Authorization

Mesos 0.20.0 adds support for framework authorization. Authorization allows

1. Frameworks to (re-)register with authorized roles.
2. Frameworks to launch tasks/executors as authorized users.
3. Authorized principals to shutdown framework(s) through "/shutdown" HTTP endpoint.

ACLs

Authorization is implemented via Access Control Lists (ACLs). For each of the 3 cases described above there is a corresponding ACL(s) that can be set to restrict access. Operators can setup ACLs in JSON format. See mesos.proto for details.

Each ACL specifies a set of Subjects that can perform an Action on a set of Objects.

The currently supported Actions are :

1. "register_frameworks" : Register Frameworks
2. "run_tasks" : Run tasks/executors
3. "shutdown_frameworks" : Shutdown frameworks

The currently supported Subjects are :

1. "principals"
   • Framework principals (used by "register_frameworks" and "run_tasks" actions)
   • Usernames (used by "shutdown_frameworks" action)

The currently supported Objects are :

1. "roles" : Resource roles that framework can register with (used by "register_frameworks" action)
2. "users" : Unix user to launch the task/executor as (used by "run_tasks" action)
3. "framework_principals" : Framework principals that can be shutdown by HTTP POST (used by "shutdown_frameworks" action).

NOTE: Both Subjects and Objects can take a list of strings or special values (ANY or NONE).

How does it work?

The Mesos master checks the ACLs to verify whether a request is authorized or not.

For example, when a framework (re-)registers with the master, the "register_frameworks" ACLs are checked to see if the framework (FrameworkInfo.principal) is authorized to receive offers for the given resource role (FrameworkInfo.role). If not authorized, the framework is not allowed to (re-)register and gets an Error message back (which aborts the scheduler driver).

Similarly, when a framework launches a task(s), "run_tasks" ACLs are checked to see if the framework (FrameworkInfo.principal) is authorized to run the task/executor as the given user. If not authorized, the launch is rejected and the framework gets a TASK_LOST.

In the same vein, when a user/principal attempts to shutdown a framework through the "/shutdown" HTTP endpoint on the master, "shutdown_frameworks" ACLs are checked to see if the principal is authorized to shutdown the given framework. If not authorized, the shutdown is rejected and the user receives an Unauthorized HTTP response.

There are couple of important things to note:

1. ACLs are matched in the order that they are setup. In other words, the first matching ACL determines whether a request is authorized or not.

2. If none of the specified ACLs match the given request, whether the request is authorized or not is defined by ACLs.permissive field. By default this is "true" i.e., a non-matching request is authorized.

Examples

1. Frameworks foo and bar can run tasks as user alice.

       {
         "run_tasks": [
                        {
                          "principals": { "values": ["foo", "bar"] },
                          "users": { "values": ["alice"] }
                        }
                      ]
       }
   

2. Any framework can run tasks as user guest.

       {
         "run_tasks": [
                        {
                          "principals": { "type": "ANY" },
                          "users": { "values": ["guest"] }
                        }
                      ]
       }
   

3. No framework can run tasks as root.

       {
         "run_tasks": [
                        {
                          "principals": { "type": "NONE" },
                          "users": { "values": ["root"] }
                        }
                      ]
       }
   

4. Framework foo can run tasks only as user guest and no other user.

       {
         "run_tasks": [
                        {
                          "principals": { "values": [ "foo" ] },
                          "users": { "values": ["guest"] }
                        },
                        {
                          "principals": { "values": [ "foo" ] },
                          "users": { "type": "NONE" }
                        }
                      ]
       }
   

5. Framework foo can register with analytics and ads roles.

       {
         "register_frameworks": [
                                  {
                                    "principals": { "values": ["foo"] },
                                    "roles": { "values": ["analytics", "ads"] }
                                  }
                                ]
       }
   

6. Only framework foo and no one else can register with analytics role.

       {
         "register_frameworks": [
                                  {
                                    "principals": { "values": ["foo"] },
                                    "roles": { "values": ["analytics"] }
                                  },
                                  {
                                    "principals": { "type": "NONE" },
                                    "roles": { "values": ["analytics"] }
                                  }
                                ]
       }
   

7. Framework foo can only register with analytics role but no other roles. Also, no other framework can register with any roles.

       {
         "permissive" : false,
   
         "register_frameworks": [
                                  {
                                    "principals": { "values": ["foo"] },
                                    "roles": { "values": ["analytics"] }
                                  }
                                ]
       }
   

8. Only ops principal can shutdown any frameworks through "/shutdown" HTTP endpoint.

       {
         "permissive" : false,
   
         "shutdown_frameworks": [
                                  {
                                    "principals": { "values": ["ops"] },
                                    "framework_principals": { "type": "ANY" }
                                  }
                                ]
       }
   

Enabling authorization.

As part of this feature, a new flag was added to the master.

• acls : The value could be a JSON formatted string of ACLs or a file path containing the JSON formatted ACLs used for authorization. Path could be of the form 'file:///path/to/file' or '/path/to/file'. See the ACLs protobuf in mesos.proto for the expected format.

For the complete list of master options: ./mesos-master.sh --help