This is just a my playground
ngx_postgres
is an upstream module that allows nginx
to communicate directly
with PostgreSQL
database.
Response is generated in rds
format, so it's compatible with ngx_rds_json
and ngx_drizzle
modules.
This module is production-ready and it's compatible with following nginx releases:
- 0.7.x (tested with 0.7.60 to 0.7.69),
- 0.8.x (tested with 0.8.0 to 0.8.55),
- 0.9.x (tested with 0.9.0 to 0.9.7),
- 1.0.x (tested with 1.0.0 to 1.0.11),
- 1.1.x (tested with 1.1.0 to 1.1.12).
- 1.2.x (tested with 1.2.3 to 1.2.3).
- 1.3.x (tested with 1.3.4 to 1.3.4).
- syntax:
postgres_server ip[:port] dbname=dbname user=user password=pass
- default:
none
- context:
upstream
Set details about the database server.
- syntax:
postgres_keepalive off | max=count [mode=single|multi] [overflow=ignore|reject]
- default:
max=10 mode=single overflow=ignore
- context:
upstream
Configure keepalive parameters:
max
- maximum number of keepalive connections (per worker process),mode
- backend matching mode,overflow
- eitherignore
the fact that keepalive connection pool is full and allow request, but close connection afterwards orreject
request with503 Service Unavailable
response.
- syntax:
postgres_pass upstream
- default:
none
- context:
location
,if location
Set name of an upstream block that will be used for the database connections (it can include variables).
- syntax:
postgres_query [methods] query
- default:
none
- context:
http
,server
,location
,if location
Set query string (it can include variables). When methods are specified then query is used only for them, otherwise it's used for all methods.
This directive can be used more than once within same context.
- syntax:
postgres_rewrite [methods] condition [=]status_code
- default:
none
- context:
http
,server
,location
,if location
Rewrite response status_code
when given condition is met (first one wins!):
no_changes
- no rows were affected by the query,changes
- at least one row was affected by the query,no_rows
- no rows were returned in the result-set,rows
- at least one row was returned in the result-set.
When status_code
is prefixed with =
sign then original response body is
send to the client instead of the default error page for given status_code
.
By design both no_changes
and changes
apply only to INSERT
,
UPDATE
, DELETE
, MOVE
, FETCH
and COPY
SQL queries.
This directive can be used more than once within same context.
- syntax:
postgres_output rds|text|value|binary_value|none
- default:
rds
- context:
http
,server
,location
,if location
Set output format:
rds
- return all values from the result-set inrds
format (with appropriateContent-Type
),text
- return all values from the result-set in text format (with defaultContent-Type
), values are separated by new line,value
- return single value from the result-set in text format (with defaultContent-Type
),binary_value
- return single value from the result-set in binary format (with defaultContent-Type
),none
- don't return anything, this should be used only when extracting values withpostgres_set
for use with other modules (withoutContent-Type
).
- syntax:
postgres_set $variable row column [optional|required]
- default:
none
- context:
http
,server
,location
Get single value from the result-set and keep it in $variable.
When requirement level is set to required
and value is either out-of-range,
NULL
or zero-length, then nginx returns 500 Internal Server Error
response.
Such condition is silently ignored when requirement level is set to optional
(default).
Row and column numbers start at 0. Column name can be used instead of column number.
This directive can be used more than once within same context.
- syntax:
postgres_escape $escaped [[=]$unescaped]
- default:
none
- context:
http
,server
,location
Escape and quote $unescaped
string. Result is stored in $escaped
variable
which can be safely used in SQL queries.
Because nginx cannot tell the difference between empty and non-existing strings,
all empty strings are by default escaped to NULL
value. This behavior can be
disabled by prefixing $unescaped
string with =
sign.
- syntax:
postgres_connect_timeout timeout
- default:
10s
- context:
http
,server
,location
Set timeout for connecting to the database.
- syntax:
postgres_result_timeout timeout
- default:
30s
- context:
http
,server
,location
Set timeout for receiving result from the database.
Number of columns in received result-set.
Number of rows in received result-set.
