Adds a script which install certificates from let's encrypt.

The script looks for nginx, apache2 or jetty configuration and edits the first one found. Nginx and apache2 will be reloaded, while jvb will be stopped, configured and started again.

debian/jitsi-meet-web-config.postinst

             # SSL for nginx
             db_get jitsi-meet/cert-choice
             CERT_CHOICE="$RET"
-            UPLOADED_CERT_CHOICE="A certificate is available and the files are uploaded on the server"
+            UPLOADED_CERT_CHOICE="I want to use my own certificate"
 
             if [ "$CERT_CHOICE" = "$UPLOADED_CERT_CHOICE" ] ; then
                 db_set jitsi-meet/cert-path-key "/etc/ssl/$JVB_HOSTNAME.key"
             invoke-rc.d apache2 reload
         fi
 
+        echo "----------------"
+        echo ""
+        echo "You can now switch to a Let’s Encrypt certificate. To do so, execute:"
+        echo "/usr/share/jitsi-meet/scripts/install-letsencrypt-cert.sh"
+        echo ""
+        echo "----------------"
+
         # and we're done with debconf
         db_stop
     ;;

debian/jitsi-meet-web-config.templates

 Template: jitsi-meet/cert-choice
 Type: select
-__Choices: Self-signed certificate will be generated, A certificate is available and the files are uploaded on the server
+__Choices: Generate a new self-signed certificate (You will later get a chance to obtain a Let's encrypt certificate), I want to use my own certificate
 _Description: SSL certificate for the Jitsi Meet instance
  Jitsi Meet is best to be set up with an SSL certificate.
  Having no certificate, a self-signed one will be generated.
+ By choosing self-signed you will later have a chance to install Let’s Encrypt certificates.
  Having a certificate signed by a recognised CA, it can be uploaded on the server
  and point its location. The default filenames will be /etc/ssl/--domain.name--.key
  for the key and /etc/ssl/--domain.name--.crt for the certificate.

debian/jitsi-meet-web.install

 images					/usr/share/jitsi-meet/
 lang					/usr/share/jitsi-meet/
 connection_optimization	/usr/share/jitsi-meet/
+resources/*.sh			/usr/share/jitsi-meet/scripts/

debian/po/templates.pot

 #. Type: select
 #. Choices
 #: ../jitsi-meet-web-config.templates:1001
-msgid "Self-signed certificate will be generated"
+msgid "Generate a new self-signed certificate (You will later get a chance to obtain a Let's encrypt certificate)"
 msgstr ""
 
 #. Type: select
 #. Choices
 #: ../jitsi-meet-web-config.templates:1001
-msgid "A certificate is available and the files are uploaded on the server"
+msgid "I want to use my own certificate"
 msgstr ""
 
