BEGIN;
SET LOCAL client_min_messages = WARNING;
CREATE EXTENSION IF NOT EXISTS pg_curl;
END;
DO $plpgsql$ BEGIN
    BEGIN
        PERFORM curl_easy_reset();
        PERFORM curl_easy_setopt_timeout(1);
        PERFORM curl_easy_setopt_url('http://localhost/status/202');
        PERFORM curl_easy_perform();
        PERFORM curl_easy_getinfo_http_connectcode();
        SET pg_curl.httpbin = 'http://localhost';
    EXCEPTION WHEN OTHERS THEN
        SET pg_curl.httpbin = 'https://httpbin.org';
    END;
END;$plpgsql$;
BEGIN;
select curl_easy_reset();
 curl_easy_reset 
-----------------
 t
(1 row)

select curl_easy_setopt_url(current_setting('pg_curl.httpbin') || '/get?');
 curl_easy_setopt_url 
----------------------
 t
(1 row)

select curl_url_append('a', 'b');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('c', '');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('d');
 curl_url_append 
-----------------
 t
(1 row)

select curl_easy_perform();
 curl_easy_perform 
-------------------
 t
(1 row)

with s as (
    select regexp_matches(curl_easy_getinfo_header_in(), E'([^ \t\r\n\f]+): ?([^\t\r\n\f]+)', 'g') as s
) select lower(s[1]) as key, s[2] as value from s where lower(s[1]) not in ('date', 'server', 'content-length', 'connection');
               key                |      value       
----------------------------------+------------------
 content-type                     | application/json
 access-control-allow-origin      | *
 access-control-allow-credentials | true
(3 rows)

-- args/headers are selected explicitly (rather than deleting the noisy keys
-- with jsonb's -/#- operators, which only exist since PostgreSQL 9.5) so this
-- keeps working back to PostgreSQL 9.4, which has -> and json_build_object
with j as (
    select convert_from(curl_easy_getinfo_data_in(), 'utf-8')::jsonb as data
) select json_build_object(
    'args', j.data->'args',
    'headers', json_build_object('Accept', j.data->'headers'->>'Accept')
) from j;
                            json_build_object                            
-------------------------------------------------------------------------
 {"args" : {"a": "b", "c": "", "d": ""}, "headers" : {"Accept" : "*/*"}}
(1 row)

select curl_easy_getinfo_errcode(), curl_easy_getinfo_errdesc(), curl_easy_getinfo_errbuf();
 curl_easy_getinfo_errcode | curl_easy_getinfo_errdesc | curl_easy_getinfo_errbuf 
---------------------------+---------------------------+--------------------------
                         0 | No error                  | 
(1 row)

END;
BEGIN;
select curl_easy_reset();
 curl_easy_reset 
-----------------
 t
(1 row)

select curl_easy_setopt_postfields(convert_to('{"e":"f","g":"","h":null}', 'utf-8'));
 curl_easy_setopt_postfields 
-----------------------------
 t
(1 row)

select curl_easy_setopt_url(current_setting('pg_curl.httpbin') || '/post?');
 curl_easy_setopt_url 
----------------------
 t
(1 row)

select curl_url_append('a', 'b');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('c', '');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('d');
 curl_url_append 
-----------------
 t
(1 row)

select curl_header_append('Content-Type', 'application/json; charset=utf-8');
 curl_header_append 
--------------------
 t
(1 row)

select curl_easy_perform();
 curl_easy_perform 
-------------------
 t
(1 row)

with s as (
    select regexp_matches(curl_easy_getinfo_header_in(), E'([^ \t\r\n\f]+): ?([^\t\r\n\f]+)', 'g') as s
) select lower(s[1]) as key, s[2] as value from s where lower(s[1]) not in ('date', 'server', 'content-length', 'connection');
               key                |      value       
----------------------------------+------------------
 content-type                     | application/json
 access-control-allow-origin      | *
 access-control-allow-credentials | true
(3 rows)

with j as (
    select convert_from(curl_easy_getinfo_data_in(), 'utf-8')::jsonb as data
) select json_build_object(
    'args', j.data->'args',
    'data', j.data->>'data',
    'form', j.data->'form',
    'json', j.data->'json',
    'files', j.data->'files',
    'headers', json_build_object(
        'Accept', j.data->'headers'->>'Accept',
        'Content-Type', j.data->'headers'->>'Content-Type',
        'Content-Length', j.data->'headers'->>'Content-Length'
    )
) from j;
                                                                                                                            json_build_object                                                                                                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 {"args" : {"a": "b", "c": "", "d": ""}, "data" : "{\"e\":\"f\",\"g\":\"\",\"h\":null}", "form" : {}, "json" : {"e": "f", "g": "", "h": null}, "files" : {}, "headers" : {"Accept" : "*/*", "Content-Type" : "application/json; charset=utf-8", "Content-Length" : "25"}}
(1 row)

select curl_easy_getinfo_errcode(), curl_easy_getinfo_errdesc(), curl_easy_getinfo_errbuf();
 curl_easy_getinfo_errcode | curl_easy_getinfo_errdesc | curl_easy_getinfo_errbuf 
---------------------------+---------------------------+--------------------------
                         0 | No error                  | 
(1 row)

