roryqi commented on code in PR #10883: URL: https://github.com/apache/gravitino/pull/10883#discussion_r3154324846
########## design-docs/gravitino-local-idp.md: ########## @@ -0,0 +1,679 @@ +<!-- + Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. +--> + +# Design of Local Authentication Support in Gravitino + +## 1. Background + +Apache Gravitino already has mature support for OAuth 2.0 authentication. Today, Gravitino acts as +an OAuth 2.0 client and delegates authentication to an external identity provider (IdP), typically +using the Client Credentials flow together with Bearer JWT. + +This model works well in enterprise deployments where an external IdP such as Okta, Azure AD, or +Keycloak already exists. However, it introduces friction in several important scenarios: + +- **POC and demo environments**: users want to start Gravitino in minutes, without first deploying + and configuring a dedicated IdP. +- **Offline or isolated environments**: air-gapped, edge, or embedded deployments may not have + access to an external identity service. +- **Data sovereignty requirements**: some organizations do not allow identity information to be + managed by an external service. +- **Operational simplicity**: small deployments may not want the cost and maintenance burden of a + separate OAuth server. + +To address these cases, Gravitino should provide an optional built-in local IdP mode with a simple +username/password authentication flow. + +--- + +## 2. Goals + +1. **Lower the barrier to entry**: allow users to evaluate and use Gravitino without deploying an + external IdP. + +2. **Support self-contained deployments**: provide a fully local authentication mechanism for + offline, air-gapped, and privacy-sensitive environments. + +3. **Keep the design intentionally simple**: optimize for POC and small deployment scenarios rather + than building a full-featured general-purpose identity platform. + +4. **Avoid vendor lock-in**: let users run Gravitino in environments where third-party IdPs are + impractical, undesirable, or cost-prohibitive. + +--- + +## 3. Proposal + +### 3.1 Authentication Model + +The local IdP is introduced as a new Gravitino authenticator mode: **basic**. + +When enabled, Gravitino authenticates incoming requests through HTTP Basic authentication: + +```text +Authorization: Basic <base64(username:password)> +``` + +This mode is intended for quick-start deployments and isolated environments. It should work out of +the box with a minimal configuration and without any dependency on an external identity system. + +### 3.2 Why Basic Authentication + +The surveyed systems show that local authentication support typically converges on +username/password-based flows. For Gravitino, simplicity matters more than protocol richness: + +- it shortens time-to-first-use, +- it is easy to explain and operate, +- it fits POC and offline scenarios well, +- and it avoids introducing token lifecycle complexity into the server. + +For these reasons, the initial local IdP implementation uses: + +| Item | Decision | +|---|---| +| Credential type | Username / password | +| Password storage | Database | +| Local token support | No | +| Recommended deployment scope | POC, offline, and isolated scenarios | + +### 3.3 Why Database Storage + +Passwords and user/group metadata should be stored in the Gravitino relational store rather than in +files: + +- **File-based storage** requires a server restart to add users or rotate passwords. +- **Database storage** supports normal metadata-style CRUD operations and matches Gravitino's + existing persistence model. + +Database-backed storage is the most practical choice for a built-in local IdP. + +### 3.4 Module Layout + +The local IdP feature should be implemented as an independent Gravitino module rather than being +scattered directly across the existing `server-common`, `server`, and `core` modules. + +The recommended module name is: + +- `authenticators:authenticator-local-idp` + +This naming keeps the capability grouping explicit and avoids tying the module name to the HTTP +Basic transport syntax alone. Although the initial login flow uses Basic authentication, the module +itself is responsible for the broader local IdP capability set, including: + +- local user and local group management, +- password hashing and verification, +- bootstrap credential handling, +- and the local IdP management API wiring. + +At a high level, the implementation can still integrate with existing Gravitino modules as needed: + +- `core` for relational storage integration, +- `server-common` for authenticator/filter extension points, +- and `server` for REST resource exposure. + +However, the Local IdP-specific logic should be owned primarily by +`authenticators:authenticator-local-idp` so that the feature has a clear packaging boundary and can +evolve independently from the generic server authentication framework. + +--- + +## 4. Password Hashing + +User credentials