chore: Use a single `COPY` by better leveraging `.dockerignore` patterns

.dockerignore

@@ -1,2 +1,11 @@
+# Exclude everything from the Docker build context:
+*
+
+# Except for this content:
+!bin/
+!etc/
+!testssl.sh
+
+# But additionally exclude this nested content:
 bin/openssl.Darwin.*
 bin/openssl.FreeBSD.*

Dockerfile

@@ -12,9 +12,8 @@ RUN apk update && \
 USER testssl
 WORKDIR /home/testssl/
 
-COPY --chown=testssl:testssl etc/. /home/testssl/etc/
-COPY --chown=testssl:testssl bin/. /home/testssl/bin/
-COPY --chown=testssl:testssl testssl.sh /home/testssl/
+# Copy over build context (after filtered by .dockerignore): bin/ etc/ testssl.sh
+COPY --chown=testssl . /home/testssl/
 
 ENTRYPOINT ["testssl.sh"]