How flexible is that pipe? You'll need longer lengths if it needs to be bent at 90 degree angles rather than in a semi circular shape.
Not sure whether a cane will be too small to fit into the pipe snugly - it might be OK but might fall out. (You often put a cane into each end of the pipe, and put the cane into the ground).
Don't forget you may need to brace a series of 'hoops' so they remain rigid along the length of the bed.