must never be stored in plaintext. Passwords are stored as password hashes in the +database. + +Among the common password hashing algorithms, **Argon2id** is the recommended choice for +Gravitino. + +| Algorithm | Status | +|---|---| +| Argon2id | Recommended default | + +The initial design uses **Argon2id** as the only supported algorithm, which keeps the +implementation simple while aligning with modern password storage recommendations. + +To make this implementable, the password hashing design should also define the storage and +dependency model explicitly: + +- introduce one dedicated server-side password-hashing dependency that supports Argon2id +- store the full Argon2id hash string in `password_hash`, including algorithm marker, parameters, + salt, and hash output +- use a self-describing format so future parameter tuning does not require schema changes + +For example, `password_hash` should store a PHC-style string such as: + +```text +$argon2id$v=19$m=65536,t=3,p=1$<salt>$<hash> +``` + +This keeps verification logic simple and allows future upgrades of Argon2id cost parameters without +introducing additional columns. + +--- + +## 5. Data Model + +The local IdP requires three new tables: + +1. `local_user_meta` — local user records +2. `local_group_meta` — local group records +3. `local_group_user_rel` — user/group membership mapping + +These tables follow Gravitino's existing metadata table conventions: + +- numeric primary keys, +- `audit_info`, +- optimistic version fields, +- and `deleted_at` for soft deletion. + +Soft-deleted rows in `local_user_meta` and `local_group_meta` should be cleaned asynchronously by +Gravitino's GC thread, following the same lifecycle management pattern used by other metadata +tables. When a local user or local group is physically removed by the GC thread, the implementation +should also clean the corresponding soft-deleted rows in `local_group_user_rel` to avoid leaving +orphaned membership records. + +Unlike Gravitino's existing `user_meta` and `group_meta` tables, `local_user_meta` and +`local_group_meta` are intentionally designed as **global identity tables** and therefore **do not +contain `metalake_id`**. The purpose of these tables is to store local authentication identities +and credentials once at the server level, instead of duplicating the same login identity in every +metalake. + +### 5.1 `local_user_meta` + +```sql +CREATE TABLE IF NOT EXISTS `local_user_meta` ( + `user_id` BIGINT(20) UNSIGNED NOT NULL COMMENT 'user id', + `user_name` VARCHAR(128) NOT NULL COMMENT 'username', + `password_hash` VARCHAR(1024) NOT NULL COMMENT 'hashed password', + `audit_info` MEDIUMTEXT NOT NULL COMMENT 'user audit info', + `current_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'user current version', + `last_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'user last version', + `deleted_at` BIGINT(20) UNSIGNED NOT NULL DEFAULT 0 COMMENT 'user deleted at', + PRIMARY KEY (`user_id`), + UNIQUE KEY `uk_un_del` (`user_name`, `deleted_at`) +) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT 'local user metadata'; +``` + +### 5.2 `local_group_meta` + +```sql +CREATE TABLE IF NOT EXISTS `local_group_meta` ( + `group_id` BIGINT(20) UNSIGNED NOT NULL COMMENT 'group id', + `group_name` VARCHAR(128) NOT NULL COMMENT 'group name', + `audit_info` MEDIUMTEXT NOT NULL COMMENT 'group audit info', + `current_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'group current version', + `last_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'group last version', + `deleted_at` BIGINT(20) UNSIGNED NOT NULL DEFAULT 0 COMMENT 'group deleted at', + PRIMARY KEY (`group_id`), + UNIQUE KEY `uk_gn_del` (`group_name`, `deleted_at`) +) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT 'local group metadata'; +``` + +### 5.3 `local_group_user_rel` + +```sql +CREATE TABLE IF NOT EXISTS `local_group_user_rel` ( + `id` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT 'auto increment id', + `group_id` BIGINT(20) UNSIGNED NOT NULL COMMENT 'local group id', + `user_id` BIGINT(20) UNSIGNED NOT NULL COMMENT 'local user id', + `audit_info` MEDIUMTEXT NOT NULL COMMENT 'relation audit info', + `current_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'relation current version', + `last_version` INT UNSIGNED NOT NULL DEFAULT 1 COMMENT 'relation last version', + `deleted_at` BIGINT(20) UNSIGNED NOT NULL DEFAULT 0 COMMENT 'relation deleted at', + PRIMARY KEY (`id`), + UNIQUE KEY `uk_gi_ui_del` (`group_id`, `user_id`, `deleted_at`), + KEY `idx_uid` (`user_id`) +) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT 'local group user relation'; +``` + +### 5.4 Relationship Model + +The logical entity relationship is straightforward: + +```text +local_user_meta + └──< local_group_user_rel >── local_group_meta +``` + +For integration with Gravitino's existing access control model, the local IdP tables are also +logically associated with the existing metadata