Zowe is an open source project that is created to host technologies that benefit the Z platform from all members of the Z community, including Integrated Software Vendors, System Integrators, and z/OS consumers. Zowe, like Mac or Windows, comes with a set of APIs and OS capabilities that applications build on and also includes some applications out of the box.
Zowe offers modern interfaces to interact with z/OS and allows you to work with z/OS in a way that is similar to what you experience on cloud platforms today. You can use these interfaces as delivered or through plug-ins and extensions that are created by clients or third-party vendors.
Zowe consists of the following main components. For details of each component, see the corresponding section.
Zowe Application Framework: A web user interface (UI) that provides a virtual desktop containing a number of apps allowing access to z/OS function. Base Zowe includes apps for traditional access such as a 3270 terminal and a VT Terminal, as well as an editor and explorers for working with JES, MVS Data Sets and Unix System Services.
z/OS Services: Provides a range of APIs for the management of z/OS JES jobs and MVS data set services.
API Mediation Layer: Provides a gateway that acts as a reverse proxy for z/OS services, together with a catalog of REST APIs and a dynamic discovery capability. Base Zowe provides core services for working with MVS Data Sets, JES, as well as working with z/OSMF REST APIs. The API Mediation Layer also provides a framework for Single Sign On (SSO).
Zowe CLI: Provides a command-line interface that lets you interact with the mainframe remotely and use common tools such as Integrated Development Environments (IDEs), shell commands, bash scripts, and build tools for mainframe development. It provides a set of utilities and services for application developers that want to become efficient in supporting and building z/OS applications quickly. It provides a core set of commands for working with data sets, USS, JES, as well as issuing TSO and console commands. Some Zowe extensions are powered by Zowe CLI, for example the Visual Studio Code Extension for Zowe.
Check out the video below for a demo of the modern interfaces that Zowe provides.
Zowe Application Framework
The Zowe Application Framework modernizes and simplifies working on the mainframe. With the Zowe Application Framework, you can create applications to suit your specific needs. The Zowe Application Framework contains a web UI that has the following features:
- The web UI works with the underlying REST APIs for data, jobs, and subsystem, but presents the information in a full screen mode as compared to the command line interface.
- The web UI makes use of leading-edge web presentation technology and is also extensible through web UI plug-ins to capture and present a wide variety of information.
- The web UI facilitates common z/OS developer or system programmer tasks by providing an editor for common text-based files like REXX or JCL along with general purpose data set actions for both Unix System Services (USS) and Partitioned Data Sets (PDS) plus Job Entry System (JES) logs.
The Zowe Application Framework consists of the following components:
The desktop, accessed through a browser.
Zowe Application Server
The Zowe Application Server runs the Zowe Application Framework. It consists of the Node.js server plus the Express.js as a webservices framework, and the proxy applications that communicate with the z/OS services and components.
The ZSS Server provides secure REST services to support the Zowe Application Server.
Several application-type plug-ins are provided. For more information, see Using the Zowe Application Framework application plug-ins.
Zowe provides a z/OS® RESTful web service and deployment architecture for z/OS microservices. Zowe contains the following core z/OS services:
z/OS Datasets services
Get a list of jobs, get content from a job file output, submit job from a data set, and more.
z/OS Jobs services
Get a list of data sets, retrieve content from a member, create a data set, and more.
You can view the full list of capabilities of the RESTful APIs from the API catalog that displays the Open API Specification for their capabilities.
- These APIs are described by the Open API Specification allowing them to be incorporated to any standard-based REST API developer tool or API management process.
- These APIs can be exploited by off-platform applications with proper security controls.
As a deployment architecture, the z/OS Services are running as microservices with a Springboot embedded Tomcat stack.
