Files
Compass/backend/shared/src/monitoring/log.ts
2025-08-27 21:30:05 +02:00

116 lines
3.7 KiB
TypeScript

import { format } from 'node:util'
import { isError, pick, omit } from 'lodash'
import { dim, red, yellow } from 'colors/safe'
import { getMonitoringContext } from './context'
// mapping JS log levels (e.g. functions on console object) to GCP log levels
const JS_TO_GCP_LEVELS = {
debug: 'DEBUG',
info: 'INFO',
warn: 'WARNING',
error: 'ERROR',
} as const
const JS_LEVELS = Object.keys(JS_TO_GCP_LEVELS) as LogLevel[]
const DEFAULT_LEVEL = 'info'
const IS_GCP = process.env.GOOGLE_CLOUD_PROJECT != null
// keys to put in front to categorize a log line in the console
const DISPLAY_CATEGORY_KEYS = ['endpoint', 'job'] as const
// keys to ignore when printing out log details in the console
const DISPLAY_EXCLUDED_KEYS = ['traceId'] as const
export type LogLevel = keyof typeof JS_TO_GCP_LEVELS
export type LogDetails = Record<string, unknown>
export type TextLogger = (msg: unknown, ...args: unknown[]) => void
export type StructuredLogger = (msg: unknown, props?: LogDetails) => void
export type Logger = TextLogger & {
[Property in LogLevel]: StructuredLogger
}
function toString(obj: unknown) {
if (isError(obj)) {
return obj.stack ?? obj.message // stack is formatted like "Error: message\n[stack]"
} else {
return String(obj)
}
}
function replacer(_key: string, value: unknown) {
if (typeof value === 'bigint') {
return value.toString()
} else if (isError(value)) {
return {
// custom enumerable properties on error, like e.g. status code on APIErrors
...value,
// these properties aren't enumerable so we need to include them explicitly
// see https://stackoverflow.com/questions/18391212/
name: value.name,
message: value.message,
stack: value.stack,
}
} else {
return value
}
}
function ts() {
return `[${new Date().toISOString()}]`
}
// handles both the cases where someone wants to write unstructured
// stream-of-consciousness console logging like log('count:', 1, 'user': u)
// and also structured key/value logging with severity
function writeLog(
level: LogLevel,
msg: unknown,
opts?: { props?: LogDetails; rest?: unknown[] }
) {
try {
const { props, rest } = opts ?? {}
const contextData = getMonitoringContext()
const message = format(toString(msg), ...(rest ?? []))
const data = { ...(contextData ?? {}), ...(props ?? {}) }
if (IS_GCP) {
const severity = JS_TO_GCP_LEVELS[level]
const output: LogDetails = { severity, message, ...data }
if (msg instanceof Error) {
// record error properties in GCP if you just do log(err)
output['error'] = msg
}
console.log(JSON.stringify(output, replacer))
} else {
const category = Object.values(pick(data, DISPLAY_CATEGORY_KEYS)).join()
const categoryLabel = category ? dim(category) + ' ' : ''
const details = Object.entries(
omit(data, [...DISPLAY_CATEGORY_KEYS, ...DISPLAY_EXCLUDED_KEYS])
).map(([key, value]) => `\n ${key}: ${JSON.stringify(value)}`)
const result = `${dim(ts())} ${categoryLabel}${message}${details}`
if (level === 'error') {
return console.error(red(result))
} else if (level === 'warn') {
return console.warn(yellow(result))
} else if (level === 'debug') {
return console.debug(dim(result))
} else {
return console[level](result)
}
}
} catch (e) {
console.error('Could not write log output.', e)
}
}
export function getLogger(): Logger {
const logger = ((msg: unknown, ...rest: unknown[]) =>
writeLog(DEFAULT_LEVEL, msg, { rest })) as Logger
for (const level of JS_LEVELS) {
logger[level] = (msg: unknown, props?: LogDetails) =>
writeLog(level, msg, { props })
}
return logger
}
export const log = getLogger()