[*] optimize Scalefield image and enable async mode for prometheus (#785)

Author: ermajn

docker-launcher-scalefield.sh

@@ -1,4 +1,6 @@
-#!/bin/bash
+#!/bin/sh
+
+# Export environment variables with default values
 export USER=${DATA_SOURCE_USER:-postgres}
 export PASSWORD=${DATA_SOURCE_PASS:-postgres}
 export NAME=${DATA_SOURCE_URI:-localhost}
@@ -7,8 +9,9 @@ export CUSTOMER=${PG_EXPORTER_CONSTANT_LABEL_CUSTOMER:-customer}
 export CLUSTER_NAME=${PG_EXPORTER_CONSTANT_LABEL_CLUSTER_NAME:-cluster_name}
 export SUPPORT_PLAN=${PG_EXPORTER_CONSTANT_LABEL_SUPPORT_PLAN:-support_plan}
 
-cat /pgwatch2/config/scalefield.template | sed "s/%USER%/$USER/;s/%PASSWORD%/$PASSWORD/;s/%NAME%/$NAME/;s/%CUSTOMER%/$CUSTOMER/;s/%CLUSTER_NAME%/$CLUSTER_NAME/;s/%SUPPORT_PLAN%/$SUPPORT_PLAN/" > /pgwatch2/config/scalefield.yaml
+# Use envsubst to substitute the variables in the template
+envsubst < /pgwatch2/config/scalefield.template > /pgwatch2/config/scalefield.yaml
 
 /pgwatch2/metrics/00_helpers/rollout_helper.py --mode single-db --host "$CLUSTERNAME" --dbname postgres --user "$USER" --password "$PASSWORD" --monitoring-user "$USER" --confirm --metrics-path /pgwatch2/metrics/00_helpers/ --helpers get_load_average,get_psutil_cpu,get_psutil_disk_io_total,get_psutil_disk,get_psutil_mem --excluded-helpers ""
 
-exec /pgwatch2/pgwatch2 -c /pgwatch2/config/scalefield.yaml --adhoc-create-helpers=true --prometheus-port=9189 --datastore=prometheus
+exec /pgwatch2/pgwatch2 -c /pgwatch2/config/scalefield.yaml --adhoc-create-helpers=true --prometheus-async-mode=true --prometheus-port=9189 --datastore=prometheus

docker/Dockerfile-scalefield

@@ -9,10 +9,14 @@ ENV GIT_TIME=${GIT_TIME}
 ADD pgwatch2 /pgwatch2
 RUN cd /pgwatch2 && bash build_gatherer.sh
 
-
-FROM ubuntu:22.04
-
-RUN apt-get -q update && apt-get -qy install wget git python3 python3-psycopg2 python3-yaml && apt autoremove -y && mkdir /pgwatch2
+FROM alpine
+
+RUN apk update && \
+    apk add --no-cache git python3 py3-psycopg2 py3-yaml && \
+    apk add --no-cache --virtual .build-deps && \
+    apk add --no-cache gettext && \
+    apk add --no-cache libc6-compat && \
+    mkdir /pgwatch2
 
 ADD pgwatch2/metrics /pgwatch2/metrics
 ADD pgwatch2/config /pgwatch2/config

pgwatch2/config/scalefield.template

@@ -1,9 +1,9 @@
-- unique_name: %NAME%
+- unique_name: ${NAME}
   dbtype: postgres
   host: 127.0.0.1
   dbname: postgres
-  user: %USER%
-  password: %PASSWORD%
+  user: ${USER}
+  password: ${PASSWORD}
   sslmode: require    # supported options: disable, require, verify-ca, verify-full
   stmt_timeout: 5 # in seconds
   is_superuser: true
@@ -15,9 +15,9 @@
   dbname_exclude_pattern:
   is_enabled: true
   custom_tags:
-    support_plan: %SUPPORT_PLAN%
-    customer: %CUSTOMER%
-    cluster_name: %CLUSTER_NAME%
+    support_plan: ${SUPPORT_PLAN}
+    customer: ${CUSTOMER}
+    cluster_name: ${CLUSTER_NAME}
   group: default # just for logical grouping of DB hosts or for "sharding", i.e. splitting the workload between many gatherer daemons
   sslrootcert: ''
   sslcert: ''