Azure Key Vault integration to resolve secrets (#4090)

vault/vault.go

@@ -0,0 +1,38 @@
+package vault
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/actions/actions-runner-controller/vault/azurekeyvault"
+)
+
+// Vault is the interface every vault implementation needs to adhere to
+type Vault interface {
+	GetSecret(ctx context.Context, name string) (string, error)
+}
+
+// VaultType represents the type of vault that can be used in the application.
+// It is used to identify which vault integration should be used to resolve secrets.
+type VaultType string
+
+// VaultType is the type of vault supported
+const (
+	VaultTypeAzureKeyVault VaultType = "azure_key_vault"
+)
+
+func (t VaultType) String() string {
+	return string(t)
+}
+
+func (t VaultType) Validate() error {
+	switch t {
+	case VaultTypeAzureKeyVault:
+		return nil
+	default:
+		return fmt.Errorf("unknown vault type: %q", t)
+	}
+}
+
+// Compile-time checks
+var _ Vault = (*azurekeyvault.AzureKeyVault)(nil)