From b01415a23ab38bda59f749586ac6c7b27be9fee3 Mon Sep 17 00:00:00 2001
From: Victor <ioan.1931@gmail.com>
Date: Sun, 5 Apr 2026 12:49:11 -0400
Subject: [PATCH] env variable substitution

---
 docker-compose.observability.prod.yml | 15 ++++++++++++++-
 docker-compose.yml                    | 15 ++++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/docker-compose.observability.prod.yml b/docker-compose.observability.prod.yml
index f85b30ad..03e26ae8 100644
--- a/docker-compose.observability.prod.yml
+++ b/docker-compose.observability.prod.yml
@@ -2,10 +2,23 @@ services:
   prometheus:
     image: prom/prometheus:latest
     restart: always
+    entrypoint: /bin/sh
+    command:
+      - -c
+      - |
+        sed -e "s|\${DO_HOST_1}|$$DO_HOST_1|g" \
+            -e "s|\${DO_HOST_2}|$$DO_HOST_2|g" \
+            -e "s|\${DO_OBSERVABILITY}|$$DO_OBSERVABILITY|g" \
+            /etc/prometheus/prometheus.tmpl.yml > /tmp/prometheus.yml \
+        && exec /bin/prometheus --config.file=/tmp/prometheus.yml --storage.tsdb.path=/prometheus
+    environment:
+      DO_HOST_1: ${DO_HOST_1}
+      DO_HOST_2: ${DO_HOST_2}
+      DO_OBSERVABILITY: ${DO_OBSERVABILITY}
     ports:
       - "9090:9090"
     volumes:
-      - ${PWD}/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
+      - ${PWD}/prometheus/prometheus.yml:/etc/prometheus/prometheus.tmpl.yml:ro
       - ${PWD}/prometheus/alerts.yml:/etc/prometheus/alerts.yml:ro
       - prometheus-data:/prometheus
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 31a261e5..621d9122 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -209,10 +209,23 @@ services:
   # ── Observability stack ─────────────────────────────────────────────
   prometheus:
     image: prom/prometheus:latest
+    entrypoint: /bin/sh
+    command:
+      - -c
+      - |
+        sed -e "s|\${DO_HOST_1}|$$DO_HOST_1|g" \
+            -e "s|\${DO_HOST_2}|$$DO_HOST_2|g" \
+            -e "s|\${DO_OBSERVABILITY}|$$DO_OBSERVABILITY|g" \
+            /etc/prometheus/prometheus.tmpl.yml > /tmp/prometheus.yml \
+        && exec /bin/prometheus --config.file=/tmp/prometheus.yml --storage.tsdb.path=/prometheus
+    environment:
+      DO_HOST_1: ${DO_HOST_1}
+      DO_HOST_2: ${DO_HOST_2}
+      DO_OBSERVABILITY: ${DO_OBSERVABILITY}
     ports:
       - 9090:9090
     volumes:
-      - ./prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
+      - ./prometheus/prometheus.yml:/etc/prometheus/prometheus.tmpl.yml:ro
       - ./prometheus/alerts.yml:/etc/prometheus/alerts.yml:ro
 
   alertmanager: