Практикум. Сервис systemd для Pangolin

Подготовка юнита

1. Проверьте, существует ли юнит systemd для управления экземпляром PostgreSQL:

   sudo systemctl list-unit-files | grep postgres

   Предполагается, что приведенная выше команда ничего не вернет. Если юнит уже имеется, переходите к пункту 2 лабораторной работы.

2. При отсутствии сервиса создайте его управляющий файл командой:

   $ sudo tee /etc/systemd/system/postgresql.service << EOF
   [Unit]
   Description=Runners PostgreSQL service
   After=syslog.target network.target
   [Service]
   Type=notify
   Environment="PG_LICENSE_PATH=/opt/pangolin_license"
   Environment="PG_PLUGINS_PATH=/usr/pangolin-6.2.0/lib"
   Environment="PGCTLTIMEOUT=120"
   Environment="LD_LIBRARY_PATH=/usr/pangolin-6.2.0/lib"
   LimitNOFILE=65536
   # Pre-commands to start watchdog device
   User=postgres
   Group=postgres
   PermissionsStartOnly=true
   ExecStartPre=/bin/mkdir -p /var/run/postgresql
   ExecStartPre=/bin/chown -R postgres:postgres /var/run/postgresql
   ExecReload=/bin/kill -HUP $MAINPID
   WorkingDirectory=/usr/pangolin-6.2.0
   ExecStart=/bin/bash -i -c "/usr/pangolin-6.2.0/bin/postgres -D /pgdata/06/data"
   Restart=on-failure
   [Install]
   WantedBy=multi-user.target
   EOF

   Если копирование и выполнение этой команды вызывают затруднения, просто скопируйте выделенный цветом текст и вставьте его с помощью привычного текстового редактора в файл /etc/systemd/system/postgresql.service . При этом редактор должен быть запущен от имени суперпользователя ОС (с правами root).

Включение юнита и запуск сервиса

1. Проверьте правильность копирования:

   $ cat /etc/systemd/system/postgresql.service [Unit]
   Description=Runners PostgreSQL service After=syslog.target network.target
   [Service]
   Type=notify
   Environment="PG_LICENSE_PATH=/opt/pangolin_license"
   Environment="PG_PLUGINS_PATH=/usr/pangolin-6.2.0/lib"
   Environment="PGCTLTIMEOUT=120"
   Environment="LD_LIBRARY_PATH=/usr/pangolin-6.2.0/lib"
   LimitNOFILE=65536
   # Pre-commands to start watchdog device
   User=postgres
   Group=postgres
   PermissionsStartOnly=true
   ExecStartPre=/bin/mkdir -p /var/run/postgresql
   ExecStartPre=/bin/chown -R postgres:postgres /var/run/postgresql
   ExecReload=/bin/kill -HUP $MAINPID
   WorkingDirectory=/usr/pangolin-6.2.0
   ExecStart=/bin/bash -i -c "/usr/pangolin-6.2.0/bin/postgres -D /pgdata/06/data"
   Restart=on-failure
   [Install]
   WantedBy=multi-user.target

2. Перечитайте конфигурацию systemd:

   $ sudo systemctl daemon-reload

3. Проверьте, подключился ли юнит postgresql.service:

   $ sudo systemctl list-unit-files | grep postgresql postgresql.service enabled disabled

4. Запустите его, сконфигурировав его при этом для автозапуска:

   $ sudo systemctl enable --now postgresql
   Created symlink /etc/systemd/system/multi-user.target.wants/postgresql.service → /etc/systemd/system/postgresql.service.

5. Проверьте статус сервиса postgresql:

   $ sudo systemctl status postgresql
   ● postgresql.service - Runners PostgreSQL service
   Loaded: loaded (/etc/systemd/system/postgresql.service; enabled; vendor
   preset: disabled)
   Active: active (running) since Sun 2024-12-08 19:08:00 MSK; 1min 37s ago
   Process: 2913 ExecStartPre=/bin/mkdir -p /var/run/postgresql (code=exited,
   status=0/SUCCESS)
   Process: 2914 ExecStartPre=/bin/chown -R postgres:postgres
   /var/run/postgresql (code=exited, status=0/SUCCESS)
   Main PID: 2915 (postgres)
   Tasks: 10 (limit: 4652)
   Memory: 32.7M
   CPU: 329ms
   CGroup: /system.slice/postgresql.service
   ├─ 2915 /usr/pangolin-6.2.0/bin/postgres -D /pgdata/06/data
   ├─ 2939 "postgres: checkpointer " "" "" "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2940 "postgres: background writer " "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2942 "postgres: idle sessions terminator " "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" ""
   ├─ 2943 "postgres: walwriter " "" "" "" "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2944 "postgres: license checker " "" "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2945 "postgres: autovacuum launcher " "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2946 "postgres: autounite launcher " "" "" "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" "" "" "" "" ""
   ├─ 2947 "postgres: integrity check launcher " "" "" "" "" "" "" ""
   "" "" "" "" "" "" "" "" ""
   └─ 2948 "postgres: logical replication launcher " "" "" "" "" "" ""
   "" "" "" "" "" ""
   Dec 08 19:08:00 p620.class.edu bash[2915]: 2024-12-08 19:08:00.511 MSK [2915]
   LOG:  listening on IPv4 address "0.0.0.0", port 5432
   Dec 08 19:08:00 p620.class.edu bash[2915]: 2024-12-08 19:08:00.511 MSK [2915]
   LOG:  listening on IPv6 address "::", port 5432
   Dec 08 19:08:00 p620.class.edu bash[2915]: 2024-12-08 19:08:00.519 MSK [2915]
   LOG:  listening on Unix socket "/tmp/.s.PGSQL.5432"
   Dec 08 19:08:00 p620.class.edu bash[2941]: 2024-12-08 19:08:00.526 MSK [2941]
   LOG:  database system was shut down at 2024-12-08 19:07:38 MSK
   Dec 08 19:08:00 p620.class.edu bash[2942]: 2024-12-08 19:08:00.527 MSK [2942]
   LOG:  idle terminator started
   Dec 08 19:08:00 p620.class.edu bash[2944]: 2024-12-08 19:08:00.564 MSK [2944]
   LOG:  License checker started
   Dec 08 19:08:00 p620.class.edu bash[2915]: 2024-12-08 19:08:00.575 MSK [2915]
   LOG:  database system is ready to accept connections
   Dec 08 19:08:00 p620.class.edu bash[2947]: 2024-12-08 19:08:00.576 MSK [2915]
   LOG:  Start integrity check launcher
   Dec 08 19:08:00 p620.class.edu bash[2947]: 2024-12-08 19:08:00.579 MSK [2947]
   LOG:  Start of integrity check
   Dec 08 19:08:00 p620.class.edu systemd[1]: Started Runners PostgreSQL service.