Merge pull request #142 from arangodb/documentation/deployment-replic…

…ation-spec

Adding deployment replication spec

docs/Manual/Deployment/Kubernetes/DeploymentReplicationResource.md

@@ -0,0 +1,110 @@
+# ArangoDeploymentReplication Custom Resource
+
+The ArangoDB Replication Operator creates and maintains ArangoDB
+`arangosync` configurations in a Kubernetes cluster, given a replication specification.
+This replication specification is a `CustomResource` following
+a `CustomResourceDefinition` created by the operator.
+
+Example minimal replication definition:
+
+```yaml
+apiVersion: "replication.database.arangodb.com/v1alpha"
+kind: "ArangoDeploymentReplication"
+metadata:
+  name: "replication-from-a-to-b"
+spec:
+  source:
+    deploymentName: cluster-a
+  destination:
+    deploymentName: cluster-b
+  auth:
+    clientAuthSecretName: client-auth-cert
+```
+
+This definition results in:
+
+- the arangosync `SyncMaster` in deployment `cluster-b` is called to configure a synchronization
+  from `cluster-a` to `cluster-b`, using the client authentication certificate stored in
+  `Secret` `client-auth-cert`.
+
+## Specification reference
+
+Below you'll find all settings of the `ArangoDeploymentReplication` custom resource.
+
+### `spec.source.deploymentName: string`
+
+This setting specifies the name of an `ArangoDeployment` resource that runs a cluster
+with sync enabled.
+
+This cluster configured as the replication source.
+
+### `spec.source.deploymentNamespace: string`
+
+This setting specifies the Kubernetes namespace of an `ArangoDeployment` resource specified in `spec.source.deploymentName`.
+
+If this setting is empty, the namespace of the `ArangoDeploymentReplication` is used.
+
+### `spec.source.masterEndpoints: []string`
+
+This setting specifies zero or more master endpoint URL's of the source cluster.
+
+Use this setting if the source cluster is not running inside a Kubernetes cluster
+that is reachable from the Kubernetes cluster the `ArangoDeploymentReplication` resource is deployed in.
+
+Specifying this setting and `spec.source.deploymentName` at the same time is not allowed.
+
+### `spec.source.auth.jwtSecretName: string`
+
+This setting specifies the name of a `Secret` containing a JWT `token` used to authenticate
+with the SyncMaster at the specified source.
+
+This setting is required, unless `spec.source.deploymentName` has been set.
+
+### `spec.source.tls.caSecretName: string`
+
+This setting specifies the name of a `Secret` containing a TLS CA certificate `ca.crt` used to verify
+the TLS connection created by the SyncMaster at the specified source.
+
+This setting is required, unless `spec.source.deploymentName` has been set.
+
+### `spec.destination.deploymentName: string`
+
+This setting specifies the name of an `ArangoDeployment` resource that runs a cluster
+with sync enabled.
+
+This cluster configured as the replication destination.
+
+### `spec.destination.deploymentNamespace: string`
+
+This setting specifies the Kubernetes namespace of an `ArangoDeployment` resource specified in `spec.destination.deploymentName`.
+
+If this setting is empty, the namespace of the `ArangoDeploymentReplication` is used.
+
+### `spec.destination.masterEndpoints: []string`
+
+This setting specifies zero or more master endpoint URL's of the destination cluster.
+
+Use this setting if the destination cluster is not running inside a Kubernetes cluster
+that is reachable from the Kubernetes cluster the `ArangoDeploymentReplication` resource is deployed in.
+
+Specifying this setting and `spec.destination.deploymentName` at the same time is not allowed.
+
+### `spec.destination.auth.jwtSecretName: string`
+
+This setting specifies the name of a `Secret` containing a JWT `token` used to authenticate
+with the SyncMaster at the specified destination.
+
+This setting is required, unless `spec.destination.deploymentName` has been set.
+
+### `spec.destination.tls.caSecretName: string`
+
+This setting specifies the name of a `Secret` containing a TLS CA certificate `ca.crt` used to verify
+the TLS connection created by the SyncMaster at the specified destination.
+
+This setting is required, unless `spec.destination.deploymentName` has been set.
+
+### `spec.auth.clientAuthSecretName: string`
+
+This setting specifies the name of a `Secret` containing a client authentication certificate,
+used to authenticate the SyncMaster in the destination cluster with the SyncMaster in the
+source cluster.