超軟之家: 2019

2019年10月23日星期三

命令

/opt/vc/bin/vcgencmd

CPU溫度

pi@raspberrypi:~ $ /opt/vc/bin/vcgencmd version

Jul 9 2019 14:40:53

Copyright (c) 2012 Broadcom

version 6c3fe3f096a93de3b34252ad98cdccadeb534be2 (clean) (release) (start)

pi@raspberrypi:~ $ uname -a

Linux raspberrypi 4.19.57-v7+ #1244 SMP Thu Jul 4 18:45:25 BST 2019 armv7l GNU/Linux

pi@raspberrypi:~ $ /opt/vc/bin/vcgencmd measure_temp

temp=45.1'C

2019年9月23日星期一

阿班 Bash 常用指令範例

Last Modified Date: 2025-03-28

mkdir

Date: 08-27 v1

建立新目錄

語法

mkdir [-p] <目錄名>

OPTION

無參數: 如果該目錄不存在，才建立它。若該目錄在則顯示目錄已存在錯誤訊息，並且回傳值為1

-p: 如果該目錄不存在，才建立它。若該目錄在則略過，並且回傳值為 0

範例

$ mkdir new_directory
$ mkdir new_directory
mkdir: can't create directory 'new_directory': File exists
$ echo $?
1
$ mkdir -p new_directory
$ echo $?
0

mktemp

Date: 05-14 v1

產生暫存檔案或目錄

語法

mktemp [OPTION] ... [TEMPLATE]

OPTION

-u: --dry-run 不產生任何檔案或目錄，只顯示名稱 (不安全, 僅供測試, 因為有可能重複產生)

範例

$ mktemp -u /you_path/path2/your_prefix.XXXXXXXXXX

/you_path/path2/your_prefix.zjvveu0Ncs

# mktemp /tmp/your_prefix.XXXXXXXXXX
/tmp/your_prefix.5eEu7vU0zi
# ls -la /tmp/your_prefix.5eEu7vU0zi

-rw------- 1 test test 0 May 15 00:06 /tmp/your_prefix.5eEu7vU0zi

read

語法

read [argument1] [argument2] ...

範例

$ bash read_example_01.sh
./type_example_01.sh
./read_example_01.sh
$ find . -type f | while read filename ; do echo "$filename" ; done
./type_example_01.sh
./read_example_01.sh

sed

刪除空白行

語法

sed -e "/^$/d"

範例

bash-5.0# echo -e "te\n\nst" | sed "/^$/d"
te
st

type

語法

type command1 command2 ...

範例

a() { echo 'a'; }
b() {
echo 'b'
}

c()
{
echo 'c'
}

# type is a shell builtin
type a b c

執行結果

$ bash type_example_01.sh
a is a function
a ()
{
echo 'a'
}
b is a function
b ()
{
echo 'b'
}
c is a function
c ()
{
echo 'c'
}

如果 type 配合 grep 指令把 is a function 去掉，則有自動排版函式的效果。

$ bash type_example_01.sh | grep -v "is a function"
a ()
{
echo 'a'
}
b ()
{
echo 'b'
}
c ()
{
echo 'c'
}

xargs

語法

xargs [argument1] [argument2] ...

範例

bash-5.0# find . -type f | xargs wc -l | sed -e "s/^[ \t]*//g"
2 ./b.txt
1 ./c.txt
3 ./a.txt
6 total

2019年9月16日星期一

阿班 Docker 指令備忘範例

啟動 Docker Container

自動啟動 Container

編修日期: 2019-9-23

使用情境

docker machine 重啟後，依設定規則來自動執行對應的 Docker Containers

參考文件

https://docs.docker.com/config/containers/start-containers-automatically/

語法

docker update --restart always container-id [...]

docker update --restart always container-name [...]

範例

docker update --restart always my-testapp my-testapp2

2019年6月29日星期六

Bash Tip - Why .bashrc (dot bashrc) not loaded after new user created?

Recently, I reinstalled ubuntu 16.04LTS on my desktop as a Linux server.

After a new user created, ssh into the server each time, but .bashrc (dot bashrc) not loaded after new user created? Please try to modify the profile as bellow.

Append some commands into ~/.profile

result of test-cases.sh example

~$ source .profile
load /home/ben/.bashrc by ~/.profile
.bashrc has been executed once

Appendix

2019年5月13日星期一

開源 RISC OS Pi 系統 - 初探

1987 開始發展的RISC OS, 終於在2018年10月以Apache 2.0 License 開源，允許商業使用。

近來忙裡偷閒，用樹梅派最新版本 Raspberry Pi 3 Model B+ 安裝了RISC OS PI ，號稱是ARM 架構下快速也易於客制化的作業系統 (A fast and easily customized operating system for ARM devices)。

初步試用, 它的視窗環境用起來執行程式反應很快（相比Raspbian based X-Window 來說)。

並試了一些常用工具都有替代的APP可以使用
Ex:

Nettle(ssh/telnet client)
LanMan (Samba client)
NetSurf (Browser) ...

