Python-Sys-Admin-Scripts/verify-postgresql-backup at master · jjriv/Python-Sys-Admin-Scripts · GitHub

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#!/usr/bin/python3

import lxc
import os
import subprocess
import sys
import time
import datetime
import smtplib

backupdir = "/nas/servers/databaseserver/"
dbname = "postgresdatabase"
mediadir = "/media/postgresql-backup"
mountentry = backupdir + " media/postgresql-backup none bind,create=dir 0 0"
statusfile = "postgresql-status"
datefile = "postgresql-date"
consistentcheck = "consistent recovery state reached"
readycheck = "database system is ready to accept connections"
today = datetime.date.today()
yesterday = datetime.datetime.utcnow() - datetime.timedelta(1)

#db files
dbfiles = [
        backupdir + "base.tar.gz",
        backupdir + "pg_wal.tar.gz",
        ]

try:
    #decrypt db backup files
    for dbfile in dbfiles:
        cmd = "gpg --batch --passphrase-fd 0 --output " + dbfile + "  --decrypt " + dbfile + ".gpg < /root/.backup_passphrase"
        subprocess.call(cmd, shell=True)

    #create the container object
    c = lxc.Container("postgresql", "/home/lxc")

    #create the container
    c.create(
        "download",
        lxc.LXC_CREATE_QUIET,
        {"dist": "centos", "release": "7", "arch": "amd64"})

    #append the mount point
    if not mountentry in c.get_config_item("lxc.mount.entry"):
        c.append_config_item("lxc.mount.entry", mountentry)

    #start the container
    c.start()

    #wait for connectivity
    #this is not enough time, need to loop through it a few times until container network is ready
    while not c.get_ips(timeout=1):
        print('Waiting for network...')

    #sleep for a little longer just to be sure
    print('Network found, pausing a moment to let it finish starting...')
    time.sleep(5)

    #run some network commands to install postgres and update all the things
    c.attach_wait(lxc.attach_run_command,
        ["yum", "install", "https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm", "-y"])
    c.attach_wait(lxc.attach_run_command,
        ["yum", "install", "postgresql10-server", "-y"])
    c.attach_wait(lxc.attach_run_command,
        ["yum", "install", "postgresql10-contrib", "-y"])
    #c.attach_wait(lxc.attach_run_command,
    #    ["yum", "update", "-y"])

    #uncompress data files into postgres data directory
    c.attach_wait(lxc.attach_run_command,
        ["mkdir", "/var/lib/pgsql/10/wal_archive"])
    c.attach_wait(lxc.attach_run_command,
        ["chmod", "0700", "/var/lib/pgsql/10/wal_archive"])
    c.attach_wait(lxc.attach_run_command,
        ["tar", "-xzvf", mediadir + "/base.tar.gz", "-C", "/var/lib/pgsql/10/data"])
    c.attach_wait(lxc.attach_run_command,
        ["tar", "-xzvf", mediadir + "/pg_wal.tar.gz", "-C", "/var/lib/pgsql/10/wal_archive"])
    c.attach_wait(lxc.attach_run_command,
        ["chown", "-R", "postgres:postgres", "/var/lib/pgsql/10/wal_archive"])
    c.attach_wait(lxc.attach_run_command,
        ["chown", "-R", "postgres:postgres", "/var/lib/pgsql/10/data"])

    #modify postgresql.conf
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/shared_buffers/#shared_buffers/g", "/var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/effective_cache_size/#effective_cache_size/g", "/var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/archive_mode/#archive_mode/g", "/var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/maintenance_work_mem/#maintenance_work_mem/g", "/var/lib/pgsql/10/data/postgresql.conf"])
    #second, add numbers better for this server
    c.attach_wait(lxc.attach_run_command,
        ["sh", "-c", "echo 'shared_buffers = 2GB' >> /var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sh", "-c", "echo 'effective_cache_size = 4GB' >> /var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sh", "-c", "echo 'archive_mode = off' >> /var/lib/pgsql/10/data/postgresql.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sh", "-c", "echo 'maintenance_work_mem = 250MB' >> /var/lib/pgsql/10/data/postgresql.conf"])

    #modify recovery.conf
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/standby_mode/#standby_mode/g", "/var/lib/pgsql/10/data/recovery.conf"])
    c.attach_wait(lxc.attach_run_command,
        ["sed", "-i", "s/primary_conninfo/#primary_conninfo/g", "/var/lib/pgsql/10/data/recovery.conf"])

