All posts by chang

Command Pattern


class Document:
    text = ""
    def __str__(self):
        return self.text

import abc
class DocumentCommand(abc.ABC):
    doc = None
    @abc.abstractmethod
    def execute(self):
        pass
    @abc.abstractmethod
    def undo(self):
        pass

class AddStrCommand(DocumentCommand):
    def __init__(self, doc, txt):
        self.text = txt
        self.doc = doc
    def execute(self):
        self.doc.text += self.text
        return self.doc
    def undo(self):
        return DeleteStrCommand(self.doc, self.text).execute()

class DeleteStrCommand(DocumentCommand):
    def __init__(self, doc, txt):
        self.text = txt
        self.doc = doc
    def execute(self):
        idx = self.doc.text.find(self.text)
        if idx == -1:
            return self.doc
        self.doc.text = self.doc.text[:idx]
        return self.doc
    def undo(self):
        return AddStrCommand(self.doc, self.text).execute()

doc = Document()
addingTexts = [AddStrCommand(doc,"hello\n"), AddStrCommand(doc,"My name is Chang\n"),  AddStrCommand(doc,"I hope you have a good day")]
for c in addingTexts:
    c.execute()
print("#"*5)
print(doc)
print("#"*5)
print(addingTexts[-1].undo())
print("#"*5)
print(addingTexts[-1].undo())
print("#"*5)
print("*"*30)
d = DeleteStrCommand(doc,"My name is Chang\n")
print(d.execute())
print("#"*5)
print(d.undo())
print("#"*5)

Golang with decoupling S3 Buckets and clients

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX - License - Identifier: Apache - 2.0
package main

import (
"context"
"fmt"
"strconv"


"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/service/s3"

)

func main() {
cfg, err := config.LoadDefaultConfig(context.Background())
if err != nil {
panic("configuration error, " + err.Error())
}


client := s3.NewFromConfig(cfg)
// ListBuckets(client, cfg)
// BucketLocation(client, cfg.Region, "dnb-vedi")
// BucketLocation(client, cfg.Region, "ag-glue-shaping-test-code")
// cfg.Region = "us-east-1"
// client = s3.NewFromConfig(cfg)
// ListObjects(client, cfg, "dnb-vedi", "2022-06-10")
// ListObjects(client, cfg,  , "")
// if IsObjectExistsInS3Bucket(client, cfg, "ag-glue-shaping-test-code", "experiment-data/top50%_caac_fake_entity_newHash.csv") {
//  fmt.Println("%s exists %s", "ag-glue-shaping-test-code", "experiment-data/top50%_caac_fake_entity_newHash.csv")
// } else {
//  fmt.Println("%s not exists %s", "ag-glue-shaping-test-code", "experiment-data/top50%_caac_fake_entity_newHash.csv")
// }

// if IsObjectExistsInS3Bucket(client, cfg, "dnb-vedi", "2022-06-10/BEMFAB_FILE1.TXT.gz.pgp") {
//  fmt.Println("%s exists %s", "dnb-vedi", "2022-06-10/BEMFAB_FILE1.TXT.gz.pgp")
// } else {
//  fmt.Println("%s not exists %s", "dnb-vedi", "2022-06-10/BEMFAB_FILE1.TXT.gz.pgp")
// }

// if IsObjectExistsInS3Bucket(client, cfg, "dnb-vedi", "2022-06-10/") {
//  fmt.Println("%s exists %s", "dnb-vedi", "2022-06-10/")
// } else {
//  fmt.Println("%s not exists %s", "dnb-vedi", "2022-06-10")
// }
items, err := GetObjects(client, cfg, "dnb-vedi", "2022-06-10")
if err != nil {
    panic("configuration error, " + err.Error())
}
for _, item := range items {
    for k, v := range item {
        fmt.Printf("%s: %s ", k, v)
    }
    fmt.Println()
}

}

func IsObjectExistsInS3Bucket(client *s3.Client, cfg aws.Config, bucket, objectKey string) bool {
region, _ := GetBucketLocation(client, cfg, bucket)
cfg.Region = region
client = s3.NewFromConfig(cfg)


headObj := s3.HeadObjectInput{
    Bucket: aws.String(bucket),
    Key:    aws.String(objectKey),
}
_, err := client.HeadObject(context.TODO(), &headObj)
return err == nil

}

func GetObjects(client *s3.Client, cfg aws.Config, bucket, prefix string) ([]map[string]string, error) {
region, _ := GetBucketLocation(client, cfg, bucket)
cfg.Region = region
// fmt.Println(cfg.Region)
client = s3.NewFromConfig(cfg)
params := &s3.ListObjectsV2Input{
Bucket: aws.String(bucket),
Prefix: aws.String(prefix),
}


resp, err := client.ListObjectsV2(context.Background(), params)
if err != nil {
    fmt.Println("Got error retrieving list of objects:")
    return nil, err
}
var returnArray []map[string]string
for _, item := range resp.Contents {
    var obj = map[string]string{}
    obj["path"] = string(*item.Key)
    obj["lastmodified"] = (*item.LastModified).Format("2006-01-02T15:04:05")
    obj["size"] = strconv.FormatInt(item.Size, 10)
    obj["storageClass"] = string(item.StorageClass)
    returnArray = append(returnArray, obj)
}
return returnArray, nil

