We can write
x2+y2+z2+1=xy+yz+zx+∣x−y+z−y∣
hence
(x−y)2+(y−z)2+(z−x)2+2=2∣x−y+z−y∣.
It follows
(x−y)2+(y−z)2+(z−x)2+2≤2∣x−y∣+2∣y−z∣.
The last relation is equivalent to
(∣x−y∣−1)2+(∣y−z∣−1)2+(z−x)2≤0.
We get ∣x−y∣=1, ∣y−z∣=1 and x=z. The desired triples (x,y,z) are (a,a−1,a), (a,a+1,a), where a∈R.