Zowe CLI is a command-line interface that lets application developers interact with the mainframe in a familiar format. Zowe CLI helps to increase overall productivity, reduce the learning curve for developing mainframe applications, and exploit the ease-of-use of off-platform tools. Zowe CLI lets application developers use common tools such as Integrated Development Environments (IDEs), shell commands, bash scripts, and build tools for mainframe development. It provides a set of utilities and services for application developers that want to become efficient in supporting and building z/OS applications quickly.
Zowe CLI provides the following benefits:
- Enables and encourages developers with limited z/OS expertise to build, modify, and debug z/OS applications.
- Fosters the development of new and innovative tools from a computer that can interact with z/OS.
- Ensure that business critical applications running on z/OS can be maintained and supported by existing and generally available software development resources.
- Provides a more streamlined way to build software that integrates with z/OS.
Note: For information about prerequisites, software requirements, installing and upgrading Zowe CLI, see Installing Zowe.
Zowe CLI capabilities
With Zowe CLI, you can interact with z/OS remotely in the following ways:
- Interact with mainframe files:
Create, edit, download, and upload mainframe files (data sets) directly from Zowe CLI.
- Submit jobs:
Submit JCL from data sets or local storage, monitor the status, and view and download the output automatically.
- Issue TSO and z/OS console commands:
Issue TSO and console commands to the mainframe directly from Zowe CLI.
- Integrate z/OS actions into scripts:
Build local scripts that accomplish both mainframe and local tasks.
- Produce responses as JSON documents:
Return data in JSON format on request for consumption in other programming languages.
For detailed information about the available functionality in Zowe CLI, see Zowe CLI Command Groups.
For information about extending the functionality of Zowe CLI by installing plug-ins, see Extending Zowe CLI.
API Mediation Layer
The API Mediation Layer provides a single point of access for mainframe service REST APIs. The layer offers enterprise, cloud-like features such as high-availability, scalability, dynamic API discovery, consistent security, a single sign-on experience, and documentation. The API Mediation Layer facilitates secure communication across loosely coupled microservices through the API Gateway. The API Mediation Layer includes an API Catalog that provides an interface to view all discovered microservices, their associated APIs, and Swagger documentation in a user-friendly manner. The Discovery Service makes it possible to determine the location and status of microservice instances running inside the ecosystem.
- High availability of services in which application instances on a failing node are distributed among surviving nodes
- Microservice UIs available through the API Gateway and API Catalog by means of reverse proxying
- Support for standardization and normalization of microservice URLs and routing to provide API Mediation Layer users with a consistent way of accessing microservices.
- Minimal effort to register a microservice with the gateway (configuration over code)
- Runs on Windows, Linux, and z/OS (target platform)
- Written in Java utilizing Spring Boot (2.x), Angular 5, and the Netflix CloudStack
- Supports multiple client types for discovery (including Spring Boot, Java, and NodeJS)
- Contains enablers that allow for easy discovery and exposure of REST APIs and Swagger documentation for each microservice
API Mediation Layer architecture
The following diagram illustrates the single point of access with the API Gateway and the interactions between the API Gateway, API Catalog, and the Discovery Service:
The API Layer consists of the following key components:
The microservices that are contained within the ecosystem are located behind a reverse proxy. Clients interact with the gateway layer (reverse proxy). This layer forwards API requests to the appropriate corresponding service through the microservice endpoint UI. The gateway is built using Netflix Zuul and Spring Boot technology.
The Discovery service is the central point in the API Gateway infrastructure that accepts "announcements of REST services" and serves as a repository of active services. Back-end microservices register with this service either directly by using a Eureka client. Non-Spring Boot applications register with the Discover Service indirectly through a Sidecar. The Discovery Service is built on Eureka and Spring Boot technology.
The API Catalog is the catalog of published APIs and their associated documentation that are discoverable or can be available if provisioned from the service catalog. The API documentation is visualized using the Swagger UI. The API Catalog contains APIs of services available as product versions. A service can be implemented by one or more service instances, which provide exactly the same service for high-availability or scalability.