Logs & Parsers

Runeya streams your process logs in real-time and allows transforming them via configurable JavaScript parsers.

Log Interface

In a service's log panel:

• Real-time streaming via WebSocket
• Filters: log level, free text, stream (stdout/stderr)
• Clear the log buffer (doesn't affect active parsers)
• Export displayed logs

Log Levels

Runeya automatically detects log levels via regex patterns:

Level	Color	Detected Patterns
error	Red	ERROR, ERR, FATAL, CRIT
warn	Orange	WARN, WARNING
info	White	INFO, LOG
debug	Grey	DEBUG, TRACE, VERBOSE

JavaScript Parsers

Parsers allow transforming each log line before display. They run in a pipeline: the output of one is the input of the next.

LogLine Interface

interface LogLine {
  raw: string       // Raw text (immutable)
  stream: string    // 'stdout' | 'stderr' (immutable)
  level: string     // Detected level (mutable)
  message: string   // Displayed message (mutable)
  hidden: boolean   // Hide the line (mutable)
  metadata: object  // Enriched data (mutable)
  json?: object     // If the line is valid JSON
}

Creating a Parser (v2)

// v2 signature: receives a LogLine, returns a LogLine
(line) => {
  // Automatic JSON parsing
  if (line.json) {
    return {
      ...line,
      level: line.json.level || line.level,
      message: line.json.message || line.raw,
      metadata: line.json,
    }
  }
  return line  // pass-through if not applicable
}

Practical Examples

Structured JSON parser (winston, pino...):

(line) => {
  if (!line.json) return line
  return {
    ...line,
    level: line.json.level ?? line.level,
    message: line.json.msg ?? line.json.message ?? line.raw,
    metadata: { service: line.json.service, trace: line.json.trace },
  }
}

Hide healthcheck lines:

(line) => {
  if (line.raw.includes('GET /health')) {
    return { ...line, hidden: true }
  }
  return line
}

Extract a custom timestamp:

(line) => {
  const match = line.raw.match(/^\[(\d{4}-\d{2}-\d{2}T[^\]]+)\] (.+)/)
  if (match) {
    return {
      ...line,
      message: match[2],
      metadata: { ...line.metadata, timestamp: match[1] },
    }
  }
  return line
}

Execution Pipeline

Raw line from process
        │
        ▼
   detectLevel()     ← automatic regex (step 0)
        │
        ▼
   Parser 1          ← in list order
        │
        ▼
   Parser 2
        │
        ▼
   ...
        │
        ▼
   Sanitisation      ← message truncated to 16KB, max 100 metadata keys
        │
        ▼
   UI Display

Security Constraints

Parsers run in a Node.js sandbox (vm.Script) with:

• 100ms timeout per line
• No access to require, import, eval
• No access to filesystem or network
• On error: the line passes to the next parser unchanged

Managing Parsers

Global parsers are defined in Settings → Log Parsers.

To attach them to a service:

1. Open the service config → Logs tab
2. Drag and drop parsers in the desired execution order
3. Save

Order matters — a parser can modify a line before the next one receives it.