Can't get Mojo::Redis2 to subscribe - perl

Question

I wrote the following program (redis.pl), Redis is running locally with the default port settings, but when I run redis.pl with morbo redis.pl I never get ********* 1 on the screen. Why is that? It seems the subscription never happens. How can I fix this?
#!/usr/bin/perl
use v5.18;
use warnings;
use Mojolicious::Lite;
use Mojo::Redis2;
say "Welcome";
my $redis = Mojo::Redis2->new();
$redis->subscribe(['pubsub'] => sub {
say "********* 1";
});
get '/' => sub {
my $self = shift;
$self->render(json => {a => 1});
};
app->start;

Answer 1

I don't have a redis instance installed currently, but I think this should work.
#!/usr/bin/perl
use v5.18;
use warnings;
use Mojolicious::Lite;
use Mojo::Redis2;
say "Welcome";
helper redis => sub {state $redis = Mojo::Redis2->new()};
app->redis->subscribe(['pubsub'] => sub {
say "********* 1";
});
get '/' => sub {
my $self = shift;
$self->render(json => {a => 1});
};
app->start;
I suspect that once the redis instance goes out of scope, you lose it and its connections.

Answer 2

I solved it, by making sure I retain the return value of $redis->subscribe in a permanent variable, like so:
Instead of...
$redis->subscribe(['pubsub'] => sub {
say "********* 1";
});
...I wrote...
our $subscription = $redis->subscribe(['pubsub'] => sub {
say "********* 1";
});
That fixed the problem. I guess it's similar to AnyEvent, where the return value must stay alive.