Linux fundamentals

Steps to  Launch the Lab from LMS

> Go to https://lms.simplilearn.com/
> Click on to Program button under DEVOPS program 
> Select the secod course which has tab for lab, click on labs.
> Go to Practice Lab on left side and click on it
> Click on DevOps in AWS V2
> Click on Launch Lab button at right bottom
> Click on RDP (Remote Desktop protocol) access 
> Click on Start Instance button and click Yes
> It will take a while for the lab environment to start. Pls wait
> Click on RDP Access
> Click on Auth URL - blue button - to launch the lab
> Lab will launch , click on OK button to proceed
> Lab desktop will launch

*********
[OR]

Steps to Launch Lab via SSH

> Go to https://lms.simplilearn.com/
> Click on to Program button under Post Graduate Program in DevOps 
> Select Course 2 - PD DO - DevOps Certification Training
> Go to Practice Lab on left side and click on it
> Click on DevOps in AWS V2
> Click on Launch Lab button at right bottom
> Click on Web Console
> Open a SSH client like GIT bash
> Enter the below command - 
      ssh yourusername@ip_on_webconsole -p 42006
> It will ask for a password. Give the password from WebConsole.
> you will be connected to lab via SSH

************
IF ANY ISSUES WITH ACCESSING THE LAB- PLS REACH OUT TO SUPPORT TEAM
*************

Linux  Commands

Click on the Terminal at button[ it will be a square balck button].
Terminal application will open. It will be black screen

Linux commands are case sensitive.


Check Version of our OS
          
                 $ lsb_release -a  ⇒ ubuntu
                $ cat /etc/os-release ⇒ centos

Clear the screen
$ clear
Check your present working directory
$ pwd
List the files and directories inside a directory
            $ ls
            $ ls Desktop/
            $ ls -l
            $ ls -la 
Manual command

$ man pwd
Press q to come out of the page
Use up arrow and down arrow to scroll

$ pwd –help ⇒ this will also provide details about the command

$ apropos [keyword] ⇒ this command will search the manual and provide you related commands

Create a directory
$ mkdir myfiles

Change to the directory myfiles

$ cd myfiles
Create an empty file
$ touch file1
$ ls 
Enter data inside the file

$ echo "Hello Everyone!" > file1

$ cat file1 ⇒ to see contents of the file1

$ echo “hello devops” >> file1   => append the line in the file

$ echo -n “foo” >> file1    : this will remove the new line
-n : appends to the file without a new line at the end so next entry will be on same line

Use editors to create a file ,  add contents in the file and save the file

Vim Editor

$ vim file2
Press i   => to insert data

Press ESC
:wq!

Press enter

$ ls
$ cat file2


Vi editor - to be tried by learners

Nano editor

             $ nano file3

               Write the content in the file 

                To save the file 

              Ctl+x => Y => press enter

           $  ls 
           $  cat file3

Copy the contents of 1 file to another
$ cp file3 copyfile
$ ls
$ cat copyfile  ⇒ it will have same contents of file3
Rename a file
$ mv copyfile file4
$ ls
$ mv file4 /tmp/file4  ⇒ move file4 to tmp directory
Become a super user - admin
$ sudo su -



Create a new user in your machine
               $ useradd alice

              $ cat /etc/passwd
              $ useradd bob
   14 . Create a new group
            $ groupadd caltech

15. Add users to above created group
         $ usermod -G cattech alice 

            $ cat /etc/passwd ⇒ see user details
            $ cat /etc/group ⇒ see the group details

16. Edit permissions of a file


 -rw-r--r--  1 root root    0 Mar 13 17:27 file1

Root - user
Root - group

: file , d=> directory

Read write executable

Rw-  ⇒ permission for the owner of the file

R–   ⇒ permission for the users that are part of group root

R–  → permission for the other users that are not part of the group

Different User ⇒ 
User  ⇒ u
Group ⇒ g
All users ⇒ a



add permission to write for all users

$ chmod  a+w file1

Add permission to remove write for all users

$ chmod a-w file1


Add executable permission for user of the file

$ chmod u+x file1

Remove write permission for group

$ chmod g-w file1


Remove a file:

rm filename

rm copiedfile 

ls

removes the files

Remove directories

rm -rf mynewprojects

       -r, -R, --recursive
              remove directories and their contents recursively

       -d, --dir
              remove empty directories

  -f, --force
              ignore nonexistent files and arguments, never prompt