tables: + +- `local_user_meta` is associated with `user_meta` through `user_name` +- `local_group_meta` is associated with `group_meta` through `group_name` + +In other words, `local_user_meta` stores local authentication credentials, while `user_meta` +continues to represent the Gravitino user object used by the current authorization model. +Similarly, `local_group_meta` stores local group identities, while `group_meta` remains the +authorization-side group metadata. + +Because `user_meta` and `group_meta` are metalake-scoped while `local_user_meta` and +`local_group_meta` are global, this association should be treated as a **name-based logical +mapping**, not as a database-level one-to-one foreign key constraint. A single local user or local +group may correspond to multiple `user_meta` or `group_meta` entries with the same name across +different metalakes. + +The combined relationship can be viewed as: + +```text +local_user_meta --(user_name, logical mapping)--> user_meta[*] +local_group_meta --(group_name, logical mapping)--> group_meta[*] + +local_user_meta + └──< local_group_user_rel >── local_group_meta +``` + +This supports direct username lookup for authentication, group resolution for authorization, and a +clear mapping from local IdP identities to Gravitino's existing user/group metadata model while +preserving the requirement that local identity tables remain global and metalake-agnostic. + +--- + +## 6. Bootstrap Experience + +To keep local IdP mode usable immediately after installation, Gravitino should provision a default +administrator account on first startup. + +### 6.1 Initial Administrator + +- only one bootstrap account is created by default: the configured **service admin** account (for + example, **adminUser**) +- the default password is **123456** +- the default password **123456** is intended only for the initial bootstrap login and the immediate + password reset flow +- other management operations must not rely on the bootstrap password +- after the first login, the service admin is expected to reset the bootstrap password immediately + +This design favors usability for POC scenarios. The default password is intentionally simple so that +the service admin can complete the bootstrap flow immediately, but it must be treated as a +bootstrap-only credential rather than as a secure long-term password or a general-purpose access +credential for other APIs. + +### 6.2 Bootstrap Process + +The bootstrap process should be: + +1. When the `basic` authenticator is enabled for the first time, check whether the configured + bootstrap **service admin** account already exists in `local_user_meta`. +2. If the bootstrap account does not exist, the web filter allows the configured bootstrap service + admin account (for example, **adminUser**) with password **123456** to pass Basic verification + only for the bootstrap login and immediate password reset flow. +3. Reject other management operations until the bootstrap password has been reset successfully. +4. During the first successful password reset, create the bootstrap service admin record and store + the new password hash in `password_hash`. +5. After the password reset succeeds, treat the account as a normal service admin account for later + authentication and authorization. + +### 6.3 Example Basic Authentication Bootstrap Flow + +The following end-to-end flow shows how a user can start from a fresh Gravitino deployment, enable +Basic authentication, configure the bootstrap service admin identity, and immediately rotate the +bootstrap password. + +1. Deploy Gravitino with the `basic` authenticator enabled: + + ```properties + gravitino.authenticators=basic + gravitino.authenticator.basic.passwordHasher=Argon2id + gravitino.authorization.serviceAdmins=adminUser + ``` + +2. Start Gravitino. + +3. On first startup, no active `adminUser` record exists yet in `local_user_meta`, so Gravitino + accepts the bootstrap credential `adminUser:123456` only for the bootstrap login and immediate + password reset flow. + +4. Call the password reset API with HTTP Basic authentication: + + ```bash + curl -X PUT \ + -u 'adminUser:123456' \ + -H 'Content-Type: application/json' \ + https://<gravitino-host>/api/idp/users/adminUser \ + -d '{ + "password": "ChangeMeToAStrongPassword" + }' + ``` + +5. If the request succeeds, Gravitino creates the bootstrap `adminUser` record in + `local_user_meta` and stores the new Argon2id password hash. + +6. After that point, the bootstrap password `123456` is no longer accepted, and the service admin + must use the new password for later management APIs: + + ```bash + curl -u 'adminUser:ChangeMeToAStrongPassword' \ + https://<gravitino-host>/api/idp/users/adminUser + ``` + +This flow makes the first-use experience explicit: deployment enables the feature, the +`adminUser` identity is recognized through `gravitino.authorization.serviceAdmins`, and the +default bootstrap password is usable only once