Add Flow CR documentation (#252)

Co-authored-by: Amanda Lindsay <v-amanda.lindsay@hazelcast.com>

docs/modules/ROOT/examples/flow.yaml

@@ -0,0 +1,29 @@
+apiVersion: hazelcast.com/v1alpha1
+kind: Flow
+metadata:
+  labels:
+    app.kubernetes.io/name: hazelcast-platform-operator
+  name: flow
+spec:
+  size: 3
+  licenseKeySecretName: hazelcast-license-key
+  externalConnectivity:
+    ingress:
+      hostname: ""
+      ingressClassName: nginx
+      path: "/"
+      annotations:
+        kubernetes.io/ingress.class: "nginx"
+        nginx.ingress.kubernetes.io/ssl-redirect: "false"
+        nginx.ingress.kubernetes.io/enable-opentelemetry: "true"
+  database:
+    host: "flow-database"
+    secretName: flow-db-secret
+  env:
+  - name: OPTIONS
+    value: |
+      --flow.analytics.persistRemoteCallResponses=true
+      --flow.stream-server.enabled=false
+      --flow.analytics.persistResults=false
+      --flow.toggles.dashboard-enabled=true
+      --flow.config.custom.managementCenterUrl=http://233.252.0.158/mc

docs/modules/ROOT/nav.adoc

@@ -44,6 +44,7 @@
 ** xref:management-center-persistence.adoc[Persistence]
 ** xref:management-center-jvm-args.adoc[JVM Arguments]
 ** xref:management-center-ldap.adoc[LDAP Security Provider]
+* xref:flow.adoc[Flow]
 
 .Reference
 // Configuration options/spec files/any other reference docs

docs/modules/ROOT/pages/flow.adoc

@@ -0,0 +1,78 @@
+= Deploy Flow
+
+:description: In this tutorial, you'll deploy a Flow application using Hazelcast Platform Operator for Kubernetes.
+
+{description}
+
+See xref:flow:index.adoc[Flow] for more detailed information.
+
+== Prerequisites
+
+- Flow requires the Management Center application to run and be configured properly. The Management Center application should be configured to use FLow.
+
+[source,yaml]
+----
+...
+image: docker.io/hazelcast/management-center-flow <1>
+...
+hazelcastClusters:
+- address: flow <2>
+  name: flow <3>
+jvm:
+  args:
+  - "-Dhazelcast.mc.flow.addresses=http://233.252.0.158/" <4>
+  - "-Dhazelcast.mc.internal.flowAddresses=http://flow:9021" <5>
+...
+----
+
+<1> Management Center Flow image.
+<2> The service name of the Flow application. The same as the Flow Custom Resource (CR) name.
+<3> Hazelcast cluster name. Should always be `flow`.
+<4> Flow Ingress public address.
+<5> The internal address of Flow in the format of `http://<service-name>:9021`. The service name is the same as the Flow CR name.
+
+- To connect to PostgreSQL database you need create a `Secret` with the DB credentials:
+
+[source,shell]
+----
+kubectl create secret generic flow-db-secret \
+  --from-literal=database=flow \
+  --from-literal=username=flow \
+  --from-literal=password="strong-password"
+----
+
+In the created secret `username` and `password` are required, whereas `database` field is optional and will default to `flow` if not provided.
+
+== Run Flow
+
+To run Flow on Kubernetes using Hazelcast Platform Operator you need to create a Flow CR.
+
+[source,yaml,subs="attributes+"]
+----
+include::ROOT:example$/flow.yaml[]
+----
+
+Additional flow configuration can be achieved by providing additional parameters using the `OPTIONS` environment variable. See xref:flow:introduction:index.adoc[Configure Flow] for detailed information.
+
+NOTE: Parameters managed by the Hazelcast Platform Operator are not allowed in `OPTIONS`. E.g., the Database configuration can only be done via `spec.database` in the Flow CR.
+
+=== Configure OpenID support
+
+You can enable OpenID support with Management Center deployment on Flow. To configure OpenID, provide the required parameters to the `OPTIONS` environment variable.
+See xref:flow:deploy:security-recommendations.adoc[Security recommendations] to discover all available options.
+
+[source,yaml]
+----
+...
+- name: OPTIONS
+  value: |
+      --flow.security.openIdp.enabled=true
+      --flow.security.openIdp.jwks-uri=http://233.252.0.158/mc/oauth2/jwks
+      --flow.security.openIdp.issuerUrl=http://233.252.0.158/mc
+      --flow.security.openIdp.clientId=flow-client
+      --flow.security.openIdp.require-https=false
+      --flow.security.open-idp.roles.format=path
+      --flow.security.open-idp.roles.path=roles
+      --flow.security.open-idp.refreshTokensDisabled=true
+...
+----