[Sentry] ModuleIntegration wasn't able to extract modules: module integration failed

[parasssh]

hypermodeinc/dgraph#5166

A user is seeing this log message from Sentry when using our application. More details at the link above.
[Sentry] ModuleIntegration wasn't able to extract modules: module integration failed

Questions:

1. What does this message mean?
2. Under what circumstances do we see this?
3. And is it a concern or can be ignored?

FWIW, this user's sentry event with ID cc19eb68a1de4cdc8f4808283e9d17ea was indeed reported on our Sentry Dashboard.

[parasssh]

The sentry-go SDK is version 0.5.1

[rhcarvalho]

Hi @parasssh! Thanks for bringing this to our attention.

1. What does this message mean?

It means that the SDK could not get module information to attach to the error prior to reporting.

2. Under what circumstances do we see this?

It will happen whenever the SDK doesn't find a go.mod file or vendor/modules.txt or vendor/vendor.json.

Current implementation

sentry-go/integrations.go

Lines 42 to 68 in 81d3dd8

	func extractModules() map[string]string {
	extractedModules, err := getModules()
	if err != nil {
	Logger.Printf("ModuleIntegration wasn't able to extract modules: %v\n", err)
	return nil
	}
	return extractedModules
	}
	func getModules() (map[string]string, error) {
	if fileExists("go.mod") {
	return getModulesFromMod()
	}
	if fileExists("vendor") {
	// Priority given to vendor created by modules
	if fileExists("vendor/modules.txt") {
	return getModulesFromVendorTxt()
	}
	if fileExists("vendor/vendor.json") {
	return getModulesFromVendorJSON()
	}
	}
	return nil, fmt.Errorf("module integration failed")
	}

3. And is it a concern or can be ignored?

It can be totally ignored. The only consequence is that the event in Sentry will not include a list of modules/packages.

In case of dgraph, which AFAIK is a program rather than a library, I'd say it is not so critical to have a list of packages listed in Sentry, since the dependencies for a given binary are known and do not change in runtime.

---

Whenever we fix #184, we'll likely be able to get a list of modules from the running binary itself, without a dependency on go.mod (via https://golang.org/pkg/runtime/debug/#BuildInfo).

In the meantime, if the message is bothering and you'd like to get rid of it right now, one way to do so is to disable the Modules Integration:

func main() {
	err := sentry.Init(sentry.ClientOptions{
		// ...
		Integrations: func(integrations []sentry.Integration) []sentry.Integration {
			filtered := integrations[:0]
			for _, integration := range integrations {
				if integration.Name() != "Modules" {
					filtered = append(filtered, integration)
				}
			}
			return filtered
		},
	})
	// ...
}