END;
BEGIN;
select curl_easy_reset();
 curl_easy_reset 
-----------------
 t
(1 row)

select curl_postfield_append('e', 'f');
 curl_postfield_append 
-----------------------
 t
(1 row)

select curl_postfield_append('g', '');
 curl_postfield_append 
-----------------------
 t
(1 row)

select curl_postfield_append('h');
 curl_postfield_append 
-----------------------
 t
(1 row)

select curl_easy_setopt_url(current_setting('pg_curl.httpbin') || '/post?');
 curl_easy_setopt_url 
----------------------
 t
(1 row)

select curl_url_append('a', 'b');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('c', '');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('d');
 curl_url_append 
-----------------
 t
(1 row)

select curl_easy_perform();
 curl_easy_perform 
-------------------
 t
(1 row)

with s as (
    select regexp_matches(curl_easy_getinfo_header_in(), E'([^ \t\r\n\f]+): ?([^\t\r\n\f]+)', 'g') as s
) select lower(s[1]) as key, s[2] as value from s where lower(s[1]) not in ('date', 'server', 'content-length', 'connection');
               key                |      value       
----------------------------------+------------------
 content-type                     | application/json
 access-control-allow-origin      | *
 access-control-allow-credentials | true
(3 rows)

with j as (
    select convert_from(curl_easy_getinfo_data_in(), 'utf-8')::jsonb as data
) select json_build_object(
    'args', j.data->'args',
    'data', j.data->>'data',
    'form', j.data->'form',
    'json', j.data->'json',
    'files', j.data->'files',
    'headers', json_build_object(
        'Accept', j.data->'headers'->>'Accept',
        'Content-Type', j.data->'headers'->>'Content-Type',
        'Content-Length', j.data->'headers'->>'Content-Length'
    )
) from j;
                                                                                                           json_build_object                                                                                                            
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 {"args" : {"a": "b", "c": "", "d": ""}, "data" : "", "form" : {"e": "f", "g": "", "h": ""}, "json" : null, "files" : {}, "headers" : {"Accept" : "*/*", "Content-Type" : "application/x-www-form-urlencoded", "Content-Length" : "8"}}
(1 row)

select curl_easy_getinfo_errcode(), curl_easy_getinfo_errdesc(), curl_easy_getinfo_errbuf();
 curl_easy_getinfo_errcode | curl_easy_getinfo_errdesc | curl_easy_getinfo_errbuf 
---------------------------+---------------------------+--------------------------
                         0 | No error                  | 
(1 row)

END;
BEGIN;
select curl_easy_reset();
 curl_easy_reset 
-----------------
 t
(1 row)

select curl_easy_setopt_url(current_setting('pg_curl.httpbin') || '/post?');
 curl_easy_setopt_url 
----------------------
 t
(1 row)

select curl_url_append('a', 'b');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('c', '');
 curl_url_append 
-----------------
 t
(1 row)

select curl_url_append('d');
 curl_url_append 
-----------------
 t
(1 row)

select curl_mime_data('f', name:='e');
 curl_mime_data 
----------------
 t
(1 row)

select curl_mime_data('', name:='g');
 curl_mime_data 
----------------
 t
(1 row)

select curl_mime_data(null, name:='h');
 curl_mime_data 
----------------
 t
(1 row)

select curl_mime_data('content', name:='filename.txt', file:='filename.txt');
 curl_mime_data 
----------------
 t
(1 row)

select curl_easy_perform();
 curl_easy_perform 
-------------------
 t
(1 row)

with s as (
    select regexp_matches(curl_easy_getinfo_header_in(), E'([^ \t\r\n\f]+): ?([^\t\r\n\f]+)', 'g') as s
) select lower(s[1]) as key, s[2] as value from s where lower(s[1]) not in ('date', 'server', 'content-length', 'connection');
               key                |      value       
----------------------------------+------------------
 content-type                     | application/json
 access-control-allow-origin      | *
 access-control-allow-credentials | true
(3 rows)

with j as (
    select convert_from(curl_easy_getinfo_data_in(), 'utf-8')::jsonb as data
) select json_build_object(
    'args', j.data->'args',
    'data', j.data->>'data',
    'form', j.data->'form',
    'json', j.data->'json',
    'files', j.data->'files',
    'headers', json_build_object('Accept', j.data->'headers'->>'Accept')
) from j;
                                                                                 json_build_object                                                                                 
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 {"args" : {"a": "b", "c": "", "d": ""}, "data" : "", "form" : {"e": "f", "g": "", "h": ""}, "json" : null, "files" : {"filename.txt": "content"}, "headers" : {"Accept" : "*/*"}}
(1 row)

select curl_easy_getinfo_errcode(), curl_easy_getinfo_errdesc(), curl_easy_getinfo_errbuf();
 curl_easy_getinfo_errcode | curl_easy_getinfo_errdesc | curl_easy_getinfo_errbuf 
---------------------------+---------------------------+--------------------------
                         0 | No error                  | 
(1 row)

END;