We also sang this at school in French classes: it would be difficult to do a phonetic version as the French vowel pronunciation is distinctively their own, but roughly speaking:

Eel e nay, lu diveen onfon,
Joo-ay aubwa hrezonay myuzetta,
Eel e nay, lu diveen onfon,
Shonton touss son avenumon.

I'll leave the verses to you!