Parameter resolvers

You can use parameter resolvers to resolve values for stack parameters at deployment time. Takomo has a few built-in parameter resolvers, and you can also implement your own.

Stack output resolver reads the parameter value from a stack output of another stack configured within the same Takomo project. The source stack automatically becomes the target stack's dependency. Takomo reads the output value using the credentials associated with the source stack.

The external stack output resolver reads the parameter value from a stack output of a stack. The source stack does not have to belong to the same Takomo project as the target stack.

The command resolver executes a specified shell command and uses the command output as a parameter value.

The file contents resolver reads a file and uses the file contents as a parameter value.

The hook output resolver reads parameter values from hook outputs.

The SSM parameter resolver reads parameter values from SSM parameter store. The parameter can be encrypted.

The secret parameter resolver reads parameter values from secrets stored in Secrets Manager.

You can provide custom parameter resolvers by placing plain JavaScript files, with .js file extension, into the resolvers directory. Each file must export a parameter resolver provider object. Takomo uses the provider to initialize the actual parameter resolver.