A lightweight, general-purpose workflow executor.
Workflows are modeled as finite-state machines and are instantiated as Jobs through which the wfx and a client progress in lock-step to perform a task. Such a task could be software updating the client, progressing a work item through Kanban, … in essence anything requiring cooperation and coordination.
As being general purpose, wfx is only concerned with driving the (state) machinery, the specific actions a client should perform are encoded in the client implementation(s). Hence, one wfx instance can drive a multitude of wholly different workflows. Instantiating a workflow as a job augments it with additional metadata, the Job Definition, which contains job-specific information such as, e.g., URLs or other data the client (implementation) can make use of for this particular job.
To illustrate the concepts as well as the wfx / client interaction, consider the following figure
┌──────────────────────────────────────┐ ┌──────────────┐
│ wfx │ ┌─┴────────────┐ │
│ │ │ Client Y │ │
│ │ poll for jobs │ │ │
│ instantiate ┌───────┐ │◀────────────────────│ │ │
│ ┌────────────┐ ┌──▶│ Job 1 │ │────────────────────▶│──────┐ │ │
│ │ Workflow A ├────────┤ └───────┘ │◀─┐ job information │ ▼ │ │
│ └────────────┘ │ ┌───────┐ │ │ │ act │ │
│ ┌────┼──▶│ Job 2 │ │ └──────────────────│◀─────┘ │ │
│ ┌────────────┐ │ │ └───────┘ │ update state │ │ │
│ │ Workflow B ├───┘ │ ┌───────┐ │ │ │ │
│ └────────────┘ └──▶│ Job 3 │ │ . │ │ │
│ └───────┘ │ . │ │ │
│ ... ... │ . │ │ │
│ │ │ ├─┘
└──────────────────────────────────────┘ └──────────────┘with the wfx having loaded a number of workflows Workflow A, Workflow B, … that got instantiated as Job 1, Job 2, Job 3, … with a Client Y working on Job 1: It polls the wfx for a new job or the current job's status, in return receives the job information, performs actions if applicable, and finally reports the new job status back to the wfx. This lock-step procedure is repeated until the workflow reaches a terminal state which could be identified with, e.g., success or failure.
wfx in (Example) Action
An exemplary Kanban-inspired workflow illustrating the interplay between the wfx as Kanban "Board", a Product Owner creating jobs, and a Developer executing them:
wfx Features & Non-Features
- Design Guidelines
- Compact, scalable core focusing on the essentials
- Proper interfaces to external systems for modularity and integrability: Accompanying and necessary services like artifact storage and device registry are likely already available or are better provided by specialized solutions
- Implementation
- Extendable modularized source code architecture
- Lightweight, no dependencies (statically linked binaries)
- Efficient, native code for a wide variety of platforms and operating systems (as supported by the Go Language)
- Fully documented REST API, see wfx OpenAPI Specification
- Extensive test suite including load tests
- Deployment / Usability
- Load / Unload workflows at run-time
- Hot / Live reload of configuration file
- Persistent Storage: built-in support for SQLite, PostgreSQL and MySQL
- A complimentary built-in file server serving as artifact storage for dynamic deployments and integration without external file storage
- Transport Layer Security (HTTPS) with support for custom certificates
wfx Clients
Currently, the following clients have support for wfx:
- SWUpdate - Software Update for Embedded Linux Devices implementing support for the Device Artifact Update Workflow Family
Grouped by topic, the following documentation is available in docs/:
- Workflows: Core concepts of Workflows and Jobs
- Installation: How to install and deploy wfx.
- Configuration: How to configure wfx.
- Operation: How to operate wfx.
- Use-Cases: A collection of use-cases for wfx.
- API: wfx's north- and southbound APIs.
You can also browse the rendered documentation at https://siemens.github.io/wfx/.
The roadmap is tracked via Github issues.
Contributions are encouraged and welcome!
See CONTRIBUTING.md for details.
Copyright ©️ 2023 Siemens AG.
Released under the Apache-2.0 license.