Hi Aarushi, Well thought questions. Some answers/comments inline.
Thanks -Thejaka On Tue, Jun 25, 2019 at 6:38 AM Bisht, Aarushi <[email protected]> wrote: > Hi Thejaka, > > Thank you for the project structure. Besides the above-mentioned modules, > I have also added > > 1. custos-commons - for common utility methods used across custos services > 2. custos-profile-service - which has profile service APIs, handlers and > other utility function for user profile service, tenant profile service and > iamadminservice > 3. thrift-interfaces - thrift files for all models and custos APIs > > Please let me know if any reorganization is required for the above modules. > This is good. We need these. > > I also have a couple of doubts related to some of the points mentioned in > the mail. > > 1. As you mentioned that Custos will provide multi-tenancy > functionalities. If I understand correctly, this means multiple tenants can > be initialized in Custos using Tenant Profile Service(which is currently > present in Airavata). Since I am migrating this service to custos, I want > to understand what does it mean for Airavata. Since Airavata will use > custos profile services, does this mean all tenant operation to Airavata > will be delegated to Custos? > Yes (Assuming "tenant operation" is referring to add/delete/modify tenants, add users to tenants, etc.). Airavata should only work with a reference to the tenant (e.g., tenant id). However, we need to make sure tenant isolation is properly implemented in Airavata (i.e., users in tenant1 should not be able to access any resource belong to a user in tenant2 (unless if they are shared)). > > Also, I am a little confused with the terminology. Airavata is a gateway, > what does allowing multi-tenants in airavata mean? When "public Gateway > addGateway(AuthzToken authzToken, Gateway gateway)" of TenantProfileService > is invoked, does gateway here refers to tenants like PGA, Seagrid? > This is a very good question and I believe Marlon already answered this. As Marlon described, Airavata is a gateway middleware. Scientists can use Airavata to build gateways. Each tenant is a separate gateway. "does gateway here refer to tenants like PGA, Seagrid?" -- correct. > 2. There are modules related to authentication and authorization in > Custos. I can understand the new authenticate flow but I am not very clear > about authorization. When a user invokes an API call, its authentication > will be delegated by Airavata to Custos which will authenticate the user > using the authztoken with Keycloak and return the result to Airavata. > > In case of authorization, every Airavata API call is authorized based on > the group user belongs to, which is either AdminGroup, ReadsOnlyAdminGroup > or a gateway user. The user group information and what groups are > authorized for which API call is kept with Airavata. I do not understand > how will authorization in Custos work? > Good question and I am not 100% sure whether I know the answer for this. I have not touched Airavata code base for a while and I don't clearly understand why we maintain groups within Airavata (why not in Keycloak groups and roles?). Maybe Suresh/Dimuthu or Marlon can explain why we maintain groups in Airavata but not in Keycloak. The way I envision the authorization functionality should be implemented is as follows: The authorization is performed on a particular resource. A resource can be represented using a unique string (sometimes called "permission string") and this string can be associated with an API function. Sometimes these resources hierarchical (e.g., a directory structure) in such cases those string can also be hierarchical ("api/addUser" etc.). Then, there is an action that can be performed on a resource (e.g., "read/write/invoke" etc.). In an API call, we need to make sure the current user has "invoke" permission on the resource associated with the API. So, in summary, Custos need to provide an API like following for authorization: "bool isAuthorize(tenantId, userId, permissionString, action)" Airavata should invoke above Custos API upon invoking the Airavata API. The underlying authorization method is irrelevant to Airavata (i.e., whether Custos is using RBAC or fine-grained authorization etc.) and possibly above method should inspect all inheriting permissions through groups, roles and sharing as well. > Also, I am currently following the first approach to integrate Keycloak > with Custos ie using keycloak as an external service as Airavata was using > this approach. Let me know if this needs to be changed. > +1, let's use this approach. > > Thanks & Regards, > Aarushi Bisht > ________________________________________ > From: Thejaka Amila J Kanewala <[email protected]> > Sent: Monday, June 24, 2019 1:07 PM > To: [email protected] > Subject: Re: Module structure > > Hi Dimuthu, > > I am sorry for the late reply. I thought I play around this first and reply > to your email but I got busy during the weekend and did not get a chance to > experiment around this. Therefore, I do not want to hold you on this > anymore. > > Here is what I had in mind: > > Custos provides the following functionalities: > > 1. Delegate science gateway authentication > 2. Provide transparent resource authentication to science gateways > 3. Provide sharing/multi-tenancy functionalities (what is already in > Airavata) > > To provide some of these functionalities we need an identity server like > Keycloak. So there are two ways we can integrate Keycloak with Custos: 1. > As an external service, 2. As an embedded server running inside Custos > server. > We had different opinions about these two approaches, however, I favored > the second approach as it simplifies the deployment complexity (and I guess > Suresh favored the first approach). The issue with the second approach is > there is no straightforward way to run Keycloak inside Tomcat as an > embedded server. There are a couple of blog posts saying that it is > possible however, I did not get enough time to successfully run them > (theoretically this is possible). > > So, back to your question about the structure. Assuming we take the first > approach (deploy Keycloak as an external server), I would imagine the > directory structure would be something similar to the following: > > modules > - custos-connectors (Connectors to connect to Keycloak or any other > identity server) > - custos-authentication (Delegated authentication) > - custos-authorisation > - custos-resource-authentication (Resource authentication e.g., Amazon, > Google clouds, SSH etc) > - custos-sharing (Airavata sharing) > - custos-credential-store > - custos-dist (Distribution + tomcat server) > - custos-client (Custos client library which will be used by science > gateways) > - custos-test (Integration tests) > > If we use the second approach, in addition to above modules, we will have a > module called "custos-server" which includes changes to embed keycloak > within Tomcat. > > In either case, the above-described structure is not static, it's just a > starting point. We definitely need to re-organize as we develop > functionality. > > Thanks > Best Regards, > Thejaka Amila Kanewala, PhD > https://github.com/thejkane/agm > > On Sun, Jun 16, 2019 at 9:17 PM DImuthu Upeksha < > [email protected]> > wrote: > > > Hi Folks, > > > > Is there a decided module structure for the project? If you have any > > suggestion, please let me know. I'm working on refactoring credential > store > > to support multiple protocols (SSH, S3, Azure, Box and etc) and I believe > > that this might me useful for Custos as well. > > > > Thanks > > Dimuthu > > > > > -- > -- Best Regards, Thejaka Amila Kanewala, PhD https://github.com/thejkane/agm
