Allow container export engine to be specified in the environment
This will make it easier for users that prefer a buildah/podman-based
local workflow, because they can specify their preference once and
forget about it, without having to always specify `--engine=buildah`
every time they use the exporter.
@@ -88,6 +88,7 @@ pub fn cli_arg<'a, 'b>() -> Arg<'a, 'b> {
Arg::with_name("ENGINE").value_name("ENGINE")
.long("engine")
.required(true)
+ .env("HAB_PKG_EXPORT_CONTAINER_ENGINE")
.takes_value(true)
.multiple(false)
.default_value("docker")
