Support `registration_shared_secret` in a file (#13614)

A new `registration_shared_secret_path` option. This is kinda handy for k8s deployments and things.

1 files changed, 18 insertions, 0 deletions

diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md

index 8ae018e628..e9ab58854e 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -2124,10 +2124,28 @@ registration_requires_token: true
 If set, allows registration of standard or admin accounts by anyone who
 has the shared secret, even if registration is otherwise disabled.
 
+See also [`registration_shared_secret_path`](#registration_shared_secret_path).
+
 Example configuration:
 ```yaml
 registration_shared_secret: <PRIVATE STRING>
 ```
+
+---
+### `registration_shared_secret_path`
+
+An alternative to [`registration_shared_secret`](#registration_shared_secret):
+allows the shared secret to be specified in an external file.
+
+The file should be a plain text file, containing only the shared secret.
+
+Example configuration:
+```yaml
+registration_shared_secret_file: /path/to/secrets/file
+```
+
+_Added in Synapse 1.67.0._
+
 ---
 ### `bcrypt_rounds`