Getting Started with Gloo Mesh and Argo Rollouts

In modern software development, the ability to deploy applications swiftly and seamlessly is an important competitive advantage. This is where Argo Rollouts truly shines. By harnessing the power of Argo Rollouts, organizations can ensure a smooth and controlled transition from one version of an application to the next, minimizing downtime and reducing the risk of disruptions. This level of precision not only enhances the end-user experience but also bolsters an organization’s reliability and reputation.

Furthermore, Argo Rollouts empowers teams to adopt advanced deployment strategies like canary releases and blue-green deployments, allowing for safe experimentation with new features and configurations. The result? Faster innovation cycles, higher customer satisfaction, and ultimately, a stronger market position for the organization.

At Solo.io, we’ve integrated Argo Rollouts’ traffic management capabilities with Gloo Mesh’s advanced routing mechanisms through a supported plugin. This integration is a testament to our dedication to empowering organizations with the tools they need to succeed in the ever-evolving landscape of Kubernetes deployments. This blog provides a comprehensive guide on how to install, use, and implement various patterns for progressive delivery using Argo Rollouts and Gloo Mesh.

Prerequisites

• K8s cluster deployed
• Gloo Mesh installed and configured on a single cluster
• Istio deployed
  • This guide uses a revision based install method which uses the istio.io/rev: 1-19 namespace label. If using the default istio injection label you can replace with istio-injection: enabled instead.
  • This guide assumes that istiod is deployed in istio-system and the ingressgateway is deployed in istio-gateways
• VirtualGateway configured with the name north-south-gw in the istio-gateways namespace

Gloo Mesh Workspace Setup

Let’s set up a simple catchall workspace for our rollouts demo.

kubectl apply -f- <<EOF
apiVersion: admin.gloo.solo.io/v2
kind: Workspace
metadata:
  name: all
  namespace: gloo-mesh
spec:
  workloadClusters:
  - name: '*'
    namespaces:
    - name: '*'
---
apiVersion: admin.gloo.solo.io/v2
kind: WorkspaceSettings
metadata:
  name: all
  namespace: gloo-mesh
spec: {}
EOF

Install the argo-rollouts Controller

Install the kubectl argo-rollouts plugin as described here.

If you’re using brew, you can install it using:

brew install argoproj/tap/kubectl-argo-rollouts

Create the argo-rollouts namespace:

kubectl create namespace argo-rollouts

Create a kustomization file named kustomization.yaml with the following content:

cat > kustomization.yaml << EOF
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

namespace: argo-rollouts

resources:
- https://raw.githubusercontent.com/argoproj/argo-rollouts/v1.5.1/manifests/install.yaml

patchesJson6902:
  - target:
      kind: ClusterRole
      name: argo-rollouts
      version: v1
    patch: |
      - op: add
        path: /rules/-
        value:
          apiGroups:
          - networking.gloo.solo.io
          resources:
          - routetables
          verbs:
          - '*'
          
  - target:
      kind: ConfigMap
      name: argo-rollouts-config
      version: v1
    patch: |
      - op: add
        path: /data
        value:
          trafficRouterPlugins: |
            - name: "solo-io/glooplatform"
              location: "https://github.com/argoproj-labs/rollouts-plugin-trafficrouter-glooplatform/releases/download/v0.0.0-beta2/glooplatform-api-plugin-linux-amd64"
EOF

Apply the kustomization using:

kubectl apply -k .

Verify if the argo-rollouts controller has been deployed:

% kubectl get pods -n argo-rollouts
NAME                             READY   STATUS    RESTARTS   AGE
argo-rollouts-758c6d9456-7phwn   1/1     Running   0          4m41s

You can see in the logs of the argo-rollouts pod that the solo-io/glooplatform plugin was loaded in the output below.