 #. Type: select

resources/install-letsencrypt-cert.sh

+#!/bin/bash
+
+set -e
+
+DEB_CONF_RESULT=`debconf-show jitsi-meet-web-config | grep jvb-hostname`
+DOMAIN="${DEB_CONF_RESULT##*:}"
+# remove whitespace
+DOMAIN="$(echo -e "${DOMAIN}" | tr -d '[:space:]')"
+
+echo "-------------------------------------------------------------------------"
+echo "This script will:"
+echo "- Need a working DNS record pointing to this machine(for domain ${DOMAIN})"
+echo "- Download certbot-auto from https://dl.eff.org to /usr/local/sbin"
+echo "- Install additional dependencies in order to request Let’s Encrypt certificate"
+echo "- If running with jetty serving web content, will stop Jitsi Videobridge"
+echo "- Configure and reload nginx or apache2, whichever is used"
+echo ""
+echo "You need to agree to the ACME server's Subscriber Agreement (https://letsencrypt.org/documents/LE-SA-v1.1.1-August-1-2016.pdf) "
+echo "by providing an email address for important account notifications"
+
+echo -n "Enter your email and press [ENTER]: "
+read EMAIL
+
+cd /usr/local/sbin
+
+if [ ! -f certbot-auto ] ; then
+  wget https://dl.eff.org/certbot-auto
+  chmod a+x ./certbot-auto
+fi
+
+CRON_FILE="/etc/cron.weekly/letsencrypt-renew"
+echo "#!/bin/bash" > $CRON_FILE
+echo "/usr/local/sbin/certbot-auto renew >> /var/log/le-renew.log" >> $CRON_FILE
+
+CERT_KEY="/etc/letsencrypt/live/$DOMAIN/privkey.pem"
+CERT_CRT="/etc/letsencrypt/live/$DOMAIN/fullchain.pem"
+
+if [ -f /etc/nginx/sites-enabled/$DOMAIN.conf ] ; then
+
+    ./certbot-auto certonly --noninteractive \
+    --webroot --webroot-path /usr/share/jitsi-meet \
+    -d $DOMAIN \
+    --agree-tos --email $EMAIL
+
+    echo "Configuring nginx"
+
+    CONF_FILE="/etc/nginx/sites-available/$DOMAIN.conf"
+    CERT_KEY_ESC=$(echo $CERT_KEY | sed 's/\./\\\./g')
+    CERT_KEY_ESC=$(echo $CERT_KEY_ESC | sed 's/\//\\\//g')
+    sed -i "s/ssl_certificate_key\ \/etc\/jitsi\/meet\/.*key/ssl_certificate_key\ $CERT_KEY_ESC/g" \
+        $CONF_FILE
+    CERT_CRT_ESC=$(echo $CERT_CRT | sed 's/\./\\\./g')
+    CERT_CRT_ESC=$(echo $CERT_CRT_ESC | sed 's/\//\\\//g')
+    sed -i "s/ssl_certificate\ \/etc\/jitsi\/meet\/.*crt/ssl_certificate\ $CERT_CRT_ESC/g" \
+        $CONF_FILE
+
+    echo "service nginx reload" >> $CRON_FILE
+    service nginx reload
+
+elif [ -f /etc/apache2/sites-enabled/$DOMAIN.conf ] ; then
+
+    ./certbot-auto certonly --noninteractive \
+    --webroot --webroot-path /usr/share/jitsi-meet \
+    -d $DOMAIN \
+    --agree-tos --email $EMAIL
+
+    echo "Configuring apache2"
+
+    CONF_FILE="/etc/apache2/sites-available/$DOMAIN.conf"
+    CERT_KEY_ESC=$(echo $CERT_KEY | sed 's/\./\\\./g')
+    CERT_KEY_ESC=$(echo $CERT_KEY_ESC | sed 's/\//\\\//g')
+    sed -i "s/SSLCertificateKeyFile\ \/etc\/jitsi\/meet\/.*key/SSLCertificateKeyFile\ $CERT_KEY_ESC/g" \
+        $CONF_FILE
+    CERT_CRT_ESC=$(echo $CERT_CRT | sed 's/\./\\\./g')
+    CERT_CRT_ESC=$(echo $CERT_CRT_ESC | sed 's/\//\\\//g')
+    sed -i "s/SSLCertificateFile\ \/etc\/jitsi\/meet\/.*crt/SSLCertificateFile\ $CERT_CRT_ESC/g" \
+        $CONF_FILE
+
+    echo "service apache2 reload" >> $CRON_FILE
+    service apache2 reload
+else
+    service jitsi-videobridge stop
+
+    ./certbot-auto certonly --noninteractive \
+    --standalone \
+    -d $DOMAIN \
+    --agree-tos --email $EMAIL
+
+    echo "Configuring jetty"
+
+    CERT_P12="/etc/jitsi/videobridge/$DOMAIN.p12"
+    CERT_JKS="/etc/jitsi/videobridge/$DOMAIN.jks"
+    # create jks from  certs
+    openssl pkcs12 -export \
+        -in $CERT_CRT -inkey $CERT_KEY -passout pass:changeit > $CERT_P12
+    keytool -importkeystore -destkeystore $CERT_JKS \
+        -srckeystore $CERT_P12 -srcstoretype pkcs12 \
+        -noprompt -storepass changeit -srcstorepass changeit
+
+    service jitsi-videobridge start
+
+fi
+
+# the cron file that will renew certificates
+chmod a+x $CRON_FILE