packer-cn/hcl2template/function/env.go

33 lines
767 B
Go

package function
import (
"os"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/function"
)
// EnvFunc constructs a function that returns a string representation of the
// env var behind a value
var EnvFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "key",
Type: cty.String,
AllowNull: false,
AllowUnknown: false,
},
},
Type: function.StaticReturnType(cty.String),
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
key := args[0].AsString()
value := os.Getenv(key)
return cty.StringVal(value), nil
},
})
// Env returns a string representation of the env var behind key.
func Env(key cty.Value) (cty.Value, error) {
return EnvFunc.Call([]cty.Value{key})
}