Merge branch 'fix-architecture-docs-ssh' into 'master'

Fix SSH architecture diagram

See merge request gitlab-org/gitlab!28031

doc/development/architecture.md

@@ -563,18 +563,23 @@ sequenceDiagram
     participant Git on server
 
     Note left of Git on client: git fetch
-    Git on client->>SSH server: git fetch-pack
-    SSH server-->>AuthorizedKeysCommand: gitlab-shell-authorized-keys-check git AAAA...
-    AuthorizedKeysCommand-->>Rails: GET /internal/api/authorized_keys?key=AAAA...
+    Git on client->>+SSH server: ssh git fetch-pack request
+    SSH server->>+AuthorizedKeysCommand: gitlab-shell-authorized-keys-check git AAAA...
+    AuthorizedKeysCommand->>+Rails: GET /internal/api/authorized_keys?key=AAAA...
     Note right of Rails: Lookup key ID
-    Rails-->>SSH server: 200 OK, command="gitlab-shell upload-pack key_id=1"
-    SSH server-->>GitLab Shell: gitlab-shell upload-pack key_id=1
-    GitLab Shell-->>Rails: GET /internal/api/allowed?action=upload_pack&key_id=1
+    Rails-->>-AuthorizedKeysCommand: 200 OK, command="gitlab-shell upload-pack key_id=1"
+    AuthorizedKeysCommand-->>-SSH server: command="gitlab-shell upload-pack key_id=1"
+    SSH server->>+GitLab Shell: gitlab-shell upload-pack key_id=1
+    GitLab Shell->>+Rails: GET /internal/api/allowed?action=upload_pack&key_id=1
     Note right of Rails: Auth check
-    Rails-->>GitLab Shell: 200 OK, { gitaly: ... }
-    GitLab Shell-->>Gitaly: SSHService.SSHUploadPack bidirectional request
-    Gitaly-->>Git on server: git upload-pack
-    Git on server->>Git on client: SSHService.SSHUploadPack bidirectional response
+    Rails-->>-GitLab Shell: 200 OK, { gitaly: ... }
+    GitLab Shell->>+Gitaly: SSHService.SSHUploadPack request
+    Gitaly->>+Git on server: git upload-pack request
+    Note over Git on client,Git on server: Bidirectional communication between Git client and server
+    Git on server-->>-Gitaly: git upload-pack response
+    Gitaly -->>-GitLab Shell: SSHService.SSHUploadPack response
+    GitLab Shell-->>-SSH server: gitlab-shell upload-pack response
+    SSH server-->>-Git on client: ssh git fetch-pack response
 ```
 
 The `git push` operation is very similar, except `git receive-pack` is used