Servers

Ensim virtualhosting filelists explained

Posted on by Andy

IN THE FILELISTS ARE SOME LETTERS USED. HERE AN EXPLANAITON:

[[T:][U,(|admin):][G,(|admin):][L:][M,:][C:][R:][P:][A:][N:][I:][S,:]( [ // ]| <[!]pattern>)

The optional characters at the beginning are flags. Here are their meanings:

T: This file should be considered a template file (i.e. copied into the domain, and not hardlinked) 

U,(<user>|admin): this file should be owned by the top level user <user>, or by the site admin (if admin is given). This will generally be used with T:, although it could be hard-linked. If hard-linked, the user parameter must be a top-level user, and not the special keyword admin. While expected to be rarely used, one example would be if you wanted to hardlink in an apache-owned file into each domain.

G,(<group>|admin): similar to U:, except that this controls the group ownership 

L: Indicates that this file is a symlink that should be created. <filename2> must be specified, and will be what the created symlink will point to. Symlinks imply the T: flag, since hardlinked symlinks aren't supported over NFS.

M,<mode>: this file should be created with the permissions as given in <mode>. <mode> may be specified as octal (with a leading 0), hexidecimal (leading 0x), or integer. The common case would be to specify it as octal. 

C: this file should be taken from the root filesystem but placed in a different location under the domain filesystem. <filename2> must be specified. For example, you might have the line "/usr/lib/opcenter/sendmail/install/sendmail.mc.site // /etc/mail/sendmail.mc" 

R: this path is a directory, and all files under it should be handled recursively. 

P: this path is a permanent template file, and should not be removed or updated under the templates directory. 

A: this file should always be updated. 

S,<pkg type>: The end of the line contains a package name and pattern. The contents of the package should be listed, and the pattern applied to the list. The resulting list of files will be added to the manifest as if they were listed separately with the rest of the flags given on the original line. If the pattern begins with an !, then the pattern is used to remove files from the package's manifest.

N: should only be specified along with the S flag. Specifies that this package should not be considered a strict dependency of the containing fst package. 

I: Include files that aren't listed in the package file list, but are generated / owned by that package. Example of such file are the files generated in %post scriptlet of rpm. 

<filename> and <filename2> must be absolute paths.

Create a master zone in BIND9 (CentOS)

Posted on by Andy

After installing BIND with your package manager (yum) you need to edit the main configuration file. The following configuration was adopted to my needs but you should get the points. For more infos about the config switches you can look at the named manual pages.

edit /etc/named.conf and change following lines:

options {
    listen-on-v6 { none; };
    listen-on port 53 { 127.0.0.1; YOUR_LOCAL_IP; };
    allow-query { localhost; };
    allow-transfer { none; };
    recursion no;
}

add your zone information to the file:

zone "MYDOMAIN" {
    type master;
    file "MYDOMAIN.zone";
    allow-query { any; };
}

now create your zone file /var/named/MYDOMAIN.zone and add following lines:

$TTL 3h
@             IN SOA          ns.MYDOMAIN. root.MYDOMAIN. (
                                     MODIFICATION ; serial
                                     3h ; refresh
                                     1h ; retry
                                     1w ; expiry
                                     1d  ; minimum
)
MYDOMAIN.             IN MX          0 mail.MYDOMAIN.
MYDOMAIN.             IN TXT         "v=spf1 ip4:YOUR_PUBLIC_IP/32 mx ptr mx:mail.MYDOMAIN -all"
MYDOMAIN.             IN NS           ns.MYDOMAIN.
MYDOMAIN.             IN NS           SLAVE_DNS_SERVER
www.MYDOMAIN.      IN A             MYHOST_IP
ns.MYDOMAIN.         IN A             MYHOST_IP
mail.MYDOMAIN.       IN A             MYHOST_IP
HOST.MYDOMAIN.    IN A             MYHOST_IP

now, save the file and make sure it has the right permissions:

# chown root:named /var/name/MYDOMAIN.zone
# chmod 640 /var/name/MYDOMAIN.zone

then add a firewall rule if not alreaqdy done:

# iptables -A INPUT -m state –state NEW -p udp –dport 53 -j ACCEPT

and (re-)start the nameserver.

article based on this howto

No space left on device error (Apache)

Posted on by Andy

If you find in your apache error logs some lines with:

No space left on device. Couldn't create accept lock

and a normal service restart does not help it has likely something to do with Semaphores running out.

Try a service shutdown and check your apache semaphores afterwards with:
# ipcs | grep apache

Should there still be a lot of them you can delete them with following command:
# ipcs -s | grep apache | perl -e 'while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}'

Now start your apache normally and verify the logs if the problem has gone.