Adding SSL support to eole-redis.

Ubuntu don't build redis with SSL support so we
use Stunnel to fill the gap.

Here we add Stunnel full EOLE integration and Redis specifics.

Maybe later we will want to have a specific package for eole-stunnel.

ref #30338

tmpl/90-stunnel_dynamic_rules

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+%for %%tunnel in %%stunnel_name
+   %for %%int_idx in %%range(0, %%int(%%nombre_interfaces))
+/sbin/iptables -A eth%%{int_idx}-root -s 0.0.0.0/0.0.0.0  -p tcp -m tcp --dport %%tunnel.stunnel_accept_port --tcp-flags FIN,SYN,RST,ACK SYN -j ACCEPT
+   %end for
+%end for

tmpl/redis-ssl.conf

@@ -0,0 +1,12 @@
+pid = /var/run/redis-stunnel.pid
+
+%if %%redisMode == "Local"
+[redis-local]
+cert = %%server_cert
+key = %%server_key
+CApath  = %%os.path.dirname(%%server_cert)
+verify = 2
+SSLversion=%%redisSSLVersion
+accept = %%redisSSLPort
+connect = %%redisPort
+%end if

tmpl/stunnel.conf

@@ -0,0 +1,19 @@
+pid = /var/run/stunnel.pid
+%for %%tunnel in %%stunnel_name
+[%%tunnel]
+cert = %%server_cert
+key = %%server_key
+CApath  = %%os.path.dirname(%%server_cert)
+verify = 2
+SSLversion=%%tunnel.stunnel_ssl_version
+    %if %%is_empty(%%tunnel.stunnel_accept_ip)
+accept = %%tunnel.stunnel_accept_port
+    %else
+accept = %%{tunnel.stunnel_accept_ip}:%%{tunnel.stunnel_accept_port}
+    %end if
+    %if %%is_empty(%%tunnel.stunnel_connect_ip)
+connect = %%tunnel.stunnel_connect_port
+    %else
+connect = %%{tunnel.stunnel_connect_ip}:%%{tunnel.stunnel_connect_port}
+    %end if
+%end for

tmpl/stunnel_default

@@ -0,0 +1,18 @@
+# /etc/default/stunnel
+# Julien LEMOINE <speedblue@debian.org>
+# September 2003
+
+# Change to one to enable stunnel automatic startup
+ENABLED=1
+FILES="/etc/stunnel/*.conf"
+OPTIONS="%%stunnel_opts"
+
+# Change to one to enable ppp restart scripts
+PPP_RESTART=0
+
+# Change to enable the setting of limits on the stunnel instances
+# For example, to set a large limit on file descriptors (to enable
+# more simultaneous client connections), set RLIMITS="-n 4096"
+# More than one resource limit may be modified at the same time,
+# e.g. RLIMITS="-n 4096 -d unlimited"
+RLIMITS=""