% kubectl logs -n argo-rollouts deploy/argo-rollouts
time="2023-10-31T17:41:08Z" level=info msg="Argo Rollouts starting" version=v1.2.0+423be7b
time="2023-10-31T17:41:08Z" level=info msg="Creating event broadcaster"
time="2023-10-31T17:41:08Z" level=info msg="Setting up event handlers"
time="2023-10-31T17:41:08Z" level=info msg="Setting up experiments event handlers"
time="2023-10-31T17:41:08Z" level=info msg="Setting up analysis event handlers"
time="2023-10-31T17:41:08Z" level=info msg="Downloading plugin solo-io/glooplatform from: https://github.com/argoproj-labs/rollouts-plugin-trafficrouter-glooplatform/releases/download/v0.0.0-beta2/glooplatform-api-plugin-linux-amd64"
time="2023-10-31T17:41:11Z" level=info msg="Download complete, it took 2.290603376s"
time="2023-10-31T17:41:11Z" level=info msg="Leaderelection get id argo-rollouts-758c6d9456-7phwn_65ac5f0a-f125-4f37-b32c-c5e2df674e3c"
time="2023-10-31T17:41:11Z" level=info msg="Starting Healthz Server at 0.0.0.0:8080"
time="2023-10-31T17:41:11Z" level=info msg="attempting to acquire leader lease argo-rollouts/argo-rollouts-controller-lock...\n"
time="2023-10-31T17:41:11Z" level=info msg="Starting Metric Server at 0.0.0.0:8090"
time="2023-10-31T17:41:11Z" level=info msg="successfully acquired lease argo-rollouts/argo-rollouts-controller-lock\n"
time="2023-10-31T17:41:11Z" level=info msg="New leader elected: argo-rollouts-758c6d9456-7phwn_65ac5f0a-f125-4f37-b32c-c5e2df674e3c"
time="2023-10-31T17:41:11Z" level=info msg="I am the new leader: argo-rollouts-758c6d9456-7phwn_65ac5f0a-f125-4f37-b32c-c5e2df674e3c"
time="2023-10-31T17:41:11Z" level=info msg="Starting Controllers"
time="2023-10-31T17:41:11Z" level=info msg="invalidated cache for resource in namespace: argo-rollouts with the name: argo-rollouts-notification-secret"
time="2023-10-31T17:41:11Z" level=info msg="Waiting for controller's informer caches to sync"
time="2023-10-31T17:41:11Z" level=info msg="Started controller"
time="2023-10-31T17:41:11Z" level=info msg="Starting Service workers"
time="2023-10-31T17:41:11Z" level=info msg="Starting Ingress workers"
time="2023-10-31T17:41:11Z" level=info msg="Starting analysis workers"
time="2023-10-31T17:41:11Z" level=info msg="Started Ingress workers"
time="2023-10-31T17:41:11Z" level=info msg="Started 30 analysis workers"
time="2023-10-31T17:41:11Z" level=info msg="Starting Experiment workers"
time="2023-10-31T17:41:11Z" level=info msg="Started Experiment workers"
time="2023-10-31T17:41:11Z" level=info msg="Started Service workers"
time="2023-10-31T17:41:11Z" level=info msg="Starting Rollout workers"
time="2023-10-31T17:41:11Z" level=warning msg="Controller is running."
time="2023-10-31T17:41:11Z" level=info msg="Started rollout workers"
time="2023-10-31T17:41:11Z" level=info msg="Istio detected"
time="2023-10-31T17:41:11Z" level=info msg="Starting istio workers"
time="2023-10-31T17:41:11Z" level=info msg="Istio workers (10) started"

You can also check the logs of the argo-rollouts pod to ensure that the solo-io/glooplatform plugin was loaded.

Review Canary Rollout Strategy

A Canary rollout is a deployment strategy where the operator releases a new version of their application to a small percentage of the production traffic. We can use weights, pause durations, and manual promotion in order to control how our application is rolled out across the stable and canary services

The Argo Rollouts Canary strategy supports the K8s API directly basic example here, as well as many examples of integrations for Traffic Management that allow more advanced rollout scenarios.

The example below uses the Canary strategy, implemented by the Gloo Mesh Argo Rollouts Plugin. This plugin allows Argo Rollouts to manage Gloo Mesh objects such as RouteTable and Routes.

