Sunday, September 30, 2012

WSO2 API Manager Introduction-1

WSO2 API Manager is a complete solution for publishing APIs, creating and managing a developer community and for scalably routing API traffic. It leverages proven, production-ready, integration, security and governance components from the WSO2 Enterprise Service Bus, WSO2 Identity Server, andWSO2 Governance Registry. In addition, as it is also powered by the WSO2 Business Activity Monitor, the WSO2 API Manager is ready for massively scalable deployment immediately. Here in this post i will briefly describe key functionalities and terms in WSO2 API manager.

API Gateway
This is responsible for securing, protect, manage, and scale API calls. The API gateway is a simple API proxy which intercepts API requests and applies policies such as throttling and security checks. It is also instrumental in gathering API usage statistics. We are using set for handlers to security validation and throttling purposes.  It will pass web service call to actual back end after these validation steps. If it is token request call then directly pass to keymgt server to handle it. We can add remove these handlers using source view of synapse configuration. When it comes to production deployments this server hits higher number of requests as all api calls goes through this server. So we have to handle this very carefully. Fine tuning and additional configuration changes according to environment is must to achieve highest performance

API Publisher
This enables API providers to easily publish their APIs, share documentation,provision API keys, and gather feedback on APIs features, quality and usage. You can create new apis by pointing to actual back end service and also define rate limiting policies available for this api.
Here are the some of publisher features.
Create, manage API and publish them to gateway.
Monitor API consumers, behaviour, response time, last accessed time and etc.
List the active subscriptions per each API.
Manage life cycles versions and policies. Based on the state of API you can set it to any of following state.
CREATED: API metadata has been added to API store, but it is not visible to subscribers
yet, nor deployed to the API gateway
PUBLISHED: API is visible in API store, and eventually ( if the “Push to Gateway” option is selected at publishing time)
DEPRECATED: API is still deployed into API gateway (available at runtime to existing users) but not visible to subscribers. An API can automatically be deprecated when a new version is published.
RETIRED: API is not unpublished from the API gateway and retired.
BLOCKED: Access is temporarily blocked.

API Store
Provides a space for consumers to self-register, discover APIs functionality, subscribe to APIs, evaluate them and interact with API publishers. Here users can come and view existing apis created and self sign in. After that they can create their own application by bundle multiple apis together to one application. Once user creates application he can generate 3 type of keys.
Application Token - This is security token that can use to call created application API’s
Consumer key, Consumer secret key – These key pair can use to generate a new access token for given application and user.
Later we will see how we can use these key to make actual API call. Here are the feature list for API store.
View top used, new featured APIs and search by name, tag or creator.
API rate, share comments, feature requests and participate forum discussions.
Create, manage application, add remove APIs to application.
Generate application keys consumer and consumer secret keys for application.
Download help and documents contact owners of API and ask questions.
Self-signup for API consumption.

API Key Manager Server
This is responsible for all security and key related operations. Normally when gateway hits API call it calls keymgt service and verify the validity of token provided. And if gateway gets login call it directly forward it to keymgt server. If we discuss little bit about this login call its basically use for get a new access token. So for this we have to pass user name, password, consumer key and consumer secret key you got when you register your application. All tokens use for validation are based on OAuth 2.0.0 protocol.  All secure authorization of APIs is provided using the OAuth 2.0 standard for key management. The API gateway supports API authentication with OAuth 2.0, and it enables IT organizations to enforce rate limits and throttling policies for APIs by consumer.

There are 3 types of users we can consider in API story. Here are those. These roles are based on the privileges they have and tasks they perform.

Creator( The technical owner of an API)
A creator will typically be a person in a technical role who understands the technical aspects of the API (interfaces, documentation, versions, how it will be exposed by API gateway) and uses the API publisher web application to provision APIs into the API store. The creator will use the API store to consult ratings and feedback provided by API users. Creator can add APIs to the store but cannot manage their lifecycle

Publisher( The business owner of an API)
The publisher typically manages a set of APIs across the enterprise or business unit and controls the API lifecycle and monetization aspects. The publisher is also interested in usage patterns for APIs and as such has access to all API statistics.

Consumer(The developer or consumer of an API)
the consumer uses the API store to discover APIs, consult the documentation and forums as well as rate/comments on the API. He/she subscribes to APIs to obtain an API key. Consumers can bundle multiple API’s together into one application and use it. Actual application consumers are user devices it may be computer application or mobile application.
See the following diagram to understand this concept clearly.


1 comment:

  1. Are there WSO2 API's available for BPEL (Human Task) and Single Sign-On external GUI development?