pg_diag_setup

pg_diag_setup
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Introduction

A tool for managing Tantor BE configuration with profile support and rollback capability.

System Requirements

Python 3.x (tested on CentOS 7)
Tantor BE accessible via Unix Domain Socket
psql utility available in PATH

Installation

Copy the pg_diag_setup.py file to the server.
Create a profiles directory and place profile files inside (e.g., default.yaml).
Make the script executable:
```
chmod +x pg_diag_setup.py
```

Usage

Basic run (configuration check)

sudo ./pg_diag_setup.py --port 5432 --unix-socket-dir /tmp

Apply a configuration profile

sudo ./pg_diag_setup.py --port 5432 --unix-socket-dir /tmp --profile default.yaml --bin-dir /opt/path_to_binaries

View available backups

sudo ./pg_diag_setup.py --port 5432 --unix-socket-dir /tmp --list-backups

Roll back changes

sudo ./pg_diag_setup.py --port 5432 --unix-socket-dir /tmp --undo 20240529_143022 --bin-dir /opt/path_to_binaries

Command Line Options

--port - Tantor BE port (default: 5432)
--unix-socket-dir - Unix socket directory (default: /tmp)
--profile - YAML profile file to apply
--undo - timestamp for rollback
--list-backups - show available backup list
--bin-dir - directory where the Tantor BE distribution is installed
-V - show utility version
-v - enable verbose mode

What the Program Does

Tasks 1-2: Connection and Configuration Discovery

Connects to Tantor BE via Unix Domain Socket
Locates the postgresql.conf file

Task 3: Checking postgresql.auto.conf

Verifies existence of the postgresql.auto.conf file

Task 4: Parameter Analysis

Parses all configuration files
Compiles a parameter list with source info
Handles include directives

Task 5: Profile Application

Reads YAML profile with extension settings
Checks available extensions via pg_available_extensions
Creates configuration backups
Appends to shared_preload_libraries without overwriting existing entries
Adds new parameters to the end of postgresql.conf
Tags added parameters with “Added by pg_diag_setup” comment

Task 6: Rollback System

Creates timestamped backups
Allows rollback to any previous backup

Profile File Format

extension_name:
  shared_preload_lib: library_name
  create_cmd: CREATE EXTENSION command
  params:
    parameter1: value1
    parameter2: value2

Safety

All changes are accompanied by backups
Existing parameters are preserved
Extensions are checked before installation
New parameters are added to the end of the file

Backup Examples

After changes are applied, the following files are created:

postgresql.conf_backup_pds_20240529_143022
postgresql.auto.conf_backup_pds_20240529_143022

Logging

The program provides detailed output for all operations:

Located configuration files
Detected parameters
Backup creation
Applied changes
Operation results

Limitations

Requires psql utility
Only works with Unix Domain Socket connections
Simple YAML parser (doesn’t support full YAML spec)
Does not perform automatic Tantor BE restart

Troubleshooting

Tantor BE connection error
- Check the --unix-socket-dir path
- Ensure Tantor BE is running
- Verify socket file permissions
Configuration read error
- Check configuration file permissions
- Ensure the user has read/write access
YAML parsing error
- Check profile file syntax
- Validate indentation (use 2 or 4 spaces)

Recommendations

Always create full backups before applying changes
Test changes in a staging environment
Tantor BE restart may be required after applying a profile
Track applied profiles and their timestamps

Support

If issues arise, check:

Tantor BE logs
File access permissions
YAML profile syntax
Extension availability in the system

pg_diag_setup#