Today I installed the nvm tool in my Linux server. When I run the ‘nvm ls-remote’ command, I got the below weird message: #nvm ls-remote N/A Because the Linux server is behind the company firewall, I have setup the environment… Read More
do not display skipping tasks in ansible
Recently one of our developers complained the skipping tasks displayed in the ansible output. She insisted that the skipping tasks names and the skipping keyword should not be displayed, because these stuffs may confuse customers. I agree with her. Without… Read More
token bucket 算法简析
最近在解决一个Linux下DHCP无法获取IPv6地址的问题。在分析过程中发现，把IPv6防火墙停掉的话，用dhclient就可以给网卡获取到IPv6地址，否则就无法获取。初步判断，是IPv6的防火墙的问题。 在查看/var/log/iptables.log时，发现里面的log很少，几乎没有什么有用的log。在查看ip6tables rules时，发现有如下的一条规则用于控制log的输出： -A LOGGING6 -m limit –limit 2/hour -j LOG –log-prefix “IP6TABLES DROP:”
avoid ignored error message in ansible
In ansbile playbook, the below style can be used to check the result of a script or command, and give a meaningful message if the task fails. – name: check stack existance hosts: localhost any_errors_fatal: True tasks: – name: check… Read More
package selection in rhel6 and rhel7 kickstart
Recently our product is migrating from rhel6 to rhel7. During this process, we encountered a wired issue that some rpm packages couldn’t be installed during Linux installation. We are using a customized rhel iso, which is originally downloaded from redhat… Read More
在RHEL7上搭建kubernetes 1.11集群
在RHEL7的虚拟机上搭建一个kubernetes 1.11集群，环境如下 master: 192.168.10.1 node1: 192.168.10.2 node2: 192.168.10.3
setup an externally accessible etcd in kubernetes
As we know, the IP addresses of pods and services in kubernetes are not accessible from the outside of the kubernetes cluster. In order for an application deployed in kubernetes to be reached from the outside of the kuberenetes, different… Read More
a good website about raft
Etcd is a distributed reliable key-value store, which can be used in various scenarios. These days I am trying to setup a single node Etcd cluster in kubernetes for project demo purpose. I am a little curious about how multiple… Read More
nslookup in busybox 1.29 does not work in kubernetes
Recently I was trying to use nslookup in pod initContainers in order to make sure that some services are available during pod startup. However, it didn’t work when I was using nslookup from busybox:1.29. After several tries, the DNS lookup still failed. I… Read More
hello world
This is a hello world web page.