Ovirt devel - Mar 2009 - [PATCH server] verify hostname is not on the loopback entry in /etc/hosts

To prevent kerberos errors the fqdn must never be on the loopback entry

---
 installer/bin/ovirt-installer |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/installer/bin/ovirt-installer b/installer/bin/ovirt-installer
index a2aae9f..28b269c 100755
--- a/installer/bin/ovirt-installer
+++ b/installer/bin/ovirt-installer
@@ -96,6 +96,20 @@ welcome =  "This installer will configure the ovirt
installation based on a seri
 of questions. When complete, you will be asked to install oVirt or\n\
 do the installation manually. Would you like to continue?"
 
+# verify hostname is not on the loopback line in /etc/hosts to prevent kerberos
problems
+hostname = `hostname`
+hostsfile = File.new("/etc/hosts", "r")
+while (line = hostsfile.gets)
+     if line =~ /127.0.0.1/ && line.include?(hostname.chomp)
+         if hostname !~ /localhost.localdomain/
+         @cli.say("\nHostname must not be on the loopback 127.0.0.1 line
in /etc/hosts")
+         @cli.say("#{line}")
+         exit(0)
+         end
+     end
+end
+hostsfile.close
+
 if (prompt_yes_no(welcome, :default => "y") == "n")
     exit(0)
 end
-- 
1.6.0.6

On Wed, 2009-03-25 at 15:21 -0400, Joey Boggs wrote: 
> +# verify hostname is not on the loopback line in /etc/hosts to prevent
kerberos problems
> +hostname = `hostname`
> +hostsfile = File.new("/etc/hosts", "r")
> +while (line = hostsfile.gets)
> +     if line =~ /127.0.0.1/ && line.include?(hostname.chomp)
> +         if hostname !~ /localhost.localdomain/
> +         @cli.say("\nHostname must not be on the loopback 127.0.0.1
line in /etc/hosts")
> +         @cli.say("#{line}")
> +         exit(0)
> +         end
> +     end
> +end
> +hostsfile.close
This can produce false positives in a number of ways: (1) it will get
confused by comments:

        # We used to have, but that's wrong
        # 127.0.0.1 host.exmaple.com
        127.0.0.1 localhost.localdomain
        
It also gets confused if hostname is 'host.example.com' and the
127.0.0.1 line has an alias 'myhost.example.com'.

Finally, (but that should happen throughout the installer), the
installer shouldn't exit with status 0 when there was an error. It would
be good to have a convention like status == 0 when installer finished
successfully, status == 1 when an error happened, status == 2 when user
exited installer (e.g., by answering 'no' to some question)

A more robust implementation of the above would be:

        aug = Augeas::init(nil, nil, 0)
        hosts = "/files/etc/hosts/*"
        paths = aug.match("#{hosts}/canonical[../ipaddr =
'127.0.0.1']") +
                aug.match("#{hosts}/alias[../ipaddr =
'127.0.0.1']")
        paths.each do |p|
          name = aug.get(p)
          if hostname == name
            @cli.say("\nHostname must not be on the loopback 127.0.0.1 line
in /etc/hosts")
            if (prompt_yes_no("Should I fix that ?", :default =>
"n") == "y")
              aug.rm(p)
              aug.save
            end
          end
        end

David