Configure location:
location / {
auth_basic "closed site";
auth_basic_user_file htpasswd;
}
Create password file:
yum install httpd-tools</pre>
New file:
htpasswd -c htpasswd-file "username"
New password:
Append user to existing file:
htpasswd htpasswd-file "username"
Current running kernel
uname -an
Show installed kernels:
rpm -q kernel
CentOS 7: Remove old kernels with package-cleanup (yum-utils required)
package-cleanup --oldkernels package-cleanup --oldkernels --count=2
CentOS 8: Remove old kernels with dnf
dnf remove --oldinstallonly
dnf remove --oldinstallonly --setopt installonly_limit=2
Open Terminal / shell:
kmenuedit
In KDE Menu Editor:
* go to System -> Dolphin
* Context Menu -> Advanced -> Current shortcut key
Scenario: Homeserver should send e-mails by your ISP-hosted domain:
Packages:
yum -y install postfix
Edit the following lines in the postfix main config:
/etc/postfix/main.cf
mydomain = "MY-DOMAIN"
myorigin = $myhostname
myorigin = $mydomain
inet_interfaces = all
inet_interfaces = localhost
inet_protocols = ipv4
mydestination = $myhostname- localhost.$mydomain- localhost
mynetworks_style = host
relayhost = <STMP.HOST.ADDRESS>:<PORT>
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = smtpd
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_type = cyrus
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
Helps for system administration with systemd:
Control and manipulate services
systemctl
systemctl enable [servicename]
systemctl stop/start [servicename]
systemctl disable [servicename]
Remove services from systemd
systemctl stop [servicename]
systemctl disable [servicename]
rm /etc/systemd/system/[servicename]
systemctl daemon-reload
systemctl reset-failed
vi /etc/ssh/sshd_config
PermitRootLogin no
To give a user rights on a root privileged command:
vi /etc/sudoers
<USER> ALL = NOPASSWD: /bin/systemctl restart httpd
Now the user could restart the httpd deamon:
sudo systemctl restart httpd
Postfix:
mailq # show queue
postqueue -f # Resend all queued messages
postsuper -d ALL # clear message queue
postcat -q # Show message (-v)
selinux immediately change:
getenforce # show selinux state
setenforce 0 # turn off selinux
telnet <MAILSERVER> 25
HELO <MAILSERVER>
mail from: test-mail@wiki.kissel.ch
rcpt to: receiver@<MAILSERVER>
data
from: test-mail@wiki.kissel.ch
to: receiver@<MAILSERVER>
subject: TestMessage
Hello World!
.
quit
Position of the interface configuration files:
/etc/sysconfig/network-scripts
ip addr
shows the names of available interfaces:
enp0s3: <BROADCAST-MULTICAST-UP-LOWER_UP> mtu 1500 qdisc
pfifo_fast state UP qlen 1000
link/ether 08:00:27:66:c7:99 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.40/24 brd 192.168.0.255 scope global enp0s3
valid_lft forever preferred_lft forever
inet6 fe80::a00:27ff:fe66:c799/64 scope link
valid_lft forever preferred_lft forever
Now the config file ifcfg-enp0s3 can be edited with the static config:
TYPE="Ethernet"
NAME="enp0s3"
ONBOOT="yes"
IPADDR="192.168.0.40"
BOOTPROTO="static"
GATEWAY="192.168.0.1"