Linux:Services
From Cheatsheet
named
Checks
# Perform a test load of all primary zones within named.conf, as the named user sudo -u named named-checkconf -z # Check zone file 192.168.77.0 defined in the 77.168.192.in-addr.arpa zone named-checkzone 77.168.192.in-addr.arpa 192.168.77.0 # Check zone file brammerloo.nl defined in the brammerloo.nl zone named-checkzone brammerloo.nl brammerloo.nl
Configuration
Basic configuration for the options field in /etc/named.conf
options {
# Define on what IP to listen on, for port 53
listen-on port 53 { 127.0.0.1; 192.168.0.1; 192.168.1.1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
secroots-file "/var/named/data/named.secroots";
recursing-file "/var/named/data/named.recursing";
# Only allow DNS queries from specific local subnets
# To allow from anything use: allow query { any; };
allow-query { localhost; 127.0.0.1; 192.168.0.0/24; 192.168.1.0/24; };
# If the server can't resolve an address locally, use the following DNS servers for help
forwarders {
8.8.8.8;
1.1.1.1;
};
recursion yes;
dnssec-validation no;
managed-keys-directory "/var/named/dynamic";
geoip-directory "/usr/share/GeoIP";
pid-file "/run/named/named.pid";
session-keyfile "/run/named/session.key";
/* https://fedoraproject.org/wiki/Changes/CryptoPolicy */
include "/etc/crypto-policies/back-ends/bind.config";
};
Zone defnitions: named.rfc1912.zones
# Define zones to listen for
zone "brammerloo.nl" IN {
type master;
file "brammerloo.nl";
allow-update { none; };
};
zone "1.168.192.in-addr.arpa" IN {
type master;
file "192.168.1.0";
allow-update { none; };
};
Zone file for Reverse lookup: /var/named/192.168.1.0
$TTL 300
@ IN SOA ns1.brammerloo.nl. admin.brammerloo.nl. (
2023101102 ; serial
180 ; refresh
60 ; retry
108000 ; expire
60 ) ; minimum
IN NS ns1.brammerloo.nl.
; PTR Records
11 IN PTR node1.
21 IN PTR server1.
Zone file for domain: /var/named/brammerloo.nl
$TTL 300
@ IN SOA ns1.brammerloo.nl. admin.brammerloo.nl. (
2023101306 ; serial
180 ; refresh
60 ; retry
108000 ; expire
60 ) ; minimum
IN NS ns1.brammerloo.nl.
@ IN A 192.168.1.6 ; domain brammerloo.nl is me!
ns1.brammerloo.nl. IN A 192.168.78.31 ; FQDN for my domain
node1 IN A 192.168.78.31 ; Basic A-record
www IN CNAME node1 ; Point my website to my node1 A-record
dhcpd
dhclient
# Request an IPv4 adres from a DHCP server dhclient -4 # Show verbose information when requesting an IPv4 adres from a DHCP server dhclient -4 -v
Configuration
Basic configuration options in the /etc/dhcp/dhcpd.conf file
# Set the domain clients should use when resolving hostnames (equivalent to search domain)
option domain-name "brammerloo.nl";
# Set the domain name servers for DHCP clients
option domain-name-servers ns1.brammerloo.nl, 8.8.8.8;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
# Best practice = define any connected subnets, but don't configure DHCP for them
subnet 192.168.1.0 netmask 255.255.255.0 {
}
# Basic DHCP for a subnet configuration
subnet 192.168.0.0 netmask 255.255.255.0 {
range 192.168.0.100 192.168.0.150;
option routers 192.168.0.1;
}
Docker
Checks
# List Docker containers docker ps # List all Docker container IDs docker ps -aq # List logs for container 987sdh3qrasdhj docker logs 987sdh3qrasdhj # List RAM/CPU usage for Docker container asdlkasd67k docker stats asdlkasd67k # Show verbose container information such as commands run, network, ID, etc docker inspect oiu2398sda87
Commands
# Enter the shell inside a docker container
docker exec -ti a89sd98sa7d /bin/bash
# Execute a command inside a container as a specific user, root in this case
docker exec -it -u root asd87289hasdadz tail /var/log/nginx/access.log
docker exec -u 0 -it as892asnj2as /bin/bash
# Restart docker container yoga
docker restart yoga
# Restart the 3 given containers
docker restart 79f71c7f4d91 bbb3d3f5c3b1 b0a3204d4098
# Start this container
docker start as9823nzxc0
# Stop this container
docker stop as9823nzxc0
# Restart all unhealthy Docker containers
for i in $(docker ps | grep unhealthy | awk '{print $1}'); do docker restart "$i"; done;
PowerDNS
- https://doc.powerdns.com/authoritative/index.html
- https://doc.powerdns.com/authoritative/manpages/pdns_server.1.html
- https://doc.powerdns.com/authoritative/manpages/pdnsutil.1.html
Checks
# List commands pdns_server --help # Check config and parse for errors pdns_server --config=check
# List available commands pdnsutil --help # Check config and parse for errors pdnsutil --config=check # List all available zones pdnsutil list-all-zones # List all domains in the primary zone pdnsutil list-all-zones primary # See zone information for a specific domain pdnsutil show-zone mydomain.com pdnsutil show-zone 77.5.10.in-addr.arpa # Check zone for errors pdnsutil check-zone mydomain.com # List all created TSIG keys pdnsutil list-tsig-keys
Commands
# Activate TSIG key for domain "myexample.com" in the primary zone pdnsutil " myexample.com transfer primary
MAAS
Checks
Logs in either place: /var/log/maas/ /var/snap/maas/common/log
# List status of MAAS services maas status # List MAAS commands maas --help # List available arguments for the init command maas init --help
