DNS [WIP]

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/dns/manager.go

@@ -0,0 +1,121 @@
+package dns
+
+import (
+	"darvaza.org/core"
+	"darvaza.org/resolver"
+	"darvaza.org/slog"
+
+	"git.jpi.io/amery/jpictl/pkg/cluster"
+)
+
+// Manager is a DNS Manager instance
+type Manager struct {
+	p Provider
+	r resolver.Resolver
+	l slog.Logger
+}
+
+// ManagerOption configures a Manager
+type ManagerOption func(*Manager) error
+
+func newErrorManagerOption(err error, hint string) ManagerOption {
+	return func(*Manager) error {
+		if hint != "" {
+			err = core.Wrap(err, hint)
+		}
+		return err
+	}
+}
+
+// WithProvider attaches a libdns Provider to the Manager
+func WithProvider(p Provider) ManagerOption {
+	var err error
+
+	if p == nil {
+		p, err = DefaultDNSProvider()
+	}
+
+	if err != nil {
+		return newErrorManagerOption(err, "WithProvider")
+	}
+
+	return func(mgr *Manager) error {
+		mgr.p = p
+		return nil
+	}
+}
+
+// WithLookuper attaches a resolver.Lookuper to the Manager
+func WithLookuper(h resolver.Lookuper) ManagerOption {
+	if h == nil {
+		h = cluster.DefaultLookuper()
+	}
+
+	return func(mgr *Manager) error {
+		mgr.r = resolver.NewResolver(h)
+		return nil
+	}
+}
+
+// WithResolver attaches a resolver.Resolver to the Manager
+func WithResolver(r resolver.Resolver) ManagerOption {
+	if r == nil {
+		r = cluster.DefaultResolver()
+	}
+
+	return func(mgr *Manager) error {
+		mgr.r = r
+		return nil
+	}
+}
+
+// WithLogger attaches a logger to the Manager
+func WithLogger(log slog.Logger) ManagerOption {
+	if log == nil {
+		log = cluster.DefaultLogger()
+	}
+
+	return func(mgr *Manager) error {
+		mgr.l = log
+		return nil
+	}
+}
+
+func (mgr *Manager) setDefaults() error {
+	var opts []ManagerOption
+
+	if mgr.p == nil {
+		opts = append(opts, WithProvider(nil))
+	}
+
+	if mgr.r == nil {
+		opts = append(opts, WithResolver(nil))
+	}
+
+	if mgr.l == nil {
+		opts = append(opts, WithLogger(nil))
+	}
+
+	for _, opt := range opts {
+		if err := opt(mgr); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// NewManager creates a DNS manager with the
+func NewManager(opts ...ManagerOption) (*Manager, error) {
+	mgr := new(Manager)
+
+	for _, opt := range opts {
+		if err := opt(mgr); err != nil {
+			return nil, err
+		}
+	}
+
+	if err := mgr.setDefaults(); err != nil {
+		return nil, err
+	}
+	return mgr, nil
+}