Calvin's Home

Akamai Pragma Header

curl -H 'Pragma: akamai-x-cache-on, akamai-x-cache-remote-on, akamai-x-check-cacheable, akamai-x-get-cache-key, akamai-x-get-true-cache-key, akamai-x-get-extracted-values, akamai-x-get-ssl-client-session-id, akamai-x-serial-no, akamai-x-get-request-id' 'https://www.yourpage.com'

• Remove blank lines
  :g/^$/d g = all occurence, d = delete
• Search and replace
  • Replace foo with bar
    :%s/foo/bar/g %s = all lines, all occurence
    :s/foo/bar/g s = current line, all occurence
    :5,12s/foo/bar/g lines 5-12, all occurence

In this article, I will try to use the administrator account to setup all necessary components for another IAM user to do all CodeCommit and CodeBuild related tasks. Finally, the IAM user is able to maintain CodeBuild projects with minimal permissions.

Below diagram illustrates the network design and layout of my testing environment:

In office, I have two LAN ports and the IPs are assigned by the DHCP server. Therefore, I cannot assign static IPs to the servers. I decided to use the retired router to setup a subnet, so that I can allocate static IP address to the server attached to the router.

Environment

1. Red Hat Enterprise Linux 7.4 VM on Oracle VM Server
2. Docker 1.12.6 (from Red Hat yum repository)
3. Oracle JDK SE 9 (from Oracle)
4. Apache HTTPD 2.4.6 (from Red Hat yum repository)
5. Tomcat 8.5.23 (from Apache)

1. Check current virtual disk

   [root@localhost ~]# fdisk -l /dev/xvda
   
   Disk /dev/xvda: 21.5 GB, 21474836480 bytes, 41943040 sectors
   Units = sectors of 1 * 512 = 512 bytes
   Sector size (logical/physical): 512 bytes / 512 bytes
   I/O size (minimum/optimal): 512 bytes / 512 bytes
   Disk label type: dos
   Disk identifier: 0x000b3dc8
   
       Device Boot      Start         End      Blocks   Id  System
   /dev/xvda1   *        2048     1026047      512000   83  Linux
   /dev/xvda2         1026048    41943039    20458496   8e  Linux LVM

curl

1
2

# Print cookies to stdout
curl -c - 'http://google.com'

Change terminal directory text color

LS_COLORS=$LS_COLORS:'di=1;32:' ; export LS_COLORS

The first number is how light or dark you want the color to be, followed by a semicolon, and then the actual number of the color.

Blue = 34
Green = 32
Light Green = 1;32
Cyan = 36
Red = 31
Purple = 35
Brown = 33
Yellow = 1;33
white = 1;37
Light Grey = 0;37
Black = 30
Dark Grey= 1;30

Soure:
https://askubuntu.com/questions/466198/how-do-i-change-the-color-for-directories-with-ls-in-the-console

List files recursively with last modified date

1

find . -type f -print0 | xargs -0 ls -lt --time-style="+%F %T"

cut command

1
2
3
4
5
6
7
8

-d -d':'     # Use : as delimeter
-c -c1-3     # 1-3 characters
   -c3-      # 3rd character to end of line
   -c-8      # start of line to 8th character
-f -f1-4,6,7 # fields 1-4, 6 and 7

cut -d':' -f1-4,6,7 test.txt

Check Linux version

1

cat /etc/os-release

Authenticating to Your Server Using SSH Keys

• Creating SSH Keys:

  1	$ ssh-keygen

• Add public key to ~/.ssh/authorized_keys on target server

Installation

Basic

# Install Node.js
sudo apt-get install nodejs

# Install node package manager (npm)
sudo apt-get install npm

# Install git 
sudo apt-get install git # yum install git-core 

# Install hexo
npm install -g hexo-cli

Hexo site folder and install theme

In this blog, I will install freemind:

$ hexo init blog #blog is the folder to contains all hexo related files
$ cd blog
$ npm install
$ git clone https://github.com/wzpan/hexo-theme-freemind.git themes/freemind

For security reasons, browsers restrict cross-origin HTTP requests initiated from within scripts (e.g. AJAX request). For below scenario, we need to modify the HTTP response headers:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS

