Adding postgreSQL / pgAdmin example

Signed-off-by: Leon Stoldt <tech@leon-stoldt.de>

README.md

@@ -35,6 +35,7 @@ application with an Nginx proxy and a MySQL database.
 - [`NGINX / Go`](https://github.com/docker/awesome-compose/tree/master/nginx-golang) - Sample Nginx proxy with a Go backend.
 - [`NGINX / WSGI / Flask`](https://github.com/docker/awesome-compose/tree/master/nginx-wsgi-flask) - Sample Nginx reverse proxy with a Flask backend using WSGI.
 - [`Pi-hole / cloudflared`](https://github.com/docker/awesome-compose/tree/master/pihole-cloudflared-DoH) - Sample Pi-hole setup with use of DoH cloudflared service
+- [`PostgreSQL / pgAdmin`](https://github.com/docker/awesome-compose/tree/master/postgresql-pgadmin) - Sample setup for postgreSQL database with pgAdmin web interface
 - [`React / Spring / MySQL`](https://github.com/docker/awesome-compose/tree/master/react-java-mysql) - Sample React
 application with a Spring backend and a MySQL database.
 - [`React / Express / MySQL`](https://github.com/docker/awesome-compose/tree/master/react-express-mysql) - Sample React

postgresql-pgadmin/.env

@@ -0,0 +1,5 @@
+POSTGRES_USER=yourUser
+POSTGRES_PW=changeit
+POSTGRES_DB=postgres
+PGADMIN_MAIL=your@email.com
+PGADMIN_PW=changeit

postgresql-pgadmin/README.md

@@ -0,0 +1,68 @@
+## PostgreSQL and pgAdmin
+This example provides a base setup for using [PostgreSQL](https://www.postgresql.org/) and [pgAdmin](https://www.pgadmin.org/).
+More details on how to customize the installation and the compose file can be found [here (PostgreSQL)](https://hub.docker.com/_/postgres) and [here (pgAdmin)](https://www.pgadmin.org/docs/pgadmin4/latest/container_deployment.html).
+
+Project structure:
+```
+.
+├── .env
+├── docker-compose.yaml
+└── README.md
+```
+
+[_docker-compose.yaml_](docker-compose.yaml)
+``` yaml
+services:
+  postgres:
+    image: postgres:latest
+    ...
+  pgadmin:
+    image: dpage/pgadmin4:latest
+```
+
+## Configuration
+
+### .env
+Before deploying this setup, you need to configure the following values in the [.env](.env) file.
+- POSTGRES_USER
+- POSTGRES_PW
+- POSTGRES_DB (can be default value)
+- PGADMIN_MAIL
+- PGADMIN_PW
+
+## Deploy with docker-compose
+When deploying this setup, the pgAdmin web interface will be available at port 5050 (e.g. http://localhost:5050).  
+
+``` shell
+$ docker-compose up
+Starting postgres ... done
+Starting pgadmin ... done
+```
+
+## Add postgres database to pgAdmin
+After logging in with your credentials of the .env file, you can add your database to pgAdmin. 
+1. Right-click "Servers" in the top-left corner and select "Create" -> "Server..."
+2. Name your connection
+3. Change to the "Connection" tab and add the connection details:
+- Hostname: "postgres" (this would normally be your IP address of the postgres database - however, docker can resolve this container ip by its name)
+- Port: "5432"
+- Maintenance Database: $POSTGRES_DB (see .env)
+- Username: $POSTGRES_USER (see .env)
+- Password: $POSTGRES_PW (see .env)
+  
+## Expected result
+
+Check containers are running:
+```
+$ docker ps
+CONTAINER ID   IMAGE                           COMMAND                  CREATED             STATUS                 PORTS                                                                                  NAMES
+849c5f48f784   postgres:latest                 "docker-entrypoint.s…"   9 minutes ago       Up 9 minutes           0.0.0.0:5432->5432/tcp, :::5432->5432/tcp                                              postgres
+d3cde3b455ee   dpage/pgadmin4:latest           "/entrypoint.sh"         9 minutes ago       Up 9 minutes           443/tcp, 0.0.0.0:5050->80/tcp, :::5050->80/tcp                                         pgadmin
+```
+
+Stop the containers with
+``` shell
+$ docker-compose down
+# To delete all data run:
+$ docker-compose down -v
+```

postgresql-pgadmin/docker-compose.yaml

@@ -0,0 +1,22 @@
+version: '3.7'
+services:
+  postgres:
+    container_name: postgres
+    image: postgres:latest
+    environment:
+      - POSTGRES_USER=${POSTGRES_USER}
+      - POSTGRES_PASSWORD=${POSTGRES_PW}
+      - POSTGRES_DB=${POSTGRES_DB} #optional (specify default database instead of $POSTGRES_USER)
+    ports:
+      - "5432:5432"
+    restart: always
+
+  pgadmin:
+    container_name: pgadmin
+    image: dpage/pgadmin4:latest
+    environment:
+      - PGADMIN_DEFAULT_EMAIL=${PGADMIN_MAIL}
+      - PGADMIN_DEFAULT_PASSWORD=${PGADMIN_PW}
+    ports:
+      - "5050:80"
+    restart: always