Is it technically a legal combination? Would it work on each berry individually?
This is a purely theoretical speculation, I won't allow it and won't expect anyone to allow it for me, but it just struck me as a super munchkin combo 
I think there's another thread covering this, maybe in another subforum, but my interpretation is that the spell itself doesn't restore any HP, it creates berries and those berries can provide nourishment and restore 1 HP. Therefore, I would say that there is no interaction.
If you wanted, you could rule otherwise and make goodberry a very strong out-of-combat healing spell, or do as one poster suggested and allow the spell to conjure 3 more berries for a Life cleric, because 3 berries = 3 HP.
FWIW I asked Co-Creator Jeremy Crawford about this specifically and here's his answer;
@Plaguescarred Hola gents! Quick question, does Discipline of Life works on Goodberry granting every goodberry additional HP?
@JeremyECrawford I would allow it.
I will be limiting life cleric ability to cleric spells only. There's enough healing going around as is! Combining it with goodberry is CRAZY powerful. Eg, night before adventure begins, PC declares casting goodberry with all unused slots, which is going to be a HEAP of goodberries,which last 24 hours. So even 3rd level guy will be making something like 60 berries from memory (4 x 1st, 2x 2nd?). So thats 60 hp free healing normally for the next adventuring day. With life cleric adding in.... it's 240 hp!!! no thanks!
Psikerlord wrote:
It does not provide a full meal, you don't have to eat or drink for 24 hours, it's not the same.
Also the theoretical "cast all spells before going to sleep" is just that. If you haven't spent the spell slot already, and if you want to risk not having any spells for the night and want to have berries for out of combat healing and if you have a container that can keep 60 berries safe and unsquashed, then yes its 60 healing the next Day. In actual play though I doubt you will ever see that.
Speaking of unsquahsed, good berry smoothie/milkshake sounds tasty!
E-Tallitnics wrote:
Just for the record, I agree with everyone that it's an insane combination and doesn't seem to be the intended use for the cleric feature.
The more I read on these forums, the more multiclassing just seems broken as hell ;) in fact the rules seems rather rushed....wonder when we will see 5.5
Psikerlord wrote:
Psikerlord wrote:
"When ever you use a spell of 1st level or higher to restore hit poins to a creature, the creature regains additional hit points equal to 2+ the spell's level"
1/ So Goodberry isn't just healing a creature, it is multiple creatures so therefore the power does not work.
However I don't see a problem stretching the power to either:
2/ If you eat all the berries then you get the Life power up
or
3/ Spead the bonus over all the berries.
The 2/ would lead to things like creating only one berry so that you can get a quick combat boost, as you can only eat one berry per round.
I'm afraid that doesn't work either 
Pc one eats a berry, I am now healing "a" creature
Pc two eats a berry, I am now healing "a" creature
Pc three, etc.
There is no indication that the feature is limited to any amount of creatures. "A" is not the same as "one" even if it can be used that way.
The sentence even starts "when ever" instead of "once"
otherwise se the feature wouldn't work with mass cure spells either.
I think we have to pass this one as, it works by RAW and even Jeremy Crawford would allow it....but a sense of game balance would dictate to overlook RAW in this instance, if you want to have HP being an important resource between encounters.
Keendk wrote:
Im sorry, but by that logic the level 6 ability can also only be used on "a creature" as thats in the description, and that is BLATANTLY usable on several creatures.
"This feature can restore a creature to no more than half of its hit point maximum"
Just leafing through: Dragonsbreath page 34 "a creature hit" by your definition would only hit one creature in the cone.
Yeah sure, you have your good berries replace high level spells and read the rules obviously outside their intent and have fun with that.
Keendk wrote:
Meh, I see this as something that doesn't work. You summon the berries, the players must EAT said berries to heal.
Unless you let your Necromancers heal with Grim Harvest any time something is killed by Create/Animate Dead...
I don't mind people ruling otherwise, but I wouldn't rule it, myself. This may change once this ability actually sees play (especially depending on who is actually PLAYING said character), but we'll have to wait and see!