refactor: use container library instead of embedded helpers (#25)

Dockerfile

@@ -7,13 +7,21 @@ LABEL org.opencontainers.image.url="https://github.com/owncloud-ops/registry"
 LABEL org.opencontainers.image.source="https://github.com/owncloud-ops/registry"
 LABEL org.opencontainers.image.documentation="https://github.com/owncloud-ops/registry"
 
+ARG CONTAINER_LIBRARY_VERSION
+
+# renovate: datasource=github-releases depName=owncloud-ops/container-library
+ENV CONTAINER_LIBRARY_VERSION="${CONTAINER_LIBRARY_VERSION:-v0.1.0}"
+
 ADD overlay/ /
 ADD src/bin/registry /bin/registry
 
 RUN addgroup -g 1001 -S app && \
     adduser -S -D -H -u 1001 -h /home/app -s /bin/sh -G app -g app app
 
-RUN apk add --no-cache ca-certificates && \
+RUN apk --update add --virtual .build-deps curl tar && \
+    apk add --no-cache ca-certificates && \
+    curl -SsL "https://github.com/owncloud-ops/container-library/releases/download/${CONTAINER_LIBRARY_VERSION}/container-library.tar.gz" | tar xz -C / && \
+    apk del .build-deps && \
     rm -rf /var/cache/apk/* && \
     rm -rf /tmp/*
 

overlay/usr/bin/entrypoint

@@ -1,7 +1,9 @@
 #!/usr/bin/env sh
 
+# shellcheck disable=SC3040
 set -eo pipefail
 
+# shellcheck disable=SC3046,SC1091
 source /usr/local/lib/log.sh
 
 log_info "Start Docker Registry\n"

overlay/usr/bin/healthcheck

@@ -1,5 +1,6 @@
 #!/usr/bin/env sh
 
+# shellcheck disable=SC3040
 set -eo pipefail
 
 URL=http://127.0.0.1:5000