From d1de47b636232496ccbddd82e882e329858b093f Mon Sep 17 00:00:00 2001
From: Ainar Garipov <a.garipov@adguard.com>
Date: Fri, 27 Aug 2021 16:19:15 +0300
Subject: [PATCH] Pull request: all: document migrations

Closes #3507.

Squashed commit of the following:

commit c177bfeb0a656fbf5e40529f856c53a84d486fd5
Merge: 8293a6f9 e5c73877
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Aug 27 16:09:17 2021 +0300

    Merge branch 'master' into 3507-doc-migrations

commit 8293a6f9b104fefcda845ac49275066010f14382
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Aug 27 15:55:38 2021 +0300

    all: imp schema version wording

commit 56313e97f88903bcca955b1aacf36b98f968e9e9
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Aug 27 15:46:23 2021 +0300

    all: document migrations
---
 CHANGELOG.md | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dfca88f3..a803de1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,46 @@ and this project adheres to
   file, together with the new `group` and `user` settings ([#2763]).
 - Permissions on filter files are now `0o644` instead of `0o600` ([#3198]).
 
+#### Configuration Changes
+
+In this release, the schema version has changed from 10 to 12.
+
+- Parameter `dns.querylog_interval`, which in schema versions 11 and earlier
+  used to be an integer number of days, is now a string with a human-readable
+  duration:
+
+  ```yaml
+  # BEFORE:
+  'dns':
+    # …
+    'querylog_interval': 90
+
+  # AFTER:
+  'dns':
+    # …
+    'querylog_interval': '2160h'
+  ```
+
+  To rollback this change, convert the parameter back into days and change the
+  `schema_version` back to `11`.
+
+- Parameter `rlimit_nofile`, which in schema versions 10 and earlier used to be
+  on the top level, is now moved to the new `os` object:
+
+  ```yaml
+  # BEFORE:
+  'rlimit_nofile': 42
+
+  # AFTER:
+  'os':
+    'group': ''
+    'rlimit_nofile': 42
+    'user': ''
+  ```
+
+  To rollback this change, move the parameter on the top level and change the
+  `schema_version` back to `10`.
+
 ### Deprecated
 
 - Go 1.16 support.  v0.108.0 will require at least Go 1.17 to build.