use alpine with https://github.com/just-containers/s6-overlay for run…

…ning multiple processes in a container

Dockerfile

@@ -11,13 +11,12 @@ RUN shards build
 RUN ldd /docker_mdns/bin/docker_mdns | tr -s '[:blank:]' '\n' | grep '^/' | \
    xargs -I % sh -c 'mkdir -p $(dirname deps%); cp % deps%;'
 
-FROM alpine
+FROM lsiobase/alpine
 
-RUN apk add --update --no-cache avahi
+RUN apk add --update --no-cache \
+      avahi \
+      augeas
 
 COPY --from=builder /docker_mdns/deps /
 COPY --from=builder /docker_mdns/bin/docker_mdns /usr/local/bin/docker_mdns
-COPY entrypoint.sh /opt/entrypoint.sh
-RUN chmod +x /opt/entrypoint.sh
-
-#ENTRYPOINT ["/opt/entrypoint.sh"]
+COPY root/ /

root/etc/cont-init.d/20-config

@@ -0,0 +1,25 @@
+#!/usr/bin/with-contenv bash
+
+AUG_BASE="/files/etc/avahi/avahi-daemon.conf"
+
+avahi_set() {
+  if [ $# -lt 3 ]; then
+    >&2 echo "Usage: avahi_set SECTION KEY VALUE"
+    return 1
+  fi
+  augtool set "${AUG_BASE}/$1/$2" "$3"
+}
+
+# Defaults
+SERVER_ENABLE_DBUS=${SERVER_ENABLE_DBUS:-no}
+
+# server section
+if [ -n "${SERVER_HOST_NAME}" ]; then
+  avahi_set "server" "host-name" "${SERVER_HOST_NAME}"
+fi
+if [ -n "${SERVER_DOMAIN_NAME}" ]; then
+  avahi_set "server" "domain-name" "${SERVER_DOMAIN_NAME}"
+fi
+if [ -n "${SERVER_ENABLE_DBUS}" ]; then
+  avahi_set "server" "enable-dbus" "${SERVER_ENABLE_DBUS}"
+fi

root/etc/services.d/avahi/run

@@ -0,0 +1,3 @@
+#!/usr/bin/with-contenv bash
+
+exec avahi-daemon

root/etc/services.d/mdns/run

@@ -0,0 +1,3 @@
+#!/usr/bin/with-contenv bash
+
+exec s6-setuidgid abc /usr/local/bin/docker_mdns "$NETWORK_INTERFACE"