Add systemd instantiated service nginx@.service, allowing e.g.

"systemctl start nginx@foobar.service" to start an instance of
nginx using /etc/nginx/foobar.conf as the configuration.

instance.conf

@@ -0,0 +1,20 @@
+#
+# This is an example instance-specific configuration file.
+#
+# To use this example, copy instance.conf to /etc/nginx/foobar.conf
+# and replace all the references to @INSTANCE@, for example using:
+#
+#   # sed s/@INSTANCE@/foobar/g < instance.conf > /etc/nginx/foobar.conf
+#
+# This new configuration file be used instead of /etc/nginx/nginx.conf
+# when running:
+#
+#   # systemctl start nginx@foobar.service
+#
+# This example configuration adjust the location of the PID file,
+# access and error logs to be instance-specific.  Further
+# customisations will be required for an instance to run
+# simultaneously to nginx.service under the default configuration,
+# e.g. changing the port and root directory as appropriate.
+#
+

nginx.spec

@@ -84,9 +84,11 @@ Source14:          nginx-upgrade.8
 Source15:          macros.nginxmods.in
 Source16:          nginxmods.attr
 Source17:          nginx-ssl-pass-dialog
+Source18:          nginx@.service
 Source102:         nginx-logo.png
 Source200:         README.dynamic
 Source210:         UPGRADE-NOTES-1.6-to-1.10
+Source220:         instance.conf
 
 # removes -Werror in upstream build scripts.  -Werror conflicts with
 # -D_FORTIFY_SOURCE=2 causing warnings to turn into errors.
@@ -267,10 +269,10 @@ Requires:          zlib-devel
 cat %{S:2} %{S:3} %{S:4} %{S:5} %{S:6} > %{_builddir}/%{name}.gpg
 %{gpgverify} --keyring='%{_builddir}/%{name}.gpg' --signature='%{SOURCE1}' --data='%{SOURCE0}'
 %autosetup -p1
-cp %{SOURCE200} %{SOURCE210} %{SOURCE10} %{SOURCE12} .
+cp %{SOURCE200} %{SOURCE210} %{SOURCE10} %{SOURCE12} %{SOURCE18} %{SOURCE220} .
 
 %if 0%{?rhel} > 0 && 0%{?rhel} < 8
-sed -i -e 's#KillMode=.*#KillMode=process#g' nginx.service
+sed -i -e 's#KillMode=.*#KillMode=process#g' nginx.service nginx@.service
 sed -i -e 's#PROFILE=SYSTEM#HIGH:!aNULL:!MD5#' nginx.conf
 %endif
 
@@ -281,6 +283,13 @@ sed \
   -i auto/lib/openssl/conf
 %endif
 
+# Prepare template config for instances
+sed -e '/^error_log /s|error\.log|@INSTANCE@_error.log|' \
+    -e '/^pid /s|nginx\.pid|nginx-@INSTANCE@.pid|' \
+    -e '/^ *access_log/s|access\.log|@INSTANCE@_access.log|' \
+    nginx.conf >> instance.conf
+touch -r %{SOURCE12} instance.conf
+
 # Prepare sources for installation
 cp -a ../%{name}-%{version} ../%{name}-%{version}-%{release}-src
 mv ../%{name}-%{version}-%{release}-src .
@@ -377,6 +386,8 @@ find %{buildroot} -type f -iname '*.so' -exec chmod 0755 '{}' \;
 
 install -p -D -m 0644 ./nginx.service \
     %{buildroot}%{_unitdir}/nginx.service
+install -p -D -m 0644 ./nginx@.service \
+    %{buildroot}%{_unitdir}/nginx@.service
 install -p -D -m 0644 %{SOURCE11} \
     %{buildroot}%{_sysconfdir}/logrotate.d/nginx
 
@@ -538,11 +549,12 @@ fi
 %{_mandir}/man8/nginx.8*
 %{_mandir}/man8/nginx-upgrade.8*
 %{_unitdir}/nginx.service
+%{_unitdir}/nginx@.service
 %{_libexecdir}/nginx-ssl-pass-dialog
 
 %files core
 %license LICENSE
-%doc CHANGES README README.dynamic
+%doc CHANGES README README.dynamic instance.conf
 %{_sbindir}/nginx
 %config(noreplace) %{_sysconfdir}/nginx/fastcgi.conf
 %config(noreplace) %{_sysconfdir}/nginx/fastcgi.conf.default

nginx@.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=The nginx HTTP and reverse proxy server
+After=network-online.target remote-fs.target nss-lookup.target
+Wants=network-online.target
+
+[Service]
+Type=forking
+Environment=NGINX_INSTANCE=%i
+PIDFile=/run/nginx-%i.pid
+# Nginx will fail to start if /run/nginx.pid already exists but has the wrong
+# SELinux context. This might happen when running `nginx -t` from the cmdline.
+# https://bugzilla.redhat.com/show_bug.cgi?id=1268621
+ExecStartPre=/usr/bin/rm -f /run/nginx-%i.pid
+ExecStartPre=/usr/sbin/nginx -t -c /etc/nginx/%i.conf
+ExecStart=/usr/sbin/nginx -c /etc/nginx/%i.conf
+ExecReload=/usr/sbin/nginx -s reload -c /etc/nginx/%i.conf
+KillSignal=SIGQUIT
+TimeoutStopSec=5
+KillMode=mixed
+PrivateTmp=true
+
+[Install]
+WantedBy=multi-user.target