Patch nginx so it does graceful shutdown on SIGTERM and fast shutdown…

bin/start-nginx

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+trap "echo start-nginx got SIGTERM. Ignoring while nginx shuts down gracefully" SIGTERM
+
 psmgr=/tmp/nginx-buildpack-wait
 rm -f $psmgr
 mkfifo $psmgr

bin/start-nginx-debug

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+trap "echo start-nginx-debug got SIGTERM. Ignoring while nginx shuts down gracefully" SIGTERM
+
 psmgr=/tmp/nginx-buildpack-wait
 rm -f $psmgr
 mkfifo $psmgr

bin/start-nginx-solo

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+trap "echo start-nginx-solo got SIGTERM. Ignoring while nginx shuts down gracefully" SIGTERM
+
 psmgr=/tmp/nginx-buildpack-wait
 rm -f $psmgr
 mkfifo $psmgr

changelog.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [x.x] - xxxx-xx-xx
+### Changes
+- [all] Patched nginx so it gracefully shuts down on SIGTERM.
+- [all] start-nginx scripts ignore the SIGTERM signal so they do not kill off nginx abruptly.
+
 ## [1.7] - 2021-06-04
 ### Changes
 - [heroku-18] updated nginx to 1.20.1

scripts/build_nginx

@@ -36,6 +36,23 @@ echo "Downloading $zlib_url"
 echo "Downloading $uuid4_url"
 (cd nginx-${NGINX_VERSION} && curl -L $uuid4_url | tar xvz )
 
+if [ -d "/buildpack/scripts/patchfiles/${NGINX_VERSION}" ]
+then
+    PATCHFILES=$(find /buildpack/scripts/patchfiles/${NGINX_VERSION} -name '*.patch')
+else
+    PATCHFILES=$(find /buildpack/scripts/patchfiles/default -name '*.patch')
+fi
+
+
+(
+  cd nginx-${NGINX_VERSION}
+  for f in $PATCHFILES
+  do
+    echo "patch: $f"
+    patch -p0 < $f
+  done
+)
+
 # This will build `nginx`
 (
   cd nginx-${NGINX_VERSION}

scripts/patchfiles/default/0001-Custom-Terminate-Signal.patch

@@ -0,0 +1,13 @@
+--- src/core/ngx_config.h	2020-05-23 04:21:07.000000000 +0000
++++ src/core/ngx_config.h	2020-05-23 04:15:17.000000000 +0000
+@@ -56,9 +56,8 @@
+
+ #define ngx_random               random
+
+-/* TODO: #ifndef */
+-#define NGX_SHUTDOWN_SIGNAL      QUIT
+-#define NGX_TERMINATE_SIGNAL     TERM
++#define NGX_SHUTDOWN_SIGNAL      TERM
++#define NGX_TERMINATE_SIGNAL     QUIT
+ #define NGX_NOACCEPT_SIGNAL      WINCH
+ #define NGX_RECONFIGURE_SIGNAL   HUP