upgrade chart to support multiple replicas

Author: lucasfcosta

chart/Chart.yaml

@@ -2,5 +2,5 @@ apiVersion: v2
 name: briefer
 description: The helm chart for Briefer's open-source version.
 type: application
-version: 0.1.3
-appVersion: '0.1.3'
+version: 0.1.4
+appVersion: '0.1.4'

chart/templates/ai-deployment.yaml

@@ -8,7 +8,7 @@ metadata:
       app.kubernetes.io/name: briefer
       app.kubernetes.io/component: ai
 spec:
-  replicas: 1
+  replicas: {{ .Values.ai.replicaCount | default 1 }}
   selector:
     matchLabels:
       app.kubernetes.io/name: briefer

chart/templates/api-deployment.yaml

@@ -7,7 +7,7 @@ metadata:
     app.kubernetes.io/name: briefer
     app.kubernetes.io/component: api
 spec:
-  replicas: 1
+  replicas: {{ .Values.api.replicaCount | default 1 }}
   selector:
     matchLabels:
       app.kubernetes.io/name: briefer

chart/templates/web-deployment.yaml

@@ -7,7 +7,7 @@ metadata:
     app.kubernetes.io/name: briefer
     app.kubernetes.io/component: web
 spec:
-  replicas: 1
+  replicas: {{ .Values.web.replicaCount | default 1 }}
   selector:
     matchLabels:
       app.kubernetes.io/name: briefer

chart/values.yaml

@@ -3,11 +3,12 @@ enableLocalPostgres: true
 
 ai:
   enabled: true
+  replicaCount: 1
 
   image:
     repository: docker.io
     name: briefercloud/briefer-ai
-    tag: v0.0.42
+    tag: v0.0.65
     pullPolicy: Always
 
   resources:
@@ -42,10 +43,11 @@ ai:
   #     effect: 'NoSchedule'
 
 web:
+  replicaCount: 1
   image:
     repository: docker.io
     name: briefercloud/briefer-web
-    tag: v0.0.42
+    tag: v0.0.65
     pullPolicy: Always
 
   # optional
@@ -74,10 +76,12 @@ web:
   #     effect: 'NoSchedule'
 
 api:
+  replicaCount: 1
+
   image:
     repository: docker.io
     name: briefercloud/briefer-api
-    tag: v0.0.42
+    tag: v0.0.65
     pullPolicy: Always
 
   resources:
@@ -148,7 +152,7 @@ jupyter:
   image:
     repository: docker.io
     name: briefercloud/briefer-jupyter
-    tag: v0.0.42
+    tag: v0.0.65
     pullPolicy: Always
 
   # tolerations:

docs/deployment/kubernetes.mdx

@@ -52,11 +52,11 @@ Using Briefer's Helm chart is the easiest way of setting up Briefer on your Kube
    Feel free to change the namespace if you want to. If you're using an existing namespace, please remove the `--create-namespace` flag.
 4. After installing Briefer's Helm chart, you can confirm that the manifests have been applied by listing all the pods in the chart's target namespace (usually `kubectl get pods -n briefer`).
    <Note>
-     If you're running a Postgres instance within your cluster, it might be that
-     the API will be ready before the Postgres instance is up. In that case,
-     you'll see that the API pod will keep restarting for a few minutes. That's
-     _normal_. It happens because the API needs to connect to the database to
-     start, so it'll just keep trying to start until Postgres is ready.
+   If you're running a Postgres instance within your cluster, it might be that
+   the API will be ready before the Postgres instance is up. In that case,
+   you'll see that the API pod will keep restarting for a few minutes. That's
+   _normal_. It happens because the API needs to connect to the database to
+   start, so it'll just keep trying to start until Postgres is ready.
    </Note>
 5. Create the necessary `Ingress` resources so that you can access Briefer's API and Web containers.
    Make sure to use the same URLs you've configured in step 2.
@@ -105,6 +105,25 @@ api:
     postgresPassword: password
 ```
 
+### Using more than one replica for Briefers' services
+
+If you want to use more than one replica for Briefer's services, you must set the `replicas` for each service in your `values.yaml` file.
+
+After doing that, make sure to enable sticky sessions in your `Ingress` resources. Without sticky sessions (also known as Session Affinity), Briefer will not work correctly when using multiple replicas.
+
+If you're using NGINX as your Ingress controller, you can enable sticky sessions by adding the annotations below to your `Ingress` resources, for example.
+
+```yaml
+nginx.ingress.kubernetes.io/affinity: 'cookie'
+nginx.ingress.kubernetes.io/session-cookie-name: 'http-cookie'
+nginx.ingress.kubernetes.io/session-cookie-expires: '172800'
+nginx.ingress.kubernetes.io/session-cookie-max-age: '172800'
+```
+
+<Note>
+It's not necessary to use sticky sessions if you're using only one replica.
+</Note>
+
 ### Configuring pod sizes
 
 We recommend that you explicitly configure the size of your `jupyter` pod so that it has enough memory and vCPUs to run your analyses.