POST header Prefer: return=headers-only not returning LOCATION information

[brucer42]

Environment

• PostgreSQL version: 16.0 postgres
• PostgREST version: 12.0.2 postgrest/postgrest
• Operating system: macOS

Description of issue

Some research indicated (to me) that this was addressed in 4b46c4e#diff-b032808b94623f64b08323b5ff13143d5ce0623cd14d49b4060ad1e417a19a6c

Prefer: return=headers-only HEADER does not return location information
Prefer: return=representation does return full representation

I am using the tutorial with the todos table to reproduce this

(Steps to reproduce: Include a minimal SQL definition plus how you make the request to PostgREST and the response body)

[laurenceisla]

What is the exact request you're doing and the response you're getting? If you're seeing an error like "permission denied for sequence..." then you need to grant permissions to the SEQUENCE generated by serial as seen in the Tutorial 1.

[brucer42]

Purely by the tutorial, using secret 01234567012345670123456701234567, running in an emacs shell so using json_pp to print

brucer42@brucer42s-MBP postgrest % curl http://localhost:3000/todos -X POST
-H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoidG9kb191c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y"
-H "Prefer: return=headers-only"
-H "Content-Type: application/json"
-d '{"task": "learn how to auth"}' | json_pp
curl http://localhost:3000/todos -X POST \

 -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoidG9kb191c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y"   \
 -H "Prefer: return=headers-only" \
 -H "Content-Type: application/json" \
 -d '{"task": "learn how to auth"}' **| json_pp**

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 29 0 0 100 29 0 534 --:--:-- --:--:-- --:--:-- 537
malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "(end of string)") at /usr/bin/json_pp5.30 line 52.
brucer42@brucer42s-MBP postgrest % curl http://localhost:3000/todos -X POST
-H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoidG9kb191c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y"
-H "Prefer: return=representation"
-H "Content-Type: application/json"
-d '{"task": "learn how to auth"}' | json_pp
curl http://localhost:3000/todos -X POST \

 -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoidG9kb191c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y"   \
 -H "Prefer: return=representation" \
 -H "Content-Type: application/json" \
 -d '{"task": "learn how to auth"}' | json_pp

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 90 0 61 100 29 4468 2124 --:--:-- --:--:-- --:--:-- 6923
[
{
"done" : false,
"due" : null,
"id" : 7,
"task" : "learn how to auth"
}
]
brucer42@brucer42s-MBP postgrest %

[laurenceisla]

malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "(end of string)") at /usr/bin/json_pp5.30 line 52.

Ah, that seems to be an output given by json_pp because it can't parse the content, since Prefer: return=headers-only returns an empty body (no content at all, only headers). Try removing json_pp from the curl request when using that header and it should work.

Also add -i to that curl request, in order to see the Location header.

[brucer42]

works! thank you. See trace of it working:

brucer42@brucer42s-MBP postgrest % curl http://localhost:3000/todos -X POST
-H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoidG9kb191c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y"
-H "Prefer: return=headers-only"
-H "Content-Type: application/json"
-d '{"task": "learn how to auth"}' -i
curl http://localhost:3000/todos -X POST
<1c2VyIn0.qrlieu5zvSLJcyDFJ_ZoWTbLkDZbVm1LAsdtPKM7J1Y" \

 -H "Prefer: return=headers-only" \
 -H "Content-Type: application/json" \
 -d '{"task": "learn how to auth"}' -i

HTTP/1.1 201 Created
Transfer-Encoding: chunked
Date: Thu, 25 Apr 2024 02:15:40 GMT
Server: postgrest/12.0.2
Location: �]8;;http://localhost:3000/todos?id=eq.8�\/todos?id=eq.8
�]8;;�\Content-Range: /
Preference-Applied: return=headers-only

brucer42@brucer42s-MBP postgrest %