Add support for GCP Secret Manager

provider.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"strings"
+	"time"
 )
 
 // Provider for secrets.
@@ -55,3 +56,59 @@ func ToBinary(s string) (bytes []byte) {
 	}
 	return
 }
+
+type providerOptions struct {
+	timeout     time.Duration
+	apiKey      string
+	credentials string
+	clientID    string
+	secretID    string
+	region      string
+}
+
+// Option for providers.
+type Option func(*providerOptions)
+
+func newProviderOptions(opts ...Option) *providerOptions {
+	options := new(providerOptions)
+	for _, opt := range opts {
+		opt(options)
+	}
+	return options
+}
+
+// WithAPIKey sets the provider API key.
+func WithAPIKey(key string) Option {
+	return func(p *providerOptions) {
+		p.apiKey = key
+	}
+}
+
+// WithCredentials specifies the API credentials.
+func WithCredentials(credentials string) Option {
+	return func(p *providerOptions) {
+		p.credentials = credentials
+	}
+}
+
+// WithOAuth sets the provider client ID & secret options.
+func WithOAuth(clientID, secret string) Option {
+	return func(p *providerOptions) {
+		p.clientID = clientID
+		p.secretID = secret
+	}
+}
+
+// WithTimeout sets the provider timeout option.
+func WithTimeout(timeout time.Duration) Option {
+	return func(p *providerOptions) {
+		p.timeout = timeout
+	}
+}
+
+// WithRegion sets the provider (cloud) region.
+func WithRegion(region string) Option {
+	return func(p *providerOptions) {
+		p.region = region
+	}
+}