Should Request Headers be Displayed When a Request is Made to a Stored Procedure?

[eceppda]

Environment

• PostgreSQL version: postgres:12.12 (docker container)
• PostgREST version: postgrest/postgrest:v9.0.1.20220802 (docker container)
• Operating system: macos

Description of issue

I've written a function to retrieve request headers.

I have added the following stored procedure in postgres:

CREATE FUNCTION schema.get_headers()
RETURNS json AS $$
 SELECT current_setting('request.headers', true)::json;
$$ LANGUAGE SQL IMMUTABLE;

And I'm testing it using curl and postgrest:

curl http://localhost:3000/schema/rpc/get_headers -H "User-Agent: Mozilla"

The response is:

{}

(Expected behavior vs actual behavior)

My expectation is that all request headers will be returned in json format. In particular, since I've specified a request header (User-Agent) in my curl request, I expected to see it when I made a request to the rpc url.

Instead, I receive an empty json response.

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

The question should be reproducible using the above function and curl command. I'm using a compose file similar to this:

  db:
    image: postgres:12.12
    ports:
      - "5432:5432"
    environment:
      POSTGRES_DB: schema
      POSTGRES_USER: dbuser
      POSTGRES_PASSWORD: password
  
  server:
    image: postgrest/postgrest:v9.0.1.20220802
    ports:
      - "3000:3000"
    environment:
      PGRST_DB_URI: postgres://dbuser:password@db:5432/schema
      PGRST_DB_SCHEMA: schema
      PGRST_DB_ANON_ROLE: web_anon
      PGRST_DB_USE_LEGACY_GUCS: "False"
    depends_on:
      - db

[steve-chavez]

Should Request Headers be Displayed When a Request is Made to a Stored Procedure?

Yes, should work.

PGRST_DB_USE_LEGACY_GUCS: "False"

I'm not sure if the above config works, try with PGRST_DB_USE_LEGACY_GUCS: 1 or try using postgres 14.

[eceppda]

I created a simple example demonstrating what I'm seeing here. It uses postgres 14.5 and postgrest v9.0.1.20220802.

I used the following SQL:

CREATE SCHEMA test;

create role web_anon nologin;

grant usage on schema test to web_anon;

CREATE FUNCTION test.get_headers()
RETURNS json AS $$
    SELECT current_setting('request.headers', true)::json;
$$ LANGUAGE SQL IMMUTABLE;

I guess that's the minimum to recreate what I'm troubleshooting.

Running the compose file will create the schema, web_anon role, and get_headers function. curl http://localhost:3000/test/rpc/get_headers -H "User-Agent: Mozilla" returns {} and I expect to see the request headers.

[laurenceisla]

I think the url path is wrong, it should not have /test in it. Adding -i to the Curl shows that a 404 is returned. This should call the function and return the headers:

curl http://localhost:3000/rpc/get_headers -H "User-Agent: Mozilla" -i