| Prev | Part II. Administrator's Guide | Next |
|---|
This section takes a blank PC and sets up some supporting software. You should do this section as-is if you have a machine you can reformat and you want to be sure that your installation works and is secure; it should take about an hour. You can skip this section if you already have a machine ready with this software (see the section called “Individual Programs” for details):
libxml2
tcl
gmake and the compile and build environment.
and these optional items
emacs
cvs
ImageMagick
DocBook and supporting software
(In my experience, it's almost always a net time savings of several hours to install a new machine from scratch compared to installing each of these packages installed independently.)
Unplug the network cable from your computer. We don't want to connect to the network until we're sure the computer is secure. (Wherever you see the word secure, you should always read it as, "secure enough for our purposes, given the amount of work we're willing to exert and the estimated risk and consequences.")
Insert Red Hat 8.0 Disk 1 into the CD-ROM and reboot the computer
At the boot: prompt, press Enter for a graphical install. The text install is fairly different, so if you need to do that instead proceed with caution, because the guide won't match the steps.
Checking the media is probably a waste of time, so when it asks press Tab and then Enter to skip it.
After the graphical introduction page loads, click
Choose the language you want to use and then click
Select the keyboard layout you will use and Click
Choose your mouse type and Click
Red Hat has several templates for new computers. We'll start with the "Server" template and then fine-tune it during the rest of the install. Choose Server and click .
Reformat the hard drive. If you know what you're doing, do this step on your own. Otherwise: we're going to let the installer wipe out the everything on the main hard drive and then arrange things to its liking.
Choose Automatically Partition and click
Uncheck Review (and modify if needed) the partitions created and click
On the pop-up window asking "Are you sure you want to do this?" click IF YOU ARE WIPING YOUR HARD DRIVE.
Click on the boot loader screen
Configure Networking. Again, if you know what you're doing, do this step yourself, being sure to note the firewall holes. Otherwise, follow the instructions in this step to set up a computer directly connected to the internet with a dedicated IP address.
DHCP is a system by which a computer that joins a network (such as on boot) can request a temporary IP address and other network information. Assuming the machine has a dedicated IP address (if it doesn't, it will be tricky to access the OpenACS service from the outside world), we're going to set up that address. If you don't know your netmask, 255.255.255.0 is usually a pretty safe guess. Click , uncheck Configure using DHCP and type in your IP and netmask. Click .
Type in your host name, gateway, and DNS server(s). Then click .
We're going to use the firewall template for high security, meaning that we'll block almost all incoming traffic. Then we'll add a few holes to the firewall for services which we need and know are secure. Choose High security level. Check WWW, SSH, and Mail (SMTP). In the Other ports box, enter 443, 8000, 8443. Click . Port 443 is for https (http over ssl), and 8000 and 8443 are http and https access to the development server we'll be setting up.
Select any additional languages you want the computer to support and then click
Choose your time zone and click .
Type in a root password, twice. To improve security, we're going to prevent anyone from connecting to the computer directly as root. Instead, we'll create a different user, called remadmin, used solely to connect to the computer for administration. Click and enter username remadmin and a password, twice, then click . Then click .
On the Package selection page, we're going to uncheck a lot of packages that install software we don't need, and add packages that have stuff we do need. You should install everything we're installing here or the guide may not work for you; you can install extra stuff, or ignore the instructions here to not install stuff, with relative impunity - at worst, you'll introduce a security risk that's still screened by the firewall, or a resource hog. Just don't install a database or web server, because that would conflict with the database and web server we'll install later.
check Editors (this installs emacs),
click Details next to Text-based Internet, check lynx, and click ;
check Authoring and Publishing (this installs docbook),
uncheck Server Configuration Tools,
uncheck Web Server,
uncheck Windows File Server,
check Development Tools (this installs gmake and other build tools),
uncheck Administration Tools, and
uncheck Printing Support.
At the bottom, check Select Individual Packages and click
We need to fine-tune the exact list of packages. The same rules apply as in the last step - you can add more stuff, but you shouldn't remove anything the guide adds. We're going to go through all the packages in one big list, so select Flat View and wait. In a minute, a list of packages will appear.
uncheck apmd (monitors power, not very useful for servers),
check ImageMagick (required for the photo-album packages,
uncheckisdn4k-utils (unless you are using isdn, this installs a useless daemon),
check mutt (a mail program that reads Maildir),
uncheck nfs-utils (nfs is a major security risk),
uncheck pam-devel (I don't remember why, but we don't want this),
uncheck portmap,
uncheck postfix (this is an MTA, but we're going to install qmail later),
uncheck rsh (rsh is a security hole),
uncheck sendmail (sendmail is an insecure MTA; we're going to install qmail instead later),
check tcl (we need tcl), and
uncheck xinetd (xinetd handles incoming tcp connections. We'll install a different, more secure program, ucspi-tcp).
