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Module ngx_http_headers_module
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Example Configuration
Directives add_header add_trailer expires |
ngx_http_headers_module
module allows adding
the “Expires” and “Cache-Control” header
fields, and arbitrary fields, to a response header.
Example Configuration
expires 24h;
expires modified +24h;
expires @24h;
expires 0;
expires -1;
expires epoch;
expires $expires;
add_header Cache-Control private;
Adds the specified field to a response header provided that
the response code equals 200, 201 (1.3.10), 204, 206, 301, 302, 303, 304,
307 (1.1.16, 1.0.13), or 308 (1.13.0).
Parameter value can contain variables.
There could be several
add_header
directives.
These directives are inherited from the previous configuration level
if and only if there are no
add_header
directives
defined on the current level.
If the
always
parameter is specified (1.7.5),
the header field will be added regardless of the response code.
Syntax:
add_trailer
name
value
[
always
];
This directive appeared in version 1.13.2.
Adds the specified field to the end of a response provided that
the response code equals 200, 201, 206, 301, 302, 303, 307, or 308.
Parameter value can contain variables.
There could be several
add_trailer
directives.
These directives are inherited from the previous configuration level
if and only if there are no
add_trailer
directives
defined on the current level.
If the
always
parameter is specified
the specified field will be added regardless of the response code.
Syntax:
expires
[
modified
]
time
;
expires
epoch
|
max
|
off
;
Enables or disables adding or modifying the “Expires”
and “Cache-Control” response header fields provided that
the response code equals 200, 201 (1.3.10), 204, 206, 301, 302, 303, 304,
307 (1.1.16, 1.0.13), or 308 (1.13.0).
The parameter can be a positive or negative
time
.
The time in the “Expires” field is computed as a sum of the
current time and
time
specified in the directive.
If the
modified
parameter is used (0.7.0, 0.6.32)
then the time is computed as a sum of the file’s modification time and
the
time
specified in the directive.
In addition, it is possible to specify a time of day using
the “
@
” prefix (0.7.9, 0.6.34):
expires @15h30m;
The contents of the “Cache-Control” field depends
on the sign of the specified time:
time is negative — “Cache-Control: no-cache”.
time is positive or zero —
“Cache-Control: max-age=
t
”,
where
t
is a time specified in the directive, in seconds.
The
epoch
parameter sets “Expires”
to the value “
Thu, 01 Jan 1970 00:00:01 GMT
”,
and “Cache-Control” to “
no-cache
”.
The
max
parameter sets “Expires”
to the value “
Thu, 31 Dec 2037 23:55:55 GMT
”,
and “Cache-Control” to 10 years.
The
off
parameter disables adding or modifying the
“Expires” and “Cache-Control” response
header fields.
The last parameter value can contain variables (1.7.9):
map $sent_http_content_type $expires {
default off;
application/pdf 42d;
~image/ max;