Run the app in the container as a non-root user (#1575)

* Run as a non-root user. Fixes #1555

Signed-off-by: Roman Zabaluev <rzabaluev@provectus.com>

* Fix line break

Signed-off-by: Roman Zabaluev <rzabaluev@provectus.com>

Co-authored-by: Ruslan Ibragimov <94184844+5hin0bi@users.noreply.github.com>

kafka-ui-api/Dockerfile

@@ -1,5 +1,9 @@
 FROM alpine:3.15.0
-RUN apk add --no-cache openjdk13-jre libc6-compat gcompat
+
+RUN apk add --no-cache openjdk13-jre libc6-compat gcompat \
+&& addgroup -S kafkaui && adduser -S kafkaui -G kafkaui
+
+USER kafkaui
 
 ARG JAR_FILE
 COPY "/target/${JAR_FILE}" "/kafka-ui-api.jar"