Linux System Administration Recipes A Problem-Solution Approach

More documents

Recommendations

Info

CHAPTER 6 ■ SECURING YOUR SYSTEMSparticularly heavy email day), you won’t get another one. Another option is to integrate it into Nagios(see Chapter 3 for a discussion of Nagios).6-15. Using cron-apt to Keep UpdatedIf you’re using Debian or Ubuntu, cron-apt is a really useful tool that checks for package updates andwill e-mail you to let you know about them. Install the package with sudo apt-get install cron-apt, andthen edit your /etc/crontab to include this line:0 4 * * * root test -x /usr/sbin/cron-apt && /usr/sbin/cron-aptThis will run cron-apt every night at 4 a.m.To configure it, edit the file /etc/cron-apt/config. Most of this you should be able to leave as is.These are important lines to check and change:MAILTO="admin@example.com"MAILON="upgrade"Possible MAILON values are always, upgrade (when a package is upgraded), error (when there’s anerror in the run), changes (when the output changes as the result of an action), and output (wheneveroutput is generated). If it’s left empty, mail will never be sent. upgrade is probably the most useful valueand avoids clogging up your inbox.By default, cron-apt will download only the upgraded packages (you then have to install them whenyou get the email notifying you about them). The actions are controlled by the files in /etc/cronapt/action.d.The files in this directory will be used as options to apt-get when cron-apt runs. Two areprovided by default. The first is 0-update, which runs the following:apt-get update -o quiet=2-o will set an option string (there isn’t one given here). The second is 3-download, which runs thefollowing:apt-get upgrade -d -y -o APT::Get::Show-Upgraded=true-d sets this to just download (not install), and -y assumes “yes” to any questions asked. Note that ifsomething really undesirable, such as removing an essential file, is set to happen, apt-get will abort evenif -y is set. -o APT::Get::Show-Upgraded=true sets the APT::Get::Show-Upgraded option, thus giving aprinted-out list of all packages to be upgraded, which is what shows up in your e-mail.154Download at WoweBook.Com
CHAPTER 6 ■ SECURING YOUR SYSTEMS■ Note To automatically run the upgrades, rather than just downloading them, you could remove the -d option inthe 3-download line. This is not recommended because it’s far better to review the changes before they happen,and in most situations, you probably want to run the upgrade on a test box to make sure nothing breaks before youroll it out. Certainly it is a very bad idea to automatically upgrade servers.If you decide to do this, you should remove -y and insert --trivial-only. This will make apt-get use the defaultoption when asked a question, so old config files will be retained rather than overwritten.155Download at WoweBook.Com
Page 2:
Download at WoweBook.Com
Page 5 and 6:
Download at WoweBook.Comiii
Page 7 and 8:
Contents■About the Author .......
Page 9 and 10:
■ CONTENTS3-7. Writing a Nagios P
Page 11 and 12:
■ CONTENTS■Chapter 8: Using the
Page 13 and 14:
■ CONTENTSAbout the Author■Juli
Page 15 and 16:
■ CONTENTSAcknowledgmentsMany tha
Page 17 and 18:
■ CONTENTSIntroductionThis book i
Page 19 and 20:
■ INTRODUCTIONDownloading the Cod
Page 21 and 22:
C H A P T E R 1■ ■ ■Saving Yo
Page 23 and 24:
CHAPTER 1 ■ SAVING YOURSELF EFFOR
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
C H A P T E R 2■ ■ ■Centraliz
Page 43 and 44:
CHAPTER 2 ■ CENTRALIZING YOUR NET
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
C H A P T E R 3■ ■ ■Monitorin
Page 85 and 86:
CHAPTER 3 ■ MONITORING AND UPDATI
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
C H A P T E R 4■ ■ ■Taking Ba
Page 117 and 118:
CHAPTER 4 ■ TAKING BACKUPS AND MA
Page 119 and 120:
Page 121 and 122:
Page 123 and 124: CHAPTER 4 ■ TAKING BACKUPS AND MA
Page 139 and 140: C H A P T E R 5■ ■ ■Working w
Page 141 and 142: CHAPTER 5 ■ WORKING WITH FILESYST
Page 155 and 156: C H A P T E R 6■ ■ ■Securing
Page 157 and 158: CHAPTER 6 ■ SECURING YOUR SYSTEMS
Page 173: CHAPTER 6 ■ SECURING YOUR SYSTEMS
Page 179 and 180: CHAPTER 7 ■ WORKING WITH APACHEOn
Page 181 and 182: CHAPTER 7 ■ WORKING WITH APACHEdi
Page 183 and 184: CHAPTER 7 ■ WORKING WITH APACHE4.
Page 185 and 186: CHAPTER 7 ■ WORKING WITH APACHE
Page 187 and 188: CHAPTER 7 ■ WORKING WITH APACHEAl
Page 189 and 190: CHAPTER 7 ■ WORKING WITH APACHE
Page 191 and 192: C H A P T E R 8■ ■ ■Making Be
Page 193 and 194: CHAPTER 8 ■ USING THE COMMAND LIN
Page 207 and 208: CHAPTER 9 ■ WORKING WITH TEXT IN
Page 223 and 224: C H A P T E R 10■ ■ ■Things G
Page 225 and 226:
CHAPTER 10 ■ THINGS GO IN, THINGS
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
C H A P T E R 11■ ■ ■Tracking
Page 235 and 236:
CHAPTER 11 ■ TRACKING DOWN BUGSTh
Page 237 and 238:
CHAPTER 11 ■ TRACKING DOWN BUGS01
Page 239 and 240:
CHAPTER 11 ■ TRACKING DOWN BUGS
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
CHAPTER 11 ■ TRACKING DOWN BUGSTh
Page 247 and 248:
CHAPTER 11 ■ TRACKING DOWN BUGSAn
Page 249 and 250:
CHAPTER 11 ■ TRACKING DOWN BUGS#
Page 251 and 252:
C H A P T E R 12■ ■ ■Managing
Page 253 and 254:
CHAPTER 12 ■ MANAGING TIME AND PE
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
APPENDIX■ ■ ■Perl TipsSee rec
Page 269 and 270:
APPENDIX ■ PERL TIPS• Date::Par
Page 271 and 272:
APPENDIX ■ PERL TIPSPerl Syntax N
Page 273 and 274:
■ ■ ■Index■Symbols$CDPATH,
Page 275 and 276:
■ INDEXenscript option (printing)
Page 277 and 278:
■ INDEX■NNagiosadding hosts to,
Page 279 and 280:
■ INDEXsyslogcentralized logging
Page 281 and 282:
Download at WoweBook.Com
show all

Linux System Administration Recipes A Problem-Solution Approach

Create successful ePaper yourself

Delete template?

Save as template?