-
Notifications
You must be signed in to change notification settings - Fork 3
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Instrument Deno.Command() - replaces Deno.run()
Better late than never
- Loading branch information
Showing
3 changed files
with
205 additions
and
31 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,146 @@ | ||
| import { type Span, SpanStatusCode } from "../opentelemetry/api.js"; | ||
| import type { Attributes } from "../opentelemetry/api.js"; | ||
| import { | ||
| isWrapped, | ||
| InstrumentationBase, | ||
| type InstrumentationConfig, | ||
| } from "../opentelemetry/instrumentation.js"; | ||
|
|
||
| function wrapChildPromise<T extends Deno.CommandStatus>(span: Span, promise: Promise<T>) { | ||
| return promise.then(status => { | ||
| recordChildExit(span, status); | ||
| return status; | ||
| }, err => { | ||
| recordChildFailed(span, err as Error) | ||
| return Promise.reject(err); | ||
| }); | ||
| } | ||
| function recordChildExit(span: Span, output: Deno.CommandStatus) { | ||
| span.setAttribute('exec.success', output.success); | ||
| span.setAttribute('exec.exit_code', output.code); | ||
| if (output.signal) { | ||
| span.setAttribute('exec.signal', output.signal); | ||
| } | ||
| span.setStatus({ | ||
| code: SpanStatusCode.OK, | ||
| }); | ||
| } | ||
| function recordSpawnFailed(span: Span, err: Error) { | ||
| // This is hit when the requested program doesn't exist, for example | ||
| span.recordException(err); | ||
| span.setStatus({ | ||
| code: SpanStatusCode.ERROR, | ||
| message: 'Failed to launch subprocess', | ||
| }); | ||
| } | ||
| function recordChildFailed(span: Span, err: Error) { | ||
| // I'm not sure what situation hits this. | ||
| span.recordException(err); | ||
| span.setStatus({ | ||
| code: SpanStatusCode.ERROR, | ||
| message: `Subprocess failed: ${err.message}`, | ||
| }); | ||
| } | ||
|
|
||
| export class DenoCommandInstrumentation extends InstrumentationBase { | ||
| readonly component: string = 'Deno.Command'; | ||
| moduleName = this.component; | ||
|
|
||
| constructor(config?: InstrumentationConfig) { | ||
| super('Deno.Command', '0.1.0', config); | ||
| } | ||
|
|
||
| init(): void {} | ||
|
|
||
| /** | ||
| * Patches the constructor of Command | ||
| */ | ||
| private _patchConstructor(): (original: typeof Deno.Command) => typeof Deno.Command { | ||
| // deno-lint-ignore no-this-alias | ||
| const plugin = this; | ||
|
|
||
| // We need to capture the arguments to the constructor, and also override the methods | ||
| // Let's see if subclassing will get us close enough without causing other issues | ||
| return original => class InstrumentedCommand extends original { | ||
| constructor(program: string | URL, opts: Deno.CommandOptions) { | ||
| super(program, opts); | ||
|
|
||
| this._spanName = `exec: ${program.toString().split('/').at(-1)}`; | ||
| this._attributes = { | ||
| 'exec.command': program.toString(), | ||
| 'exec.arguments': opts.args?.map(x => x.toString()) ?? [], | ||
| // 'component': plugin.moduleName, | ||
| } | ||
| } | ||
| private readonly _spanName: string; // Maybe we can accept an attributes->string transformer? | ||
| private readonly _attributes: Attributes; | ||
| private _span: Span | null = null; | ||
|
|
||
| override output(): Promise<Deno.CommandOutput> { | ||
| // output() can be called after spawn() - we don't want to double-instrument in that case | ||
| if (this._span) return super.output(); | ||
|
|
||
| const span = this._span ??= plugin.tracer.startSpan(this._spanName, this._attributes); | ||
| try { | ||
| return wrapChildPromise(span, super.output()) | ||
| .finally(() => span.end()); | ||
| } catch (err) { | ||
| // The child failed before making a promise. | ||
| recordSpawnFailed(span, err as Error); | ||
| span.end(); | ||
| throw err; | ||
| } | ||
| } | ||
| outputSync(): Deno.CommandOutput { | ||
| const span = this._span ??= plugin.tracer.startSpan(this._spanName, this._attributes); | ||
| try { | ||
| const output = super.outputSync(); | ||
| recordChildExit(span, output); | ||
| span.end(); | ||
| return output; | ||
| } catch (err) { | ||
| // The child at some point, likely when spawning, we assume that. | ||
| recordSpawnFailed(span, err as Error); | ||
| span.end(); | ||
| throw err; | ||
| } | ||
| } | ||
| spawn(): Deno.ChildProcess { | ||
| const span = this._span ??= plugin.tracer.startSpan(this._spanName, this._attributes); | ||
| try { | ||
| const process = super.spawn(); | ||
| // We replace the promise so that the calling code can catch our pass-thru rejection | ||
| Object.defineProperty(process, 'status', { | ||
| writable: false, | ||
| value: wrapChildPromise(span, process.status) | ||
| .finally(() => span.end()), | ||
| }); | ||
| return process; | ||
| } catch (err) { | ||
| // The child failed before making a promise. | ||
| recordSpawnFailed(span, err as Error); | ||
| span.end(); | ||
| throw err; | ||
| } | ||
| } | ||
| }; | ||
| } | ||
|
|
||
| /** | ||
| * implements enable function | ||
| */ | ||
| override enable(): void { | ||
| if (isWrapped(Deno.Command)) { | ||
| this._unwrap(Deno, 'Command'); | ||
| this._diag.debug('removing previous patch for constructor'); | ||
| } | ||
| this._wrap(Deno, 'Command', this._patchConstructor()); | ||
| } | ||
|
|
||
| /** | ||
| * implements unpatch function | ||
| */ | ||
| override disable(): void { | ||
| this._unwrap(Deno, 'Command'); | ||
| } | ||
| } |