entrypoint: Monitor config dir for changes

Dockerfile-alpine-slim.template

@@ -99,6 +99,11 @@ RUN set -x \
 # forward request and error logs to docker log collector
     && ln -sf /dev/stdout /var/log/nginx/access.log \
     && ln -sf /dev/stderr /var/log/nginx/error.log \
+# Ensure we can run our entrypoint and make it debian compatible
+    && apk add --no-cache tini \
+    && ln -s /sbin/tini /usr/bin/tini \
+# Add support for manually monitoring files to trigger server reloads
+    && apk add --no-cache inotify-tools \
 # create a docker-entrypoint.d directory
     && mkdir /docker-entrypoint.d
 

Dockerfile-alpine.template

@@ -75,4 +75,9 @@ RUN set -x \
     && if [ -n "/etc/apk/keys/abuild-key.rsa.pub" ]; then rm -f /etc/apk/keys/abuild-key.rsa.pub; fi \
     && if [ -n "/etc/apk/keys/nginx_signing.rsa.pub" ]; then rm -f /etc/apk/keys/nginx_signing.rsa.pub; fi \
 # Bring in curl and ca-certificates to make registering on DNS SD easier
-    && apk add --no-cache curl ca-certificates
+    && apk add --no-cache curl ca-certificates \
+# Ensure we can run our entrypoint and do it compatible with alpine
+    && apk add --no-cache tini \
+    && ln -s /sbin/tini /usr/bin/tini
+# Add support for manually monitoring files to trigger server reloads
+    && apk add --no-cache inotify-tools

Dockerfile-debian.template

@@ -82,6 +82,9 @@ RUN set -x \
                         $nginxPackages \
                         gettext-base \
                         curl \
+                        tini \
+                        inotify-tools \
+    && ln -s /usr/bin/tini /sbin/tini \
     && apt-get remove --purge --auto-remove -y && rm -rf /var/lib/apt/lists/* /etc/apt/sources.list.d/nginx.list \
     \
 # if we have leftovers from building, let's purge them (including extra, unnecessary build deps)

entrypoint/99-monitor-config-changes.sh

@@ -0,0 +1,44 @@
+#!/bin/sh
+# vim:sw=2:ts=2:sts=2:et
+
+set -eu
+if [ -n "${DEBUG_TRACE_SH:-}" ] && \
+   [ "${DEBUG_TRACE_SH:-}" != "${DEBUG_TRACE_SH#*"$(basename "${0}")"*}" ] || \
+   [ "${DEBUG_TRACE_SH:-}" = 'all' ]; then
+  set -x
+fi
+
+LC_ALL=C
+
+if [ -e "${NGINX_ENTRYPOINT_MONITOR_PID:=/run/nginx_monitor.pid}" ] ||
+   [ -z "${NGINX_ENTRYPOINT_MONITOR_CONFIG+monitor}" ] || \
+   ! command -v inotifywait; then
+  exit 0
+fi
+
+echo "Monitoring for changes in '${NGINX_ENTRYPOINT_MONITOR_CONFIG:=/etc/nginx}'"
+while true; do
+  inotifywait \
+    --recursive \
+    --event 'create' \
+    --event 'delete' \
+    --event 'modify' \
+    --event 'move' \
+    "${NGINX_ENTRYPOINT_MONITOR_CONFIG}"
+
+  sleep "${NGINX_ENTRYPOINT_MONITOR_DELAY:-10s}"
+
+  if [ ! -e "${NGINX_ENTRYPOINT_MONITOR_PID}" ]; then
+    logger -s -t 'nginx' -p 'local0.3' 'Monitor failure or exit requested'
+    break
+  fi
+
+  if nginx -t; then
+    nginx -s
+  else
+    logger -s -t 'nginx' -p 'local0.3' 'Refusing to reload config, config error'
+  fi
+done &
+echo "${!}" > "${NGINX_ENTRYPOINT_MONITOR_PID}"
+
+exit 0

entrypoint/docker-entrypoint.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/sbin/init /bin/sh
 # vim:sw=4:ts=4:et
 
 set -e