Improve reliability to download hostlink artifact

scripts/linux/install.sh

@@ -1,11 +1,122 @@
 #!/usr/bin/env bash
 
+# Exit codes
+EXIT_GENERAL=1
+EXIT_DEPENDENCY=2
+EXIT_VERSION_FETCH=3
+EXIT_DOWNLOAD=4
+EXIT_UNSUPPORTED_ARCH=5
+
+# Retry configuration
+MAX_RETRIES=5
+INITIAL_DELAY=1
+MAX_DELAY=60
+DOWNLOAD_TIMEOUT=60
+
 # Check if running as root
 if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root (use sudo)"
-  exit 1
+  exit $EXIT_GENERAL
 fi
 
+check_dependencies() {
+  # Check for curl
+  if ! command -v curl &> /dev/null; then
+    echo "ERROR: curl is required but not installed."
+    echo "Please install curl and try again."
+    exit $EXIT_DEPENDENCY
+  fi
+
+  # Check for gzip validation tool (in priority order)
+  if command -v xxd &> /dev/null; then
+    GZIP_VALIDATOR="xxd"
+  elif command -v od &> /dev/null; then
+    GZIP_VALIDATOR="od"
+  elif command -v file &> /dev/null; then
+    GZIP_VALIDATOR="file"
+  else
+    echo "ERROR: No gzip validation tool found."
+    echo "Please install one of: xxd, od, or file"
+    exit $EXIT_DEPENDENCY
+  fi
+}
+
+create_temp_dir() {
+  TEMP_DIR=$(mktemp -d)
+  if [ ! -d "$TEMP_DIR" ]; then
+    echo "ERROR: Failed to create temporary directory."
+    exit $EXIT_GENERAL
+  fi
+  echo "Using temporary directory: $TEMP_DIR"
+}
+
+validate_gzip() {
+  local file="$1"
+
+  if [ ! -f "$file" ]; then
+    return 1
+  fi
+
+  case $GZIP_VALIDATOR in
+    xxd)
+      local magic=$(xxd -p -l 2 "$file" 2>/dev/null)
+      [ "$magic" = "1f8b" ]
+      ;;
+    od)
+      local magic=$(od -A n -t x1 -N 2 "$file" 2>/dev/null | tr -d ' \n')
+      [ "$magic" = "1f8b" ]
+      ;;
+    file)
+      file "$file" 2>/dev/null | grep -q gzip
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+calculate_backoff() {
+  local attempt=$1
+  local delay=$((INITIAL_DELAY << (attempt - 1)))
+  if [ "$delay" -gt "$MAX_DELAY" ]; then
+    delay=$MAX_DELAY
+  fi
+  # Add jitter (0-1 second)
+  local jitter
+  jitter=$(awk 'BEGIN{srand(); printf "%.2f", rand()}')
+  awk "BEGIN{printf \"%.2f\", $delay + $jitter}"
+}
+
+show_download_error() {
+  local url="$1"
+  local http_status="$2"
+  local file="$3"
+  local file_size=0
+  local file_content=""
+
+  if [ -f "$file" ]; then
+    file_size=$(stat -c%s "$file" 2>/dev/null || stat -f%z "$file" 2>/dev/null || echo "unknown")
+    file_content=$(head -c 100 "$file" 2>/dev/null | tr -cd '[:print:]')
+  fi
+
+  echo ""
+  echo "ERROR: Failed to download hostlink after $MAX_RETRIES attempts."
+  echo ""
+  echo "Last attempt details:"
+  echo "  - HTTP Status: $http_status"
+  echo "  - File size received: $file_size bytes"
+  if [ -n "$file_content" ]; then
+    echo "  - File content (first 100 chars): \"$file_content\""
+  fi
+  echo "  - Expected: Valid gzip archive (>1MB typically)"
+  echo ""
+  echo "Manual download URL:"
+  echo "  $url"
+  echo ""
+  echo "You can download this file manually and extract it to /usr/bin/hostlink"
+  echo "Downloaded file location: $file"
+}
+
 # Default values
 TOKEN_ID="default-token-id"
 TOKEN_KEY="default-token-key"
@@ -61,8 +172,63 @@ uninstall_existing() {
 }
 
