Rudder

I've run into a strange behavior of "File key-value present" method and couldn't understand if this correct behavior or not.

Steps:

1. Create custom Technique
2. Use generic method "File key-value present" with following params:
   1. File: /etc/mysql/mysql.conf.d/mysqld.cnf
   2. Key: bind-address
   3. Value: ${sys.ipv4}
   4. Separator: =
3. Created necessary directive and assigned it to a particular node
4. When I run rudder agent update && rudder agent run I can see that Technique is being applied to node and it shows that Technique is compliant

Observed: In /etc/mysql/mysql.conf.d/mysqld.cnf is bind-address = 127.0.0.1
Expected: In /etc/mysql/mysql.conf.d/mysqld.cnf is bind-address = 10.0.2.46

Contents of /etc/mysql/mysql.conf.d/mysqld.cnf:

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address            = 127.0.0.1
mysqlx-bind-address     = 127.0.0.1

Additional findings:

• If I remove or comment bind-address in /etc/mysql/mysql.conf.d/mysqld.cnf - everything works as expected i.e. bind-address = 10.0.2.46 is added in the end of file.
• If in /etc/mysql/mysql.conf.d/mysqld.cnf I replace bind-address = 127.0.0.1 with bind-address =127.0.0.1 (remove space after =) - works as expected.
• Value = 10.0.2.46 - doesn't work.
• Value = 192.168.0.1 - works
• Value = 10.0.2.1 - works
• Value = 10.0.2.10 - doesn't work
• Value = 10.0.20.10 - works

Please see outputs from rudder agent run -v | grep -C200 ncf_maintain_keys_values_option when replacement works and doesn't in the attachment.