Using a zabbix_agent module that takes an array for zabbix_user_parameters that populates the user_parameters configuration file.

This is a valid array as used in puppet to configure the variable for monitoring MySQL with Zabbix:

[
  'mysql.uptime[*],mysqladmin -u$1 -p$2 status|cut -f2 -d":"|cut -f1 -d"T"',
  'mysql.threads[*],mysqladmin -u$1 -p$2 status|cut -f3 -d":"|cut -f1 -d"Q"',
  'mysql.questions[*],mysqladmin -u$1 -p$2 status|cut -f4 -d":"|cut -f1 -d"S"',
  'mysql.slowqueries[*],mysqladmin -u$1 -p$2 status|cut -f5 -d":"|cut -f1 -d"O"',
  'mysql.qps[*],mysqladmin -u$1 -p$2 status|cut -f9 -d":"',
  'mysql.status[*],mysqladmin -u$1 -p$2 extended-status | awk \'$$2 ~ /^$3$/ { if($$4 != "|") print $$4 }\'',
  'mysql.ping[*],mysqladmin -u$1 -p$2 ping | egrep alive | wc -l',
  'mysql.version,mysql -V',
  'mysql.slave[*],mysql -u$1 -p$2 -e "show slave status\G"| awk \'/$3:/ {print $NF}\' | sed s/Yes/1/ | sed s/No/0/',
]

When entered (no whitespace) as a default value for the parameter in the UI, the following error is generated:

(<unknown>): found unexpected ':' while scanning a plain scalar at line 1 column 624

It is failing to determine that the ' used in the awk statement is escaped by a \

This can be fixed by reversing the use of quotations, replacing ' with " and " with ' and escaping any existing "s. This is how the setting is detected if it is set in the module and then imported:

[
  "mysql.uptime[*],mysqladmin -u$1 -p$2 status|cut -f2 -d\":\"|cut -f1 -d\"T\"",
  "mysql.threads[*],mysqladmin -u$1 -p$2 status|cut -f3 -d\":\"|cut -f1 -d\"Q\"",
  "mysql.questions[*],mysqladmin -u$1 -p$2 status|cut -f4 -d\":\"|cut -f1 -d\"S\"",
  "mysql.slowqueries[*],mysqladmin -u$1 -p$2 status|cut -f5 -d\":\"|cut -f1 -d\"O\"",
  "mysql.qps[*],mysqladmin -u$1 -p$2 status|cut -f9 -d\":\"",
  "mysql.status[*],mysqladmin -u$1 -p$2 extended-status | awk '$$2 ~ /^$3$/ { if($$4 != \"|\") print $$4 }'",
  "mysql.ping[*],mysqladmin -u$1 -p$2 ping | egrep alive | wc -l",
  "mysql.version,mysql -V",
  "mysql.slave[*],mysql -u$1 -p$2 -e \"show slave status\\G\"| awk '/$3:/ {print $NF}' | sed s/Yes/1/ | sed s/No/0/" 
]

Despite using the original notation in the file, the reversed notation is displayed in the UI.

I do not believe the original notation is invalid and therefore it ought to be correctly parsed by the UI; or at least should be converted into the reversed notation as done when loaded via the module's own defaults.