Installing letscrypt certificate in grails

   Installing letsrcrypt certificate in grails.
   assumptions:
    domain name: app.example.com
    password   : supersecret
    linux app user account : appuser
 Use this URL to generate command for your site:

   As root:

   =============================================
   Step 1.
   Renew certificate using this command.
#certbot certonly
   (choose to renew option 1)
   It will create two file:
   /etc/letsencrypt/live/app.example.com/fullchain.pem
   and
   /etc/letsencrypt/live/app.example.com/privkey.pem
  
   Step 2.
   Combine cert and private key using this command.
#mkdir -p /home/appuser/etc/app.example.com
#openssl pkcs12 -export -in /etc/letsencrypt/live/app.example.com/fullchain.pem -inkey /etc/letsencrypt/live/app.example.com/privkey.pem -out /home/appuser/etc/app.example.com/app.example.com.cert.p12 -name app.example.com
<secret

as password>>
#chown -R appuser.appuser /home/appuser/etc/app.example.com

   As app user:

   =============================================
   Step 3.
   Convert p12 file into jks file using this command. Change supersecret to something that is really kept super secret.
$keytool -importkeystore -deststorepass supersecret -destkeypass supersecret -destkeystore /home/appuser/etc/app.example.com/app.example.com.cert.jks -srckeystore /home/appuser/etc/app.example.com/app.example.com.cert.p12 -srcstorepass secret  -srcstoretype PKCS12  -alias app.example.com
$rm /home/appuser/etc/app.example.com/app.example.com.cert.p12

   Step 4.
   Now pass these arguments to grails .
  
$./grailsw \
        -Dserver.address=0.0.0.0 \
        -Dserver.port=8443 \
        -Dserver.ssl.enabled=true \
        -Dserver.ssl.key-store-password=supersecret \
        -Dserver.ssl.key-store=/home/appuser/etc/app.example.com/app.example.com.cert.jks \
        -Dserver.ssl.key-alias=app.example.com \
        prod run-app


The form below hosted at https://jsfiddle.net/a2bfxdeq/2 generates command for you.

Fixing grub2 on windows 10

Problem: Installed Linux on a external HDD connected to windows 10 using live CD and Grub got installed on internal HDD pointing to grub.cfg on external HDD. So if I remove the external HDD, grub.cfg is not found and can't boot windows.

Resolution:
1. Boot Linux by connecting the external HDD.
2. Mount the efi partition (Lets say its /dev/sda1. In my case it was first partition on internal HDD, about 256M in size)
  #mkdir /tmp/efi
  #mount /dev/sda1 /tmp/efi
3. Install grub.
  #grub-install --boot-directory /tmp/efi/grub --efi-directory /tmp/efi --uefi-secure-boot

4. Create the cfg file
  #grub-mkconfig > /tmp/efi/grub/grub/grub.cfg
 
 
Not tried but may be useful:
when you have grub prompt, try this:
echo $prefix

By default grub will look for $prefix/grub.cfg. If you can copy your grub.cfg from external HDD to the default location, that may work.