yin_bill_wang-优快云博客

原创 [k8s] kubectl返回certificate has expired or is not yet valid错误

前两天在k8s master上执行kubectl get pod时，返回x509 certificate has expired or is not yet valid错误。原因使用kubeadm安装k8s时，默认生成的client certificate的有效期是1年。可以使用kubeadm certs check-expiration或kubeadm alpha certs check-expiration(较早的kubeadm版本中，该命令还是在alpha阶段)查看当前证书的信息。后续命令为了

2021-08-12 14:58:07 4843 1

原创 [containerd] 配置containerd使用proxy来pull image

最近在捣鼓k8s v1.20，使用containerd作为container runtime，但是在执行kubeadm config images pull的时候报错。因为在公司环境下，需要配置代理。mkdir /etc/systemd/system/containerd.service.dcat > /etc/systemd/system/containerd.service.d/http_proxy.conf << EOF> [Service]> Environ

2021-01-27 16:49:36 10203 1

原创 [Linux]SSH hangs at 'debug1: SSH2_MSG_KEXINIT sent'

最近我在尝试从一台linux服务器SSH登录到另一台服务器时发现链接错误。通过加入-vvv参数后，发现卡在debug1: SSH2_MSG_KEXINIT sent通过搜索，发现可能是网络接口MTU设置的问题。我尝试在/etc/sysconfig/network-scripts/ifcfg-eth0中添加MTU=1500，在重启网络服务后，发现并没有生效。由于我是通过DHCP获取IP地址的，那么...

2018-11-29 10:56:13 3426

原创 [Docker] docker run -p shows iptables fail on CentOS 7

I was playing around with Sentry, and when I tried to run it with docker run \ --detach \ --link sentry-redis:redis \ --link sentry-postgres:postgres \ --env SENTRY_SECRET_KEY=123456 \ -...

2018-06-07 12:28:59 413

原创 [Python] Paramiko 初探

Paramiko• Paramiko是对ssh2协议的实现，不仅仅提供远程shell的安全接入功能，还可以为其他远程服务建立安全的隧道（SFTP） • 自身完全由python实现，但是依赖于第三方的C wrapper提供底层的加密功能当我们使用paramiko作为client与服务器进行连接时，有以下步骤： 1. 定义Transport 连接的远端socket 2. 协商...

2018-05-17 13:47:13 1546

原创 [Python] python-ldap installation and usage notes

Installationpython-ldap installation is very simple. On CentOS 7, you just need to# install openldap-develyum install openldap-devel# then install python-ldap via pippip install python-ldapUsageTo us

2017-07-12 12:16:41 844

原创 [Python]Attempted relative import in non-package

Python relative import is a topic that bugs me for a long time. Today, I came across these two articles which helps me to understand the topic better.

2017-06-07 13:43:47 2555

原创 [PhantomJS] Https Redirect Problem with PhantomJS + Selenium

A few days ago, I was writing a python script with PhantomJS and Selenium. The problem is that the redirection doesn’t work properly.ProblemFor example,driver.get("https://redirect-to-login.example.com

2017-06-07 12:37:45 1603

原创 [RabbitMQ] beam.smp high cpu load

A customer reported a function is not working in our django app. That app runs using celery and RabbitMQ. I found out that the celery worker cannot receive tasks from RabbitMQ. Then I checked my Rabbit

2016-10-10 14:24:26 13290

原创 [HAPrxoy]First thing to check when using HAProxy

Recently, I’ve encountered a few connection lost/timeout issues in my project. All of them are caused by wrong timeout server and timemout client value in HAProxy. Just a reminder to myself, “Be sure t

2016-08-15 13:46:33 520

原创 [Linux]NetworkManager and the nmcli command return a 'symbol lookup error' in RHEL 7

Recently, I ran into a problem when starting NetworkManager service in CentOS 7. I checked the /var/log/message and it contains the following linessystemd: Starting Network Manager...NetworkManager:

2016-08-02 15:19:52 2282

原创 [Django] use django modules in standalone python script

This post only serves as a reminder of how to use django modules, such as django.template in a standalone python script.Here is the link from official site.

