Respect Kibana / Fleet config schema when inheriting ES credentials

internal/clients/config/fleet.go

@@ -13,8 +13,24 @@ import (
 
 type fleetConfig fleet.Config
 
+// Structure to keep track of which keys were explicitly set in the config.
+// This allows us to determine the difference between explicitly set empty
+// values and values that were not set at all. Building this intermediate
+// representation allows for compatibility with plugin framework and sdkv2.
+type fleetConfigKeys struct {
+	URL      bool
+	Username bool
+	Password bool
+	APIKey   bool
+	Insecure bool
+	CACerts  bool
+}
+
 func newFleetConfigFromSDK(d *schema.ResourceData, kibanaCfg kibanaOapiConfig) (fleetConfig, sdkdiags.Diagnostics) {
-	config := kibanaCfg.toFleetConfig()
+	config := fleetConfig{}
+
+	// Keep track of keys that are explicitly set in the config.
+	knownKeys := fleetConfigKeys{}
 
 	// Set variables from resource config.
 	if fleetDataRaw, ok := d.GetOk("fleet"); ok {
@@ -31,51 +47,64 @@ func newFleetConfigFromSDK(d *schema.ResourceData, kibanaCfg kibanaOapiConfig) (
 		}
 		if v, ok := fleetData["endpoint"].(string); ok && v != "" {
 			config.URL = v
+			knownKeys.URL = true
 		}
 		if v, ok := fleetData["username"].(string); ok && v != "" {
 			config.Username = v
+			knownKeys.Username = true
 		}
 		if v, ok := fleetData["password"].(string); ok && v != "" {
 			config.Password = v
+			knownKeys.Password = true
 		}
 		if v, ok := fleetData["api_key"].(string); ok && v != "" {
 			config.APIKey = v
+			knownKeys.APIKey = true
 		}
 		if v, ok := fleetData["ca_certs"].([]interface{}); ok && len(v) > 0 {
 			for _, elem := range v {
 				if vStr, elemOk := elem.(string); elemOk {
 					config.CACerts = append(config.CACerts, vStr)
 				}
 			}
+			knownKeys.CACerts = true
 		}
 		if v, ok := fleetData["insecure"].(bool); ok {
 			config.Insecure = v
+			knownKeys.Insecure = true
 		}
 	}
 
-	return config.withEnvironmentOverrides(), nil
+	return config.withEnvironmentOverrides().withDefaultsApplied(kibanaCfg.toFleetConfig(), knownKeys), nil
 }
 
 func newFleetConfigFromFramework(ctx context.Context, cfg ProviderConfiguration, kibanaCfg kibanaOapiConfig) (fleetConfig, fwdiags.Diagnostics) {
-	config := kibanaCfg.toFleetConfig()
+	config := fleetConfig{}
+	// Keep track of keys that are explicitly set in the config
+	knownKeys := fleetConfigKeys{}
 
 	if len(cfg.Fleet) > 0 {
 		fleetCfg := cfg.Fleet[0]
 		if fleetCfg.Username.ValueString() != "" {
 			config.Username = fleetCfg.Username.ValueString()
+			knownKeys.Username = true
 		}
 		if fleetCfg.Password.ValueString() != "" {
 			config.Password = fleetCfg.Password.ValueString()
+			knownKeys.Password = true
 		}
 		if fleetCfg.Endpoint.ValueString() != "" {
 			config.URL = fleetCfg.Endpoint.ValueString()
+			knownKeys.URL = true
 		}
 		if fleetCfg.APIKey.ValueString() != "" {
 			config.APIKey = fleetCfg.APIKey.ValueString()
+			knownKeys.APIKey = true
 		}
 
 		if !fleetCfg.Insecure.IsNull() && !fleetCfg.Insecure.IsUnknown() {
 			config.Insecure = fleetCfg.Insecure.ValueBool()
+			knownKeys.Insecure = true
 		}
 
 		var caCerts []string
@@ -86,10 +115,41 @@ func newFleetConfigFromFramework(ctx context.Context, cfg ProviderConfiguration,
 
 		if len(caCerts) > 0 {
 			config.CACerts = caCerts
+			knownKeys.CACerts = true
 		}
 	}
 
-	return config.withEnvironmentOverrides(), nil
+	return config.withEnvironmentOverrides().withDefaultsApplied(kibanaCfg.toFleetConfig(), knownKeys), nil
+}
+
+func (config fleetConfig) withDefaultsApplied(defaults fleetConfig, knownKeys fleetConfigKeys) fleetConfig {
+
+	// Apply defaults for non-auth fields
+	if !knownKeys.URL {
+		config.URL = defaults.URL
+	}
+	if !knownKeys.Insecure {
+		config.Insecure = defaults.Insecure
+	}
+
+	if !knownKeys.CACerts {
+		config.CACerts = defaults.CACerts
+	}
+
+	// Handle auth defaults. APIKey and Username are mutually exclusive. If one is already set don't apply any auth defaults
+	if knownKeys.APIKey || knownKeys.Username {
+		return config
+	}
+
+	// Only apply a single provided auth default
+	if defaults.APIKey != "" {
+		config.APIKey = defaults.APIKey
+	} else if defaults.Username != "" {
+		config.Username = defaults.Username
+		config.Password = defaults.Password
+	}
+
+	return config
 }
 
 func (c fleetConfig) withEnvironmentOverrides() fleetConfig {