workflow-plugin-authz

workflow-plugin-authz

⚠️ Experimental — This plugin compiles and passes its unit tests but has not been validated in any active GoCodeAlone-internal production deployment. Use with caution. Please open an issue if you adopt it so we can promote it to verified status.

RBAC authorization plugin for the workflow engine using Casbin.

Capabilities

authz.casbin module

Loads a Casbin PERM model and policy from inline YAML config. The enforcer is thread-safe and shared with all step.authz_check_casbin steps that reference the module by name.

modules:
  - name: authz
    type: authz.casbin
    config:
      model: |
        [request_definition]
        r = sub, obj, act
        [policy_definition]
        p = sub, obj, act
        [role_definition]
        g = _, _
        [policy_effect]
        e = some(where (p.eft == allow))
        [matchers]
        m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act
      policies:
        - ["admin", "/*", "*"]
        - ["editor", "/api/*", "GET"]
        - ["editor", "/api/*", "POST"]
        - ["viewer", "/api/*", "GET"]
      roleAssignments:
        - ["alice", "admin"]
        - ["bob", "editor"]
        - ["carol", "viewer"]

step.authz_check_casbin pipeline step

Checks whether the authenticated user (injected by step.auth_required) has permission to perform the configured action on the configured object. Returns HTTP 403 and stops the pipeline on denial.

steps:
  - type: step.auth_required   # sets auth_user_id in output
    config: {}

  - type: step.authz_check_casbin
    config:
      module: authz             # authz.casbin module name (default: "authz")
      subject_key: auth_user_id # step output key for the subject (default: "auth_user_id")
      object: "/api/v1/tenants" # static path, or Go template: "{{.request_path}}"
      action: "POST"            # static method, or Go template: "{{.request_method}}"

On success the step outputs:

{
  "authz_subject": "alice",
  "authz_object": "/api/v1/tenants",
  "authz_action": "POST",
  "authz_allowed": true
}

On denial (HTTP 403):

{
  "response_status": 403,
  "response_body": "{\"error\":\"forbidden: bob is not permitted to POST /api/v1/tenants\"}",
  "response_headers": {"Content-Type": "application/json"},
  "authz_allowed": false
}

step.authz_add_policy pipeline step

Adds a policy rule to the Casbin enforcer at runtime; when the rule actually changes the policy (that is, it is newly added), the step saves the updated policy via the module's configured Casbin adapter (file/GORM adapters persist to their backing store, while the in-memory adapter keeps changes for the lifetime of the process). Each element of rule may be a static string or a Go template rendered against the merged pipeline context (trigger data, prior step outputs, and current context).

steps:
  - type: step.authz_add_policy
    config:
      module: authz                        # authz.casbin module name (default: "authz")
      rule: ["editor", "/api/posts", "POST"] # policy rule; each element may be a Go template

Template-based rule (values resolved from the pipeline context at runtime):

steps:
  - type: step.authz_add_policy
    config:
      module: authz
      rule: ["{{.role}}", "{{.resource}}", "{{.method}}"]

On success the step outputs:

{
  "authz_policy_added": true,
  "authz_rule": ["editor", "/api/posts", "POST"]
}

authz_policy_added is false when the rule already existed in the enforcer.

step.authz_remove_policy pipeline step

Removes a policy rule from the Casbin enforcer at runtime. Mirrors step.authz_add_policy in configuration; each element of rule may be a static string or a Go template.

steps:
  - type: step.authz_remove_policy
    config:
      module: authz                        # authz.casbin module name (default: "authz")
      rule: ["editor", "/api/posts", "POST"] # policy rule to remove; elements may be Go templates

Template-based rule:

steps:
  - type: step.authz_remove_policy
    config:
      module: authz
      rule: ["{{.role}}", "{{.resource}}", "{{.method}}"]

On success the step outputs:

{
  "authz_policy_removed": true,
  "authz_rule": ["editor", "/api/posts", "POST"]
}

authz_policy_removed is false when the rule did not exist in the enforcer.

step.authz_role_assign pipeline step

Adds or removes role mappings (grouping policies) in the Casbin enforcer at runtime. Useful for provisioning authorization when new users or tenants are onboarded.

Assign roles (static):

steps:
  - type: step.authz_role_assign
    config:
      module: authz
      action: add                          # "add" (default) or "remove"
      assignments:
        - ["alice", "admin"]
        - ["bob", "editor"]

Assign a role using templates (values resolved from the pipeline context at runtime):

steps:
  - type: step.authz_role_assign
    config:
      module: authz
      action: add
      assignments:
        - ["{{.new_user_id}}", "{{.tenant_role}}"]

Revoke a role:

steps:
  - type: step.authz_role_assign
    config:
      module: authz
      action: remove
      assignments:
        - ["bob", "editor"]

On success the step outputs:

{
  "authz_role_action": "add",
  "authz_role_assignments": [["alice", "admin"], ["bob", "editor"]]
}

Unified authorization decisions

step.authz_check routes one Workflow gate through the configured provider and mode. Use it for route guards, workflow action guards, and module-owned admin actions without coupling YAML to Casbin, Keto, or Permit-specific APIs.

steps:
  - type: step.authz_require_capabilities
    config:
      provider: keto
      module: authz
      requirements:
        - mode: rebac
          operations: [check, manage_relations]

  - type: step.authz_check
    config:
      provider: casbin
      module: authz
      mode: rbac
      subject: "{{.auth_user_id}}"
      context: admin
      scope: admin:authz.roles:update

Go modules can call the same service surface through Workflow's module/service registry; the request shape is provider-neutral:

decision, err := authzService.InvokeMethod("CheckRelation", map[string]any{
    "subject": userID,
    "context": "frontend",
    "object": documentID,
    "relation": "owner",
})

Build

make build   # outputs bin/workflow-plugin-authz
make test    # run tests with race detector

Install

make install INSTALL_DIR=data/plugins/workflow-plugin-authz