In the Rollout config, we will configure the plugin integration with Gloo Mesh by defining a trafficRouting.plugin.solo-io/glooplatform. The below example uses label selection for the routeTableSelector and routeSelector

trafficRouting:
  plugins:
    solo-io/glooplatform:
      routeTableSelector:
        labels:
          app: rollouts-demo
        namespace: rollouts-demo
      routeSelector:
        labels:
          route: rollouts-demo

It is also useful to note that it is possible to use static references instead of label selection as well.

trafficRouting:
  plugins:
    solo-io/glooplatform:
      routeTableSelector:
        # can also support direct reference 
        name: rollouts-demo-routetable
        namespace: rollouts-demo
      routeSelector:
        # can also support direct reference  
        name: rollouts-demo

Canary Rollout Diagram

Deploy and Configure the Initial Rollout

First we will create the rollouts-demo namespace

kubectl apply -f- <<EOF
apiVersion: v1
kind: Namespace
metadata:
  name: rollouts-demo
  labels:
    istio.io/rev: 1-19
EOF

Next, we can deploy the v1 of our rollouts demo which uses the blue image tag

kubectl apply -f- <<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  name: rollouts-demo
  namespace: rollouts-demo
---
apiVersion: v1
kind: Service
metadata:
  name: rollouts-demo-active
  namespace: rollouts-demo
  labels:
    app: rollouts-demo
    service: rollouts-demo
spec:
  ports:
  - name: http
    port: 8080
    targetPort: 8080
  selector:
    app: rollouts-demo
---
apiVersion: v1
kind: Service
metadata:
  name: rollouts-demo-preview
  namespace: rollouts-demo
  labels:
    app: rollouts-demo
    service: rollouts-demo
spec:
  ports:
  - name: http
    port: 8080
    targetPort: 8080
  selector:
    app: rollouts-demo
---
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
  namespace: rollouts-demo
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  strategy:
    canary:
      canaryService: rollouts-demo-preview
      stableService: rollouts-demo-active
      trafficRouting:
        plugins:
          solo-io/glooplatform:
            routeTableSelector:
              labels:
                app: rollouts-demo
              namespace: rollouts-demo
            routeSelector:
              labels:
                route: rollouts-demo
      steps:
      - setWeight: 10
      - pause: {duration: 5}
      - setWeight: 25
      - pause: {duration: 5}
      - setWeight: 50
      - pause: {duration: 5}
      - setWeight: 75
      - pause: {duration: 5}
      - setWeight: 100
      - pause: {duration: 5}
  template:
    metadata:
      labels:
        app: rollouts-demo
        version: stable
      annotations:
        proxy.istio.io/config: '{ "holdApplicationUntilProxyStarts": true }'
    spec:
      containers:
      - name: rollouts-demo
        image: argoproj/rollouts-demo:blue
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP
        resources:
          requests:
            cpu: 5m
            memory: 32Mi
EOF

Check your rollout status:

kubectl argo rollouts get rollout rollouts-demo -n rollouts-demo

Output should look similar to below:

% kubectl argo rollouts get rollout rollouts-demo -n rollouts-demo
Name:            rollouts-demo
Namespace:       rollouts-demo
Status:          ✔ Healthy
Strategy:        Canary
  Step:          10/10
  SetWeight:     100
  ActualWeight:  100
Images:          argoproj/rollouts-demo:blue (stable)
Replicas:
  Desired:       1
  Current:       1
  Updated:       1
  Ready:         1
  Available:     1

NAME                                      KIND        STATUS     AGE  INFO
⟳ rollouts-demo                           Rollout     ✔ Healthy  95s  
└──# revision:1                                                       
   └──⧉ rollouts-demo-858974c74           ReplicaSet  ✔ Healthy  95s  stable
      └──□ rollouts-demo-858974c74-hkhgn  Pod         ✔ Running  13s  ready:2/2

Next we can expose our rollout deployment through the ingress gateway.

kubectl apply -f- <<EOF
apiVersion: networking.gloo.solo.io/v2
kind: RouteTable
metadata:
  name: rollouts-demo-routetable
  namespace: rollouts-demo
  labels:
    app: rollouts-demo
spec:
  hosts:
    - '*'
  virtualGateways:
    - name: north-south-gw
      namespace: istio-gateways
  http:
    - name: rollouts-demo
      matchers:
      - uri:
          prefix: /
      labels:
        route: rollouts-demo
      forwardTo:
        destinations:
        - ref:
            name: rollouts-demo-active
            namespace: rollouts-demo
          port:
            number: 8080
          subset: 
            version: stable
          weight: 100	
        - ref:	
            name: rollouts-demo-preview	
            namespace: rollouts-demo
          port:	
            number: 8080
EOF

