COWMAN-CHIANG

[Python] Produces a circular image of 001-100

Posted on 2024 年 08 月 07 日 by cowman.chiang

import matplotlib.pyplot as plt
import numpy as np

def draw_circle_with_number(number, filename):
    fig, ax = plt.subplots(figsize=(5, 5))
    ax.set_xlim(0, 1)
    ax.set_ylim(0, 1)

    # draw circular
    circle = plt.Circle((0.5, 0.5), 0.4, color='blue', fill=False, linewidth=4)
    ax.add_artist(circle)

    # add text
    ax.text(0.5, 0.5, f'{number:03}', color='black', fontsize=90,
            ha='center', va='center', weight='bold')

    # hide axis
    ax.set_xticks([])
    ax.set_yticks([])
    ax.set_aspect('equal')

    # save to file
    plt.savefig(filename, bbox_inches='tight', pad_inches=0)
    plt.close()

# ceate 001 ~ 100
for i in range(1, 101):
    draw_circle_with_number(i, f'circle_{i:03}.png')

Posted in Python | Comments Off

[Postman] Upload file to s3 in pre-request script

Posted on 2024 年 08 月 07 日 by cowman.chiang

First, select binary in the body settings, and assign a file at will.
Then the real file path will be obtained through the syntax in pre-script.

In some cases, you may need to set the file directory to Postman’s working directory first.

pm.request.body.update({
    mode: "file",
    file: {
        src: pm.environment.get("filePath")
    }
})

Posted in Postman | Comments Off

CSS: Center text (horizontally and vertically)

Posted on 2024 年 01 月 29 日 by cowman.chiang





    
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Ref.: iThome: 29. CSS 水平置中/ 垂直置中的方法

Posted in CSS, HTML | Comments Off

Mac OS X upgrade cURL with SSL support

Posted on 2023 年 11 月 16 日 by cowman.chiang

┌─Cowman@CLOUD-42:~/Downloads/20160511 └──$ sh curl.sh guList curl: (1) Protocol “‘https” not supported or disabled in libcurl

┌─Cowman@CLOUD-42:~/Downloads/20160511 └──$ brew install curl –with-nghttp2 ==> Installing dependencies for curl: openssl, pkg-config, libev, libevent, jansson, boost, libxml2, spdylay, nghttp2

….

Posted in Mac | Leave a comment

Delete snapshots older than 7 days

Posted on 2023 年 11 月 16 日 by cowman.chiang

To avoid running out of disk space in our test environment, we developed a plan to regularly execute shell scripts to clean up unnecessary snapshots.

#!/bin/bash

week=`date --date='7 days ago' +'%Y%m%d'`
echo "list_snapshots" | /home/webuser/hbase-1.2.9/bin/hbase shell | grep "pattern " | \
while read CMD; do
    filename=($CMD)
#    echo $filename
    date=`echo $filename | awk -F "_" '{print $2}'`
#    echo  "${filename#*_}"
#    echo $date
#    echo ${date:0:8}
    if [ "${date:0:8}" -lt $week ]
    then
        echo "delete_snapshot '$filename'" | /home/webuser/hbase-1.2.9/bin/hbase shell
    fi
done

Posted in HBase, Shell Script | Comments Off

Continuously print the file content

Posted on 2023 年 10 月 25 日 by cowman.chiang

Use the command ‘tail’ to print the file contents, starting from the beginning of the file and print new contents continuously.

tail +1f 'file'

Posted in Linux | Comments Off

HBase Client 2.5.5 in JDK 11

Posted on 2023 年 10 月 02 日 by cowman.chiang

Because of the vulnerability scan results of the project, the JDK version must be upgraded from 8 to 11 to complete the repair.

The original HBase Client version 1.2 we used was incompatible with JDK 11, so we had to update the HBase Client version.
After collecting and comparing information on the Internet, I am planning to upgrade the HBase Client version to 2.5.5. The main reason why not choose a newer version (such as version 3) is that the difference between the versions is too big.

However, version 2.5.5 is still incompatible with JDK 11, so some adjustments must be made to make the service work properly.
Referring to the instructions at https://www.cnblogs.com/yjmyzz/p/hbase_client_with_jdk17.html, we must add this setting to the jvm startup parameters.

"--add-opens=java.base/java.lang=ALL-UNNAMED"

Due to the upgrade of HBase Client, “NoSuchColumnFamilyException” errors will occur in existing usage methods (such as using tableExists to confirm whether the table exists).
After referring to the relevant instructions on the Internet, this error is mainly due to the different table management mechanism of version 2.5.5 (https://stackoverflow.com/a/58498721). Therefore, the related usage methods need to be changed and adjusted.

Adjust checkTableExist method

We first obtain all table information through “listTableDescriptors”, and then use this information to check whether it exists.
Adjust isTableEnabled method (check whether table status is enabled)

Use try-catch block to catch exceptions, and use the captured exceptions to determine whether the required state is already in place.
```
try {
    hbaseAdmin.disableTable(TABLE_NAME);
} catch (TableNotEnabledException e) {
    LOG.debug("TABLE_NAME is already disable");
} catch (Exception e) {
    throw e;
}
```

Posted in HBase, Java | Comments Off

AES decrypt in postman

Posted on 2023 年 05 月 31 日 by cowman.chiang

sample code:

var CryptoJS = require("crypto-js"); 
let secretKey = 'yourSecretKey'; 

function decrypt(aesStr, key) { 
    return CryptoJS.AES.decrypt( 
        aesStr, 
        CryptoJS.enc.Utf8.parse(padding(key)), 
        { 
            mode: CryptoJS.mode.ECB, 
            padding: CryptoJS.pad.Pkcs7 
        } 
    ).toString(CryptoJS.enc.Utf8) 
} 

function padding(key) { 
    return key.padEnd(32, '\0'); 
} 

//decrypt("encryptedData", secretKey)

Here we choose AES-256 to encrypt / decrypt the secure information. When using AES, the length of the secretKey is important. The length of secretKey in AES-128 is 16 bits, and in AES-256 is 32 bits.

And in our case, the length of secretKey is no enough. So we will use the function padding to fill in the missing length.

source: CSDN: AES解密，key长度不够16处理

Posted in JavaScript, Postman | Comments Off

[Java] Create CSV files with BOM

Posted on 2023 年 03 月 10 日 by cowman.chiang

public static final String UTF8_BOM = "\uFEFF";

public ByteArrayInputStream createFile(Object object) {
    try {
        CSV csv = (CSV) object;
        StringBuffer sb = new StringBuffer();
        sb.append(UTF8_BOM);

        if (csv.getHeaderList() != null) {
            sb.append(StringUtils.join(csv.getHeaderList().toArray(new String[0]), ",")).append("\n");
        }

        for (List<String> row : csv.getDataList()) {
            sb.append(StringUtils.join(row.toArray(new String[0]), ",")).append("\n");
        }

        return new ByteArrayInputStream(sb.toString().getBytes("UTF-8"));
    } catch (Exception e) {
        return null;
    }
}

Posted in Java | Comments Off

[Linux] pkill command

Posted on 2023 年 02 月 23 日 by cowman.chiang

I don’t know what’s going on.

But we can use command “pkill” to delete those abnormal processes.

sudo pkill -f pgrep

Reference: stackoverflow: How to kill all processes with a given partial name?

Posted in Linux | Comments Off

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