update 12.0 cluster deployment (#559)

* update 12.0 cluster deployment

* adjuest format of some sentences

manual/repo/k8s/cluster/seafile-backend-deployment.yaml

@@ -52,16 +52,6 @@ spec:
                 configMapKeyRef:
                   name: seafile-env
                   key: SITE_ROOT
-            - name: ENABLE_SEADOC
-              valueFrom:
-                configMapKeyRef:
-                  name: seafile-env
-                  key: ENABLE_SEADOC
-            - name: SEADOC_SERVER_URL
-              valueFrom:
-                configMapKeyRef:
-                  name: seafile-env
-                  key: SEADOC_SERVER_URL
             - name: DB_HOST
               valueFrom:
                 configMapKeyRef:

manual/setup/cluster_deploy_with_docker.md

@@ -4,7 +4,7 @@
 
 The Seafile cluster solution employs a 3-tier architecture:
 
-* Load balancer tier: Distribute incoming traffic to Seafile servers. HA can be achieved by deploying multiple load balancer instances.
+* Load balancer tier: Distribute incoming traffic to Seafile servers. HA (high availability) can be achieved by deploying multiple load balancer instances.
 * Seafile server cluster: a cluster of Seafile server instances. If one instance fails, the load balancer will stop handing traffic to it. So HA is achieved.
 * Backend storage: Distributed storage cluster, e.g.  S3, Openstack Swift or Ceph.
 
@@ -48,9 +48,6 @@ Please refer [here](./system_requirements.md#seafile-cluster) for the details ab
 
 2. Pulling Seafile image
 
-    !!! tip
-        Since v12.0, Seafile PE versions are hosted on DockerHub and does not require username and password to download.
-
     ```bash
     docker pull seafileltd/seafile-pro-mc:12.0-latest
     ```
@@ -81,7 +78,7 @@ Please refer [here](./system_requirements.md#seafile-cluster) for the details ab
 
     !!! success "Cluster init mode"
     
-        Because CLUSTER_INIT_MODE is true in the `.env` file, Seafile docker will be started in init mode and generate configuration files. As the results, you can see the following lines if you trace the Seafile container (i.e., `docker logs seafile`):
+        Because `CLUSTER_INIT_MODE` is true in the `.env` file, Seafile docker will be started in init mode and generate configuration files. As the results, you can see the following lines if you trace the Seafile container (i.e., `docker logs seafile`):
 
         ```log
         ---------------------------------
@@ -126,7 +123,7 @@ Please refer [here](./system_requirements.md#seafile-cluster) for the details ab
     - [seahub_settings.py](../config/seahub_settings_py.md)
 
 8. After initailizing the cluster, the following fields can be removed in `.env`
-    - `CLUSTER_INIT_MODE`, must be removed from .env file
+    - `CLUSTER_INIT_MODE`, must be removed from `.env` file
     - `CLUSTER_INIT_MEMCACHED_HOST`
     - `CLUSTER_INIT_ES_HOST`
     - `CLUSTER_INIT_ES_PORT`

manual/setup/system_requirements.md

@@ -91,6 +91,6 @@ This page shows the minimal requirements of Seafile.
 - **Docker-base deployment integration services**: *Seafile* only
 
 !!! note "More suggestions in Seafile cluster"
-    - We assume you have already deployed ***Memcached*** (*redis* is not supported in cluster), ***MariaDB***, file indexer (e.g., ***ElasticSearch***) in separate machines and use ***S3*** like object storage. 
+    - We assume you have already deployed ***Memcached*** (or *redis*), ***MariaDB***, file indexer (e.g., ***ElasticSearch***) in separate machines and use ***S3*** like object storage. 
 
     - Generally, when deploying Seafile in a cluster, we recommend that you use a **storage backend** (such as AWS S3) to store Seafile data. However, according to the Seafile image startup rules and K8S persistent storage strategy, you still need to **prepare a persistent directory** for configuring the startup of the Seafile container. 

manual/setup_binary/cluster_deployment.md

@@ -454,7 +454,6 @@ For **seafile.conf**:
 ```
 [cluster]
 enabled = true
-memcached_options = --SERVER=<IP of memcached node> --POOL-MIN=10 --POOL-MAX=100
 
 ```