This document provides an overview of a presentation on custom policies with Rust for Anypoint Flex Gateway. The agenda includes an introduction to Flex Gateway, writing custom policies, a demo, trivia, and wrap-up. Custom policies for Flex Gateway can be written in Rust as WebAssembly (WASM) filters using the Proxy WASM SDK. The presentation will demonstrate compiling a sample Rust policy and deploying it by publishing the schema and definition files and adding the binary implementation file. Attendees are invited to nominate future topics and provide feedback to help improve future meetup events.

1. 23rd July 2022
Surat MuleSoft Meetup Group
Anypoint Flex Gateway
Custom Policies With Rust

2. Safe Harbour Statement
● Both the speaker and the host are organizing this meet-up in individual capacity only. We are
not representing our companies here.
● This presentation is strictly for learning purposes only. Organizer/Presenter do not hold any
responsibility that same solution will work for your business requirements.
● This presentation is not meant for any promotional activities.
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Housekeeping
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4. Organizers
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Jitendra Bafna
Senior Solution Architect
EPAM Systems
Nitish Jain
Application Developer
Accenture

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●About the organizer:
○ MuleSoft Ambassador
○ Architect @Cognizant
○ 3xMule Certifications
○ Delivery Champion
○ GoToMarket Champion
●About Cognizant:
○ Cognizant is a global system integrator
○ Founded in 1994. It has 320.000 employees
○ More than 250 Mule projects
○ More than 1.000 MuleSoft certified consultants
Introductions

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● Introduction
● Writing Flex Gateway Custom Policies
● Demo
● Trivia
● Wrap - up
Agenda

7. Flex Gateway

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● Designed to manage and secure
any API, built anywhere
● Ultrafast. Delivers the
performance required for the
most demanding applications
● Built to integrate seamlessly
with DevOps and CI/CD
workflows,
● Manage any service across any
architecture — microservices to
monolith
● Gateway that can be deployed
anywhere, including cloud-
native and containerized
environments.
What is Anypoint Flex Gateway

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Flex Gateway
• Anypoint Flex Gateway is an ultrafast API gateway
designed to manage and secure APIs running
anywhere. Built to seamlessly integrate with
DevOps and CI/CD workflows, Anypoint Flex
Gateway delivers the performance required for the
most demanding applications and microservices
while providing enterprise security and
manageability across any environment.
Mule Gateway
• Mule Runtime includes an embedded API Gateway.
Using this gateway, any user can, for example,
apply a basic authentication policy on top of a Mule
application or enrich an incoming/outgoing
message, without having to write any code.
Anypoint Service Mesh
• Anypoint Service Mesh enables you to extend
Anypoint Platform API Management capabilities to
your Istio service mesh through the deployment of
a Mule Adapter. Once installed, you can manage
and secure your distributed applications running
within your Istio service mesh seamlessly from a
single pane.
MuleSoft Gateways offering

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MuleSoft Runtime vs Flex
❑ MuleSoft Runtime license is based on vCores
and Flex in API calls (i.e. packages of 100 M)
❑ In MuleSoft Runtime, typically a container
executes just one API. In Flex, the same
Gateway hosts lots of APIs.
❑ Flex is designed to talk to back-ends that
already expose HTTP traffic.
❑ Flex is not designed to do transformations,
proprietary connections to backends like SAP,
send files to FTP servers, etc.
❑ Not all the policies of MuleSoft Runtime already
work today in Flex
❑ MuleSoft Runtime polices are written as Mule
flows. Flex policies are written in languages like
Rust.

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Deployment patterns - Modes

12. Flex Gateway Custom Policies

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● At the heart of Anypoint Flex / Envoy proxy lies a variety of filters that provide features such as network
routing, observability and security:
Flex custom policies
● Those filters can be written in C++, Lua, or WASM (Web Assembly). WASM filters can be written in
languages like Rust.

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● An Envoy WASM filter is a C++ filter that “translates” Envoy internal C++ API to a WASM engine via the
WASM ABI (Abstract Binary Interface ). Envoy supports WASM filters for both the network pipeline as
well as the HTTP pipeline (HTTP filters).
Flex custom policies – WASM filters

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● SDK provided base classes:
Flex custom policies – Proxy WASM SDK

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Flex custom policies – Example of policy (1)
?

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Flex custom policies – Example of policy (2)

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Download
Rust using
rustup
Install
build-
essentials
Configure
Rust
Download
or write
source
code
Add
wasm32
as a
target:
Compile
with cargo
build
Optionally,
optimize
with
wasm-gc
Compiling a Rust policy

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Write
schema.json
Write
definition.yaml
Write
implementation.
yaml
Publish custom
policy
(schema.json +
definition.yaml)
Add
implementation
(implementation
.yaml + binary)
Deploying a policy

20. Demo

21. Q & A

22. Take a stand !
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●Nominate yourself for the next meetup speaker and suggest a topic as well.

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● Share:
○ Tweet using the hashtag #MuleSoftMeetups
○ Invite your network to join: https://meetups.mulesoft.com/surat/
● Feedback:
○ Fill out the survey feedback and suggest topics for upcoming events
○ Contact MuleSoft at meetups@mulesoft.com for ways to improve the program
What’s next?

24. Thank you