docker compose postgres在docker入口点initdb.d中运行脚本后重新启动

Question

我有一个简单的Docker Compose文件来初始化Postgres DB实例：

version: '3.8'
services:
my-database:
container_name: my-database
image: library/postgres:13.1
volumes:
- ./db/init-my-database.sql:/docker-entrypoint-initdb.d/init-db-01.sql
environment:
- POSTGRES_DB=my-database
- POSTGRES_USER=admin
- POSTGRES_PASSWORD=password
ports:
- 10040:5432
restart: always
networks:
- app-network

我的脚本init我的数据库.sql看起来像这样：

DROP DATABASE IF EXISTS myschema;
CREATE DATABASE myschema;
-- Make sure we're using our `myschema` database
c myschema;

CREATE SEQUENCE IF NOT EXISTS recipient_seq
START WITH 1
MINVALUE 1
MAXVALUE 9223372036854775807
CACHE 1;
CREATE TABLE IF NOT EXISTS recipient
(
id                      BIGINT                   NOT NULL,
recipient_id            VARCHAR(255)             NOT NULL,
first_name              VARCHAR(255)             NOT NULL,
middle_name             VARCHAR(255)             NOT NULL,
last_name               VARCHAR(255)             NOT NULL,
CONSTRAINT recipient_pk PRIMARY KEY (id)
);

当我跟踪Docker日志时，我确实看到初始化脚本正在被调用。然而，在接近尾声时，数据库被关闭并重新启动-->quot接收到快速关闭请求"；

为什么数据库在最后重新启动？由于脚本中创建的数据库和表已不可用

完整Docker日志-->

my-database    | The files belonging to this database system will be owned by user "postgres".
my-database    | This user must also own the server process.
my-database    |
my-database    | The database cluster will be initialized with locale "en_US.utf8".
my-database    | The default database encoding has accordingly been set to "UTF8".
my-database    | The default text search configuration will be set to "english".
my-database    |
my-database    | Data page checksums are disabled.
my-database    |
my-database    | fixing permissions on existing directory /var/lib/postgresql/data ... ok
my-database    | creating subdirectories ... ok
my-database    | selecting dynamic shared memory implementation ... posix
my-database    | selecting default max_connections ... 100
my-database    | selecting default shared_buffers ... 128MB
my-database    | selecting default time zone ... Etc/UTC
my-database    | creating configuration files ... ok
my-database    | running bootstrap script ... ok
my-database    | performing post-bootstrap initialization ... ok
my-database    | syncing data to disk ... ok
my-database    |
my-database    | initdb: warning: enabling "trust" authentication for local connections
my-database    | You can change this by editing pg_hba.conf or using the option -A, or
my-database    | --auth-local and --auth-host, the next time you run initdb.
my-database    |
my-database    | Success. You can now start the database server using:
my-database    |
my-database    |     pg_ctl -D /var/lib/postgresql/data -l logfile start
my-database    |
my-database    | waiting for server to start....2020-12-22 23:42:50.083 UTC [45] LOG:  starting PostgreSQL 13.1 (Debian 13.1-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
my-database    | 2020-12-22 23:42:50.085 UTC [45] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
my-database    | 2020-12-22 23:42:50.091 UTC [46] LOG:  database system was shut down at 2020-12-22 23:42:49 UTC
my-database    | 2020-12-22 23:42:50.096 UTC [45] LOG:  database system is ready to accept connections
my-database    |  done
my-database    | server started
my-database    | CREATE DATABASE
my-database    |
my-database    |
my-database    | /usr/local/bin/docker-entrypoint.sh: running /docker-entrypoint-initdb.d/init-db-01.sql
my-database    | psql:/docker-entrypoint-initdb.d/init-db-01.sql:1: NOTICE:  database "mergeletter" does not exist, skipping
my-database    | DROP DATABASE
my-database    | CREATE DATABASE
my-database    | You are now connected to database "mergeletter" as user "admin".
my-database    | CREATE SEQUENCE
my-database    | CREATE TABLE
my-database    |
my-database    |
my-database    | 2020-12-22 23:42:50.515 UTC [45] LOG:  received fast shutdown request
my-database    | waiting for server to shut down....2020-12-22 23:42:50.516 UTC [45] LOG:  aborting any active transactions
my-database    | 2020-12-22 23:42:50.521 UTC [45] LOG:  background worker "logical replication launcher" (PID 52) exited with exit code 1
my-database    | 2020-12-22 23:42:50.521 UTC [47] LOG:  shutting down
my-database    | 2020-12-22 23:42:50.541 UTC [45] LOG:  database system is shut down
my-database    |  done
my-database    | server stopped
my-database    |
my-database    | PostgreSQL init process complete; ready for start up.
my-database    |
my-database    | 2020-12-22 23:42:50.648 UTC [1] LOG:  starting PostgreSQL 13.1 (Debian 13.1-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
my-database    | 2020-12-22 23:42:50.649 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
my-database    | 2020-12-22 23:42:50.649 UTC [1] LOG:  listening on IPv6 address "::", port 5432
my-database    | 2020-12-22 23:42:50.652 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
my-database    | 2020-12-22 23:42:50.657 UTC [73] LOG:  database system was shut down at 2020-12-22 23:42:50 UTC
my-database    | 2020-12-22 23:42:50.663 UTC [1] LOG:  database system is ready to accept connections

