terraform/builtin/providers/external/util.go

36 lines
831 B
Go

package external
import (
"fmt"
"os/exec"
)
// validateProgramAttr is a validation function for the "program" attribute we
// accept as input on our resources.
//
// The attribute is assumed to be specified in schema as a list of strings.
func validateProgramAttr(v interface{}) error {
args := v.([]interface{})
if len(args) < 1 {
return fmt.Errorf("'program' list must contain at least one element")
}
for i, vI := range args {
if _, ok := vI.(string); !ok {
return fmt.Errorf(
"'program' element %d is %T; a string is required",
i, vI,
)
}
}
// first element is assumed to be an executable command, possibly found
// using the PATH environment variable.
_, err := exec.LookPath(args[0].(string))
if err != nil {
return fmt.Errorf("can't find external program %q", args[0])
}
return nil
}