PostgreSQL和Docker：需要哪个目录来保留数据

Question

In postgresql which are the directories we need to persist in general so that i can use the same data again even i rebuild

Like:

I know the main directory:

/var/lib/postgres or  /var/lib/postgres/data (small confusion, which one)

and any other like the logs etc

Answer 1

You can define the PGDATA environment variable in your docker container to specify where postgres will save its database files.

From the documentation of the official postgres Docker image:

• PGDATA:

  This optional variable can be used to define another location - like a subdirectory - for the database files. The default is /var/lib/postgresql/data, but if the data volume you're using is a filesystem mountpoint (like with GCE persistent disks), Postgres initdb recommends a subdirectory (for example /var/lib/postgresql/data/pgdata ) be created to contain the data.

Additionally from the postgres documentation transaction log files are also written to PGDATA :

By default the transaction log is stored in a subdirectory of the main Postgres data folder (PGDATA).

So by default the postgres image will write database files to /var/lib/postgresql/data

To answer your question it should be sufficient to bind mount a directory to /var/lib/postgresql/data inside of your postgres container.