This commit does a few things:
1. Make the hostname update idempotent with `grep -w`
2. Add the given hostname to `/etc/hosts` as recommended by the docs
3. Add missing tests
This commit updates the procedure for configuring arch networks to occur
in a single command. Previously, each network was configured
independently. If, for some reason, one of the networks destroyed the
SSH connection, the box would be irrecoverable. This commit does not
alleviate that behavior, but attempts to mitigate it by running all
network-related configuration commands in a single communicator (SSH)
session.
The new procedure looks like this:
1. Upload a temp file to /tmp/vagrant-network-id... for each interface
on the guest.
2. Compile a commands array (of bash) to execute after all network
configurations have been uploaded.
3. Concatenate all the commands together in a single communicator
session.
This was tested against `terrywant/archlinux` using the following Vagrantfile:
```ruby
Vagrant.configure(2) do |config|
config.vm.box = "terrywang/archlinux"
config.vm.hostname = "banana-ramama.example.com"
config.vm.network "private_network", type: "dhcp"
config.vm.network "private_network", ip: "33.33.33.10"
config.vm.provision "file", source: "Vagrantfile", destination: "/tmp/vf"
config.vm.provision "shell", inline: "echo hi"
end
```
This commit updates the procedure for changing the hostname on arch
guests to occur in a single command. Previously, setting the hostname
and adding the value of the hostname to the /etc/hosts file was done in
two different uploads. This reduces the cycle to a single upload, making
provisioning a bit faster.
Additionally, this changes the behavior of the /etc/hosts file to:
1. Not remove localhost as an alias of 127.0.0.1
2. Prepend our custom hostname before localhost
The resulting /etc/hosts file will look something like:
127.0.0.1 my-host.example.com my-host
127.0.0.1 localhost.mydomain localhost
Tested against `terrywang/archlinux` using the following Vagrantfile:
```ruby
Vagrant.configure(2) do |config|
config.vm.box = "terrywang/archlinux"
config.vm.hostname = "banana-ramama.example.com"
config.vm.network "private_network", type: "dhcp"
config.vm.network "private_network", ip: "33.33.33.10"
config.vm.provision "file", source: "Vagrantfile", destination: "/tmp/vf"
config.vm.provision "shell", inline: "echo hi"
end
```
This fixes a fairly large tempfile leak. Vagrant uses a template
renderer to write network configuration files locally to disk. Then,
that temporarily file is uploaded to the remote host and moved into
place. Since Vagrant is such a short-lived process, GC never came along
and cleaned up those tempfiles, resulting in many temporary files being
created through regular Vagrant usage.
The Util::Tempfile class uses a block to ensure the temporary file is
deleted when the block finishes. This API required small tweaks to the
usage, but provides more safety to ensure the files are deleted.
Ubuntu versions prior to 16.04 always returned a successful exit status,
even if one tried to down an interface that does not exist. This
behavior changed in Ubuntu 16.04 to return an error. This commit
preserves the old behavior.
Fixes GH-7155
Refactor and repair regular expression attempting to match present interfaces.
The refactored regular expression will match on enp* ens* eth* variants.
