Your are to represent the warden

Twenty years ago, Johnny killed his wife in a fit of rage when he came home one night and saw her in bed with another man. Based on the mandatory sentencing guidelines at the time of his conviction, Johnny was sentenced to life in prison without any opportunity for parole.
For the past 20 years, Johnny has been a model prisoner. He finished his college degree and worked as a cook in the prison kitchen. One day, a fight in the mess hall between two other prisoners resulted in the death of one prisoner and several injuries to prison guards. At the time, Johnny was working in the kitchen and took no role in the fight.
After the fight, the warden of the prison imposed a series of punishments. First, the warden ed a 24-hour lockdown of the prison. This lockdown lasted 10 days, during which prisoners were not allowed out of their cells.
Second, the warden ed that prisoners be deprived of all “treats” including adult magazines, reading materials, caffeinated sodas, candy, and desserts; visiting privileges for all prisoners were halted for one year.
Finally, and perhaps worst, the warden decided to isolate the most violent prisoners for an extended period. Because of Johnny’s murder conviction, the warden ed Johnny to serve six months in solitary confinement.
After doing his time in solitary, Johnny filed an internal complaint with the warden. In his complaint, Johnny argued that the warden’s punitive measures violated his Eighth Amendment rights. The warden denied Johnny’s complaint and Johnny then filed a complaint in the federal court.

 please represent the warden, who is most likely represented by the government.  Show, using case law and other legal arguments, how the warden’s measures did not constitute violations of the Eighth Amendment.