 latest_version() {
-  local version=$(curl -s https://api.github.com/repos/selfhost-dev/hostlink/releases/latest | grep tag_name | cut -d'"' -f4)
-  echo $version
+  local api_url="https://api.github.com/repos/selfhost-dev/hostlink/releases/latest"
+  local attempt=0
+  local version=""
+  local http_status=""
+  local temp_file="$TEMP_DIR/version_response.json"
+
+  echo "Fetching latest version..." >&2
+
+  while [ "$attempt" -lt "$MAX_RETRIES" ]; do
+    attempt=$((attempt + 1))
+
+    # Fetch with timeout and capture HTTP status
+    http_status=$(curl -sS --max-time "$DOWNLOAD_TIMEOUT" -w '%{http_code}' -o "$temp_file" "$api_url" 2>/dev/null)
+
+    # Check for 404 - fail immediately
+    if [ "$http_status" = "404" ]; then
+      echo "ERROR: Could not find release information (HTTP 404)." >&2
+      echo "The GitHub API endpoint may have changed or the repository may not exist." >&2
+      exit $EXIT_VERSION_FETCH
+    fi
+
+    # Check for success (2xx status)
+    if [[ "$http_status" =~ ^2[0-9][0-9]$ ]]; then
+      version=$(grep tag_name "$temp_file" 2>/dev/null | cut -d'"' -f4)
+
+      if [ -n "$version" ]; then
+        echo "Latest version: $version" >&2
+        rm -f "$temp_file"
+        echo "$version"
+        return 0
+      fi
+    fi
+
+    # If we get here, we need to retry (unless it's the last attempt)
+    if [ $attempt -lt $MAX_RETRIES ]; then
+      local delay
+      delay=$(calculate_backoff $attempt)
+      echo "Version fetch failed (HTTP $http_status). Retry $attempt/$MAX_RETRIES in ${delay}s..." >&2
+      sleep "$delay"
+    fi
+  done
+
+  # All retries exhausted
+  echo "" >&2
+  echo "ERROR: Failed to fetch latest version after $MAX_RETRIES attempts." >&2
+  echo "Last HTTP status: $http_status" >&2
+  if [ -f "$temp_file" ]; then
+    local content
+    content=$(head -c 100 "$temp_file" 2>/dev/null | tr -cd '[:print:]')
+    if [ -n "$content" ]; then
+      echo "Response content: \"$content\"" >&2
+    fi
+  fi
+  echo "" >&2
+  echo "Please check your internet connection and try again." >&2
+  rm -f "$temp_file"
+  exit $EXIT_VERSION_FETCH
 }
 
 detect_arch() {
@@ -75,28 +241,88 @@ detect_arch() {
       echo "arm64"
       ;;
     *)
-      echo "Unsupported architecture: $arch" >&2
-      exit 1
+      echo "ERROR: Unsupported architecture: $arch" >&2
+      exit $EXIT_UNSUPPORTED_ARCH
       ;;
   esac
 }
 
-VERSION=$(latest_version)
+# Run dependency checks first
+check_dependencies
+create_temp_dir
+
 ARCH=$(detect_arch)
+
+# latest_version outputs messages to stderr, version to stdout
+VERSION=$(latest_version)
+if [ -z "$VERSION" ]; then
+  echo "ERROR: Failed to determine version."
+  exit $EXIT_VERSION_FETCH
+fi
+
 HOSTLINK_TAR=hostlink_$VERSION.tar.gz
 
 download_tar() {
-  curl -L -o $HOSTLINK_TAR \
-    https://github.com/selfhost-dev/hostlink/releases/download/${VERSION}/hostlink_Linux_${ARCH}.tar.gz
+  local download_url="https://github.com/selfhost-dev/hostlink/releases/download/${VERSION}/hostlink_Linux_${ARCH}.tar.gz"
+  local tar_file="$TEMP_DIR/$HOSTLINK_TAR"
+  local attempt=0
+  local http_status=""
+
+  echo "Downloading hostlink $VERSION..."
+
+  while [ "$attempt" -lt "$MAX_RETRIES" ]; do
+    attempt=$((attempt + 1))
+
+    # Download with timeout and capture HTTP status
+    http_status=$(curl -L -sS --max-time "$DOWNLOAD_TIMEOUT" -w '%{http_code}' -o "$tar_file" "$download_url" 2>/dev/null)
+
+    # Check for 404 - fail immediately
+    if [ "$http_status" = "404" ]; then
+      echo ""
+      echo "ERROR: Release not found (HTTP 404)."
+      echo "Version $VERSION may not exist or the release assets may not be available."
+      echo ""
+      echo "Manual download URL:"
+      echo "  $download_url"
+      exit $EXIT_DOWNLOAD
+    fi
+
+    # Check for success (2xx status) and validate gzip
+    if [[ "$http_status" =~ ^2[0-9][0-9]$ ]]; then
+      if validate_gzip "$tar_file"; then
+        echo "Download successful."
+        return 0
+      else
+        echo "Download completed but file is not valid gzip (possibly corrupted)."
+      fi
+    fi
+
+    # If we get here, we need to retry (unless it's the last attempt)
+    if [ "$attempt" -lt "$MAX_RETRIES" ]; then
+      local delay
+      delay=$(calculate_backoff "$attempt")
+      if [[ "$http_status" =~ ^2[0-9][0-9]$ ]]; then
+        echo "Validation failed. Retry $attempt/$MAX_RETRIES in ${delay}s..."
+      else
+        echo "Download failed (HTTP $http_status). Retry $attempt/$MAX_RETRIES in ${delay}s..."
+      fi
+      sleep "$delay"
+    fi
+  done
+
+  # All retries exhausted
+  show_download_error "$download_url" "$http_status" "$tar_file"
+  exit $EXIT_DOWNLOAD
 }
 
 extract_tar() {
-  tar -xvf $HOSTLINK_TAR
+  echo "Extracting archive..."
+  tar -xvf "$TEMP_DIR/$HOSTLINK_TAR" -C "$TEMP_DIR"
 }
 
 move_bin() {
-  echo "Moving binary to /usr/bin, password prompt might be required."
-  sudo mv ./hostlink /usr/bin/hostlink
+  echo "Moving binary to /usr/bin..."
+  sudo mv "$TEMP_DIR/hostlink" /usr/bin/hostlink
 }
 
 create_directories() {
@@ -123,7 +349,7 @@ EOF
 
 install_service() {
   echo "Installing systemd service..."
-  sudo cp ./scripts/hostlink.service /etc/systemd/system/
+  sudo cp "$TEMP_DIR/scripts/hostlink.service" /etc/systemd/system/
   sudo systemctl daemon-reload
   sudo systemctl enable hostlink
   sudo systemctl start hostlink