In this tutorial we'll set up the Podtato-head demo application which will feature different Prometheus metrics and deploy the application using multistage delivery. We will then use Keptn quality gates to evaluate the quality of the application based on SLO-driven quality gates.

What we will cover

In this tutorial, we are going to install Keptn on a Kubernetes cluster.

The full setup that we are going to deploy is sketched in the following image.

demo setup

If you are interested, please have a look at this article that explains the deployment in more detail.

Modern continuous delivery on Kubernetes for Developers - dev.to

Keptn can be installed on a variety of Kubernetes distributions. Please find a full compatibility matrix for supported Kubernetes versions here.

Please find tutorials how to set up your cluster here. For the best tutorial experience, please follow the sizing recommendations given in the tutorials.

Please make sure your environment matches these prerequisites:

Download the Istio command line tool by following the official instructions or by executing the following steps.

curl -L https://istio.io/downloadIstio | ISTIO_VERSION=1.10.0 sh -

Check the version of Istio that has been downloaded and execute the installer from the corresponding folder, e.g.,

./istio-1.10.0/bin/istioctl install

The installation of Istio should be finished within a couple of minutes.

This will install the Istio default profile with ["Istio core" "Istiod" "Ingress gateways"] components into the cluster. Proceed? (y/N) y
✔ Istio core installed
✔ Istiod installed
✔ Ingress gateways installed
✔ Installation complete

Every release of Keptn provides binaries for the Keptn CLI. These binaries are available for Linux, macOS, and Windows.

There are multiple options how to get the Keptn CLI on your machine.

Now, you should be able to run the Keptn CLI:

To install the latest release of Keptn with full quality gate + continuous delivery capabilities in your Kubernetes cluster, execute the keptn install command.

keptn install --endpoint-service-type=ClusterIP --use-case=continuous-delivery

Installation details

In the Keptn namespace, the following deployments should be found:

kubectl get deployments -n keptn

Here is the output of the command:

NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
api-gateway-nginx             1/1     1            1           2m44s
api-service                   1/1     1            1           2m44s
approval-service              1/1     1            1           2m44s
bridge                        1/1     1            1           2m44s
configuration-service         1/1     1            1           2m44s
helm-service                  1/1     1            1           2m44s
jmeter-service                1/1     1            1           2m44s
lighthouse-service            1/1     1            1           2m44s
litmus-service                1/1     1            1           2m44s
mongodb                       1/1     1            1           2m44s
mongodb-datastore             1/1     1            1           2m44s
remediation-service           1/1     1            1           2m44s
shipyard-controller           1/1     1            1           2m44s
statistics-service            1/1     1            1           2m44s

We are using Istio for traffic routing and as an ingress to our cluster. To make the setup experience as smooth as possible we have provided some scripts for your convenience. If you want to run the Istio configuration yourself step by step, please take a look at the Keptn documentation.

The first step for our configuration automation for Istio is downloading the configuration bash script from Github:

curl -o configure-istio.sh https://raw.githubusercontent.com/keptn/examples/release-0.9.0/istio-configuration/configure-istio.sh

After that you need to make the file executable using the chmod command.

chmod +x configure-istio.sh

Finally, let's run the configuration script to automatically create your Ingress resources.

./configure-istio.sh

What is actually created

With this script, you have created an Ingress based on the following manifest.

---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: istio
  name: api-keptn-ingress
  namespace: keptn
spec:
  rules:
  - host: <IP-ADDRESS>.nip.io
    http:
      paths:
      - backend:
          serviceName: api-gateway-nginx
          servicePort: 80

Besides, the script has created a gateway resource for you so that the onboarded services are also available publicly.

---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: public-gateway
  namespace: istio-system
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      name: http
      number: 80
      protocol: HTTP
    hosts:
    - '*'

Besides, the helm-service pod of Keptn is restarted to fetch this new configuration.

In this section we are referring to the Linux/MacOS derivatives of the commands. If you are using a Windows host, please follow the official instructions.

KEPTN_ENDPOINT=http://$(kubectl -n keptn get ingress api-keptn-ingress -ojsonpath='{.spec.rules[0].host}')/api
KEPTN_API_TOKEN=$(kubectl get secret keptn-api-token -n keptn -ojsonpath='{.data.keptn-api-token}' | base64 --decode)

Use this stored information and authenticate the CLI.

keptn auth --endpoint=$KEPTN_ENDPOINT --api-token=$KEPTN_API_TOKEN

That will give you:

Starting to authenticate
Successfully authenticated

If you want, you can go ahead and take a look at the Keptn API by navigating to the endpoint that is given via

echo $KEPTN_ENDPOINT

api

The demo resources can be found on Github for a convenient experience. Let's clone the project's repository, so we have all the resources needed to get started.

git clone https://github.com/cncf/podtato-head.git

Now, let's switch to the directory including the demo resources.

cd podtato-head/delivery/keptn

A project in Keptn is the logical unit that can hold multiple (micro)services. Therefore, it is the starting point for each Keptn installation.
We have already cloned the demo resources from Github, so we can go ahead and create the project.