Number of rows affected by INSERT
, UPDATE
, DELETE
, MOVE
, FETCH
or COPY
SQL query.
SQL query, as seen by PostgreSQL
database.
Return content of table cats
(in rds
format).
http {
upstream database {
postgres_server 127.0.0.1 dbname=test
user=test password=test;
}
server {
location / {
postgres_pass database;
postgres_query "SELECT * FROM cats";
}
}
}
Return only those rows from table sites
that match host
filter which
is evaluated for each request based on its $http_host
variable.
http {
upstream database {
postgres_server 127.0.0.1 dbname=test
user=test password=test;
}
server {
location / {
postgres_pass database;
postgres_query SELECT * FROM sites WHERE host='$http_host'";
}
}
}
Pass request to the backend selected from the database (traffic router).
http {
upstream database {
postgres_server 127.0.0.1 dbname=test
user=test password=test;
}
server {
location / {
eval_subrequest_in_memory off;
eval $backend {
postgres_pass database;
postgres_query "SELECT * FROM backends LIMIT 1";
postgres_output value 0 0;
}
proxy_pass $backend;
}
}
}
Required modules (other than ngx_postgres
):
Restrict access to local files by authenticating against PostgreSQL
database.
http {
upstream database {
postgres_server 127.0.0.1 dbname=test
user=test password=test;
}
server {
location = /auth {
internal;
postgres_escape $user $remote_user;
postgres_escape $pass $remote_passwd;
postgres_pass database;
postgres_query "SELECT login FROM users WHERE login=$user AND pass=$pass";
postgres_rewrite no_rows 403;
postgres_output none;
}
location / {
auth_request /auth;
root /files;
}
}
}
Required modules (other than ngx_postgres
):
Simple RESTful webservice returning JSON responses with appropriate HTTP status codes.
http {
upstream database {
postgres_server 127.0.0.1 dbname=test
user=test password=test;
}
server {
set $random 123;
location = /numbers/ {
postgres_pass database;
rds_json on;
postgres_query HEAD GET "SELECT * FROM numbers";
postgres_query POST "INSERT INTO numbers VALUES('$random') RETURNING *";
postgres_rewrite POST changes 201;
postgres_query DELETE "DELETE FROM numbers";
postgres_rewrite DELETE no_changes 204;
postgres_rewrite DELETE changes 204;
}
location ~ /numbers/(?<num>\d+) {
postgres_pass database;
rds_json on;
postgres_query HEAD GET "SELECT * FROM numbers WHERE number='$num'";
postgres_rewrite HEAD GET no_rows 410;
postgres_query PUT "UPDATE numbers SET number='$num' WHERE number='$num' RETURNING *";
postgres_rewrite PUT no_changes 410;
postgres_query DELETE "DELETE FROM numbers WHERE number='$num'";
postgres_rewrite DELETE no_changes 410;
postgres_rewrite DELETE changes 204;
}
}
}
Required modules (other than ngx_postgres
):
Use GET parameter in SQL query.
location /quotes {
set_unescape_uri $txt $arg_txt;
postgres_escape $txt;
postgres_pass database;
postgres_query "SELECT * FROM quotes WHERE quote=$txt";
}
Required modules (other than ngx_postgres
):
ngx_postgres
comes with complete test suite based on Test::Nginx.
You can test core functionality by running:
$ TEST_NGINX_IGNORE_MISSING_DIRECTIVES=1 prove
You can also test interoperability with following modules:
- ngx_coolkit,
- ngx_echo,
- ngx_form_input,
- ngx_set_misc,
- ngx_http_auth_request_module,
- nginx-eval-module (agentzh's fork),
- ngx_rds_json.
by running:
$ prove
Copyright (c) 2010, FRiCKLE Piotr Sikora <info@frickle.com>
Copyright (c) 2009-2010, Xiaozhe Wang <chaoslawful@gmail.com>
Copyright (c) 2009-2010, Yichun Zhang <agentzh@gmail.com>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software includes also parts of the code from:
nginx
(copyrighted by Igor Sysoev under BSD license),ngx_http_upstream_keepalive
module (copyrighted by Maxim Dounin under BSD license).