Add example to many users

README.md

@@ -55,3 +55,7 @@ If you need to use non-standard database names (hyphens, uppercase letters etc),
 
         environment:
             - POSTGRES_MULTIPLE_DATABASES="test-db-1","test-db-2"
+
+
+The `create-multiple-postgresql-full.sh` and `docker-compose.yml` shows an example of how to create both databases and users exclusively to them and assign passwords to them. 
+`user1` will not have access to `db1`,`db2`.

create-multiple-postgresql-full.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+
+set -e
+set -u
+
+containsElement () {
+    IFS=$'\n'
+    local array=$1 val=$2 result=0
+    for var in $array; do
+        if [[ "$var" == "$val" ]]; then
+            result=1
+            break
+        fi
+   done
+   echo "$result"
+}
+
+function create_user_and_database() {
+	local database=$1 user=$2 password=$3
+	local query_users="select rolname from pg_roles;" query_databases="select datname from pg_database;"
+	local roles=$(echo "$query_users" | psql -tA)
+	local databases=$(echo "$query_databases" | psql -Aqt)
+    user_exist=$(containsElement "$roles" "$user")
+    database_exist=$(containsElement "$databases" "$database")
+
+    if [[ "$user_exist" == 1 ]]; then
+        echo "User '$user' exist. Skipping"
+    else
+        echo "Create User '$user'.";
+        psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" \
+            -c "CREATE USER $user WITH PASSWORD '$password'";
+    fi
+    if [[ "$database_exist" == 1 ]]; then
+        echo "Database '$database' exists. Skipping."
+    else
+        echo "Create Database '$database'"
+        psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" \
+            -c "CREATE DATABASE $database;"
+    fi
+    psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" \
+        -c "GRANT ALL PRIVILEGES ON DATABASE $database TO $user;"
+}
+
+if [ -n "$POSTGRES_MULTIPLE_DATABASES" ]; then
+	echo "Multiple database creation requested: $POSTGRES_MULTIPLE_DATABASES"
+	IFS=', ' read -r -a databases <<< "$POSTGRES_MULTIPLE_DATABASES"
+	IFS=', ' read -r -a users <<< "$POSTGRES_MULTIPLE_USERS"
+	IFS=', ' read -r -a passwords <<< "$POSTGRES_MULTIPLE_PASSWORDS"
+	for index in ${!databases[@]}; do
+        if [[ $index < ${#databases[*]} && $index < ${#users[*]} && $index < ${#passwords[*]} ]] ; then
+              create_user_and_database "${databases[index]//[\'\"\`]/}" "${users[index]//[\'\"\`]/}" "${passwords[index]//[\'\"\`]/}"
+        else
+            echo "DATABASE '${databases[index]}' OR USER '${users[index]}' EMPTY"
+        fi
+	done
+	echo "Multiple databases created"
+fi

docker-compose.yml

@@ -0,0 +1,17 @@
+version: "2"
+
+services:
+  postgres:
+    image: postgres:alpine
+    container_name: example-postgres
+    environment:
+      - POSTGRES_MULTIPLE_DATABASES="db1","db2","db3"
+      - POSTGRES_MULTIPLE_USERS="user1","user2","user3
+      - POSTGRES_MULTIPLE_PASSWORDS="password1","password2","password3"
+      - POSTGRES_USER=superrole
+      - POSTGRES_PASSWORD=superpassword
+    ports:
+      - "5432:5432"
+    volumes:
+      - ./create-multiple-postgresql-full.sh:/docker-entrypoint-initdb.d/create-multiple-postgresql-full.sh
+    restart: always