不過還需要更多開源高手投入時間進一步改善。

安裝方式是以ＮOOBS來安裝 RISC OS PI

https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up/3

小結

待機耗電量約在 2.93W (4.89V, 0.6A）運行較吃ＣＰＵ資源大約升高到 3.9W (4.89V, 0.8A)，以一個迷你作業系統而言，還算省電。有興趣的朋友可以裝起來試玩看看。

參考資料

Link: RISC OS Star Commands

STICKY: New to RISC OS? Read this

Wikipedia RISC_OS

Link: RISC OS is open for business!

2019年5月9日星期四

DevOps Tip - Got error - not found aws-iam-authenticator for kubectl using?

Problem

I've got error to run kubectl command with aws-iam-authenticator not found

(venv) ➜ k8s git:(develop) ✗ kubectl get pod
Unable to connect to the server: getting credentials: exec: exec: "aws-iam-authenticator": executable file not found in $PATH

Solutions

Installation tool on OSX Mojave

brew install aws-iam-authenticator

Example of installation

 (venv) ➜  k8s git:(develop) ✗ brew install aws-iam-authenticator
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 3 taps (homebrew/core, homebrew/cask and caskroom/cask).
==> New Formulae
..
==> Downloading https://homebrew.bintray.com/bottles/

aws-iam-authenticator-0.4.0.mojave.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/52...
######################################################################## 100.0%
==> Pouring aws-iam-authenticator-0.4.0.mojave.bottle.tar.gz
🍺  /usr/local/Cellar/aws-iam-authenticator/0.4.0: 5 files, 31.1MB

References

Amazon EKS Guide - Installing aws-iam-authenticator

Extended Reading

2019年4月11日星期四

Python Tip - Examples of initialize variables with sequence number in different ways

Purpose

It is used to collect sample code for python's coding tips of initialization variables.

A. Variables with constants

test_init_vars.py

#!/usr/bin/env python

a=0
b=1
c=2
d=3
e=4
f=5
print(a, b, c, d, e, f)

B. Use range()

test_init_vars_by_range.py

#!/usr/bin/env python

a, b, c, d, e, f = range(6)

print(a, b, c, d, e, f)

C. Use enum since python 3.4 supported

test_init_vars_by_enum.py

#!/usr/bin/env python3.6

from enum import IntEnum,auto

class Vars(IntEnum):
a=0
b=auto()
c=auto()
d=auto()
e=auto()
f=auto()

print("{}, {}, {}, {}, {}, {}".format(Vars.a, Vars.b, Vars.c, Vars.d, Vars.e, Vars.f))

Result

$ python2.7 test_init_vars.py
(0, 1, 2, 3, 4, 5)
$ python3.6 test_init_vars.py
0 1 2 3 4 5

$ python2.7 test_init_vars_by_range.py
(0, 1, 2, 3, 4, 5)
$ python3.6 test_init_vars_by_range.py
0 1 2 3 4 5

$ python2.7 test_init_vars_by_enum.py
Traceback (most recent call last):
File "test_init_vars_by_enum.py", line 3, in
from enum import IntEnum,auto
ImportError: cannot import name auto

$ python3.6 test_init_vars_by_enum.py
0, 1, 2, 3, 4, 5

References

2019年3月21日星期四

在執行期取得目前Makefile腳本檔所在的目錄 Absolute Path of current Makefile 含測試結果

範例程式取得Makefile所在絕對路徑 (Absolute Path of current Makefile)

test results on linux

參考

- https://www.systutorials.com/241620/how-to-get-the-full-path-and-directory-of-a-makefile-itself/

2019年3月14日星期四

Bash Tip - Run Command with multiple arguments with ssh

This is a note for logging my simple way to use ssh and bash with continuous integration on remote server.

You can execute the following test-cases.sh on your host.

It will execute remote script of the test with correct argument contents.

source code of test-cases.sh on host

directory layout of tester account on test-server

source code of tests.sh on test-server

result of test-cases.sh example

source ./test-cases.sh

➜ ~ run_cases "\"1\"\"" "b'\"" "c'#\"" "\"\"" "\'"

ssh test-server cd test-cases; /bin/bash ./tests.sh "\"1\"\"" "b\'\"" "c\'\#\"" "\"\"" "\\'"

argv[1]=["1""]

argv[2]=[b\'"]

argv[3]=[c\'\#"]

argv[4]=[""]

argv[5]=[\\']

Notes

printf %q is use to make safe quote the argument if hashtag(#), quote('), double quote(") and so on.

