Postgres

Kubemq postgres target connector allows services using kubemq server to access postgres database services.

Prerequisites

The following are required to run the postgres target connector:

• kubemq cluster

• postgres server

• kubemq-targets deployment

Configuration

Postgres target connector configuration properties:

Properties Key	Required	Description	Example
connection	yes	postgres connection string address	"postgres://postgres:postgres@localhost:5432/postgres?sslmode=disable"
max_idle_connections	no	set max idle connections	"10"
max_open_connections	no	set max open connections	"100"
connection_max_lifetime_seconds	no	set max lifetime for connections in seconds	"3600"

Example:

bindings:
  - name: kubemq-query-postgres
    source:
      kind: kubemq.query
      name: kubemq-query
      properties:
        address: "kubemq-cluster:50000"
        client_id: "kubemq-query-postgres-connector"
        auth_token: ""
        channel: "query.postgres"
        group:   ""
        auto_reconnect: "true"
        reconnect_interval_seconds: "1"
        max_reconnects: "0"
    target:
      kind: stores.postgres
      name: target-postgres
      properties:
        connection: "postgres://postgres:postgres@localhost:5432/postgres?sslmode=disable"
        max_idle_connections: "10"
        max_open_connections: "100"
        connection_max_lifetime_seconds: "3600"

Usage

Query Request

Query request metadata setting:

Metadata Key	Required	Description	Possible values
method	yes	set type of request	"query"

Query request data setting:

Data Key	Required	Description	Possible values
data	yes	query string	base64 bytes array

Example:

Query string: SELECT id,title,content FROM post;

{
  "metadata": {
    "method": "query"
  },
  "data": "U0VMRUNUIGlkLHRpdGxlLGNvbnRlbnQgRlJPTSBwb3N0Ow=="
}

Exec Request

Exec request metadata setting:

Metadata Key	Required	Description	Possible values
method	yes	set type of request	"exec"
isolation_level	no	set isolation level for exec operation	""
			"read_uncommitted"
			"read_committed"
			"repeatable_read"
			"serializable"

Exec request data setting:

Data Key	Required	Description	Possible values
data	yes	exec string	base64 bytes array

Example:

Exec string:

INSERT INTO post(ID,TITLE,CONTENT) VALUES (1,NULL,'Content One'),(2,'Title Two','Content Two');

{
  "metadata": {
    "method": "exec",
    "isolation_level": "read_uncommitted"
  },
  "data": "SU5TRVJUIElOVE8gcG9zdChJRCxUSVRMRSxDT05URU5UKSBWQUxVRVMKCSAgICAgICAgICAgICAgICAgICAgICAgKDEsTlVMTCwnQ29udGVudCBPbmUnKSwKCSAgICAgICAgICAgICAgICAgICAgICAgKDIsJ1RpdGxlIFR3bycsJ0NvbnRlbnQgVHdvJyk7" 
}

Transaction Request

Transaction request metadata setting:

Metadata Key	Required	Description	Possible values
method	yes	set type of request	"transaction"
isolation_level	no	set isolation level for exec operation	""
			"read_uncommitted"
			"read_committed"
			"repeatable_read"
			"serializable"

Transaction request data setting:

Data Key	Required	Description	Possible values
data	yes	string string	base64 bytes array

Example:

Transaction string:

DROP TABLE IF EXISTS post;
CREATE TABLE post (
         ID serial,
         TITLE varchar(40),
         CONTENT varchar(255),
         CONSTRAINT pk_post PRIMARY KEY(ID)
       );
INSERT INTO post(ID,TITLE,CONTENT) VALUES
                       (1,NULL,'Content One'),
                       (2,'Title Two','Content Two');

{
  "metadata": {
    "key": "your-postgres-key",
    "method": "delete"
  },
  "data": "CURST1AgVEFCTEUgSUYgRVhJU1RTIHBvc3Q7CiAgICBDUkVBVEUgVEFCTEUgcG9zdCAoCgkgICAgICAgICBJRCBzZXJpYWwsCgkgICAgICAgICBUSVRMRSB2YXJjaGFyKDQwKSwKCSAgICAgICAgIENPTlRFTlQgdmFyY2hhcigyNTUpLAoJICAgICAgICAgQ09OU1RSQUlOVCBwa19wb3N0IFBSSU1BUlkgS0VZKElEKQoJICAgICAgICk7CiAgICBJTlNFUlQgSU5UTyBwb3N0KElELFRJVExFLENPTlRFTlQpIFZBTFVFUwoJICAgICAgICAgICAgICAgICAgICAgICAoMSxOVUxMLCdDb250ZW50IE9uZScpLAoJICAgICAgICAgICAgICAgICAgICAgICAoMiwnVGl0bGUgVHdvJywnQ29udGVudCBUd28nKTs="
}