Category: linux

Jenkins pipeline using secret credentials and password


pipeline
{
    agent { label 'master' }
    stages
    {
        
        stage('check_credentials')
        {
            steps
            {
            
              withCredentials([usernamePassword(credentialsId: 'c1', usernameVariable: 'uname', passwordVariable: 'upass' )]) 
              {
                sh '''
                   echo "usernamePassword = $uname $upass" > test.txt
                '''
              }
               
              withCredentials([usernameColonPassword(credentialsId: 'c1', variable: 'uname')]) 
               {
                sh '''
                  echo "usernameColonPassword = $uname" >> test.txt
                '''
              }
              withCredentials([string(credentialsId: 't1', variable: 'TOKEN')]) 
              {
                sh '''
                  echo "string = $TOKEN" >> test.txt
                '''
              }
              sh 'cat test.txt'
            }
        }
        
        
    }
}

simple custom fields in logstash – ELK

sample log :

abc-xyz 123
abc-xyz 123
abc-xyz 123

Sending logs to sample log ELK server:

echo -n "abc-xyz 123" >/dev/tcp/ELK_SERVER_IP/2001

custom1.conf

input {
    tcp
    {
        port => 2001
        type => "syslog"
    }
}

filter {
  grok {
    match => {"message" => "%{WORD:word1}-%{WORD:word2} %{NUMBER:number1}"}
  }

 #add tag
  mutate {
    add_tag => { "word1" => "%{word1}" }
  }

#add custom field
  mutate {
    add_field => { "logstype=" => "sample" }
  }
}

output {

    if [type] == "syslog" {
    elasticsearch {
        hosts => ["localhost:9200"]
        index => "custom1-%{+YYYY.MM.dd}"
    }
#for debug
#stdout {codec => rubydebug} 
    }

}

Run logstash to collect the logs

logstash -f custom1.conf

NOTE:
– if number1 was already indexed as string then you have to delete the old index
– if use add_field again with same name after grok it will show double value

LXC and LXD linux container

What’s LXC?
– API to communicate with with LXD(Linux container)

What’s LXD?
– It’s like VM for Linux containers

  • Install lxc and dependency
yum -y install epel-release

yum -y install libvirt lxc lxc-templates libcap-devel libcgroup busybox wget bridge-utils lxc-extra

systemctl start libvirtd
systemctl enable libvirtd
  • Check everything is working?
[root@lxc01~]# lxc-checkconfig
Kernel configuration not found at /proc/config.gz; searching...
Kernel configuration found at /boot/config-3.10.0-862.el7.x86_64
--- Namespaces ---
Namespaces: enabled
Utsname namespace: enabled
Ipc namespace: enabled
Pid namespace: enabled
User namespace: enabled
newuidmap is not installed
newgidmap is not installed
Network namespace: enabled
Multiple /dev/pts instances: enabled

--- Control groups ---
Cgroup: enabled
Cgroup clone_children flag: enabled
Cgroup device: enabled
Cgroup sched: enabled
Cgroup cpu account: enabled
Cgroup memory controller: enabled
Cgroup cpuset: enabled

--- Misc ---
Veth pair device: enabled
Macvlan: enabled
Vlan: enabled
Bridges: enabled
Advanced netfilter: enabled
CONFIG_NF_NAT_IPV4: enabled
CONFIG_NF_NAT_IPV6: enabled
CONFIG_IP_NF_TARGET_MASQUERADE: enabled
CONFIG_IP6_NF_TARGET_MASQUERADE: enabled
CONFIG_NETFILTER_XT_TARGET_CHECKSUM: enabled

--- Checkpoint/Restore ---
checkpoint restore: enabled
CONFIG_FHANDLE: enabled
CONFIG_EVENTFD: enabled
CONFIG_EPOLL: enabled
CONFIG_UNIX_DIAG: enabled
CONFIG_INET_DIAG: enabled
CONFIG_PACKET_DIAG: enabled
CONFIG_NETLINK_DIAG: enabled
File capabilities: enabled

Note : Before booting a new kernel, you can check its configuration
usage : CONFIG=/path/to/config /usr/bin/lxc-checkconfig
  • Create container with centos template
lxc-create -n centos7container -t centos

It will pull the centos container image from the internet and will use the centos template from /usr/share/lxc/templates/

  • Start the lxd container
lxc-start -n centos7container -d
  • List container and running 
[root@lxc01 ~]# lxc-ls
centos7container

[root@lxc01  ~]# lxc-ls --active
centos7container
  • Attach to running container
lxc-attach -n centos7container
  • Stop and delete lxc container
lxc-stop -n centos7container
lxc-destroy -n centos7container