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Daily Admin Issue

Centos 6 to 7 Upgrade

I've followed https://wiki.centos.org/TipsAndTricks/CentOSUpgradeTool without issue.
But after reboot i've started seeing following error “libpcre.so.0” not found.

After looking further it appeared to the issue with “grep” package. After Successful reboot simply downgrade the grep package and error will disappear.

Also it is good idea to place selinux in permissive mode before you start upgrade.

Drupal Throw watchdog error

This error appear if variable name maxlength is exceeded.

To fix the error create/change value as suggested. (name varchar(48))

--
-- Table structure for table 'variable'
--
 
CREATE TABLE variable (
  name VARCHAR(48) NOT NULL DEFAULT '',
  VALUE longtext NOT NULL,
  PRIMARY KEY (name)
)

Locale Issue on Linux

Following error get generated on “perl -v”

perl: warning: Please check that your locale settings:
        LANGUAGE = (unset),
        LC_ALL = (unset),

In order to set locale you need to update following variable.

| /etc/sysconfig/i18n
LANG="en_US.UTF-8"

That should do it.

Reset Zencart Password

Go to phpmyadmin - select Table “admin” from zencart database.
Select Edit for admin user and add following string in admin_pass field.

351683ea4e19efe34874b501fdbf9792:9b

Now you should be login as admin / admin.

Reset WordPress Password

Go to phpmyadmin - select table “wp-users” from wordpress database.
Select Edit for admin user and replace values with following string in user_pass field.

21232f297a57a5a743894a0e4a801fc3

Now you should be login as admin / admin.

SE Linux

Since most linux started providing SELinux there is many issue fixed by turning it off.
Eventually it has been introduced for really good reason. lets try to use it.

Issue with Zend Optimizer

After Default setup - Zend optimizer does not work on apache while php-cli working fine. There is few command need to be executed in order to make it work. - Add ZendOptimizer in Shared Context user.

#Enable Shared Context
chcon -t texrel_shlib_t /usr/lib64/php/modules/ZendOptimizer.so
 
#allow execstack and execmem for Zend´s binaries
execstack -c /usr/lib64/php/modules/ZendOptimizer.so

Reset Full Context

 genhomedircon
 touch /.autorelabel
 reboot 

Reset context on Specific Folder

  restorecon -Rv /var/www/html

Building Module from Type Enforcement

checkmodule -M -m -o mysql.mod mysql.te
semodule_package -o mysql.pp -m mysql.mod
semodule -i mysql.pp 

Web Application can not connect to db

This behavior can not get logged in audit.log some time.
which make it harder to troubleshoot. you can manually enabled network connection for db on http context.

<note> -P option is to make permanent change </note>

setsebool -P httpd_can_network_connect_db on

Telnet IMAP Test

To login to imap using telnet

telnet <server> 143
01 LOGIN <username> <password>
02 LIST "" *
03 SELECT <mailbox>

You can see information about mailbox :

04 STATUS <mailbox> (<status_code>)

Following status code available :

MESSAGES
UNSEEN
RECENT
UIDNEXT
UIDVALIDITY

You can use “FETCH” command to view message.
Read following for any further information related to telnet / IMAP.

- Telnet imap
- In depth

Internet Proxy Using SSH

This is simple step to use internet from another computer / location.

ssh -N -f -D 8822 <username>@<Remote_server>

Now setup all your browser to use proxy socks5 port 8822.
You are all set.

Allow Other computer

In order to allow other computer on network to access your proxy use following command.

<note warning>This is Open Proxy please use proper firewall rule to allow access.</note>

ssh -N -f -D 0.0.0.0:9933 k2patel@vedi.k2patel.in

Now setup other computer's browser to proxy socks5 host <your IP> port <9933>.
That should do it

Download java using wget

wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u51-b16/jdk-8u51-linux-i586.rpm

Force chronyc time sync

chronyc -a 'burst 4/4'
chronyc -a makestep
daily_admin_issues.txt · Last modified: 2017/07/12 17:15 by k2patel