to complete the initial password rotation. + +--- + +## 7. Authentication Flow + +### 7.1 User Verification + +The user verification flow is: + +1. Read the `Authorization` header and verify that it uses the `Basic` scheme. +2. Decode the Base64 payload and split the decoded credential on the first colon to get `username` + and `password`. +3. Query `local_user_meta` by `user_name` and `deleted_at = 0`. +4. If no active user is found and the credential is the configured bootstrap service admin account + with the default password (for example, **adminUser:123456**), allow only the + bootstrap login and immediate password reset flow. +5. If no active user is found for any other credential, reject the request with **401**. +6. If the user is the bootstrap service admin and the bootstrap password is still in use, allow only + the bootstrap login and password reset flow. +7. If the request targets another management operation while the bootstrap password is still active, + reject the request. +8. If the user passes these checks, continue to password verification. + +### 7.2 Password Verification + +The password verification flow is: + +1. Query `local_user_meta` by `user_name` and `deleted_at = 0`. +2. Read the stored `password_hash`. +3. Verify the submitted password against `password_hash` using the configured hashing algorithm. +4. If verification succeeds, authenticate the request; otherwise reject it. + +### 7.3 Group Resolution + +The local user's groups are resolved by: + +1. Query `local_user_meta` by username and `deleted_at = 0` to get `user_id`. +2. Query `local_group_user_rel` by `user_id` to get all active `group_id` values. +3. Query `local_group_meta` by those `group_id` values to load the full group set. + +This keeps the model aligned with Gravitino's existing authorization architecture, where user-group +relationships are an input to later privilege evaluation. + +### 7.4 Web Filter Behavior + +The local authenticator is implemented as a web filter in the request pipeline. + +The proposed behavior is: + +1. Read the `Authorization` header. +2. Verify that it uses the `Basic` scheme. +3. Decode the Base64 payload. If decoding fails, return **400**. +4. Split the decoded credential on the first colon to extract `username` and `password`. +5. Look up the local user. +6. If the user does not exist or the password verification fails, return **401**. +7. If authentication is challenged, include a `WWW-Authenticate: Basic` response header. +8. If all checks pass, continue request processing as the authenticated principal. + +> The exact HTTP status mapping should be aligned with Gravitino's existing authentication and +> exception handling conventions during implementation. A better default is: +> malformed Basic header → `400`; missing user or invalid password → `401`. + +### 7.5 Transport Security + +HTTP Basic authentication should be used over **HTTPS**. + +If Basic authentication is enabled on plain HTTP, Gravitino should emit a warning-level log because +credentials are otherwise exposed on the wire. + +--- + +## 8. Configuration + +### 8.1 Authenticator Selection + +Add `basic` to the configurable values of `gravitino.authenticators`. + +| Key | New Value | Default | Optional Values | +|---|---|---|---| +| `gravitino.authenticators` | `basic` | `simple` | `simple`, `oauth`, `kerberos`, `basic` | + +This should follow Gravitino's existing multi-authenticator behavior: multiple authenticators are +comma-separated, and if a request is supported by multiple authenticators simultaneously, the first +matching authenticator wins. + +The Local IdP management capability is enabled only when `basic` is included in +`gravitino.authenticators`. If `basic` is not enabled, Gravitino should not allow Local IdP-related +management APIs to be used. + +### 8.2 Password Algorithm Configuration + +Add a dedicated configuration for password hashing. + +To align with Gravitino's current configuration naming convention, authenticator-specific settings +should use the `gravitino.authenticator.<mode>.*` prefix rather than +`gravitino.authenticators.<mode>.*`. + +| Key | Default | Optional Values | +|---|---|---| +| `gravitino.authenticator.basic.passwordHasher` | `Argon2id` | `Argon2id` | + +Even though the initial implementation supports only one algorithm, an explicit configuration key +keeps the design extensible and makes the hashing choice visible in configuration. + +--- + +## 9. Administrative Operations + +The local IdP must support the following administrator-managed operations: + +- get user +- add user +- remove user +- change user password +- get group +- add group +- remove group +- add user to group +- remove user from group + +These operations are expected to be performed by the service admin. After membership changes, +administrators should be able to inspect group information and user information to verify the +result. + +At a high level: + +1. **Get user**: read the local user