sed + how to append lines with indent

Question

I use the following sed command in order to append the lines:

       rotate 1
       size 1k

after the word missingok

the little esthetic problem is that "rotate 1" isn’t alignment like the other lines

# sed '/missingok/a      rotate 1\n    size 1k' /etc/logrotate.d/httpd

 /var/log/httpd/*log {
       missingok
rotate 1
       size 1k
       notifempty
       sharedscripts
       delaycompress
       postrotate
           /sbin/service httpd reload > /dev/null 2>/dev/null || true
       endscript
}

someone have advice how to indent the string "rotate 1" under missingok string ?

the original file

/var/log/httpd/*log {
    missingok
    notifempty
    sharedscripts
    delaycompress
    postrotate
        /sbin/service httpd reload > /dev/null 2>/dev/null || true
    endscript
 }

Answer 1

Apparently the first sequence of characers has to be escaped

sed '/missingok/a\\trotate 1\n\tsize 1k' /etc/logrotate.d/httpd