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- [Instructor] Hi and
welcome back to the course.

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In this video, we're going
to be creating another user

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so that we don't have to
log in as the root user,

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just for increased security.

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When we log in as the root user,

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I've mentioned the root user
is a very important user

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in a Unix and it has
access to do anything,

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so it potentially can mess up your server,

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making sure that you have
to create another one.

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So the root user has a lot of power,

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and sometimes that is very useful.

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For example, when installing applications

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in your server, you want
to do it as the root user

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so it has access to modify
all of the different

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files and folders in your server.

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But normally, you don't
want to be the root user

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just because the root user
has so many permissions

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that if you instal something, for example,

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and everything you do is
done by the root user,

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other users, such as the Postgres user,

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may not have access to the
files and folders you create

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using the root user.

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So what we're gonna do,
is we're gonna create

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a new user by following
the command adduser Jose.

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The name here is the name of
the user that we're creating,

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and I'm calling it Jose.

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You can call it your name
or whatever you want,

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but just know that this
is going to come up

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over and over again, so
whenever I type Jose,

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you're going to have
to type your username.

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But apart from that,
that's everything you need.

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And what this does, is
that creates a new user

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called Jose, and it creates a new group

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called Jose, as well.

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A group is a collection of users

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and you can set group permissions.

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For example, you may tell
Unix, your Ubuntu server,

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that all users in the
group Jose have access

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to a specific folder, for example.

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And then, even if an individual
users doesn't have access

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to that folder, because
they are in the group

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they will have access to it.

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It's just a way of setting
permissions in Unix.

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Next, we're going to set
the password for this user,

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and make sure that that's
different from the root password,

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just for security as well.

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Okay, then you can put in your full name,

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which I will do,

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and then there's a few things

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that I'm just gonna leave blank.

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There.

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Finally, we get this prompt,

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is the information correct,

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and because the Y is a capital letter,

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that is the default value
that we're gonna select

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if we leave it blank,

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so just pressing enter
makes sure that we say

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that the information is correct.

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Okay?

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The next thing we have to do is make sure

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that the Jose user can
temporarily gain access

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to being root so that we can do things

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like instal programmes
and things like that.

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Way we're gonna do that is by
running the visudo command.

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Okay, this brings you to a
reasonably scary-looking window,

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but this is just a file,

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and what we're gonna do is
we're gonna modify this file

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so that the Jose user has
access to being root sometimes.

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So we want to find, by
pressing the arrows,

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this line here that says
user privilege specification,

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and under root ALL=(ALL:ALL)
ALL, we're gonna type

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Jose ALL=(ALL:ALL) ALL,
so essentially copying it

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but putting in your user
name at the beginning.

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Notice that the spacing between
these things doesn't matter.

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I just left it there for
readability purposes,

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but it doesn't matter.

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Once that's done, we're
going to save the file

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to the disc and we're gonna do that

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by running this command here,

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which is CTRL+O, and then
we're gonna press enter

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to save it on top of the existing file,

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and finally we're gonna
press CTRL+X to exit.

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And that's, that's saved.

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The next thing we have
to do is to make sure

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that we can login to the server directly

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as the Jose user, as
opposed to the root user.

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So what we're gonna do is
press vi /etc/ssh/sshd_config.

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So vi /etc/ssh/sshd_config.

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And this brings you to another
nice-looking text file,

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and what we want to find
here is one specific line.

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So I'm gonna go down
pressing the down arrow,

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until you find this line
that says PermitRootLogin,

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and it says yes.

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That means that we can login to the server

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as the root user, and
this is not very safe.

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We should not be allowing
people to login as the root user

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because if the root password gets cracked,

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then our server is in a bit of trouble.

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So we're going to press
the I key in your keyboard

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and that goes into insert mode,

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and then we're going to delete
the yes and put no instead.

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Then we're gonna press the
escape key to leave insert mode.

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Then we're gonna go down to
the very bottom of the file,

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which can be a bit long,

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and we are going to, right down here,

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press the I key again
to go into insert mode,

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go to the very end of
the line and press enter,

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and we're going to write AllowUsers Jose,

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and then press escape again.

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What this does is it tells SSH,

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which is our connection protocol,

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to allow the Jose user to
connect with this server.

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So we've denied the root
user from connecting

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and now we're gonna allow
the Jose user to connect.

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Okay?

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So you have to make
sure that your password

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for the Jose user is quite strong

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because, remember, the
Jose user has access

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to being root as well.

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So if your Jose user
password is very weak,

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that poses a security threat there.

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Okay?

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So then, once you've pressed
escape to leave insert mode,

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we want to press :wq
and what that means is

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write and quit, so it's
gonna save the file,

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write it to the disc, and quit.

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And finally, at the
very end, we want to say

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service sshd reload,

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and what that does is
that reloads the service

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and allows us to use
the new configuration.

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Okay?

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Now we're gonna press exit,

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which is going to
disconnect from the server,

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and we can do ssh Jose@
and the server here.

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Oh, apologies.

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And then we're gonna press enter,

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and now it asks us for
the Jose user password,

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which we're gonna put in,

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and now we're logged in as the Jose user.

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Now, this user has access to being root,

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so the way we would be
root, or login as root now

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would be sudo su and
that is going to ask us

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for our password again,

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which we're going to put in,

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and now we are logged in as the root user.

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We can press exit, and that brings us back

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to being the Jose user,

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and then we can press exit again

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and that brings us back to our computer.

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So now we've logged out of the server.

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Okay?

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So that's everything for this video.

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We've created a new user and
now we're going to make sure

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that PostgreSQL is linked to that user

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so we can use PostgreSQL
while we are the Jose user,

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or your user if you've
created a different name.

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So that's everything for this video,

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and I'll see you in the next one.