Basic Concepts

• Working Directory
• Staging Area (.git/index)
• .git directory

Useful Commands

• Configuration files

  • Repository config file: .git/config

  • System config file: ~/.gitconfig

    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

    [core] repositoryformatversion = 0 filemode = false bare = false logallrefupdates = true worktree = C:/git/myrepo ignorecase = true [submodule] active = . [remote "origin"] url = https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo fetch = +refs/heads/*:refs/remotes/origin/* [branch "master"] remote = origin merge = refs/heads/master [branch "release/prod"] remote = origin merge = refs/heads/release/prod remote = origin merge = refs/heads/release/preprod [branch "release/test"] remote = origin merge = refs/heads/release/test [branch "release/dev"] remote = origin merge = refs/heads/release/dev

• git remote

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

  $ git remote show origin $ git remote -v origin https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo (fetch) origin https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo (push) $ git remote show origin * remote origin Fetch URL: https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo Push URL: https://git-codecommit.ap-southeast-1.amazonaws.com/v1/repos/myrepo HEAD branch: master Remote branches: develop tracked feature/test tracked master tracked release/dev tracked release/preprod tracked release/prod tracked release/test tracked Local branches configured for 'git pull': master merges with remote master release/dev merges with remote release/dev release/preprod merges with remote release/preprod release/prod merges with remote release/prod release/test merges with remote release/test Local refs configured for 'git push': master pushes to master (up to date) release/dev pushes to release/dev (up to date) release/preprod pushes to release/preprod (up to date) release/prod pushes to release/prod (up to date) release/test pushes to release/test (up to date)

• git push [repository] [refspec]

  1 2 3 4 5

  $ git status On branch release/preprod $ git push Everything up-to-date

• git rebase (current branch is topic)

          A---B---C topic*
         /
    D---E---F---G master
  
    git rebase master
    git rebase master topic
  
                  A'--B'--C' topic*
                 /
    D---E---F---G master
  
  

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

  $ git log --oneline c60c0d9 (HEAD -> release/dev, origin/release/dev) Upgrade node version 16675e8 Update oracledb version e5461ba Update oracledb version 4e70188 Change Nodejs version to 14 52cf369 Add GEO IP City Function 52cf369 -- 4e70188 -- e5461ba -- 16675e8 -- c60c0d9 Squash 4e70188 -- e5461ba -- 16675e8 -- c60c0d9 into one commit $ git rebase -i 52cf369 pick 4e70188 Change Nodejs version to 14 squash e5461ba Update oracledb version # meld into previous commit squash 16675e8 Update oracledb version # meld into previous commit squash c60c0d9 Upgrade node versiong # meld into previous commit 52cf369 -- d59392d $ git log --oneline d59392d Update Nodejs version to 14 and oracledb version 52cf369 Add GEO IP City Function

• git merge (current branch is master)

    A---B---C topic
    /
    D---E---F---G master*
  
    git merge topic
  
    A---B---C topic
    /         \
    D---E---F---G---H master*
    

  1 2 3 4 5

  # Merge topic with current branch $ git merge topic Updating ea2980a..532a0fa Fast-forward README.md | 2 +-

• git pull
  git fetch followed by git merge or git rebase (with --rebase)

  FETCH_HEAD is a short-lived ref, to keep track of what has just been fetched from the remote repository

      A---B---C master on origin
     /
    D---E---F---G master*
    ^
    origin/master in your repository  
  
      A---B---C origin/master
     /         \
    D---E---F---G---H master
  
  

• git fetch
  git fetch --all Fetch all remote branches
  git fetch origin master Fetch only remote master branch

• git commit
  Record changes to the repository
  -a Automatically stage modified and deleted files but new files are not affected (use git add for new files)

• git add
  Add file contents to the staging area(index)

• git checkout
  Switch branches or restore working tree files
  git checkout [<branch>]
-b - create a new branch
  -B - create a new branch or reset the branch

• git show
  Shows one or more objects (blobs, trees, tags and commits).

• git log
  --oneline

• ancestry references
  ^: the parent of that commit
  ^2: the second parent of that commit (from the branch that was merged (say, topic))
  ~: first parent
  ~2: first parent of first parent (it traverses the first parents the number of times you specify)
  ~~: first parent of first parent