2016-07-15 16:14:14 584

原创 [Jenkins] Use python requests to programatically get and set Jenkins job configuration

Jenkins provided a very nice REST api to interact. In Python, we can use requests package. For simplicity, we are going to use password based authentication. For details on requests package, please see

2016-07-11 09:41:04 887

原创 [Jenkins] Upgrade to 2.7 causes connection refused problem

Today, I upgraded my jenkins server from 1.6 to 2.7, then I visited the http://jenkins:8080. I gave me “connection refused” error.I checked the /var/log/jenkins/jenkins.log, it has:SEVERE: Container st

2016-07-08 14:50:31 1773

原创 [Linux] NFSv4 and Autofs caveats

Recently, I was doing some server setup works which involves NFS and Autofs. Of course, I ran into several problems. So I’d like to document it just in case.Problem 1. Unable to mount exported shares v

2016-06-27 18:01:24 720

原创 [RabbitMQ] RabbitMQ Cluster ConnectionClose Error with HAProxy

I setup the rabbitmq clustering according to the official doc and queue mirroring according to this article. Then I configure a HAProxy in front of the rabbitmq cluster.ProblemMy own script using pika

2016-03-28 13:56:34 1440

原创 [Linux] Install keepalived on CentOS

InstallingAlthough installing keepalived through yum is quite convenient, the package is often out-of-date.So it is recommended to install it from source code. To do so, you can follow the instructions

2016-03-23 16:23:05 752

原创 [Linux]Run cron job under system account

When configuring cron job for system account, there are a few points to pay attention to:Since system account usually does not have home directory, and cron will attempt to chdir to the home directory

2016-02-02 12:54:28 964

原创 [Nginx, Django]Securing connections with SSL

Reference: Django by Example Chapter 13Create directory under /etc/nginx, and cd to that directorymkdir /etc/nginx/sslcd /etc/nginx/sslCreating a SSL certificateopenssl req -x509 -nodes -days 365 -ne

2016-01-25 15:58:28 655

原创 [MariaDB] Setup MariaDB Galera Cluster with HAProxy

Working in ProgressSetup MariaDB Galera ClusterThe setup for Galera Cluster is reasonably easy if you follow the instructions in this article.!!!IMPORTANT!!!Initializing cluster On setups on CentOS 7

2016-01-07 11:12:42 2488

原创 [Docker] Error when starting docker in CentOS 7

On CentOS7, I installed docker using script, and manually added docker.service and docker.socket into /etc/systemd/system, I get the error when using systemctl start docker/usr/bin/docker: relocation e

2016-01-06 15:02:58 3237

原创 [djangocms] Integrate djangocms with existing projects

This instruction assumes you are using CentOS 7 and MariaDB. The Official instruction is good and clear, but I prefer to do it in a different order and point out something you should pay attention to.

2015-12-30 13:54:19 1209

原创 [Piwik] Installing piwik for website analysis

The official installation guide provides very clear instructions, the following points do require your attention though.Make sure your system setup meets the minimum requirements.Change the ownership

2015-12-30 13:00:37 786

原创 [Docker] How to setup private registry

Docker private registry

2015-12-14 14:20:01 845

原创 [Linux] Enable ssh key authentication from one user on client to multiple users on server

Linux ssh config

2015-11-24 22:22:45 681

原创 [Atom] Cannot install package behind a proxy on Win7

I’m using Atom behind a proxy on Win7. Every time I try to install new packages, it fails. So I googled around and found these two articles. 1. Setup Atom behind proxy 2. Unable to install packages b

2015-11-11 09:59:16 1293

原创 [Celery]Run celery as daemon

This HOWTO is based on instructions provided at celeryd systemd configure and celery in daemonIn my previous HOWTO, we’ve configured celery and are able to run it using celery -A proj worker -l info ma

2015-09-11 16:47:13 1332

原创 HOWTO django + celery + rabbitmq simple setup for testing purpose

This setup is simply used for testing purpose and using the official First Steps with Celery and First Steps with Django as reference.InstallationStep1. Install EPEL repositoryUsing yum search epel to

2015-08-14 22:32:08 1180

原创 [Wireshark]Sniffing with Wireshark(or tshark) as a Non-Root User on CentOS

This HOWTO is referencing the article written by StretchFilesystem Capabilities What are filesystem capabilities? From the man page: The manual goes on to list over two dozen distinct POSIX capabi

2015-07-24 10:40:44 1019

原创 HOWTO - Install Nginx + uWSGI + Django

The basics are almost identical with the uWSGI official document. Here I would like to note a few important points when setting up Nginx + uWSGI + Django on CentOS 7.ConceptA web server faces the outsi

2015-07-21 12:23:32 1640

原创 [Linux]TigerVNC failed on start

Symptom: After a power outage, my CentOS 7 server restarts. When using systemctl start vncserver@.service, error occursHOWTO fix it: - issue journctl -xn, and look for some clue. In my case, there is

2015-07-20 21:36:06 822

原创 [Python]Decorators

Decorators are very hard to understand at the beginning. There is an article about decorators, which helps me establishing a basic understanding about how decorators work in Python. http://simeonfrank

2015-07-18 17:14:31 616

原创 [Django]Solve "No module named _sqlite3" when deploying django in CentOS

Problem occurs under the following setup: - CentOS 7 - Python 2.7.10 - Django 1.8.2When using python manage.py runserver in terminal or entering import sqlite3 in the interpreter shell, the followin

2015-07-17 22:06:16 1230

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