Otter Documentation

Configuration Variables

  • Last Modified: 2018-05-17

Configuration variables are name/value pairs that you define on servers, roles, environments, and globally. You can reference these variables from within your plan, and the execution engine will automatically resolve the value based on the context of the execution.

For example, if you were to define a $WebsitesRoot variable on HDARS-WEBSV1 with a value of C:\Websites, and a $WebsitesRoot variable on HDARS-WEBSV2 with D:\Apps\web, when you install a package to $WebsitesRoot\HDars within your plan, the execution engine will automatically resolve the variable based on the server in context (i.e. the server the package is being installed on).

Defining Configuration Variables

You can define variables by going to the desired context (such as the specific server or role), and then either adding a single one, or bulk-editing the set in JSON.

  • Add Variable
  • Bulk-editing
Add Variable
Bulk import

OtterScript supports three types of variables, and if your variable's value starts with @( or %(, then it will be treated as a list or map type, respectively. For example, @(item1, item2, item3) will be considered a list variable, %(key1: value1, key2: @(list1, list2) a map variable, and @(( an invalid expression.

As such, you do not need to specify prefix ($,@, or %) for your variables.

Do not store sensitive information in variables; use credentials instead. While there is an option to "obscure the value of this variable from casual viewing", this does exactly as the name implies, and is not intended to be used as a security feature.

Cascading Behavior

Configuration Variables cascade, which means that you can define a variable of the same name in multiple places, and the correct value will be resolved at runtime. For example, if you define a variable named $HDarsPath on the Testing environment, when an orchestration or configuration plan runs against a server in the Testing environment, that variable will resolve at runtime.

If you also defined $HDarsPath on a single server in the Testing environment, then that value would be used instead.

This allows for reusing plans and templates without having to change local variables.

Resolution Rules

The variable definition that's the "closest" match to the current context is used. This is determined as follows:

  • Job
  • Server
  • Environment
  • Server Role
  • Global

Multiple Scopes

You can also assign multiple scopes to a configuration variable; for example, you could define a variable that's associated with both the Testing environment and the hdars-web role. A multi-scope variable simply adds precedence to the highest-scope (Job is still "closer" than a server or server role).

However, this can become confusing as the resolution rules are not intuitive. We generally discourage this use. You can only create multi-scoped variables from the administration section, and they are visible (but not editable) on the servers, server roles, etc., they are associated with.

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