def generate_resolv_conf(self):
"""generate a resolv.conf file to bind to the containers.
We use the template provided by scompose.
"""
resolv_conf = os.path.join(self.working_dir, "resolv.conf")
if not os.path.exists(resolv_conf):
template = read_file(get_template("resolv.conf"))
write_file(resolv_conf, template)
return resolv_conf
def create_hosts(self, lookup):
"""create a hosts file to bind to all containers, where we define the
correct hostnames to correspond with the ip addresses created.
Note: This function is terrible. Singularity should easily expose
these addresses. See issue here:
https://github.com/sylabs/singularity/issues/3751
Parameters
==========
lookup: a lookup of ip addresses to assign the containers
"""
template = read_file(get_template("hosts"))
hosts_file = os.path.join(self.working_dir, "etc.hosts")
# Add an entry for each instance hostname to see the others
for name, ip_address in lookup.items():
template = ["%s\t%s\n" % (ip_address, name)] + template
# Add the host file to be mounted
write_file(hosts_file, template)
return hosts_file