Secure connectivity to tenant specific data centers in pooled SaaS setting - google-cloud-platform

We have an application which we plan to offer as SaaS in pooled mode. In this case a backend service instance will handle requests from multiple tenants. As part of handling requests these back end service instances will have to call API's which are exposed by services that are located in tenant specific data centers. The API's are exposed through private IP's. These data centers can be located on-prem, GCP, AWS, Azure etc.
Assuming we connect SaaS VPC with each of the customer DC using CloudVPN, we can get the connectivity sorted, so that API's can be accessed through private IP's. Now I have two issues:
How do we handle private IP overlaps. Since connected data centers are owned by different tenants, there could be overlaps.
How do we restrict our SaaS backend service from accessing wrong tenant API while processing a request. Say for example, backend service is processing a request from tenant T1 and assume it has an access token associated to T1 while processing this request. With this access token, the service should be able to reach API's exposed by services running on DC of T1, but not T2. We need this access control to be provided at infrastructure level rather than as part of business logic. How can we achieve this in GCP?
Thank you

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How to expose just one microservice from kubernetes cluster outside for existing load balancer and other services - only within cluster

Hello and thanks in advance.
First I want to provide some context to make answering my question easier.
We are using Google Cloud.
We got to a situation when our needs to be able to deploy updates easily for various parts of application bumped into our monolith architectures limitations.
Our app is not super big, but it already has 2 physical services - backend (scope being updated), and caching server which caches data and makes search in a mongo-like way over data from Google Datastore.
We have 2 options here.
"plugins" - like nanoservices running within same process which are developed in a way that these nanoservices do not know they are on the same process, all they know is a set of "plugins shell API" injected at activation of a nanoservice code. This shell gives the nanoservice access to a database, logging, configuration, routes registration, control events like refresh pages map and some metadata like website root url and root of static content deployed as supply stuff for a service version. Like https://static.server.com/deployments/foo/v2
standard microservices on kubernetes where same API mentioned exposed to each service via "shell client" package deployed as part of container image.
In short, this is a common "infrastructure vs library" dilemma, often mentioned in articles about microservices i read.
For library approach I have some vision already on how to implement all that including hot modules replacement without stopping server but the more i read about kubernetes the stronger I feel that I am inventing kubernetes (or similar) wheel.
How I imagine that:
1) there is a router service which is single service exposed outside from the cluster. When a page is requested, and this service attached to the load balancer we already have as backend.
It will handle authentication/authorization of outside requests, and pick the page to be rendered or API endpoint to be invoked. When a page requested, the related template is loaded, and data for pre-rendering is picked by calling related endpoint exposed by module service. When public API endpoint is picked, the matching service endpoint is called.
There are few services, including:
caching service (that service which deployed now at separate servers group, and what
updates service, which process the module services version switch and provides API to do so via some UI for admins.
modules services (one per modules). Each module exposes endpoints for providing preloaded pages data, endpoint to give list of pages routes to be registered, API endpoints implementations, and endpoint to list exposed API routes to be invoked through router service.
router service which process external requests and dispatch them across other services when appropriate using cached routes map, updated in case if one of internal services broadcasts pages map refresh event, e. g. updates service.
What is stopping me from starting to use kubernetes right away is the lack of knowledge about how to implement the following scenarios:
1) only 1 microservice must be exposed outside cluster, the "routing service".
2) reuse builtin services discovery etc to communicate with services within cluster like caching server.
3) Cluster's router service would be attached to cloud load balancer we already have as a backend.
In my opinion, you should have a look at NGINX Ingress Controller to build your routing scheme, more information you can find here and here.
EDIT In addition, you can try some other ingress controllers and among them Istio and Traefik definitely worth your attention as alternative solutions to NGINX Ingress Controller.

