fix: iperf3 — build depuis Alpine ECR au lieu d'image communautaire Docker Hub

networkstatic/iperf3 n'est pas disponible sur ECR public (images officielles seulement).
Solution : Dockerfile.iperf3 basé sur alpine:latest + apk add iperf3.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/Dockerfile.iperf3

@@ -0,0 +1,5 @@
+ARG ALPINE_IMAGE=public.ecr.aws/docker/library/alpine:latest
+FROM ${ALPINE_IMAGE}
+RUN apk add --no-cache iperf3
+EXPOSE 5201
+ENTRYPOINT ["iperf3"]

server/docker-compose.yml

@@ -30,8 +30,11 @@ services:
       - server
 
   iperf3:
-    image: ${IPERF3_IMAGE:-public.ecr.aws/docker/library/networkstatic/iperf3:latest}
-    pull_policy: if_not_present
+    build:
+      context: .
+      dockerfile: Dockerfile.iperf3
+      args:
+        ALPINE_IMAGE: ${ALPINE_IMAGE:-public.ecr.aws/docker/library/alpine:latest}
     restart: unless-stopped
     command: ["-s"]
     ports: