Add --base-url flag for connector testability (#9)

* Add --base-url flag for connector testability

This change adds a --base-url CLI flag to allow overriding the default API
endpoint for testing purposes. When provided, the connector will use this
URL instead of the hardcoded production API URL.

This is part of the Connector Testability initiative to enable mock server
testing without modifying connector code.

Files changed: cmd/baton-fastly/main.go,pkg/config/conf.gen.go,pkg/config/config.go,pkg/connector/connector.go

* Hide base-url field from hosted UI

base-url is a dev/testing concern, not user-facing configuration.
Mark it WithHidden(true) so it doesn't appear in the hosted UI.

Good feedback from Geoff:
ConductorOne/baton-trayai#63 (comment)

* Add ExportTargetCLIOnly to base-url field

Ref: ConductorOne/baton-prismhr#13 (comment)

Author: robert-chiniquy

cmd/baton-fastly/main.go

@@ -47,7 +47,7 @@ func getConnector(ctx context.Context, cc *cfg.Fastly) (types.ConnectorServer, e
 		return nil, err
 	}
 
-	cb, err := connector.New(ctx, cc.AccessToken)
+	cb, err := connector.New(ctx, cc.AccessToken, cc.BaseUrl)
 	if err != nil {
 		l.Error("error creating connector", zap.Error(err))
 		return nil, err

pkg/config/conf.gen.go

@@ -12,6 +12,12 @@ var (
 		field.WithIsSecret(true),
 		field.WithDisplayName("Access Token"),
 	)
+	BaseURLField = field.StringField(
+		"base-url",
+		field.WithDescription("Override the Fastly API URL (for testing)"),
+		field.WithHidden(true),
+		field.WithExportTarget(field.ExportTargetCLIOnly),
+	)
 
 	// FieldRelationships defines relationships between the fields listed in
 	// Config that can be automatically validated.
@@ -21,6 +27,7 @@ var (
 //go:generate go run ./gen
 var Config = field.NewConfiguration([]field.SchemaField{
 	AccessToken,
+	BaseURLField,
 })
 
 // ValidateConfig is run after the configuration is loaded, and should return an

pkg/config/config.go

@@ -46,8 +46,15 @@ func (d *Fastly) Validate(ctx context.Context) (annotations.Annotations, error)
 }
 
 // New returns a new instance of the connector.
-func New(ctx context.Context, accessToken string) (*Fastly, error) {
-	client, err := fastly.NewClient(accessToken)
+func New(ctx context.Context, accessToken, baseURL string) (*Fastly, error) {
+	var client *fastly.Client
+	var err error
+
+	if baseURL != "" {
+		client, err = fastly.NewClientForEndpoint(accessToken, baseURL)
+	} else {
+		client, err = fastly.NewClient(accessToken)
+	}
 	if err != nil {
 		return nil, err
 	}