Re: Trying to solve a SocketError [Errno 13] Permission with PL/Python in PostgreSQL 9.3

On 05/23/2015 03:51 PM, Marcos Ortiz wrote:
>
>
> On 23/05/15 18:40, Adrian Klaver wrote:
>> On 05/23/2015 03:27 PM, Marcos Ortiz wrote:
>>> Regards to all the list.
>>> First all the info about the system:
>>>
>>> O.S: CentOS 7 64 bits
>>> PostgreSQL version:
>>>
>>> SELECT version();
>>> version
>>> --------------------------------------------------------------------------------------------------------------
>>>
>>>
>>> PostgreSQL 9.2.7 on x86_64-redhat-linux-gnu, compiled by gcc (GCC)
>>> 4.8.2 20140120 (Red Hat 4.8.2-16), 64-bit
>>> (1 row)
>>>
>>> Neo4j version: 2.1.M
>>> Py2neo version: 2.0.8
>>> Python version:
>>> python
>>> Python 2.7.5 (default, Jun 17 2014, 18:11:42)
>>> [GCC 4.8.2 20140120 (Red Hat 4.8.2-16)] on linux2
>>>
>>> Now the problem:
>>>
>>> We are working here to integrate PostgreSQL with Neo4j through PL/Python
>>> using the py2neo module for it, and when we want to send sentences to
>>> Neo4j using port 7474, the executed code raises a SocketError [Errno 13]
>>> Permission denied.
>>
>> Well first in the code below, if I am following correctly, the socket
>> is 37474.
> Yes, Adrian. Sorry for that, the correct port is 7474. I just was
> testing with higher ports to
> see if the error persisted.
>>
>>
>>>
>>> I tested the same code in a normal python script outside of PostgreSQL,
>>> and it works well, but the problem is when I use the code inside
>>> PostgreSQL with PL/Python.
>>
>> Second the plpythonu code is running as the postgres user, so does
>> that user have permissions on the socket.
> Did you mean the socket created by Neo4j's server right?
> For that reason, I created a group in the system for this named
> supervisor, where neo4j/postgres users are members.
> So, if I find the socket file for Neo4j-server, changing permissions
> could solve the problem. Right?

Not sure, but a quick search found that py2neo uses the neo4j REST API
and that API has authorization parameters:

http://neo4j.com/docs/stable/security-server.html

Have you gone through the above?

> Neo4j is a Java-based platform.
>>
>>> This is the code of a simple function to search a node in the Neo4j
>>> graph:
>>>
>>> CREATE OR REPLACE FUNCTION search_professor_node(nombre_prof text)
>>> RETURNS text AS
>>> $BODY$
>>> from py2neo import Graph
>>> from py2neo.cypher import CypherTransaction
>>>
>>> graph = Graph("http://neo4j:neo4j(at)10(dot)8(dot)45(dot)136:37474/db/data")
>>> tx = graph.cypher.begin()
>>> statement = "MATCH (pf:Professor) WHERE pf.nombre = {name} RETURN pf;" ,
>>> tx.append(statement, parameters={'name': nombre_prof})
>>> professor= tx.commit()
>>> $BODY$
>>> LANGUAGE plpythonu VOLATILE
>>> COST 100;
>>>
>>> and it can be used:
>>> SELECT search_professor_node('Max');
>>>
>>> The completed error is:
>>>
>>> ********** Error **********
>>>
>>> ERROR: py2neo.packages.httpstream.http.SocketError: Permission denied
>>> SQL state: XX000
>>> Context: Traceback (most recent call last):
>>> PL/Python function "search_professor_node", line 6, in <module>
>>> tx = graph.cypher.begin()
>>> PL/Python function "search_professor_node", line 666, in cypher
>>> PL/Python function "search_professor_node", line 212, in metadata
>>> PL/Python function "search_professor_node", line 257, in get
>>> PL/Python function "search_professor_node", line 965, in get
>>> PL/Python function "search_professor_node", line 942, in
>>> __get_or_head
>>> PL/Python function "search_professor_node", line 432, in submit
>>> PL/Python function "search_professor_node", line 361, in submit
>>> PL/Python function "search_professor_node"
>>>
>>> Thanks a lot for your time, and I hope to find a suitable solution
>>> for it.
>>>
>>>
>>
>>
>
> --
> Marcos Ortiz <http://about.me/marcosortiz>, Sr. Product Manager (Data
> Infrastructure) at UCI
> @marcosluis2186 <http://twitter.com/marcosluis2186>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com