information and its current group memberships. +2. **Add user**: create a new local user with a hashed password. +3. **Remove user**: soft-delete the user record. +4. **Change user password**: reset the password hash for an existing local user through an + administrator-managed operation. +5. **Get group**: read the local group information and its current user memberships. +6. **Add group**: create a new local group. +7. **Remove group**: soft-delete the group record. +8. **Add user to group**: create a row in `local_group_user_rel`. +9. **Remove user from group**: soft-delete the corresponding relation row. + +### 9.1 HTTP Interface Design + +The following APIs are intended for local user, local group, and group-membership management. + +Because local IdP identities are global rather than metalake-scoped, these management interfaces do +not include `{metalake}` in their paths and use the `/api/idp` prefix. + +These APIs are available only when the `basic` authenticator is enabled. If `basic` is not enabled, +requests to these Local IdP management endpoints should be rejected rather than treated as available +server APIs. + +All of the following operations are administrator-managed operations. They are intended to be called +by the configured service admin rather than by end users. + +#### 9.1.1 Get a local user + +You can get a local user by its name. The response should include the user name and current group +memberships. + +The request path for REST API is `/api/idp/users/{user}`. + +```shell +curl -X GET -H "Accept: application/vnd.gravitino.v1+json" \ +http://localhost:8090/api/idp/users/alice +``` + +#### 9.1.2 Create a local user + +You can create a local user by providing a user name and password. The password must be stored as a +hash rather than plaintext. + +The request path for REST API is `/api/idp/users`. + +```shell +curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \ +-H "Content-Type: application/json" -d '{ + "user": "alice", + "password": "Passw0rd-For-Alice" +}' http://localhost:8090/api/idp/users +``` + +#### 9.1.3 Remove a local user + +You can remove a local user by its name. This operation should soft-delete the user record rather +than physically remove it immediately. + +The request path for REST API is `/api/idp/users/{user}`. + +```shell +curl -X DELETE -H "Accept: application/vnd.gravitino.v1+json" \ +http://localhost:8090/api/idp/users/alice +``` + +#### 9.1.4 Reset a local user password + +You can reset the password of an existing local user by providing a new password. This API is an +administrator-managed password reset API rather than an end-user self-service password change API. + +The request path for REST API is `/api/idp/users/{user}`. + +```shell +curl -X PUT -H "Accept: application/vnd.gravitino.v1+json" \ +-H "Content-Type: application/json" -d '{ + "password": "Passw0rd-For-Alice-V2" +}' http://localhost:8090/api/idp/users/alice +``` + +The password reset API follows these rules: + +- it does not support end-user self-service password changes +- it does not accept `oldPassword` +- only the service admin can reset account passwords +- the user name cannot contain a colon (`:`); the Basic credential should be parsed by splitting on + the first colon, so the password may contain additional colons (RFC 7617) +- the password must be at least 12 characters long and at most 64 characters long + +The password reset API should return: + +| Error case | HTTP status | +|---|---| +| Account doesn't exist | `404` | +| Password same with old | `422` | + +#### 9.1.5 Get a local group + +You can get a local group by its name. The response should include the group name and current user +memberships. + +The request path for REST API is `/api/idp/groups/{group}`. + +```shell +curl -X GET -H "Accept: application/vnd.gravitino.v1+json" \ +http://localhost:8090/api/idp/groups/engineering +``` + +#### 9.1.6 Create a local group + +You can create a local group by providing a group name. + +The request path for REST API is `/api/idp/groups`. + +```shell +curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \ +-H "Content-Type: application/json" -d '{ + "group": "engineering" +}' http://localhost:8090/api/idp/groups +``` + +#### 9.1.7 Remove a local group + +You can remove a local group by its name. This operation should soft-delete the group record rather +than physically remove it immediately. + +The request path for REST API is `/api/idp/groups/{group}`. + +```shell +curl -X DELETE -H "Accept: application/vnd.gravitino.v1+json" \ +http://localhost:8090/api/idp/groups/engineering +``` + +#### 9.1.8 Add users to a local group + +You can add users to a local group by providing the group name in the path and the target user +names in the request body. + +The request path for REST API is `/api/idp/groups/{group}/users`. Review Comment: I am not sure whether this is ok. Maybe collect others' suggestion. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