Recommended: Create a new project with Git upstream:

To configure a Git upstream for this tutorial, the Git user (--git-user), an access token (--git-token), and the remote URL (--git-remote-url) are required. If a requirement is not met, go to the Keptn documentation where instructions for GitHub, GitLab, and Bitbucket are provided.

Let's define the variables before running the command:

GIT_USER=gitusername
GIT_TOKEN=gittoken
GIT_REMOTE_URL=remoteurl

Now let's create the project using the keptn create project command.

keptn create project pod-tato-head --shipyard=./shipyard.yaml --git-user=$GIT_USER --git-token=$GIT_TOKEN --git-remote-url=$GIT_REMOTE_URL

Alternatively: If you don't want to use a Git upstream, you can create a new project without it but please note that this is not the recommended way:

keptn create project pod-tato-head --shipyard=./shipyard.yaml

For creating the project, the tutorial relies on a shipyard.yaml file as shown below:

apiVersion: "spec.keptn.sh/0.2.0"
kind: "Shipyard"
metadata:
  name: "shipyard-sockshop"
spec:
  stages:
    - name: "hardening"
      sequences:
        - name: "delivery"
          tasks:
            - name: "deployment"
              properties:
                deploymentstrategy: "blue_green_service"
            - name: "test"
              properties:
                teststrategy: "performance"
            - name: "evaluation"
            - name: "release"
    - name: "production"
      sequences:
        - name: "delivery"
          triggeredOn:
            - event: "hardening.delivery.finished"
          tasks:
            - name: "deployment"
              properties:
                deploymentstrategy: "blue_green_service"
            - name: "release"

In the shipyard.yaml shown above, we define two stages called hardening and production with a single sequence called delivery. The hardening stage defines a delivery sequence with a deployment, test, evaluation and release task (along with some other properties) while the production stage only includes a deployment and release task. The production stage also features a triggeredOn properties which defines when the stage will be executed (in this case after the hardening stage has finished the delivery sequence). With this, Keptn sets up the environment and makes sure, that tests are triggered after each deployment, and the tests are then evaluated by Keptn quality gates. Keptn performs a blue/green deployment (i.e., two deployments simultaneously with routing of traffic to only one deployment) and triggers a performance test in the hardening stage. Once the tests complete successfully, the deployment moves into the production stage using another blue/green deployment.

After creating the project, we can continue by onboarding the helloserver as a service to your project using the keptn create service and keptn add-resource commands. You need to pass the project where you want to create the service, as well as the Helm chart of the service.
For this purpose we need the helm charts as a tar.gz archive. To archive it use following command:

tar cfvz ./helm-charts/helloserver.tgz ./helm-charts/helloserver

Then the service can be created:

keptn create service helloserver --project="pod-tato-head"
keptn add-resource --project="pod-tato-head" --service=helloserver --all-stages --resource=./helm-charts/helloserver.tgz --resourceUri=helm/helloserver.tgz

After onboarding the service, tests (i.e., functional- and performance tests) need to be added as basis for quality gates. We are using JMeter tests, as the JMeter service comes "batteries included" with our Keptn installation.

keptn add-resource --project=pod-tato-head --stage=hardening --service=helloservice --resource=jmeter/load.jmx --resourceUri=jmeter/load.jmx
keptn add-resource --project=pod-tato-head --stage=hardening --service=helloservice --resource=jmeter/jmeter.conf.yaml --resourceUri=jmeter/jmeter.conf.yaml

Now each time Keptn triggers the test execution, the JMeter service will pick up both files and execute the tests.

We are now ready to kick off a new deployment of our test application with Keptn and have it deployed, tested, and evaluated.

  1. Let us now trigger the deployment, tests, and evaluation of our demo application.
    keptn trigger delivery --project="pod-tato-head" --service=helloservice --image="gabrieltanner/hello-server" --tag=v0.1.1
    
  2. Let's have a look in the Keptn bridge what is actually going on. We can use this helper command to retrieve the URL of our Keptn bridge.
    echo http://$(kubectl -n keptn get ingress api-keptn-ingress -ojsonpath='{.spec.rules[0].host}')/bridge
    
    The credentials can be retrieved via the Keptn CLI:
    keptn configure bridge --output
    
  3. Optional: Verify the pods that should have been created for the helloservice
    kubectl get pods --all-namespaces | grep helloservice
    
    pod-tato-head-hardening    helloservice-primary-5f779966f9-vjjh4                        2/2     Running   0          4m55s
    pod-tato-head-production   helloservice-primary-5f779966f9-kbhz5                        2/2     Running   0          2m52s
    

You can get the URL for the helloservice with the following commands in the respective namespaces:

Hardening:

echo http://helloservice.pod-tato-head-hardening.$(kubectl -n keptn get ingress api-keptn-ingress -ojsonpath='{.spec.rules[0].host}')

Production:

echo http://helloservice.pod-tato-head-production.$(kubectl -n keptn get ingress api-keptn-ingress -ojsonpath='{.spec.rules[0].host}')

Navigating to the URLs should result in the following output:

After creating a project and service, you can set up Prometheus monitoring and configure scrape jobs using the Keptn CLI.

