fixes#3868
docker image - `hasura/graphql-engine:inherited-roles-preview-48b73a2de`
Note:
To be able to use the inherited roles feature, the graphql-engine should be started with the env variable `HASURA_GRAPHQL_EXPERIMENTAL_FEATURES` set to `inherited_roles`.
Introduction
------------
This PR implements the idea of multiple roles as presented in this [paper](https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/FGALanguageICDE07.pdf). The multiple roles feature in this PR can be used via inherited roles. An inherited role is a role which can be created by combining multiple singular roles. For example, if there are two roles `author` and `editor` configured in the graphql-engine, then we can create a inherited role with the name of `combined_author_editor` role which will combine the select permissions of the `author` and `editor` roles and then make GraphQL queries using the `combined_author_editor`.
How are select permissions of different roles are combined?
------------------------------------------------------------
A select permission includes 5 things:
1. Columns accessible to the role
2. Row selection filter
3. Limit
4. Allow aggregation
5. Scalar computed fields accessible to the role
Suppose there are two roles, `role1` gives access to the `address` column with row filter `P1` and `role2` gives access to both the `address` and the `phone` column with row filter `P2` and we create a new role `combined_roles` which combines `role1` and `role2`.
Let's say the following GraphQL query is queried with the `combined_roles` role.
```graphql
query {
employees {
address
phone
}
}
```
This will translate to the following SQL query:
```sql
select
(case when (P1 or P2) then address else null end) as address,
(case when P2 then phone else null end) as phone
from employee
where (P1 or P2)
```
The other parameters of the select permission will be combined in the following manner:
1. Limit - Minimum of the limits will be the limit of the inherited role
2. Allow aggregations - If any of the role allows aggregation, then the inherited role will allow aggregation
3. Scalar computed fields - same as table column fields, as in the above example
APIs for inherited roles:
----------------------
1. `add_inherited_role`
`add_inherited_role` is the [metadata API](https://hasura.io/docs/1.0/graphql/core/api-reference/index.html#schema-metadata-api) to create a new inherited role. It accepts two arguments
`role_name`: the name of the inherited role to be added (String)
`role_set`: list of roles that need to be combined (Array of Strings)
Example:
```json
{
"type": "add_inherited_role",
"args": {
"role_name":"combined_user",
"role_set":[
"user",
"user1"
]
}
}
```
After adding the inherited role, the inherited role can be used like single roles like earlier
Note:
An inherited role can only be created with non-inherited/singular roles.
2. `drop_inherited_role`
The `drop_inherited_role` API accepts the name of the inherited role and drops it from the metadata. It accepts a single argument:
`role_name`: name of the inherited role to be dropped
Example:
```json
{
"type": "drop_inherited_role",
"args": {
"role_name":"combined_user"
}
}
```
Metadata
---------
The derived roles metadata will be included under the `experimental_features` key while exporting the metadata.
```json
{
"experimental_features": {
"derived_roles": [
{
"role_name": "manager_is_employee_too",
"role_set": [
"employee",
"manager"
]
}
]
}
}
```
Scope
------
Only postgres queries and subscriptions are supported in this PR.
Important points:
-----------------
1. All columns exposed to an inherited role will be marked as `nullable`, this is done so that cell value nullification can be done.
TODOs
-------
- [ ] Tests
- [ ] Test a GraphQL query running with a inherited role without enabling inherited roles in experimental features
- [] Tests for aggregate queries, limit, computed fields, functions, subscriptions (?)
- [ ] Introspection test with a inherited role (nullability changes in a inherited role)
- [ ] Docs
- [ ] Changelog
Co-authored-by: Vamshi Surabhi <6562944+0x777@users.noreply.github.com>
GitOrigin-RevId: 3b8ee1e11f5ceca80fe294f8c074d42fbccfec63
This PR generalizes a bunch of metadata structures.
Most importantly, it changes `SourceCache` to hold existentially quantified values:
```
data BackendSourceInfo =
forall b. Backend b => BackendSourceInfo (SourceInfo b)
type SourceCache = HashMap SourceName BackendSourceInfo
```
This changes a *lot* of things throughout the code. For now, all code using the schema cache explicitly casts sources to Postgres, meaning that if any non-Postgres `SourceInfo` makes it to the cache, it'll be ignored.
That means that after this PR is submitted, we can split work between two different aspects:
- creating `SourceInfo` for other backends
- handling those other sources down the line
GitOrigin-RevId: fb9ea00f32e840fc33c5467896fb1dfa5283ab42
Fixes https://github.com/hasura/graphql-engine/issues/5704 by checking, for aggregate fields whether we are handling a numeric aggregation.
This PR also adds type information to `ColFld` such that we know the type of the field.
This is the second attempt. See #319 for a less invasive approach. @nicuveo suggested type information might be useful, and since it wasn't hard to add, I think this version is better as well.
GitOrigin-RevId: aa6a259fd5debe9466df6302839ddbbd0ea659b5
This PR makes a bunch of schema generation code in Hasura.GraphQL.Schema backend-agnostic, by moving the backend-specific parts into a new BackendSchema type class. This way, the schema generation code can be reused for other backends, simply by implementing new instances of the BackendSchema type class.
This work is now in a state where the schema generators are sufficiently generic to accept the implementation of a new backend. That means that we can start exposing MS SQL schema. Execution is not implemented yet, of course.
The branch currently does not support computed fields or Relay. This is, in a sense, intentional: computed field support is normally baked into the schema generation (through the fieldSelection schema generator), and so this branch shows a programming technique that allows us to expose certain GraphQL schema depending on backend support. We can write support for computed fields and Relay at a later stage.
Co-authored-by: Antoine Leblanc <antoine@hasura.io>
GitOrigin-RevId: df369fc3d189cbda1b931d31678e9450a6601314