Answer 1

简单地说，这是故意发生的；作者将其作为初始化的一部分。

看起来可以在图像的入口点外壳脚本中找到一些答案：

_main() {
# if first arg looks like a flag, assume we want to run postgres server
if [ "${1:0:1}" = '-' ]; then
set -- postgres "$@"
fi
if [ "$1" = 'postgres' ] && ! _pg_want_help "$@"; then
docker_setup_env
# setup data directories and permissions (when run as root)
docker_create_db_directories
if [ "$(id -u)" = '0' ]; then
# then restart script as postgres user
exec gosu postgres "$BASH_SOURCE" "$@"
fi
# only run initialization on an empty data directory
if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
docker_verify_minimum_env
# check dir permissions to reduce likelihood of half-initialized database
ls /docker-entrypoint-initdb.d/ > /dev/null
docker_init_database_dir
pg_setup_hba_conf
# PGPASSWORD is required for psql when authentication is required for 'local' connections via pg_hba.conf and is otherwise harmless
# e.g. when '--auth=md5' or '--auth-local=md5' is used in POSTGRES_INITDB_ARGS
export PGPASSWORD="${PGPASSWORD:-$POSTGRES_PASSWORD}"
docker_temp_server_start "$@"
docker_setup_db
docker_process_init_files /docker-entrypoint-initdb.d/*
docker_temp_server_stop
unset PGPASSWORD
echo
echo 'PostgreSQL init process complete; ready for start up.'
echo
else
echo
echo 'PostgreSQL Database directory appears to contain a database; Skipping initialization'
echo
fi
fi
exec "$@"
}

至于"；为什么"我认为这是因为希望以特权较低的用户身份运行。

你可以"解决"；在Compose文件中指定一个卷的问题，如下所示：

volumes:
- ./data/pgsql:/var/lib/postgresql/data

然后，它将跳过该例程以确保DATABASE_ALREADY_EXISTS。

或者，如果这没有帮助，您可以深入研究入口点脚本。

Answer 2

感谢@TorEHagermann的上述提示(https://stackoverflow.com/a/65417566/5631863)我解决了这个问题。

解决方案包括以下内容：

volumes:
- ./data/pgsql:/var/lib/postgresql/data

此外，在我的情况下，每次启动容器时，我都需要清除和刷新数据。因此，我在shell脚本中包含了以下内容来删除驱动器/data/pgsql：

rm -rf data

有了这个更改，我的docker compose文件看起来像：版本："3.8">

services:
my-database:
container_name: my-database
image: library/postgres:13.1
volumes:
- ./db/init-my-database.sql:/docker-entrypoint-initdb.d/init-db-01.sql
- ./data/pgsql:/var/lib/postgresql/data
environment:
- POSTGRES_DB=my-database
- POSTGRES_USER=admin
- POSTGRES_PASSWORD=password
ports:
- 10040:5432
restart: always
networks:
- app-network

Answer 3

如上所述，重启是有意的。原因是某些数据库服务器设置中的更改需要重新启动才能生效。对于更改这些设置的查询来说，入口点init脚本是一个方便的地方。

例如

ALTER SYSTEM SET max_connections = 300;