Strip leading and trailing hyphens in the resulting munged hostname.
Leading and trailing hyphens are not valid according to RFCs 952 and 1123.
(This problem surfaces immediately when using the default configuration of
OneFlow, since it names new VMs ending with a parenthesis.)
When setting the hostname from $SET_HOSTNAME, replace any characters
not allowed in hostnames (as specified in RFC 952) with a hyphen.
This is enables a VM template to safely use the VM's name as the
hostname (by setting the context variable SET_HOSTNAME=$NAME).
generate.sh is also modified so it copies the files from these
directories by default or use dir.$ENVIRONMENT if specified. For
example, use ENVIRONMENT=ec2 to copy the directories that end in .ec2:
ENVIRONMENT=ec2 ./generate.sh
base
base.ec2
base_deb
base_deb.ec2
Jamie Taylor
Javi Fontan