Configure Praefect as the default storage in docs

Configures Praefect as the default storage in the set up guide. This
streamlines the set up process and removes an extra step otherwise
necessary.

doc/administration/gitaly/praefect.md

@@ -103,7 +103,7 @@ GitLab](https://about.gitlab.com/install/).
 
 You will need the IP/host address for each node.
 
-1. `LOAD_BALANCER_SERVER_ADDRESS`: the IP/hots address of the load balancer
+1. `LOAD_BALANCER_SERVER_ADDRESS`: the IP/host address of the load balancer
 1. `POSTGRESQL_SERVER_ADDRESS`: the IP/host address of the PostgreSQL server
 1. `PRAEFECT_HOST`: the IP/host address of the Praefect server
 1. `GITALY_HOST`: the IP/host address of each Gitaly server
@@ -281,9 +281,15 @@ application server, or a Gitaly node.
 1. Configure the **Praefect** cluster to connect to each Gitaly node in the
    cluster by editing `/etc/gitlab/gitlab.rb`.
 
-   In the example below we have configured one virtual storage (or shard) named
-   `storage-1`. This cluster has three Gitaly nodes `gitaly-1`, `gitaly-2`, and
-   `gitaly-3`, which will be replicas of each other.
+   The virtual storage's name must match the configured storage name in GitLab
+   configuration. In a later step, we configure the storage name as `default`
+   so we use `default` here as well. This cluster has three Gitaly nodes `gitaly-1`,
+   `gitaly-2`, and `gitaly-3`, which will be replicas of each other.
+
+   CAUTION: **CAUTION:** If you have data on an already existing storage called
+   `default`, you should configure the virtual storage with another name and
+   [migrate the data to the Praefect storage](#migrating-existing-repositories-to-praefect)
+   afterwards.
 
    Replace `PRAEFECT_INTERNAL_TOKEN` with a strong secret, which will be used by
    Praefect when communicating with Gitaly nodes in the cluster. This token is
@@ -302,7 +308,7 @@ application server, or a Gitaly node.
    # Name of storage hash must match storage name in git_data_dirs on GitLab
    # server ('praefect') and in git_data_dirs on Gitaly nodes ('gitaly-1')
    praefect['virtual_storages'] = {
-     'storage-1' => {
+     'default' => {
        'gitaly-1' => {
          'address' => 'tcp://GITALY_HOST:8075',
          'token'   => 'PRAEFECT_INTERNAL_TOKEN',
@@ -555,6 +561,16 @@ Particular attention should be shown to:
    external_url 'GITLAB_SERVER_URL'
    ```
 
+1. Disable the default Gitaly service running on the GitLab host. It won't be needed
+   as GitLab will connect to the configured cluster.
+
+   CAUTION: **CAUTION** If you have existing data stored on the default Gitaly storage,
+   you should [migrate the data your Praefect storage first](#migrating-existing-repositories-to-praefect).
+
+   ```ruby
+   gitaly['enable'] = false
+   ```
+
 1. Add the Praefect cluster as a storage location by editing
    `/etc/gitlab/gitlab.rb`.
 
@@ -562,28 +578,17 @@ Particular attention should be shown to:
 
    - `LOAD_BALANCER_SERVER_ADDRESS` with the IP address or hostname of the load
      balancer.
-   - `GITLAB_HOST` with the IP address or hostname of the GitLab server
    - `PRAEFECT_EXTERNAL_TOKEN` with the real secret
 
    ```ruby
    git_data_dirs({
      "default" => {
-       "gitaly_address" => "tcp://GITLAB_HOST:8075"
-     },
-     "storage-1" => {
        "gitaly_address" => "tcp://LOAD_BALANCER_SERVER_ADDRESS:2305",
        "gitaly_token" => 'PRAEFECT_EXTERNAL_TOKEN'
      }
    })
    ```
 
-1. Allow Gitaly to listen on a TCP port by editing
-   `/etc/gitlab/gitlab.rb`
-
-   ```ruby
-   gitaly['listen_addr'] = '0.0.0.0:8075'
-   ```
-
 1. Configure the `gitlab_shell['secret_token']` so that callbacks from Gitaly
    nodes during a `git push` are properly authenticated by editing
    `/etc/gitlab/gitlab.rb`:
@@ -632,14 +637,6 @@ Particular attention should be shown to:
    gitlab-ctl reconfigure
    ```
 
-1. To ensure that Gitaly [has updated its Prometheus listen
-   address](https://gitlab.com/gitlab-org/gitaly/-/issues/2734), [restart
-   Gitaly](../restart_gitlab.md#omnibus-gitlab-restart):
-
-   ```shell
-   gitlab-ctl restart gitaly
-   ```
-
 1. Verify each `gitlab-shell` on each Gitaly instance can reach GitLab. On each Gitaly instance run:
 
    ```shell
@@ -652,16 +649,11 @@ Particular attention should be shown to:
    gitlab-rake gitlab:gitaly:check
    ```
 
-1. Update the **Repository storage** settings from **Admin Area > Settings >
-   Repository > Repository storage** to make the newly configured Praefect
-   cluster the storage location for new Git repositories.
-
-   - The default weight is 0.
-   - The Praefect weight is 100.
-
-   ![Update repository storage](img/praefect_storage_v13_1.png)
+1. Check in **Admin Area > Settings > Repository > Repository storage** that the Praefect storage
+   is configured to store new repositories. Following this guide, the `default` storage should have
+   weight 100 to store all new repositories.
 
-1. Verify everything is still working by creating a new project. Check the
+1. Verify everything is working by creating a new project. Check the
    "Initialize repository with a README" box so that there is content in the
    repository that viewed. If the project is created, and you can see the
    README file, it works!