Test config

[lippserd]

This PR introduces tests for the ParseFlags(), FromYAMLFile() and TLS.MakeConfig() functions:

ParseFlags

• Verifies that command-line flags are correctly parsed into a struct.
• Error propagation from defaults.Set().
• Nil pointer argument: Tests calling FromYAMLFile with a nil pointer argument.
• Nil argument: Tests calling FromYAMLFile with a nil argument.

FromYAMLFile

• Simple YAML: Tests parsing a simple YAML file.
• Inlined YAML: Tests parsing a YAML file with inlined fields.
• Embedded YAML: Tests parsing a YAML file with embedded fields.
• Defaults: Tests parsing a YAML file with default values.
• Overriding defaults: Tests parsing a YAML file overriding default values.
• Empty YAML: Tests parsing an empty YAML file.
• Empty YAML with directive separator: Tests parsing an empty YAML file with a directive separator.
• Faulty YAML: Tests parsing a faulty YAML file.
• Invalid YAML: Tests parsing a YAML file that is expected to fail validation.
• Nil pointer argument: Tests calling FromYAMLFile with a nil pointer argument.
• Nil argument: Tests calling FromYAMLFile with a nil argument.
• Non-existent file: Tests calling FromYAMLFile with a non-existent file.
• Permission denied: Tests calling FromYAMLFile with a file that has no read permissions.

TLS.MakeConfig()

1. Basic Configuration

   • Verifies that the function returns nil when TLS is disabled.
   • Ensures the server name is correctly set in the TLS configuration.
   • Checks that InsecureSkipVerify is set to true when specified.
   • Ensures an error is returned when the client certificate is missing.
   • Ensures an error is returned when the private key is missing.

2. x509 Certificate Handling

   • Valid certificate and key: Verifies successful configuration with valid certificate and key.
   • Mismatched certificate and key: Ensures an error is returned for mismatched certificate and key.
   • Invalid certificate path: Ensures an error is returned for a non-existent certificate file.
   • Invalid certificate permissions: Ensures an error is returned for a certificate file with no read permissions.
   • Corrupt certificate: Ensures an error is returned for a corrupt certificate file.
   • Invalid key path: Ensures an error is returned for a non-existent key file.
   • Invalid key permissions: Ensures an error is returned for a key file with no read permissions.
   • Corrupt key: Ensures an error is returned for a corrupt key file.
   • Valid CA: Verifies successful configuration with a valid CA certificate.
   • Invalid CA path: Ensures an error is returned for a non-existent CA file.
   • Invalid CA permissions: Ensures an error is returned for a CA file with no read permissions.
   • Corrupt CA: Ensures an error is returned for a corrupt CA file.

[oxzi]

There are no tests for a parser.Parse() error. However, this may require some code changes as otherwise one has to recover from os.Exit().

icinga-go-library/config/config.go

Lines 70 to 78 in d8bd22a

	if _, err := parser.Parse(); err != nil {
	var flagErr *flags.Error
	if errors.As(err, &flagErr) && flagErr.Type == flags.ErrHelp {
	fmt.Fprintln(os.Stdout, flagErr)
	os.Exit(0)
	}
	return errors.Wrap(err, "can't parse CLI flags")
	}

However, covering this is not completely necessary, imo.

[lippserd]

Recover from os.Exit() is impossible using the stdlib, at least to my knowledge. But we could test that using a subprocess. I'll give it a try.

[oxzi]

A simpler approach would have been to refactor ParseFlags(v any) to parseFlags(v any, exitOnHelp bool) and let ParseFlags call parseFlags(v, true), allowing to test parseFlags(…, false). But I really appreciate the effort.

[lippserd]

@oxzi I have adjusted the code based on your preview. Please take another look at it. I have already moved code unfortunately, so the comments are no longer aligned correctly.