You should now be able to access the application in the browser using the following command output.

echo "access the rollouts demo UI at http://$(kubectl -n istio-gateways get service istio-ingressgateway-1-19 -o jsonpath='{.status.loadBalancer.ingress[0].*}')"

Initiating a new Rollout

Now lets promote the image from the blue image tag to the green image tag and watch the traffic pattern in the UI.

kubectl argo rollouts set image rollouts-demo -n rollouts-demo rollouts-demo=argoproj/rollouts-demo:green

Compared to a typical blue/green rollout strategy which immediately switches over, here we should see a more gradual shift in traffic as defined in our rollout strategy.

steps:
- setWeight: 10
- pause: {duration: 5}
- setWeight: 25
- pause: {duration: 5}
- setWeight: 50
- pause: {duration: 5}
- setWeight: 75
- pause: {duration: 5}
- setWeight: 100
- pause: {duration: 5}

In the rollouts demo UI we should be able to see the steps and the respective weights pretty clearly in the shift from blue to green.

Bonus:

If you set the Rollout strategy steps as follows, the promotion will happen automatically every 5 seconds except for the second step (at 25%) which requires a manual promotion

steps:
- setWeight: 10
- pause: {duration: 5}
- setWeight: 25
- pause: {}
- setWeight: 50
- pause: {duration: 5}
- setWeight: 75
- pause: {duration: 5}
- setWeight: 100
- pause: {duration: 5}

When doing so, you can also run a -w watch command on the following resources to visualize the config changes being managed by the Rollouts controller which are described in the diagrams at the top of this section

kubectl get svc rollouts-demo-active -n rollouts-demo -oyaml -w
kubectl get svc rollouts-demo-preview -n rollouts-demo -oyaml -w
kubectl get routetable rollouts-demo-routetable -n rollouts-demo -oyaml -w

Run the following command to promote the rollout:

kubectl argo rollouts promote rollouts-demo -n rollouts-demo

In the rollouts demo UI we should be able to see that the rollout pauses at the 25% weight until promoted, with the rest of the rollout automatically promoted after a 5 second duration between steps.

Analysis Runs

As a part of the Rollout, analysis can be run in the background — while the canary is progressing through its rollout steps.

An AnalysisTemplate is a template spec which defines how to perform a canary analysis, such as the metrics which it should perform, its frequency, and the values which are considered successful or failed. AnalysisTemplates may be parameterized with inputs values.

Here is a very simple AnalysisTemplate which is meant to always succeed.

kubectl apply -f- <<EOF
# This AnalysisTemplate will run a Kubernetes Job every 5 seconds that succeeds.
kind: AnalysisTemplate
apiVersion: argoproj.io/v1alpha1
metadata:
  name: pass
  namespace: rollouts-demo
spec:
  metrics:
  - name: pass
    count: 1
    interval: 5s
    failureLimit: 1
    provider:
      job:
        spec:
          template:
            spec:
              containers:
              - name: sleep
                image: alpine:3.8
                command: [sh, -c]
                args: [exit 0]
              restartPolicy: Never
          backoffLimit: 0
EOF

Now we can add an strategy.canary.steps.analysis config to our Rollout

kubectl apply -f- <<EOF
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
  namespace: rollouts-demo
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  strategy:
    canary:
      canaryService: rollouts-demo-preview
      stableService: rollouts-demo-active
      trafficRouting:
        plugins:
          solo-io/glooplatform:
            routeTableSelector:
              labels:
                app: rollouts-demo
              namespace: rollouts-demo
            routeSelector:
              labels:
                route: rollouts-demo
      steps:
      - setWeight: 10
      - pause: {duration: 5}
      - setWeight: 25
      - pause: {duration: 5}
      - setWeight: 50
      - pause: {duration: 5}
      - setWeight: 75
      - pause: {duration: 5}
      - setWeight: 100
      - pause: {duration: 5}
      analysis:
        templates:
        - templateName: pass
        startingStep: 1
  template:
    metadata:
      labels:
        app: rollouts-demo
        version: stable
      annotations:
        proxy.istio.io/config: '{ "holdApplicationUntilProxyStarts": true }'
    spec:
      containers:
      - name: rollouts-demo
        image: argoproj/rollouts-demo:blue
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP
        resources:
          requests:
            cpu: 5m
            memory: 32Mi
EOF

kubectl argo rollouts get rollout rollouts-demo -n rollouts-demo

kubectl apply -f https://raw.githubusercontent.com/istio/istio/master/samples/addons/prometheus.yaml --context gloo

