test: config search path (using docker)

docker/Dockerfile

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+FROM ubuntu:22.04
+
+ADD target/debug/init /usr/local/bin/init
+ADD docker/ /
+
+RUN chmod ugo+x /etc/wingmate/services/one && chmod ugo+x /etc/wingmate/services/two.sh && \
+    chmod ugo-x /etc/wingmate/services/three.sh
+
+CMD [ "/usr/local/bin/init" ]

docker/etc/wingmate/services/one

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+#!/bin/bash
+
+exec sleep 1

docker/etc/wingmate/services/three.sh

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+#!/bin/bash
+
+exec sleep 1

docker/etc/wingmate/services/two.sh

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+#!/bin/bash
+
+exec sleep 1