Appendix

2019年2月22日星期五

Bash Tip - Use bash to implement like C's argc and argv

Test bash script capacity

I want to show how to write the advanced bash script with shift and array.
Feature:

filter the arguments with '-' leading character as options
the following inputs are the data arguments

Tested environments: - bash 4.3.48 x86_64-pc-linux-gnu ubuntu-16.04.4 LTS

2019年1月30日星期三

DevOps Tip - How to use terraform apply without prompt and input yes for CI/CD?

Problem

Took a memo about integration of CI/CD applied by terraform without prompt to input 'yes'
It is annoying to input yes every time if you already make sure already by `terraform plan`.
On the other hand, I need to integrate with different system for CI/CD. I need a way to approve it automatically.
By tests with commands official documents, I found the correct command and arguments.

Tested Solutions

terraform apply -input=false -auto-approve

or as my test, you can shorten to the following command

terraform apply -auto-approve

Test Environments

Ubuntu 16.04.04 LTS
OSX 10.14

Reference:

https://learn.hashicorp.com/terraform/development/running-terraform-in-automation

Extended Reading

DevOps Tip - How to use shared terraform plugins by -plugin-dir argument?

2019年1月29日星期二

DevOps Tip - How to use shared terraform plugins by -plugin-dir argument?

Problem

If you executed `terraform init`, you may already have the .terraform in your folder.

Because you may have many terraform repo similar to another, you can use the -plugin-dir to reduce the usage of disk space.

As a shared plugins so that we don’t need many copies of plugins into different locations.

Example

Here I used my OSX Macbook as a Demo Environment.

====================
cd /build/setupdev/

sudo mkdir -p /opt/terraform/terraform.d

mv .terraform/plugins to /opt/terraform/terraform.d/plugins

Please run the following command to apply it.

====================

terraform init -input=false \
-plugin-dir=/opt/terraform/terraform.d/plugins/darwin_amd64

Tree of .terraform

Tree of terraform plugins

Reference

https://learn.hashicorp.com/terraform/development/running-terraform-in-automation

Extended Reading

DevOps Tip - How to use terraform apply without prompt and input yes for CI/CD?

訂閱：文章 (Atom)

2019年10月23日 星期三

命令

CPU溫度

2019年9月23日 星期一

語法

OPTION

範例

語法

範例

read

語法

範例

sed

語法

範例

bash-5.0# echo -e "te\n\nst" | sed "/^$/d"test

type

語法

範例

執行結果

xargs

語法

範例

2019年9月16日 星期一

啟動 Docker Container

自動啟動 Container

使用情境

參考文件

語法

範例

2019年6月29日 星期六

Append some commands into ~/.profile

result of test-cases.sh example

Appendix

2019年5月13日 星期一

小結

參考資料

延伸閱讀

2019年5月9日 星期四

Problem

Solutions

Installation tool on OSX Mojave

Example of installation

References

Extended Reading

2019年4月11日 星期四

Purpose

A. Variables with constants

#!/usr/bin/env python a=0 b=1 c=2 d=3 e=4 f=5 print(a, b, c, d, e, f)

B. Use range()

C. Use enum since python 3.4 supported

Result

References

2019年3月21日 星期四

範例程式取得Makefile所在絕對路徑 (Absolute Path of current Makefile)

test results on linux

參考

2019年3月14日 星期四

source code of test-cases.sh on host

directory layout of tester account on test-server

source code of tests.sh on test-server

result of test-cases.sh example

Notes

Appendix

2019年2月22日 星期五

2019年1月30日 星期三

Problem

Tested Solutions

Test Environments

Reference:

Extended Reading

2019年1月29日 星期二

Problem

Example

Tree of .terraform

Tree of terraform plugins

Reference

Extended Reading

BloggerAds的廣告

2019年10月23日星期三

2019年9月23日星期一

bash-5.0# echo -e "te\n\nst" | sed "/^$/d"
te
st

2019年9月16日星期一

2019年6月29日星期六

2019年5月13日星期一

2019年5月9日星期四

2019年4月11日星期四

#!/usr/bin/env python

a=0
b=1
c=2
d=3
e=4
f=5
print(a, b, c, d, e, f)

2019年3月21日星期四

2019年3月14日星期四

2019年2月22日星期五

2019年1月30日星期三

2019年1月29日星期二