WSO2 API Manager - Exposing services to third parties

We have architecture pattern (Layered DMZ) where:
1. External facing applications are deployed in 3 layered DMZ (DMZ1 for Web Server, DMZ2 for App Server and DMZ3 for Database server)
2. We do not allow DMZ1 directly talking to LAN, however DMZ2, DMZ3 can talk to LAN
WSO2 API Manager will be installed in LAN, the issue is how do we expose services from LAN API store to external world. Which design pattern is best suited for this? I have couple of options
Option 1:
Deploy another instance of API Manager in DMZ1 which 3rd party can access
Deploy set of services in DMZ1 API Manager only for 3rd party access
Have reverse proxy in DMZ2 which talks to LAN server
Option2:
Single instance of API Manager deployed in LAN
Reverse proxy in DMZ1
Forward proxy in DMZ2 (which currently we do not have)
Forward proxy talks to LAN
I remember IBM has virtual/physical Datapower appliance which acts as ab external API gateway, how do we achieve similar design pattern with WSO2?
Many thanks in advance
WSO2 API Manager will be installed in LAN, the issue is how do we expose services from LAN API store to external world
WSO2 API Manager has a component API Gateway. Actually todays there are two ways to do that
Use API Gateway
API Gatway is an instance of API Manager with parameters specifying, that the instance is a gateway, so other modules (key manager, store, publisher) are disabled or not used
We use API Gateway in DMZ. This instace will authenticate and authorize the calling clients. However, the gateway still needs to call KeyManager web services for token validation and the publisher needs to call gateway for API deployment
(KeyManager and publisher are the services in the APIM in LAN)
Using API Micro Gateway
Needs to be deployed as individual modules and are able to validate client's tokens (jwt tokens) even without any connection to the LAN instance
Note: When not using static api keys, but OAuth authentication, then you need to expose a route to the token and revoke service
Resources:
https://docs.wso2.com/m/mobile.action#page/97564467
https://apim.docs.wso2.com/en/latest/Learn/APIGateway/overview-of-the-api-gateway/
https://wso2.com/api-management/api-microgateway/
There are several common deployment patterns recommended by WSO2 for API Manager which can be found below.
https://docs.wso2.com/display/AM260/Deployment+Patterns#DeploymentPatterns-WSO2APIManagerdeploymentpatterns
You can go for pattern #4 or #5. Pattern #5 will keep your total cost down in terms of license fee and infrastructure fee.

AWS restrict access to Limited Devices

I have hosted a web application (node.js + angular.js) on AWS ECS service. My requirement is to restrict access to this application to only certain devices and not all device in my organisation.
I am not sure if we can restrict the devices using devices private IP address of individual machine considering they are dynamic in nature.
I cannot use client certification based on this aws article.
Can somebody suggeset any other way or can redirect me in right direction.

How to make Web Services public

i created an android application that requires use of web service
i want it to be able to access the app everywhere therefore i need
my web services to be public with an external ip so i can access
what is the best way to do it?
I have an Amazon Web Services account i dont know if created an instance and run the web services there will be the best solution
My big problem with Amazon instance is that it takes a while to show in the app the result of the web service
Any ideas in how to make my web service public?
It appears that your requirement is:
Expose a public API endpoint for use by your Android application
Run some code when the API is called
There are two ways you could expose an API:
Use Amazon API Gateway, which that can publish, maintain, monitor, and secure APIs. It takes care of security and throttling. A DNS name is provided, which should be used for API calls. When a request is receive, API Gateway can pass the request to a web server or can trigger an AWS Lambda function to execute code without requiring a server.
Or, run an Amazon EC2 instance with your application. Assign an Elastic IP Address to the instance, which is a static IP address. Create an A record in Amazon Route 53 (or your own DNS server) that points a DNS name to that IP address.

How can i set up a private web app on Azure using an App Service Environment

I have a web app and a web service (which will be uploaded to Azure as an web app). How can i make my web service private (not accessible to the public, only accessible by the web app). Apparently you're able to do it with an App Service Environment but there isn't much documentation on it.
Is it possible?
You can follow this article to set it up: https://azure.microsoft.com/en-us/documentation/articles/app-service-web-how-to-create-an-app-service-environment/
The main difference between App Service and App Service Environment (ASE) is that App Services run on a pre-built, shared tenant hyper scaled web farm, but ASEs are purpose built (on demand) web farms provisioned directly in your subscription that must be attached to a VNET. Because you can attach your ASE to a VNET, you can then apply Network Security Groups (NSG) to the VNET to prevent/allow traffic to flow to the ASE.
Here is the page describing how to add the layered security to your ASE once you've built it:
Layered Security Architecture with App Service Environments
So with ASE you get the deployment/monitoring/management features of App Services, but with the network layer control of a VM.
How can i make my web service private (not accessible to the public, only accessible by the web app).
Network Security Groups could be used to control network traffic rules at the networking level, we could apply Network security group to the subnet to let Network security group act as a firewall in the cloud. #Russell Young has shared us a good article about setting up Network security group, you could read it. And you could check this blog that explained securing network access using Network Security Groups.
Besides, it is easy to implement a custom authentication to prevent unauthenticated client from accessing to your Web service at application layer. For example, we could use SOAP headers for authentication. Web service client credentials would be passed within the SOAP header of the SOAP message when the client want to access to Web service, and then Web service will validate SOAP header, if it contains the authentication credentials, the client will be authorized to access to the Web service.
You could check Implement Custom Authentication Using SOAP Headers.