Add docker-compose yaml file

Author: devopsy-ir

.gitignore

@@ -20,3 +20,4 @@
 /.metrics.*.removed
 /tools/src
 /vendor
+.env

docker-compose.yml

@@ -0,0 +1,12 @@
+version: "3.5"
+
+services:
+  postgres_exporter:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: quay.io/prometheuscommunity/postgres-exporter
+    network_mode: host
+    environment:
+      DATA_SOURCE_NAME: "postgresql://${PG_USERNAME:-postgres}:${PG_PASSWORD:-password}@${PG_HOST:-localhost}:${PG_PORT:-5432}/${DB_NAME:-postgres}?sslmode=disable"
+      PG_EXPORTER_WEB_LISTEN_ADDRESS: ":9187"

env.example

@@ -0,0 +1,6 @@
+# The database for which the Prometheus metrics must be exported
+PG_USERNAME=postgres
+PG_PASSWORD=password
+PG_HOST=localhost
+PG_PORT=5432
+DB_NAME=postgres