% kubectl get pods -n istio-system --context gloo
NAME                          READY   STATUS    RESTARTS   AGE
istiod-1-19-6456f9d9b-pwbf5   1/1     Running   0          9m56s
prometheus-7545dd48db-w2vwg   2/2     Running   0          36s

kubectl apply -f- <<EOF
apiVersion: argoproj.io/v1alpha1
kind: AnalysisTemplate
metadata:
  name: istio-success-rate
  namespace: rollouts-demo
spec:
  args:
  - name: service
  - name: namespace
  metrics:
  - initialDelay: 15s
    interval: 15s
    name: success-rate
    provider:
      prometheus:
        address: http://prometheus.istio-system:9090
        query: >+
          sum(irate(istio_requests_total{
            reporter="source",
            destination_service=~"{{args.service}}.{{args.namespace}}.svc.cluster.local",
            response_code!~"2.*"}[30s])
          )
          /
          sum(irate(istio_requests_total{
            reporter="source",
            destination_service=~"{{args.service}}.{{args.namespace}}.svc.cluster.local"}[30s])
          )
    successCondition: len(result) == 0 || result[0] < 0.05
EOF

kubectl apply -f- <<EOF
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
  namespace: rollouts-demo
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  strategy:
    canary:
      canaryService: rollouts-demo-preview
      stableService: rollouts-demo-active
      trafficRouting:
        plugins:
          solo-io/glooplatform:
            routeTableSelector:
              labels:
                app: rollouts-demo
              namespace: rollouts-demo
            routeSelector:
              labels:
                route: rollouts-demo
      steps:
      - setWeight: 10
      - pause: {duration: 15}
      - setWeight: 25
      - pause: {duration: 15}
      - setWeight: 50
      - pause: {duration: 15}
      - setWeight: 100
      - pause: {duration: 15}
      analysis:
        args:
        - name: service
          value: rollouts-demo-preview
        - name: namespace
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        startingStep: 1
        templates:
        - templateName: istio-success-rate
  template:
    metadata:
      labels:
        app: rollouts-demo
        version: stable
      annotations:
        proxy.istio.io/config: '{ "holdApplicationUntilProxyStarts": true }'
    spec:
      containers:
      - name: rollouts-demo
        image: argoproj/rollouts-demo:blue
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP
        resources:
          requests:
            cpu: 5m
            memory: 32Mi
EOF

kubectl argo rollouts set image rollouts-demo -n rollouts-demo rollouts-demo=argoproj/rollouts-demo:orange

kubectl argo rollouts get rollout rollouts-demo -n rollouts-demo -w

kubectl get analysisrun -n rollouts-demo

kubectl describe analysisrun -n rollouts-demo rollouts-demo-5bc478cfbd-8

kubectl argo rollouts set image rollouts-demo -n rollouts-demo rollouts-demo=argoproj/rollouts-demo:bad-green

% kubectl get analysisrun -n rollouts-demo
NAME                         STATUS       AGE
rollouts-demo-77c77bf74d-2   Successful   3m8s
rollouts-demo-789db855f9-3   Failed       93s

kubectl delete serviceaccount rollouts-demo -n rollouts-demo
kubectl delete service rollouts-demo-preview -n rollouts-demo
kubectl delete service rollouts-demo-active -n rollouts-demo
kubectl delete rollout rollouts-demo -n rollouts-demo
kubectl delete analysistemplate pass -n rollouts-demo
kubectl delete analysistemplate istio-success-rate -n rollouts-demo
kubectl delete routetable rollouts-demo-routetable -n rollouts-demo
kubectl delete workspacesettings all -n gloo-mesh
kubectl delete workspace all -n gloo-mesh