add documentation

Signed-off-by: Enno Boland <[email protected]>

docs/operator-manual/argocd-repo-creds.yaml

@@ -26,6 +26,16 @@ stringData:
     -----BEGIN OPENSSH PRIVATE KEY-----
     ...
     -----END OPENSSH PRIVATE KEY-----
+  sshKexAlgorithms: |
+     curve25519-sha256
+     [email protected]
+     ecdh-sha2-nistp256
+     ecdh-sha2-nistp384
+     ecdh-sha2-nistp521
+     diffie-hellman-group-exchange-sha256
+     diffie-hellman-group14-sha256
+     diffie-hellman-group14-sha1
+
 ---
 apiVersion: v1
 kind: Secret
@@ -60,4 +70,4 @@ stringData:
   githubAppPrivateKey: |
     -----BEGIN OPENSSH PRIVATE KEY-----
     ...
-    -----END OPENSSH PRIVATE KEY-----
+    -----END OPENSSH PRIVATE KEY-----

docs/operator-manual/declarative-setup.md

@@ -341,6 +341,16 @@ The following keys are valid to refer to credential secrets:
 #### SSH repositories
 
 * `sshPrivateKey` refers to the SSH private key for accessing the repositories
+* `sshKexAlgorithms` refers to the SSH key exchange algorithms to use when connecting to the repositories. If not specified, the following algorithms are used:
+   * `curve25519-sha256`
+   * `[email protected]`
+   * `ecdh-sha2-nistp256`
+   * `ecdh-sha2-nistp384`
+   * `ecdh-sha2-nistp521`
+   * `diffie-hellman-group-exchange-sha256`
+   * `diffie-hellman-group14-sha256`
+   * `diffie-hellman-group14-sha1`
+
 
 #### HTTPS repositories