Are drugs like cocaine, heroin and crack cocaine made by the government and supplied to the local users in exchange for community services?
This couldn't happen, it would be leaked
It isn't likely that this could happen via the government, although someone in government could do this themselves, that isn't likely either. The practicality of this is intelligent, if a drug user could be guaranteed their drug of choice and then be guaranteed immunity, then would be willing to perform services on this basis, and be indebted to the government. The problem is that if anyone found out, or it leaked somehow, the government would face serious consequences in the face of the drug war it has been waging. There's no way drugs are supplied to local users in exchange for services, made by the government or not.
The United States government does not supply illegal drugs to local suppliers.
Drugs like cocaine, heroin and crack cocaine are not distributed to local suppliers by the government. Those drugs in particular are high dollar, big business drugs. Even if the United States felt compelled to manufacture them, it would be with much bigger profits in mind than local users could provide.