WIP

config-vault/src/main/java/io/scalecube/config/vault/VaultInvokers.java

@@ -0,0 +1,85 @@
+package io.scalecube.config.vault;
+
+import java.util.Map;
+import java.util.Objects;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class VaultInvokers {
+
+  public static final Logger LOGGER = LoggerFactory.getLogger(VaultInvokers.class);
+
+  public static final String VAULT_MOUNT_POINT_ENV = "VAULT_MOUNT_POINT";
+  public static final String VAULT_ADDR_ENV = "VAULT_ADDR";
+  public static final String VAULT_TOKEN_ENV = "VAULT_TOKEN";
+  public static final String VAULT_ROLE_ENV = "VAULT_ROLE";
+  public static final String VAULT_JWT_PROVIDER_ENV = "VAULT_JWT_PROVIDER";
+  public static final String VAULT_ENGINE_VERSION_ENV = "VAULT_ENGINE_VERSION";
+
+  public static final String DEFAULT_VAULT_ENGINE_VERSION = "1";
+
+  private VaultInvokers() {
+    // Do not instantiate
+  }
+
+  /**
+   * Creates {@link VaultInvoker}, or throws error if {@link VaultInvoker} instance cannot be
+   * created.
+   *
+   * @return new {@code VaultInvoker} instance, or throws error
+   */
+  public static VaultInvoker newVaultInvokerOrThrow() {
+    final VaultInvoker vaultInvoker = newVaultInvoker();
+    if (vaultInvoker == null) {
+      throw new IllegalStateException("Cannot create vaultInvoker");
+    }
+    return vaultInvoker;
+  }
+
+  /**
+   * Creates and returns new {@link VaultInvoker} instance.
+   *
+   * @return new {@code VaultInvoker} instance
+   */
+  public static VaultInvoker newVaultInvoker() {
+    Map<String, String> env = System.getenv();
+
+    final String vaultAddr = env.get(VAULT_ADDR_ENV);
+    final int vaultEngineVersion =
+        Integer.parseInt(env.getOrDefault(VAULT_ENGINE_VERSION_ENV, DEFAULT_VAULT_ENGINE_VERSION));
+
+    if (isNullOrNone(vaultAddr)) {
+      return null;
+    }
+
+    String vaultToken = env.get(VAULT_TOKEN_ENV);
+    String vaultRole = env.get(VAULT_ROLE_ENV);
+
+    if (isNullOrNone(vaultToken) && isNullOrNone(vaultRole)) {
+      throw new IllegalArgumentException(
+          "Vault auth scheme is required (specify either VAULT_ROLE or VAULT_TOKEN)");
+    }
+
+    final VaultInvoker.Builder builder =
+        VaultInvoker.builder()
+            .options(config -> config.address(vaultAddr).engineVersion(vaultEngineVersion));
+
+    if (!isNullOrNone(vaultRole)) {
+      if (!isNullOrNone(vaultToken)) {
+        LOGGER.warn(
+            "Taking KubernetesVaultTokenSupplier by precedence rule, "
+                + "ignoring EnvironmentVaultTokenSupplier "
+                + "(specify either VAULT_ROLE or VAULT_TOKEN, not both)");
+      }
+      builder.tokenSupplier(new KubernetesVaultTokenSupplier());
+    } else {
+      builder.tokenSupplier(new EnvironmentVaultTokenSupplier());
+    }
+
+    return builder.build();
+  }
+
+  private static boolean isNullOrNone(String value) {
+    return Objects.isNull(value) || "none".equalsIgnoreCase(value);
+  }
+}