Running a postgresql database using singularity

First, we need to pull the postgresql image from dockerhub

singularity pull docker://postgres:14.2-alpine3.15

The image will be saved as postgres_14.2-alpine3.15.sif. Now, create an environment file

cat >> pg.env <<EOF

export TZ=Asia/Kuala_Lumpurt

export POSTGRES_USER=pguser

export POSTGRES_PASSWORD=mypguser123

export POSTGRES_DB=mydb

export POSTGRES_INITDB_ARGS="--encoding=UTF-8"

EOF

Create 2 directories for data and run

mkdir pgdata

mkdir pgrun

Run the container. The options are -B to bind mount local directory to container, -e to clean environment before running the container, -C to start the container with PID, IPC and environment, and --env-file is to pass the environment variables in the file to the container

singularity run -B pgdata:/var/lib/postgresql/data -B pgrun:/var/run/postgresql -e -C --env-file pg.env postgres_14.2-alpine3.15.sif

The postgresql will be listening on localhost at port 5432. To test it out, just open another terminal, and use the same postgres_14.2-alpine3.15.sif to run psql

singularity exec postgres_14.2-alpine3.15.sif psql -h localhost -p 5432 -d mydb

mydb=#