Alex Joh's Blog

From this blog, the redux library will be added to handle REST service. There are so many good tutorial from blogs and Youtube about the Redux, so I am skipping the redux introduction. Reference site Jest Homepage Github Sample Ex3 Currnet version D:\GitRepo\reactnative>npm --version 6.3.0 D:\GitRepo\reactnative>react-native --version react-native-cli: 2.0.1 react-native: n/a - not inside a React Native project directory D:\GitRepo\reactnative>yarn --version 1.9.4 Creating React Native App $ react-native init ex3 If you want to specify the version, add "--version 0.57.3" at the end. Add NativeBase to React Native $ npm install native-base --save ... + native-base@2.8.1 added 71 packages from 42 contributors, removed 50 packages, updated 829 packages and audited 34989 packages in 138.542s found 0 vulnerabilities $ $ yarn yarn install v1.9.4 warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advise

From this series, we will NativeBase library to the program Note. I spent almost one day to return 500 error from 0.57.2 and today I noticed that 0.57.3 is released and this version fixed the "return 500" error. Reference site NativeBase Homepage Github Sample Ex2 Currnet version D:\GitRepo\reactnative>npm --version 6.3.0 D:\GitRepo\reactnative>react-native --version react-native-cli: 2.0.1 react-native: n/a - not inside a React Native project directory D:\GitRepo\reactnative>yarn --version 1.9.4 Creating React Native App $ react-native init ex2 If you want to specify the version, add "--version 0.57.3" at the end. Add NativeBase to React Native $ npm install native-base --save ... + native-base@2.8.1 added 71 packages from 42 contributors, removed 50 packages, updated 829 packages and audited 34989 packages in 138.542s found 0 vulnerabilities $ $ yarn $ $ react-native link rnpm-install info Linking assets to ios project rnpm-install WARN ERR

From this series, we will create simple testing app with Redux and NativeBase which retrieve rest data and display on the screen. Reference site Jest https://jestjs.io/ React-devtools https://github.com/facebook/react-devtools Github Sample Ex1 Currnet version D:\GitRepo\reactnative>npm --version 6.3.0 D:\GitRepo\reactnative>react-native --version react-native-cli: 2.0.1 react-native: n/a - not inside a React Native project directory D:\GitRepo\reactnative>yarn --version 1.9.4 The development server returned response error code: 500 React Native version 0.57.2 has issue with "response error code: 500". Must use 0.57.1. Two ways; Create project with specific version $ react-native init --version 0.57.1 ex1 Update package.json file { "name": "ex1", "version": "0.0.1", "private": true, "scripts": { "start": "node node_modules/react-native/local-cli/cli.js start&qu

Adding DNS using network manager in centos If you change DNS by yourself from /etc/resolv.conf, the configuration will be gone after rebooting the computer. Assuming to run all commands with "root" account. Otherwise, the command should be run with "sudo" in front of each command 1. Find connection # nmcli con NAME    UUID                                  TYPE      DEVICE ens160  4f1de527-4257-467d-8476-c5c6efdf1c74  ethernet  ens160 2. Update DNS entry Format nmcli con mod ipv4.dns dns_servers # nmcli con mod ens160 ipv4.dns "8.8.8.8 8.8.4.4" 3. Restart network # systemctl restart network After update DNS entry, check /etc/resolv.conf file and you will see the new updated record. # cat /etc/resolve.conf

SSH can't connect to remote: "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!" After rebuilding the remote server, ssh can't make connection to remote server with following messages λ ssh -o ServerAliveInterval=60 root@10.202.0.150 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the ECDSA key sent by the remote host is SHA256:cESEZr5cIIDf+uqksrYo+G34m5xm3gu6irysqQbLGN0. Please contact your system administrator. Add correct host key in /c/Users/alex.joh/.ssh/known_hosts to get rid of this message. Offending ECDSA key in /c/Users/alex.joh/.ssh/known_hosts:13 ECDSA host key for 10.202.0.150 has changed and you have requested strict

Docker Container Exited (132) I was building entire Devops environment with ansible automation and suddenly Kong stack didn't start properly.  The problem was that the Dev server was old Dell Server and it doesn't support "sse4_2" feature from CPU. What is SSE Technology? SSE is a processor technology that enables single instruction multiple data. ... SSE is designed to replace MMX™ Technology. It expanded over the generations of Intel® Processors to include SSE2, SSE3/SSE3S, and SSE4. Each iteration has brought new instructions and increased performance. Information from CPUInfo  [root@dockerdv01 ~]# cat /proc/cpuinfo | grep sse4_ flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm ts