DOC: Add more info about request formatting in http-check send description
Only one Host header can be defined and some headers are automatically skipped
(Connection, Content-Length and Transfer-Encoding). In addition, a note about
the synchronisation of the Host header value and the request uri has been added.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index df06d85..371fd8a 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -4681,15 +4681,27 @@
In addition to the request line defined by the "option httpchk" directive,
this one is the valid way to add some headers and optionally a body to the
request sent during HTTP health checks. If a body is defined, the associate
- "Content-Length" header is automatically added. The old trick consisting to
- add headers after the version string on the "option httpchk" line is now
+ "Content-Length" header is automatically added. Thus, this header or
+ "Transfer-encoding" header should not be present in the request provided by
+ "http-check send". If so, it will be ignored. The old trick consisting to add
+ headers after the version string on the "option httpchk" line is now
deprecated. Note also the "Connection: close" header is still added if a
"http-check expect" direcive is defined independently of this directive, just
like the state header if the directive "http-check send-state" is defined.
Also "http-check send" doesn't support HTTP keep-alive. Keep in mind that it
will automatically append a "Connection: close" header, meaning that this
- header should not be present in the request provided by "http-check send".
+ header should not be present in the request provided by "http-check send". If
+ so, it will be ignored.
+
+ Note that the Host header and the request authority, when both defined, are
+ automatically synchronized. It means when the HTTP request is sent, when a
+ Host is inserted in the request, the request authority is accordingly
+ updated. Thus, don't be surprised if the Host header value overwrites the
+ configured request authority.
+
+ Note also for now, no Host header is automatically added in HTTP/1.1 or above
+ requests. You should add it explicitly.
See also : "option httpchk", "http-check send-state" and "http-check expect".