fixed debian-9 Dockerfile to use snapshot mirror

Author: AhmedBM

devops/docker/debian-9-amd64/Dockerfile

@@ -1,5 +1,13 @@
 FROM debian:stretch
 ARG DEBIAN_FRONTEND=noninteractive
+
+# debian-9 is EOL, update sources.list to use snapshot.debian.org mirrors
+RUN cat <<EOF > /etc/apt/sources.list
+deb http://snapshot.debian.org/archive/debian/20220622T000000Z stretch main
+deb http://snapshot.debian.org/archive/debian-security/20220622T000000Z stretch/updates main
+deb http://snapshot.debian.org/archive/debian/20220622T000000Z stretch-updates main
+EOF
+
 RUN apt -y update && apt-get -y install software-properties-common
 RUN apt -y update && apt-get -y install \
     git \