/[pxelator]/lib/PXElator.pod
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Contents of /lib/PXElator.pod

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Revision 414 - (show annotations)
Wed Sep 9 18:58:48 2009 UTC (11 years, 2 months ago) by dpavlin
File size: 5397 byte(s)
more installation dependencies and quick INSTALL section

1 =head1 Introduction
2
3 PXElator is just a peace of puzzle which aims to replace system administration with nice declarative programs in perl.
4 It's a experiment in replacing my work with reusable perl snippets.
5
6 It tries to solve following problems:
7
8 =over 2
9
10 =item *
11
12 support deployment of new physical or virtual machines (ip, hostname, common configuration)
13
14 =item *
15
16 maintain documentation about changes on systems, good enough to be used for disaster recovery (or deployment of similar system)
17
18 =item *
19
20 configure systems in small chunks (virtual or containers) for better management and resource tracking using normal system administration tools (but track those changes)
21
22 =item *
23
24 provide overview and monitoring of network segment and services on it with alerting and trending
25
26 =back
27
28 =head2 Deployment of new machines
29
30 What is really machine? For PXElator, it's MAC and IP address and some optional parameters (like hostname).
31 It's stored on file-system, under C<conf/server.ip/machine.ip/hostname> and can be tracked using source control if needed.
32
33 This is also shared state between all daemons implementing network protocols:
34
35 =over 2
36
37 =item *
38
39 DHCP (with PXE support)
40
41 =item *
42
43 TFTP (to deliver initial kernel and initrd using pxelinux)
44
45 =item *
46
47 HTTP (to provide alternative way to fetch files and user interface)
48
49 =item *
50
51 DNS (we already have data)
52
53 =item *
54
55 syslog
56
57 =item *
58
59 AMT for remote management
60
61 =back
62
63 Having all that protocols written in same language enables incredible flexibility in automatic configuration.
64 I can issue command using installation which has only ping because I can have special DNS names which issue commands.
65
66 But, to get real power, we need to aggregate that data. I'm currently using CouchDB from L<http://couchdb.apache.org/>
67 to store all audit data from all services into single database.
68
69 I wanted simple way to write ad-hoc queries without warring about data structure too much. At the end,
70 I opted for audit role of data, and used 1 second granularity as key when storing data.
71 Result of it is that 133 syslog messages from kernel right after boot you will create single document
72 with 133 revisions instead of flooding your database.
73
74 It would be logical to plug RRDtool L<http://oss.oetiker.ch/rrdtool/> somewhere here to provide nice graphs here,
75 but that is still on TODO list.
76
77 End user scenarios:
78
79 =over 2
80
81 =item *
82
83 Take a new machine, plug it into network, boot it from network and configure for kiosk style deployment with
84 Webconverger available at L<http://webconverger.com/>.
85 Kiosk should automatically turn on every morning at 7:30 and turn off at 20:30.
86
87 =item *
88
89 Boot virtual machine (with new ip and hostname) from backup snapshot for easy recovery or testing
90
91 =item *
92
93 Boot machine from network into fully configurable (writable) system for quick recovery or dedicated machine.
94 This is implemented using NFS server with aufs read-write overlay on top of debootstrap base machine.
95
96 =back
97
98 =head2 Disaster recovery documentation for me, two years later
99
100 I have been trying to write useful documentation snippets for years.
101 My best effort so far is I<Sysadmin Cookbook> at L<http://sysadmin-cookbook.rot13.org/> a set of semi-structured
102 shell scripts which can be executed directly on machines.
103
104 This part isn't yet integrated into PXElator, but most of the recipe will become some kind of rule which you
105 can enforce on some managed machine.
106
107 End user scenario:
108
109 =over 1
110
111 =item *
112
113 Install that B<something> also on this other machine
114
115 =back
116
117 =head2 Configure system like you normally would but track changes
118
119 This is basically requirement to track configuration changes. Currently, this feature falls out of writable snapshot
120 over base system which is read-only. Overlay data is all custom configuration that I did!
121
122 Tracking changes on existing machines will be implemented C<scp> to copy file on server into C<hostname/path/to/local/file>
123 directory structure. This structure will be tracked using source control (probably git as opposed to subversion
124 which PXElator source uses) and cron job will pull those files at some interval (daily, hourly) to create
125 C<rsync+git> equivalent of BackupPC L<http://backuppc.sourceforge.net> for this setup.
126
127 It's interesting to take a look how it's different from I<Puppet> and similar to I<cfengine3>:
128
129 =over 2
130
131 =item *
132
133 All data is kept in normal configuration files on system -- you don't need to learn new administration tools
134 or somehow maintain two sources of configuration (in configuration management and on the system)
135
136 =item *
137
138 Introspect live system and just tries to apply corrections if needed which is similar to C<cfengine3> approach.
139
140 =back
141
142 End user scenario:
143
144 =over 2
145
146 =item *
147
148 Turn useful how-to into workable configuration without much effort
149
150 =back
151
152 =head2 Provide overview and monitoring
153
154 This falls out from HTTP interface and from collecting of data into CouchDB.
155 For now, PXElator tries to manage development environment for you, opening xterms
156 (with screen inside for logging and easy scrollback) in different colors,
157 and enable you to start Wireshark on active network interfaces for debugging.
158
159 =head1 INSTALL
160
161 cd /srv
162 svn co svn://svn.rot13.org/pxelator
163 svn co svn://svn.rot13.org/Intel-AMT/trunk Intel-AMT
164
165 cd pxelator
166 sh -x bin/install-debian.sh
167
168 perl Makefile.PL
169 make
170
171 # create pxelator CouchDB using http://localhost:5984/_utils/
172 ./bin/start.sh

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