Keptn doesn't install or manage Prometheus and its components. Users need to install Prometheus and Prometheus Alert manager as a prerequisite.

Execute the following steps to install prometheus-service

Optional: Verify Prometheus setup in your cluster

Prometheus is then available on localhost:8080/targets where you can see the targets for the service:
Prometheus targets

Setup Prometheus SLI provider

During the evaluation of a quality gate, the Prometheus provider is required that is implemented by an internal Keptn service, the prometheus-service. This service will fetch the values for the SLIs that are referenced in an SLO configuration file.

We are going to add the configuration for our SLIs in terms of an SLI file that maps the name of an indicator to a PromQL statement how to actually query it.

keptn add-resource --project=pod-tato-head --stage=hardening --service=helloservice --resource=prometheus/sli.yaml --resourceUri=prometheus/sli.yaml

For your information, the contents of the file are as follows:

---
spec_version: '1.0'
indicators:
  http_response_time_seconds_main_page_sum: sum(rate(http_server_request_duration_seconds_sum{method="GET",route="/",status_code="200",job="$SERVICE-$PROJECT-$STAGE-canary"}[$DURATION_SECONDS])/rate(http_server_request_duration_seconds_count{method="GET",route="/",status_code="200",job="$SERVICE-$PROJECT-$STAGE-canary"}[$DURATION_SECONDS]))
  http_requests_total_sucess: http_requests_total{status="success"}
  go_routines: go_goroutines{job="$SERVICE-$PROJECT-$STAGE"}
  request_throughput: sum(rate(http_requests_total{status="success"}[$DURATION_SECONDS]))

Keptn requires a performance specification for the quality gate. This specification is described in a file called slo.yaml, which specifies a Service Level Objective (SLO) that should be met by a service. To learn more about the slo.yaml file, go to Specifications for Site Reliability Engineering with Keptn.

Activate the quality gates for the helloservice. Therefore, navigate to the delivery/keptn folder and upload the slo.yaml file using the add-resource command:

keptn add-resource --project=pod-tato-head --stage=hardening --service=helloservice --resource=slo.yaml --resourceUri=slo.yaml

This will add the slo.yaml file to your Keptn - which is the declarative definition of a quality gate. Let's take a look at the file contents:

---
spec_version: '0.1.0'
comparison:
  compare_with: "single_result"
  include_result_with_score: "pass"
  aggregate_function: avg
objectives:
  - sli: http_response_time_seconds_main_page_sum
    pass:
      - criteria:
          - "<=1"
    warning:
      - criteria:
          - "<=0.5"
  - sli: request_throughput
    pass:
      - criteria:
          - "<=+100%"
          - ">=-80%"
  - sli: go_routines
    pass:
      - criteria:
          - "<=100"
total_score:
  pass: "90%"
  warning: "75%"

You can now deploy another artifact and see the quality gates in action.

keptn trigger delivery --project="pod-tato-head" --service=helloservice --image="gabrieltanner/hello-server" --tag=v0.1.1

After sending the artifact you can see the test results in Keptn Bridge.

  1. Use the Keptn CLI to deploy a version of the helloservice, which contains an artificial slowdown of 2 second in each request.
    keptn trigger delivery --project="pod-tato-head" --service=helloservice --image="gabrieltanner/hello-server" --tag=v0.1.2
    
  2. Go ahead and verify that the slow build has reached your hardening environment by opening a browser. You can get the URL with this command:
    echo http://helloservice.pod-tato-head-hardening.$(kubectl -n keptn get ingress api-keptn-ingress -ojsonpath='{.spec.rules[0].host}')
    

After triggering the deployment of the helloservice in version v0.1.2, the following behaviour is expected:

Take a look in the Keptn's bridge and navigate to the last deployment. You will find a quality gate evaluation that got a fail result when evaluation the SLOs of our helloservice microservice. Thanks to this quality gate the slow build won't be promoted to production but instead automatically rolled back.

To verify, the Keptn's Bridge shows the deployment of v0.1.2 and then the failed test in hardening including the roll-back.

Here you can see that some of your defined test cases (for example, the response time) failed because you deployed a slow build that is not suitable for production. Once the test fails, the deployment will not be promoted to production and the hardening stage will return to its original state.

Thanks for taking a full tour through Keptn!
Although Keptn has even more to offer that should have given you a good overview what you can do with Keptn.

What we've covered

Keptn can be easily extended with external tools such as notification tools, other SLI providers, bots to interact with Keptn, etc.
While we do not cover additional integrations in this tutorial, please feel fee to take a look at our integration repositories:

Please visit us in our Keptn Slack and tell us how you like Keptn and this tutorial! We are happy to hear your thoughts & suggestions!

Also, make sure to follow us on Twitter to get the latest news on Keptn, our tutorials and newest releases!