Add 'sudo' support so that opam-depext can do its work

Dockerfile

@@ -25,11 +25,12 @@ RUN rm -rf /src
 FROM alpine:3.11 as target
 LABEL Description="Minimal OCaml + opam Alpine container" Vendor="OCamlPro"
 
-RUN apk add gcc make curl git
+RUN apk add gcc make curl git sudo
 COPY --from=compilation /usr/local /usr/local
 
 RUN addgroup -S ocaml && adduser -S ocaml -G ocaml -s /bin/sh
 USER ocaml
 WORKDIR /home/ocaml
+RUN echo 'ocaml ALL=(ALL) NOPASSWD: ALL' >> /etc/sudoers
 
 RUN ["/usr/local/bin/opam", "init", "-a", "--bare", "--disable-sandboxing"]