Click
Red Hat isn't completely happy with the combination of packages we've selected, and wants to satisfy some dependencies. Don't let it. On the next screen, choose Ignore Package Dependencies and click .
Click to start the copying of files.
Wait. Insert Disk 2 when asked.
Wait. Insert Disk 3 when asked.
If you know how to use it, create a boot disk. Since you can also boot into recovery mode with the Install CDs, this is less useful than it used to be, and we won't bother. Select No,I do not want to create a boot disk and click .
Click Exit, remove the CD, and watch the computer reboot.
After it finishes rebooting and shows the login prompt, log in:
yourserver login: root Password: [root@yourserver root]#
Lock down SSH
SSH is the protocol we use to connect securely to the computer (replacing telnet, which is insecure). sshd is the daemon that listens for incoming ssh connections. As a security precaution, we are now going to tell ssh not to allow anyone to connect directly to this computer as root. Type this into the shell:
emacs /etc/ssh/sshd_config
Search for the word "root" by typing C-s (that's emacs-speak for control-s) and then root.
Change the line
#PermitRootLogin yesto
PermitRootLogin noand save and exit by typing C-x C-s C-x C-c
service sshd restart
Red Hat still installed a few services we don't need, and which can be security holes. Use the service command to turn them off, and then use chkconfig to automatically edit the System V init directories to permanently (The System V init directories are the ones in /etc/rc.d. They consist of a bunch of scripts for starting and stopping programs, and directories of symlinks for each system level indicating which services should be up and down at any given service level. We'll use this system for PostGreSQL, but we'll use daemontools to perform a similar function for AOLServer. (The reason for this discrepencies is that, while daemontools is better, it's a pain in the ass to deal with and nobody's had any trouble leaving PostGreSQL the way it is.)
[root@yourserver root]# service pcmcia stop [root@yourserver root]# service netfs stop [root@yourserver root]# chkconfig --del pcmcia [root@yourserver root]# chkconfig --del netfs [root@yourserver root]#service pcmcia stop service netfs stop chkconfig --del pcmcia chkconfig --del netfs
Plug in the network cable.
Verify that you have connectivity by going to another computer and ssh'ing to yourserver, logging in as remadmin, and promoting yourself to root:
[joeuser@someotherserver]$ ssh remadmin@yourserver.test
The authenticity of host 'yourserver.test (1.2.3.4)' can't be established.
DSA key fingerprint is 10:b9:b6:10:79:46:14:c8:2d:65:ae:c1:61:4b:a5:a5.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'yourserver.test (1.2.3.4)' (DSA) to the list of known hosts.
Password:
Last login: Mon Mar 3 21:15:27 2003 from host-12-01.dsl-sea.seanet.com
[remadmin@yourserver remadmin]$ su -
Password:
[root@yourserver root]#Upgrade the kernel to fix a security hole. The default Red Hat 8.0 system kernel (2.4.18-14, which you can check with uname -a) has several security problems. Download the new kernel, install it, and reboot.
[root@yourserver root]# cd /tmp
[root@yourserver tmp]# wget http://updates.redhat.com/7.1/en/os/i686/kernel-2.4.18-27.7.x.i686.rpm
--20:39:00-- http://updates.redhat.com/7.1/en/os/i686/kernel-2.4.18-27.7.x.i686.rpm
=> `kernel-2.4.18-27.7.x.i686.rpm'
Resolving updates.redhat.com... done.
Connecting to updates.redhat.com[66.187.232.52]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 12,736,430 [application/x-rpm]
100%[======================================>] 12,736,430 78.38K/s ETA 00:00
20:41:39 (78.38 KB/s) - `kernel-2.4.18-27.7.x.i686.rpm' saved [12736430/12736430]
root@yourserver tmp]# rpm -Uvh kernel-2.4.18-27.7.x.i686.rpm
warning: kernel-2.4.18-27.7.x.i686.rpm: V3 DSA signature: NOKEY, key ID db42a60e
Preparing... ########################################### [100%]
1:kernel ########################################### [100%]
[root@yourserver tmp]# reboot
Broadcast message from root (pts/0) (Sat May 3 20:46:39 2003):
The system is going down for reboot NOW!
[root@yourserver tmp]#
cd /tmp
wget http://updates.redhat.com/7.1/en/os/i686/kernel-2.4.18-27.7.x.i686.rpm
rpm -Uvh kernel-2.4.18-27.7.x.i686.rpm
reboot