    #restart the container, because systemctl is buggy
    c.stop()
    time.sleep(10)
    c.start()
    time.sleep(10)

    #start postgresql
    c.attach_wait(lxc.attach_run_command,
        ["systemctl", "start", "postgresql-10"])

    #wait for archives to catch up
    #create status file in shared dir
    c.attach_wait(lxc.attach_run_command,
        ["touch", mediadir + "/" + statusfile])

    #check that recovery has completed
    i = 0
    while len(open(backupdir + statusfile).readlines()) == 0 and i < 30:
        c.attach_wait(lxc.attach_run_command,
            ["sh", "-c", "grep '" + consistentcheck + "' /var/lib/pgsql/10/data/pg_log/postgresql-" + str(today) + ".log > " + mediadir + "/" + statusfile])
        print('Waiting for recovery to complete...')
        time.sleep(1)
        i += 1

    #check that database is ready to accept connections
    i = 0
    while len(open(backupdir + statusfile).readlines()) == 1 and i < 30:
        c.attach_wait(lxc.attach_run_command,
            ["sh", "-c", "grep '" + readycheck + "' /var/lib/pgsql/10/data/pg_log/postgresql-" + str(today) + ".log >> " + mediadir + "/" + statusfile])
        print('Waiting for database to accept connections...')
        time.sleep(1)
        i += 1

    #create date file in shared dir and set perms
    c.attach_wait(lxc.attach_run_command,
        ["touch", mediadir + "/" + datefile])
    c.attach_wait(lxc.attach_run_command,
        ["chgrp", "postgres", mediadir + "/" + datefile])
    c.attach_wait(lxc.attach_run_command,
        ["chmod", "g+w", mediadir + "/" + datefile])

    #run a query against the database to make sure we have recent data, write to date file
    #use the mail_queue table because it's always current
    #c.attach_wait(lxc.attach_run_command,
    #    ["runuser", "-l", "postgres", "-c", "psql " + dbname + " -t -c 'SELECT create_time FROM mail_queue ORDER BY id DESC LIMIT 1' > " + mediadir + "/" + datefile])

    #runuser doesn't work when this script runs as a cron
    #use 'su' instead.
    c.attach_wait(lxc.attach_run_command,
        ["su", "-", "postgres", "-c", "psql " + dbname + " -t -c 'SELECT create_time FROM mail_queue ORDER BY id DESC LIMIT 1' > " + mediadir + "/" + datefile])

    #read the date file
    with open(backupdir + datefile, 'r') as datefileio:
        backupdate = datefileio.read().strip()

    #read the status file
    with open(backupdir + statusfile, 'r') as statusfileio:
        backupstatus = statusfileio.read()

    #stop and destroy container
    c.stop()
    c.destroy()

    #delete unencrypted files
    for dbfile in dbfiles:
        os.remove(dbfile)

    #delete status and date text files
    os.remove(backupdir + statusfile)
    os.remove(backupdir + datefile)

    #convert date string to datetime object
    backupdate = datetime.datetime.strptime(backupdate, '%Y-%m-%d %H:%M:%S')

    #if yesterday's date is not present in the date file, alert the authorities!
    if backupdate < yesterday:
        msg = "From: backup@pelagodesign.com\r\n"
        msg = msg + "To: backup@pelagodesign.com\r\n"
        msg = msg + "Subject: PostgreSQL Backup Test Failed\r\n"
        msg = msg + "\r\n"
        msg = msg + "The backup did not contain data for yesterday. Please investigate.\n"
        msg = msg + "\nDate found: "+str(backupdate)+" UTC\n"
        msg = msg + "Logs:\n"+backupstatus

        server = smtplib.SMTP('192.168.1.42')
        server.sendmail("backup@pelagodesign.com", "backup@pelagodesign.com", msg)
        server.quit()

except:
    errormessage = str(sys.exc_info()[0]) + "\n" + str(sys.exc_info()[1]) + "\n" + str(sys.exc_info()[2])

    msg = "From: backup@pelagodesign.com\r\n"
    msg = msg + "To: backup@pelagodesign.com\r\n"
    msg = msg + "Subject: PostgreSQL Backup Test Failed\r\n"
    msg = msg + "\r\n"
    msg = msg + "The backup cron had errors. Please investigate.\n"
    msg = msg + "\Error: "+errormessage+"\n"
    server = smtplib.SMTP('192.168.1.42')
    server.sendmail("backup@pelagodesign.com", "backup@pelagodesign.com", msg)
    server.quit()