I need to know the list of all entry nodes. Is it possible to do this? I found here https://www.dan.me.uk/tornodes a list of all nodes or only exit nodes but I only need entry nodes.
You already have them in that list, you only need to look at those with the "Guard" flag which specifies that they're entry nodes, for example:
You'll only have to extract those with the G flag.
https://atlas.torproject.org/#search/flag:Guard Here you can see also all nodes with the flag "Guard".
NewUser suggested, go to https://metrics.torproject.org/rs.html#search/flag:Guard, add your filters and with a quick network inspection, you will find out that there is a JSON endpoint listing all the entries and it has filters too.
For example, to get all the running Exit nodes, we have
to get all the running Guard nodes, we have