feat: Allow to define the prometheus targets (close #209)

deploy/docker-socket-proxy_before.sh

@@ -2,6 +2,6 @@
 
 EXISTING_NETWORK=`docker network ls | grep $DOCKER_SOCKET_NETWORK`
 if [ -z "$EXISTING_NETWORK" ]; then
-  echo creating $DOCKER_SOCKET_NETWORK network
+  echo [docker-socket-proxy] creating $DOCKER_SOCKET_NETWORK network
   docker network create -d overlay --attachable $DOCKER_SOCKET_NETWORK
 fi

deploy/prometheus_before.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 cp configs/prometheus/prometheus.config configs/prometheus/prometheus.yml
-for TARGET in $PROMETHEUS_TARGETS; do
-  echo adding $TARGET target
+for TARGET in $PROMETHEUS_ADDITIONAL_TARGETS; do
+  echo [Prometheus] adding $TARGET target
   yq m -i -a append configs/prometheus/prometheus.yml configs/prometheus/targets/$TARGET.yml
 done

docs/reference/environment.md

@@ -253,7 +253,7 @@ The **MapProxy** service is preconfigured to run [Gunicorn](https://gunicorn.org
 | `PROMETHEUS_CADVISOR_TAG` | The **cAdvisor** tag to be used. | `postgres` |
 | `PROMETHEUS_PUSHGATEWAY_IMAGE` | The **Pushgateway** image to be used. | `postgres` |
 | `PROMETHEUS_PUSHGATEWAY_TAG` | The **Pushgateway** tag to be used. | `postgres` |
-| `PROMETHEUS_TARGETS` | The additional targets to add. | `` |
+| `PROMETHEUS_ADDITIONAL_TARGETS` | The additional targets to add. By default the target installed are `prometheus`, `cadvisor` and `node-exppoter`. | `` |
 
 ### Redis