Adding /etc/hosts entry to host machine on vagrant up

Question

Is it possible for one to modify files on the host machine during the vagrant up process? For example, adding an entry to the host machine\'s /etc/hosts

Answer 1

I don't want to depend on some plug in to vagrant. It should be standard feature in Vagrant!!!! Untill then I use a shell script to propagate VM's in my cluster of new VMs. The key lines are :

# Obtain the hostkey based on the IP-address and add it to the known_host list 
ssh-keyscan -t ecdsa ${START}.${OFFSET} >> /home/vagrant/.ssh/known_hosts

# obtain the hostname, because you might not know it yet, with the IP address:
EXTERNAL_HOSTNAME=`ssh ${START}'.'${OFFSET} 'hostname'`
# obtain the key ot the new other VM based on hostname and also add to known_hosts
ssh-keyscan -t ecdsa ${EXTERNAL_HOSTNAME} >>  /home/vagrant/.ssh/known_hosts
# so now you have the IP address and the corresponding hostname
# add to /etc/hosts without being asked for "yes/no"
echo  ${START}'.'${OFFSET}' '${EXTERNAL_HOSTNAME} >> /etc/hosts

Where IPADRRESS is the IP address of the master VM in the cluster with several slave node VM's with succeedding ip-addresses. (IPADDRESS=IPADDRESS + 1 untill no successfull ping)

IPADDRESS=`ip addr show eth1 | grep 'inet ' | cut -d ' ' -f 6 | cut -d '/' -f1`
START=`echo ${IPADDRESS} | cut -d '.' -f1,2,3`
OFFSET=`echo ${IPADDRESS} | cut -d '.' -f4`

And then I loop trough the next IP addresses until no more succesfull pings. I do not want to hardcode anything (ip-address or hostname), but to find out itself.

Resulting /etc/hosts file (after sort /etc/hosts | uniq > /tmp/hosts.uniq && sudo sh -c 'mv /tmp/hosts.uniq /etc/hosts' :

[vagrant@master ~]$ cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
127.0.0.1       master.RHEL70.local     master
192.168.1.50 master.RHEL70.local
192.168.1.51 node01.RHEL70.local
192.168.1.52 node02.RHEL70.local
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6