docker postgres default entrypoint

[Hasdik]

If I create my entrypoint file ENTRYPOINT ["new_env.sh"], after starting docker of postgres container, if you try to restore backup db, I get an error:
pg_ctl: directory "/var/lib/postgresql/data" is not a database cluster directory

How can I call the default entrypoint-file docker postgres first?

[wglambert]

Here's a quick way to do it

test.sh script to run before docker-entrypoint.sh

#!/bin/sh
echo "test entrypoint executing"

$ cat Dockerfile 
FROM postgres
COPY test.sh /
ENTRYPOINT /bin/sh -c /test.sh && /docker-entrypoint.sh postgres

$ docker build . -t postgres:test
Sending build context to Docker daemon  38.16MB
Step 1/3 : FROM postgres
 ---> 9907cacf0c01
Step 2/3 : COPY test.sh /
 ---> 89cfee55e080
Step 3/3 : ENTRYPOINT /bin/sh -c /test.sh && /docker-entrypoint.sh postgres
 ---> Running in 410c5ee78403
Removing intermediate container 410c5ee78403
 ---> a2ccd1acf798
Successfully built a2ccd1acf798
Successfully tagged postgres:test

The logs show the first line as the test entrypoint's test entrypoint executing

$ docker run -d --name postgres -e POSTGRES_PASSWORD=pass postgres:test
9c3f2916d5dce79409fc625d1efe47f1daf09072018504f48e746ba5a088e210

$ docker logs -f postgres
test entrypoint executing
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "en_US.utf8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".

Data page checksums are disabled.

fixing permissions on existing directory /var/lib/postgresql/data ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... Etc/UTC
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok


Success. You can now start the database server using:

    pg_ctl -D /var/lib/postgresql/data -l logfile start

initdb: warning: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the option -A, or
--auth-local and --auth-host, the next time you run initdb.
waiting for server to start....2020-04-10 20:29:44.851 UTC [50] LOG:  starting PostgreSQL 12.2 (Debian 12.2-2.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
2020-04-10 20:29:44.851 UTC [50] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2020-04-10 20:29:44.865 UTC [51] LOG:  database system was shut down at 2020-04-10 20:29:44 UTC
2020-04-10 20:29:44.869 UTC [50] LOG:  database system is ready to accept connections
 done
server started

/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*

2020-04-10 20:29:44.939 UTC [50] LOG:  received fast shutdown request
waiting for server to shut down....2020-04-10 20:29:44.940 UTC [50] LOG:  aborting any active transactions
2020-04-10 20:29:44.942 UTC [50] LOG:  background worker "logical replication launcher" (PID 57) exited with exit code 1
2020-04-10 20:29:44.942 UTC [52] LOG:  shutting down
2020-04-10 20:29:44.951 UTC [50] LOG:  database system is shut down
 done
server stopped

PostgreSQL init process complete; ready for start up.

2020-04-10 20:29:45.055 UTC [8] LOG:  starting PostgreSQL 12.2 (Debian 12.2-2.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
2020-04-10 20:29:45.056 UTC [8] LOG:  listening on IPv4 address "0.0.0.0", port 5432
2020-04-10 20:29:45.057 UTC [8] LOG:  listening on IPv6 address "::", port 5432
2020-04-10 20:29:45.058 UTC [8] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2020-04-10 20:29:45.071 UTC [59] LOG:  database system was shut down at 2020-04-10 20:29:44 UTC
2020-04-10 20:29:45.075 UTC [8] LOG:  database system is ready to accept connections

Questions like these should be asked over at the Docker Community Forums, Docker Community Slack, or Stack Overflow. Since these repos aren't really a user-help forum