Add tini process pid 1

Containerfile.admin

@@ -21,6 +21,7 @@ RUN dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x
     findutils \
     gcc \
     git \
+    gnupg2 \
     jq \
     libevent \
     libevent-devel \
@@ -45,6 +46,12 @@ RUN dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x
     && ./configure \
     && make && make install \
     && dnf clean all \
+    && TINI_VERSION=v0.19.0 \
+    && curl --silent --location https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini -o /bin/tini \
+    && curl --silent --location https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini.asc -o /tmp/tini.asc \
+    && gpg --batch --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 595E85A6B1B4779EA4DAAEC70B588DFF0527A9B7 \
+    && gpg --batch --verify /tmp/tini.asc /bin/tini \
+    && chmod +x /bin/tini \
     && HURL_VERSION=4.1.0 \
     && curl --silent --location https://github.com/Orange-OpenSource/hurl/releases/download/${HURL_VERSION}/hurl-${HURL_VERSION}-x86_64-unknown-linux-gnu.tar.gz \
     | tar -xz -C /usr/local/bin --strip-components=1 --wildcards '*/hurl' '*/hurlfmt' \
@@ -59,7 +66,8 @@ COPY --from=builder /sandbox/build/sandbox-* ./
 COPY --from=builder /sandbox/tools ./tools
 COPY --from=builder /sandbox/tests ./tests
 COPY --from=builder /sandbox/db ./db
-CMD ["/usr/local/bin/tmux", "new-session", "-s", "sandbox", "-c", "/sandbox"]
+ENTRYPOINT ["/bin/tini", "--"]
+CMD ["/usr/local/bin/tmux", "new-session", "-s", "sandbox-admin", "-c", "/sandbox"]
 
 
 ENV DESCRIPTION="Image for Admins to interact with the Sandbox API"