}

func ListObjects(client *s3.Client, cfg aws.Config, bucket, prefix string) {
region, _ := GetBucketLocation(client, cfg, bucket)
cfg.Region = region
// fmt.Println(cfg.Region)
client = s3.NewFromConfig(cfg)
params := &s3.ListObjectsV2Input{
Bucket: aws.String(bucket),
Prefix: aws.String(prefix),
}


resp, err := client.ListObjectsV2(context.Background(), params)
if err != nil {
    fmt.Println("Got error retrieving list of objects:")
    fmt.Println(err)
    return
}
for _, item := range resp.Contents {
    fmt.Println("Name:          ", *item.Key)
    fmt.Println("Last modified: ", *item.LastModified)
    fmt.Println("Size:          ", item.Size)
    fmt.Println("Storage class: ", item.StorageClass)
    fmt.Println("")
}

}

func ListBuckets(client *s3.Client, cfg aws.Config) {


param := &s3.ListBucketsInput{}

result, err := client.ListBuckets(context.TODO(), param)
if err != nil {
    fmt.Println("Got an error retrieving buckets:")
    fmt.Println(err)
    return
}

fmt.Println("Buckets:")
for _, bucket := range result.Buckets {
    fmt.Print(*bucket.Name + ": " + bucket.CreationDate.Format("2006-01-02 15:04:05 Monday") + ": ")
    re, _ := GetBucketLocation(client, cfg, *bucket.Name)
    fmt.Println(re)
}

}

func GetBucketLocation(client *s3.Client, cfg aws.Config, bucket string) (string, error) {
param := &s3.GetBucketLocationInput{
Bucket: aws.String(bucket),
}
locationOutput, err := client.GetBucketLocation(context.Background(), param)
if err != nil {
return "", err
}
// fmt.Println(locationOutput.LocationConstraint)
if locationOutput.LocationConstraint == "" {
return cfg.Region, nil
} else {
return string(locationOutput.LocationConstraint), nil
}
}

Mac Terminal Setup

SetUp Mac OS Terminal

sudo systemsetup -getcomputersleep
sudo systemsetup -setcomputersleep 60
sudo pmset -a displaysleep 40 disksleep 60 sleep 600

1. Install brew

If you do not have Xcode installed

sudo chown -R $(whoami) $(brew --prefix)/*
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

If you have Xcode installed

xcode-select -- install
curl -fsSL --output homebrew_installer.sh https://raw.githubusercontent.com/Homebrew/install/master/install.sh
bash homebrew_installer.sh

Brew comes with git

git --version

git version 2.32.0 (Apple Git-132)

2. Install Sublime

brew install --cask sublime-text

3. Install Vim

brew install vim
brew install macvim
brew update

append the following line to ~/.vimrc

set clipboard=unnamed

4. Install iTerm 2

brew  install --cask iterm2

5. Check installation of Zsh

zsh --version
echo $0

6. Better Mac Terminal Window

Based on: https://opensource.com/article/20/8/iterm2-zsh

Install Oh My Zsh

Oh My Zsh uses a .zshrc file to save your customizations instead of a .bash_profile

1.

sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
2. Add the following in .zshrc

plugins=( git github zsh-syntax-highlighting zsh-autosuggestions bundler dotenv macos
  python pip pyenv virtualenv aws brew docker golang helm
  sudo tmux
  vi-mode vim-interaction
)
source /usr/local/opt/powerlevel10k/powerlevel10k.zsh-theme
# To customize prompt, run `p10k configure` or edit ~/.p10k.zsh.
[[ ! -f ~/.p10k.zsh ]] || source ~/.p10k.zsh

#ZSH_THEME="powerlevel10k/powerlevel10k"
ZSH_THEME="robbyrussell"
#ZSH_THEME="agnoster"
3. Install the recommended font

brew install romkatv/powerlevel10k/powerlevel10k
echo "source $(brew --prefix)/opt/powerlevel10k/powerlevel10k.zsh-theme" >>~/.zshrc

4. In order to re-configfure

p10k configure

5. Recommended plugins

git clone https://github.com/zsh-users/zsh-autosuggestions \ ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions
git clone https://github.com/zsh-users/zsh-syntax-highlighting.git \ ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

6. Verification of on-my-zsh

Check 'oh-my-zsh' folder

brew install tree
tree .oh-my-zsh -L  1


.oh-my-zsh
├── CODE_OF_CONDUCT.md
├── CONTRIBUTING.md
├── LICENSE.txt
├── README.md
├── SECURITY.md
├── cache
├── custom
├── lib
├── log
├── oh-my-zsh.sh
├── plugins
├── templates
├── themes
└── tools

Generating an SSH key

ssh-keygen -t rsa

Install Python3

brew install python3
brew install pyenv
python3 -m venv pyvirt
source pyvirt/bin/activate
deactivate

AWS setup

Install the AWS CLI using GUI installer

https://docs.aws.amazon.com/cli/latest/userguide/installing.html

Install the awscli tool via python pip:

pip3 install awscli --upgrade --user

Install the aws-iam-authenticator application

https://docs.aws.amazon.com/eks/latest/userguide/install-aws-iam-authenticator.html

Install kubectl

https://kubernetes.io/docs/tasks/tools/install-kubectl/

Install eksctl (admin only)

https://docs.aws.amazon.com/eks/latest/userguide/eksctl.html

References

https://docs.aws.amazon.com/eks/latest/userguide/getting-started-eksctl.html
https://github.com/weaveworks/eksctl
https://eksctl.io/

AWS

aws configure

AWS Access Key ID [None]: XXXX
AWS Secret Access Key [None]: XXXXXXXXX
Default region name [None]: us-west-2
Default output format [None]: json

aws configure list
aws s3 ls