Headers¶

HTTP requests come with headers, which can be retrieved using omni_http.header_get and omni_http.header_get_all functions:

select omni_http.http_header_get(request.headers, 'host') as host;
select omni_http.http_header_get_all(request.headers, 'accept') as accept;

The header name these functions take is case-insensitive.

Content-Length¶

omni_httpd automatically sets the Content-Length header for any non-null response body.

For instance, having:

create extension omni_httpd cascade;

update
omni_httpd.handlers
set query = $$
  select *
  from omni_httpd.http_response(
    headers => array [omni_http.http_header('Content-Type', 'text/plain')],
    body => 'Hi there'
  )
$$
where id = 1;

Will produce the response:

curl localhost:8080 -i

HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 8
Server: omni_httpd-0.1
Content-Type: text/plain

Hi there

Overriding Content-Length

omni_httpd allows overriding the Content-Length. This is useful for integrating with other HTTP handlers (e.g. Flask) that set the Content-Length. To ensure correctness, overriding works in the following way:

If the Content-Length is set lower than the actual body size. omni_httpd will use the new Content-Length and downsize the response body.
If the Content-Length is set higher than the actual body size. omni_httpd will keep its Content-Length, emit a WARNING and use the actual body size.