Code coverage report for node/src/apm/prometheus/metric.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
import {Aggregator, Registry} from 'prom-client';
import {Tags} from '@btilford/ts-base-core';
import * as os from 'os';
 
 
export type PromOptions = {
  registry?: Registry[];
  aggregator?: Aggregator;
  help: string;
  tags?: Tags;
  /**
   * `prom-client` requires configuring the tags that will be used before calling collection methods.
   * You can provide names for tags that can't be set until the method invocation here.
   */
  additionalTagNames?: string[];
  prefix?: string;
  suffix?: string;
}
 
function cleanMetricName(name: string): string {
  const result = name.replace(/\./g, ':') // prometheus namespaces on `:` instead of `.`
    .replace(/((?!:)\W)/g, '_') // convert anything left thats not a word to `_`
    .replace(/(__+|::+)/g, '_') // convert >= double  `__` or `::` to single
    .replace(/(^[:_]|[:_]$)/g, ''); // trim leading trailing word separators
 
  // use the regex from their site to verify
  console.assert(result.match(/[:A-Z_a-z][\w:]*/), 'Invalid metric name! %s', result);
  return result;
}
 
export class PromMetric {
  readonly tags: Tags;
  protected readonly options: PromOptions;
  protected readonly supportedLabels: Set<string>;
  readonly name: string;
 
  constructor(
    name: string,
    tags: Tags,
    options: PromOptions) {
    this.options = { ...options };
    this.tags = {
      pid: `${process.pid}`,
      NODE_ENV: process.env.NODE_ENV || 'not set',
      host: os.hostname(),
      os: os.type(),
      platform: os.platform(),
 
      ...options.tags,
      ...tags
    };
    this.name = cleanMetricName([options.prefix, name, options.suffix].filter(part => part).join(':'));
 
    this.supportedLabels = new Set([...(this.options.additionalTagNames || []), ...Object.keys(this.tags)])
  }
 
  filterTags(tags: Tags = {}): Tags {
    const result: Tags = {};
    for (const entry of Object.entries(tags)) {
      if (this.supportedLabels.has(entry[0])) {
        result[entry[0]] = entry[1];
      }
    }
    return result;
  }
}