "$distro" == "kali" ]]; then
-    arch="amd64"
-  else
-    arch="x86_64"
-  fi
-elif [[ "$arch" == "aarch64" || "$arch" == "arm64" ]]; then
-  if [[ "$distro" == "ubuntu" || "$distro" == "debian" || "$distro" == "kali" ]]; then
-    arch="arm64"
-  else
-    arch="aarch64"
-  fi
-else
-  echo "Unsupported architecture: $arch"
-  exit 1
-fi
+case "$arch" in
+  x86_64)
+    if [[ "$distro" =~ ^(ubuntu|debian|kali)$ ]]; then
+      arch="amd64"
+    fi
+    ;;
+  aarch64)
+    if [[ "$distro" =~ ^(ubuntu|debian|kali)$ ]]; then
+      arch="arm64"
+    fi
+    ;;
+  arm64)
+    : # This is effectively a noop
+    ;;
+  *)
+    echo "ERROR: Unsupported architecture: $arch"
+    exit 1
+    ;;
+esac
 
 # Check if vncserver is installed, and install if not
 if ! check_installed; then
-  echo "Installing KASM version: ${VERSION}"
+  # Check for NOPASSWD sudo (required)
+  if ! command -v sudo &> /dev/null || ! sudo -n true 2> /dev/null; then
+    echo "ERROR: sudo NOPASSWD access required!"
+    exit 1
+  fi
+
+  base_url="https://github.com/kasmtech/KasmVNC/releases/download/v${KASM_VERSION}"
+
+  echo "Installing KASM version: ${KASM_VERSION}"
   case $distro in
     ubuntu | debian | kali)
-      case $version in
-        "20.04")
-          install_deb "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_focal_${VERSION}_$${arch}.deb"
-          ;;
-        "22.04")
-          install_deb "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_jammy_${VERSION}_$${arch}.deb"
-          ;;
-        "24.04")
-          install_deb "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_noble_${VERSION}_$${arch}.deb"
-          ;;
-        *)
-          echo "Unsupported Ubuntu/Debian/Kali version: $${version}"
-          exit 1
-          ;;
-      esac
+      bin_name="kasmvncserver_$${codename}_${KASM_VERSION}_$${arch}.deb"
+      install_deb "$base_url/$bin_name"
       ;;
-    oracle)
-      if [[ "$version" == "8" ]]; then
-        install_rpm_oracle8 "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_oracle_8_${VERSION}_$${arch}.rpm"
-      else
-        echo "Unsupported Oracle version: $${version}"
-        exit 1
-      fi
-      ;;
-    centos)
-      if [[ "$version" == "7" ]]; then
-        install_rpm_centos7 "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_centos_core_${VERSION}_$${arch}.rpm"
-      else
-        install_rpm "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_centos_core_${VERSION}_$${arch}.rpm"
-      fi
+    oracle | fedora | opensuse)
+      bin_name="kasmvncserver_$${distro}_$${distro_version}_${KASM_VERSION}_$${arch}.rpm"
+      install_rpm "$base_url/$bin_name"
       ;;
     alpine)
-      if [[ "$version" == "3.17" || "$version" == "3.18" || "$version" == "3.19" || "$version" == "3.20" ]]; then
-        install_alpine "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvnc.alpine_$${version}_$${arch}.tgz"
-      else
-        echo "Unsupported Alpine version: $${version}"
-        exit 1
-      fi
-      ;;
-    fedora | opensuse)
-      install_rpm "https://github.com/kasmtech/KasmVNC/releases/download/v${VERSION}/kasmvncserver_$${distro}_$${version}_${VERSION}_$${arch}.rpm"
+      bin_name="kasmvnc.alpine_$${distro_version//./}_$${arch}.tgz"
+      install_alpine "$base_url/$bin_name"
       ;;
     *)
-      echo "Unsupported distribution: $${distro}"
+      echo "Unsupported distribution: $distro"
       exit 1
       ;;
   esac
 else
   echo "vncserver already installed. Skipping installation."
 fi
 
-# Coder port-forwarding from dashboard only supports HTTP
-sudo bash -c "cat > /etc/kasmvnc/kasmvnc.yaml <<EOF
+if command -v sudo &> /dev/null && sudo -n true 2> /dev/null; then
+  kasm_config_file="/etc/kasmvnc/kasmvnc.yaml"
+  SUDO=sudo
+else
+  kasm_config_file="$HOME/.vnc/kasmvnc.yaml"
+  SUDO=
+
+  echo "WARNING: Sudo access not available, using user config dir!"
+
+  if [[ -f "$kasm_config_file" ]]; then
+    echo "WARNING: Custom user KasmVNC config exists, not overwriting!"
+    echo "WARNING: Ensure that you manually configure the appropriate settings."
+    kasm_config_file="/dev/stderr"
+  else
+    echo "WARNING: This may prevent custom user KasmVNC settings from applying!"
+    mkdir -p "$HOME/.vnc"
+  fi
+fi
+
+echo "Writing KasmVNC config to $kasm_config_file"
+$SUDO tee "$kasm_config_file" > /dev/null << EOF
 network:
   protocol: http
   websocket_port: ${PORT}
   ssl:
     require_ssl: false
+    pem_certificate:
+    pem_key:
   udp:
     public_ip: 127.0.0.1
-EOF"
+EOF
 
 # This password is not used since we start the server without auth.
 # The server is protected via the Coder session token / tunnel
 # and does not listen publicly
-echo -e "password\npassword\n" | vncpasswd -wo -u $USER
+echo -e "password\npassword\n" | vncpasswd -wo -u "$USER"
 
 # Start the server
 printf "🚀 Starting KasmVNC server...\n"
-sudo -u $USER bash -c "vncserver -select-de ${DESKTOP_ENVIRONMENT} -disableBasicAuth" > /tmp/kasmvncserver.log 2>&1 &
+vncserver -select-de "${DESKTOP_ENVIRONMENT}" -disableBasicAuth > /tmp/kasmvncserver.log 2>&1 &
+pid=$!
+
+# Wait for server to start
+sleep 5
+grep -v '^[[:space:]]*$' /tmp/kasmvncserver.log | tail -n 10
+if ps -p $pid | grep -q "^$pid"; then
+  echo "ERROR: Failed to start KasmVNC server. Check full logs at /tmp/kasmvncserver.log"
+  exit 1
+fi
+printf "🚀 KasmVNC server started successfully!\n"