fix(Dockerfile): fail build when apt-get fails

Dockerfile

@@ -1,16 +1,16 @@
 FROM debian:bookworm-slim
 
-RUN set -eux; \
-    apt-get update; \
-    DEBIAN_FRONTEND=noninteractive apt-get upgrade -y; \
+RUN set -eux && \
+    apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get upgrade -y && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
         openssh-server \
         curl \
         telnet \
         net-tools \
         screen \
-    ; \
-    rm -rf /var/lib/apt/lists/*; \
+    && \
+    rm -rf /var/lib/apt/lists/* && \
     rm /etc/ssh/ssh_host_*key*
 
 ADD start.sh /

build.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-set -x
+set -ex
 
 IMAGE=pommib/jumpbox:latest
 docker pull $IMAGE