docs/vmauth.md: follow-up for 36edba9bfb

- Document `-configCheckInterval` command-line flag in `quick start` section
- Clarify the addition of `-configCheckInterval` at docs/CHANGELOG.md

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3990

app/vmauth/README.md

@@ -17,7 +17,12 @@ and pass the following flag to `vmauth` binary in order to start authorizing and
 After that `vmauth` starts accepting HTTP requests on port `8427` and routing them according to the provided [-auth.config](#auth-config).
 The port can be modified via `-httpListenAddr` command-line flag.
 
-The auth config can be reloaded either by passing `SIGHUP` signal to `vmauth` or by querying `/-/reload` http endpoint.
+The auth config can be reloaded via the following ways:
+
+- By passing `SIGHUP` signal to `vmauth`.
+- By querying `/-/reload` http endpoint. This endpoint can be protected with `-reloadAuthKey` command-line flag. See [security docs](#security) for more details.
+- By specifying `-configCheckInterval` command-line flag to the interval between config re-reads. For example, `-configCheckInterval=5s` will re-read the config
+  and apply new changes every 5 seconds.
 
 Docker images for `vmauth` are available [here](https://hub.docker.com/r/victoriametrics/vmauth/tags).
 

docs/CHANGELOG.md

@@ -30,7 +30,7 @@ created by v1.90.0 or newer versions. The solution is to upgrade to v1.90.0 or n
 * FEATURE: [vmui](https://docs.victoriametrics.com/#vmui): add the ability to manually input date and time when selecting a time range. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3968).
 * FEATURE: [vmui](https://docs.victoriametrics.com/#vmui): updated usability and the search process in cardinality explorer. Made this process straightforward for user. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3986).    
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): automatically disable progress bar when TTY isn't available. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3823).
-* FEATURE: [vmauth](https://docs.victoriametrics.com/vmauth.html): new `configCheckInterval` flag. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3990).
+* FEATURE: [vmauth](https://docs.victoriametrics.com/vmauth.html): add `-configCheckInterval` command-line flag, which can be used for automatic re-reading the `-auth.config` file. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3990).
 
 * BUGFIX: prevent from slow [snapshot creating](https://docs.victoriametrics.com/#how-to-work-with-snapshots) under high data ingestion rate. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3551).
 * BUGFIX: [vmauth](https://docs.victoriametrics.com/vmauth.html):  suppress [proxy protocol](https://www.haproxy.org/download/2.3/doc/proxy-protocol.txt) parsing errors in case of `EOF`. Usually, the error is caused by health checks and is not a sign of an actual error.

docs/vmauth.md

@@ -21,7 +21,12 @@ and pass the following flag to `vmauth` binary in order to start authorizing and
 After that `vmauth` starts accepting HTTP requests on port `8427` and routing them according to the provided [-auth.config](#auth-config).
 The port can be modified via `-httpListenAddr` command-line flag.
 
-The auth config can be reloaded either by passing `SIGHUP` signal to `vmauth` or by querying `/-/reload` http endpoint.
+The auth config can be reloaded via the following ways:
+
+- By passing `SIGHUP` signal to `vmauth`.
+- By querying `/-/reload` http endpoint. This endpoint can be protected with `-reloadAuthKey` command-line flag. See [security docs](#security) for more details.
+- By specifying `-configCheckInterval` command-line flag to the interval between config re-reads. For example, `-configCheckInterval=5s` will re-read the config
+  and apply new changes every 5 seconds.
 
 Docker images for `vmauth` are available [here](https://hub.docker.com/r/victoriametrics/vmauth/tags).