Greeting friend, about to make glass container (5)
I believe the answer is:
phial
'glass container' is the definition.
(I've seen this before)
'greeting friend about' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'friend' becomes 'pal' (pal can mean a friend).
'about' means one lot of letters goes inside another.
'hi' put within 'pal' is 'PHIAL'.
'to make' is the link.
(Other definitions for phial that I've seen before include "Ampoule" , "little bottle" , "Small bottle for potions etc" , "Small bottle (containing a drug)" , "Small glass bottle for perfume or medicine" .)