1
00:00:00,660 --> 00:00:03,930
In last section we spoke about how we make our own custom image.

2
00:00:03,930 --> 00:00:05,220
We create a docker file.

3
00:00:05,220 --> 00:00:09,690
We feed it into the docker server and that's going to eventually build a useful image that we can use

4
00:00:09,690 --> 00:00:12,210
to start up our own custom containers.

5
00:00:12,210 --> 00:00:17,570
And inside that Docker file we're gonna specify a base image run some commands and then eventually specify

6
00:00:17,580 --> 00:00:21,050
command to run when a container is created out of the image.

7
00:00:21,060 --> 00:00:24,720
So in this section we're gonna start working on our own custom Docker file.

8
00:00:25,200 --> 00:00:28,510
Let me first tell you about what we're going to be trying to build.

9
00:00:28,560 --> 00:00:34,620
So we are going to make a docker file that is going to create an image that's going to run red as server

10
00:00:34,680 --> 00:00:36,230
whenever it starts up.

11
00:00:36,300 --> 00:00:40,560
Now throughout this course we've already been making use of that red US image to start up red us on

12
00:00:40,560 --> 00:00:41,720
our local computer.

13
00:00:41,910 --> 00:00:47,760
But I want to show you how to build that thing from scratch or somewhat from scratch just to be precise.

14
00:00:48,150 --> 00:00:52,980
So this is going to be going to be the purpose of our Docker file and the image that we're going to

15
00:00:52,980 --> 00:00:54,280
create out of it.

16
00:00:54,300 --> 00:00:56,520
So let's get started right now.

17
00:00:56,520 --> 00:01:02,460
I'm going to first begin by flipping over to my terminal and I'm going to create a new working directory

18
00:01:02,460 --> 00:01:08,710
or kind of a project directory of sorts and I'm going to call it Rita's image.

19
00:01:09,080 --> 00:01:16,150
Like so now you can put this folder anywhere you want on your machine doesn't matter anywhere is good.

20
00:01:16,180 --> 00:01:22,490
I'll then change into that directory and then I'm going to start up my code editor inside that folder.

21
00:01:22,520 --> 00:01:27,020
Now quick note I am making use of visual studio code and I have configured it so that I could run it

22
00:01:27,020 --> 00:01:28,060
from the command line.

23
00:01:28,070 --> 00:01:31,400
So that is why I'm able to run code dot right here.

24
00:01:31,400 --> 00:01:35,750
If you have not gone through those same steps you will not be able to run that command and start up

25
00:01:35,750 --> 00:01:41,030
your editor essentially all you need to do right now is start up whatever code editor you like to use

26
00:01:41,120 --> 00:01:47,200
and open up that reddest image directory that we just created then inside of here.

27
00:01:47,360 --> 00:01:54,470
I want to make a new file called Docker file and notice how it has a capital D and it has no extension

28
00:01:55,010 --> 00:01:57,920
so there's no J us on here there's no shell.

29
00:01:57,920 --> 00:01:58,790
There's nothing like that.

30
00:01:58,790 --> 00:02:01,910
It is simply called Docker file.

31
00:02:01,910 --> 00:02:06,620
So then inside of here we're gonna write out a couple of comments to guide us through the process of

32
00:02:06,620 --> 00:02:12,520
creating our custom image and it's going to essentially follow this template of steps right here.

33
00:02:12,560 --> 00:02:16,430
So the first comment I'm gonna put down and notice how we create a comment by putting down the pound

34
00:02:16,430 --> 00:02:17,480
symbol.

35
00:02:17,480 --> 00:02:25,170
I'm going to say that I'm going to use an existing Docker image as a base I'm then going to download

36
00:02:25,260 --> 00:02:28,380
and install a dependency.

37
00:02:28,380 --> 00:02:37,440
And then finally I'm going to tell the image what to do when it starts as a container.

38
00:02:37,570 --> 00:02:41,990
All right now I'll be honest with you the way we're going to approach this darker file where it's going

39
00:02:41,990 --> 00:02:46,730
to write out all the code inside of here all the configuration we're going to use it to build our image

40
00:02:46,970 --> 00:02:50,930
and then we're going to come back and talk about all the configuration that we've written inside of

41
00:02:50,930 --> 00:02:51,440
here.

42
00:02:51,650 --> 00:02:55,970
To be honest it's a lot easier to understand the configuration that we're going to write after you've

43
00:02:55,970 --> 00:02:58,980
actually seen the process of creating an image.

44
00:02:59,060 --> 00:03:02,140
So a little bit of just blind copy pasting here.

45
00:03:02,200 --> 00:03:07,190
So just follow along and we'll very quickly come back and talk about the exact lines of code that we're

46
00:03:07,190 --> 00:03:08,280
adding it.

47
00:03:08,390 --> 00:03:16,030
So the first thing I'm going to write down is from Alpine then in the next section I'm going to add

48
00:03:16,210 --> 00:03:26,250
run a P.K. add dash dash update readies and then finally on the very bottom line here I'm going to add

49
00:03:26,310 --> 00:03:35,760
CMT a set of square brackets a set of double quotes and then inside there I'll put reddest dash server

50
00:03:35,850 --> 00:03:42,570
like so now I'm going to save this file I'm going to flip back over to my terminal.

51
00:03:42,860 --> 00:03:47,750
I'm going to make sure that I'm inside of that reddest dash image directory and I'm going to run the

52
00:03:47,750 --> 00:03:55,440
line run the command excuse me docker build dot don't forget the little dot on their nose how there's

53
00:03:55,440 --> 00:04:01,280
a little period so going to run that and then we're going to very quickly see a whole bunch of output

54
00:04:01,280 --> 00:04:06,230
start to stream along here and then eventually I see a message that says successfully built and then

55
00:04:06,350 --> 00:04:08,240
blah blah blah.

56
00:04:08,240 --> 00:04:14,630
Now we're going to copy this idea right here and then run Docker run and then I'll paste that idea in

57
00:04:15,840 --> 00:04:22,840
and execute this and then we're going to very quickly see all the kind of output here that we saw previously

58
00:04:22,900 --> 00:04:23,990
when we ran that Docker.

59
00:04:23,990 --> 00:04:29,570
So I mean the red is image and the last message I should see is ready to accept connections.

60
00:04:29,590 --> 00:04:29,890
OK.

61
00:04:29,920 --> 00:04:34,300
So we just went through the process of creating the docker file using it to build an image and we started

62
00:04:34,300 --> 00:04:38,700
that image up but we haven't really said anything about what really happened there.

63
00:04:38,710 --> 00:04:42,790
I'm going to stop the running container by pressing control see we're going to take a quick break come

64
00:04:42,790 --> 00:04:48,460
back the next section and talk about exactly what we just did inside this file and at the terminal.

65
00:04:48,490 --> 00:04:50,250
So quick break and I'll see you in just a minute.