Red Hat Summit 2018:

Getting Hands On With Istio on OpenShift

Purpose

As microservices-based applications become more prevalent, both the number of and complexity of their interactions increases. Up until now much of the burden of managing these complex microservices interactions has been placed on the application developer, with different or non-existent support for microservice concepts depending on language and framework.

The service mesh concept pushes this responsibility to the infrastructure, with features for traffic management, distributed tracing and observability, policy enforcement, and service/identity security, freeing the developer to focus on business value. In this hands-on session you will learn how to apply some of these features to a simple polyglot microservices application running on top of OpenShift using Istio, an open platform to connect, manage, and secure microservices.

Background

Istio is an open platform to connect, manage, and secure microservices. Istio provides an easy way to create a network of deployed services with load balancing, service-to-service authentication, monitoring, and more, without requiring any changes in application code. OpenShift can automatically inject a special sidecar proxy throughout your environment to enable Istio management for your application. This proxy intercepts all network communication between your microservices microservices, and is configured and managed using Istio’s control plane functionality -- not your application code!

Fetch connect script

First, open a terminal and run the following commands:

cd
wget https://raw.githubusercontent.com/jamesfalkner/istio-lab-summit-2018/master/scripts/connect.sh

Find your hostname

In the browser, you had requested a lab environment. On that page, you were assigned a GUID (a 4-digit alphanumeric string). For example, xxxx.

Execute connect script

To connect to your provisioned lab machine, run the following command:

MAKE SURE THAT YOU SUBSTITUTE xxxx FOR THE GUID THAT YOU WERE ASSIGNED

cd
bash connect.sh openshift-xxxx.rhpds.opentlc.com

Make sure you type yes to complete the SSH connection.

Once connected, your lab machine has several environment variables pre-defined, and has Istio added to your $PATH. You can confirm this is set correctly:

echo Istio Home: $ISTIO_HOME && \
echo Istio Lab Content: $ISTIO_LAB_HOME && \
echo Istio Lab Project Name: $ISTIO_LAB_PROJECT && \
echo Path: $PATH

Start OpenShift and install Istio

All of the exercises in this lab will be performed as the root system user. First, escalate your privileges using the following sudo command:

MAKE SURE THAT YOU EXECUTE THE SUDO COMMAND EXACTLY OR YOUR ENVIRONMENT VARIABLES WILL NOT PROPAGATE CORRECTLY

sudo -E -i

Then, execute the following two commands which will start the local OpenShift environment and install Istio into it:

cd $ISTIO_LAB_HOME
./scripts/start.sh

The start script will then output a URL for you to visit:

--------------------
Setup complete. Open the Lab Instructions in your browser: http://istio-workshop-guides.aa.bb.cc.dd.xip.io
--------------------

This is the URL for your customized lab guide that you will use for the rest of the lab. Please open that URL in your browser and continue from there.

Using this lab content elsewhere

Deploy On OpenShift

You can deploy the lab guides as a container image anywhere but most conveniently, you can deploy it on OpenShift Online or other OpenShift flavours:

oc new-project guides
oc new-app osevg/workshopper --name=istio-workshop \
      -e CONTENT_URL_PREFIX=https://raw.githubusercontent.com/jamesfalkner/istio-lab-summit-2018/master/instructions
      -e WORKSHOPS_URLS="https://raw.githubusercontent.com/jamesfalkner/istio-lab-summit-2018/master/instructions/_rhsummit18.yml" \
      -e JAVA_APP=false \
      -e OPENSHIFT_MASTER="http://127.0.0.1:8443" \
      -e APPS_SUFFIX="apps.127.0.0.1.nip.io" \
      -e ISTIO_LAB_HOSTNAME="127.0.0.1"

oc expose svc/istio-workshop

Replace OPENSHIFT_MASTER with the URL to the console of your working OpenShift environment (e.g. http://128.0.0.1:8443), APPS_SUFFIX with your default routing suffix (e.g. apps.127.0.0.1.nip.io), and ISTIO_LAB_HOSTNAME with the public hostname of your machine. These variables are used to subsitute values in the markdown content files.

The guides can then be accessed at http://istio-workshop-guides.$APPS_SUFFIX.

The lab content (.md files) will be pulled from the GitHub when users access the guides in their browser.

Note that the workshop variables can be overriden via specifying environment variables on the container itself e.g. the JAVA_APP env var in the above command

Test Locally with Docker

You can directly run Workshopper as a docker container which is specially helpful when writing the content.

docker run -p 8080:8080 -v $(pwd):/app-data \
              -e CONTENT_URL_PREFIX="file:///app-data/instructions" \
              -e WORKSHOPS_URLS="file:///app-data/instructions/_rhsummit18.yml" \
              -e OPENSHIFT_MASTER="foo" \
              -e APPS_SUFFIX="$MY_IP.xip.io" \
              -e ISTIO_LAB_HOSTNAME="MY_HOSTNAME" \
              osevg/workshopper:latest

Replace OPENSHIFT_MASTER with the URL to the console of your working OpenShift environment (e.g. http://128.0.0.1:8443), APPS_SUFFIX with your default routing suffix (e.g. apps.127.0.0.1.nip.io), and ISTIO_LAB_HOSTNAME with the public hostname of your machine. These variables are used to subsitute values in the markdown content files.

Go to http://localhost:8080 on your browser to see the rendered workshop content. You can modify the lab instructions and refresh the page to see the latest changes.