1
00:00:00,398 --> 00:00:03,038
‫So to initialize our project, we could run

2
00:00:03,038 --> 00:00:06,349
‫sam init, and I'll just have the help function here.

3
00:00:06,349 --> 00:00:10,200
‫And sam init basically generates a SAM project for you

4
00:00:10,200 --> 00:00:13,817
‫and you can specify the run time you want being python 3.6,

5
00:00:13,817 --> 00:00:17,217
‫but you could also say 2.7, node js, and so on.

6
00:00:17,217 --> 00:00:19,233
‫Sam init creates a lot of files for you

7
00:00:19,233 --> 00:00:22,305
‫and I don't want to overwhelm you, so how about we just go

8
00:00:22,305 --> 00:00:24,785
‫one by one, we don't use sam init, we're just going

9
00:00:24,785 --> 00:00:27,294
‫to create the code one file at a time

10
00:00:27,294 --> 00:00:29,883
‫so it makes a lot of sense for us.

11
00:00:29,883 --> 00:00:32,414
‫So just to make things easy, I'm going to have

12
00:00:32,414 --> 00:00:35,723
‫a source folder and the source folder will contain

13
00:00:35,723 --> 00:00:37,785
‫our application so I'll call it

14
00:00:37,785 --> 00:00:40,652
‫a new file and I'll make a app.py file,

15
00:00:40,652 --> 00:00:42,745
‫I'll just write my application in Python.

16
00:00:42,745 --> 00:00:44,569
‫That's going to be our source folder.

17
00:00:44,569 --> 00:00:47,094
‫We're also going to need to have a template file

18
00:00:47,094 --> 00:00:51,465
‫so we'll have template.yaml and this is going to be

19
00:00:51,465 --> 00:00:55,163
‫our SAM file so SAM file right here.

20
00:00:55,163 --> 00:00:58,155
‫And finally we're going to have to write

21
00:00:58,155 --> 00:01:00,745
‫our commands somewhere so I'll just say them,

22
00:01:00,745 --> 00:01:03,734
‫I'll have a commands.sh file.

23
00:01:03,734 --> 00:01:06,323
‫So now we need to go ahead and fill the app.py,

24
00:01:06,323 --> 00:01:09,014
‫sample.yaml...uh, template.yaml, and so on.

25
00:01:09,014 --> 00:01:11,625
‫So this, let's just go straight to

26
00:01:11,625 --> 00:01:13,915
‫the server application model example apps

27
00:01:13,915 --> 00:01:15,403
‫because that will be the easiest way

28
00:01:15,403 --> 00:01:17,814
‫for us to make sense of everything.

29
00:01:17,814 --> 00:01:20,665
‫And let's find a hello world python three.

30
00:01:20,665 --> 00:01:23,894
‫That sounds great, and here we have a lambda_function.py

31
00:01:23,894 --> 00:01:28,894
‫and a template.yaml, so let's open these two in two tabs

32
00:01:29,083 --> 00:01:32,812
‫and let's first look at the lambda_function.py.

33
00:01:32,812 --> 00:01:35,129
‫So this is a very easy lambda function, imports

34
00:01:35,129 --> 00:01:38,105
‫to json package and returns some events.

35
00:01:38,105 --> 00:01:40,825
‫So let's just go and import that function

36
00:01:40,825 --> 00:01:44,515
‫and I'll just have this into my source, app.py.

37
00:01:44,515 --> 00:01:46,233
‫So here this is the basic lambda function

38
00:01:46,233 --> 00:01:48,995
‫that we have from before and I'm actually going to remove

39
00:01:48,995 --> 00:01:51,994
‫a lot of stuff as well from here and I'm just going

40
00:01:51,994 --> 00:01:56,077
‫to say return "Hello World," and that's about it.

41
00:01:57,065 --> 00:01:59,864
‫Okay, a very simple lambda function.

42
00:01:59,864 --> 00:02:01,686
‫Now, let's do the more fun stuff,

43
00:02:01,686 --> 00:02:05,766
‫which is to take care of this template.yaml file.

44
00:02:05,766 --> 00:02:09,235
‫So template.yaml file, let's go back and here it is,

45
00:02:09,235 --> 00:02:11,715
‫it is going to be the yaml file that will

46
00:02:11,715 --> 00:02:14,297
‫describe how your function should be.

47
00:02:14,297 --> 00:02:16,275
‫So let me copy this entire thing

48
00:02:16,275 --> 00:02:19,029
‫and we'll analyze the lines one by one.

49
00:02:19,029 --> 00:02:22,073
‫I'll copy the yaml file right here and here we go.

50
00:02:22,073 --> 00:02:23,578
‫The first thing, the first line

51
00:02:23,578 --> 00:02:25,817
‫is the AWStemplateformatversion.

52
00:02:25,817 --> 00:02:27,935
‫It says 2010, so this is just indicating

53
00:02:27,935 --> 00:02:30,126
‫this is a cut formation template.

54
00:02:30,126 --> 00:02:32,937
‫The second thing is a transform, and a transform

55
00:02:32,937 --> 00:02:37,246
‫is indicative that we are using a sam template,

56
00:02:37,246 --> 00:02:41,897
‫because the transform says "AWS Serverless 2016-10-31."

57
00:02:41,897 --> 00:02:44,508
‫So this is what you would see at the exam.

58
00:02:44,508 --> 00:02:45,518
‫Any time you would see a transform

59
00:02:45,518 --> 00:02:48,169
‫saying this, that means it's a sam template.

60
00:02:48,169 --> 00:02:50,030
‫Now we can have description, and that's our

61
00:02:50,030 --> 00:02:53,087
‫starter AWS lambda function, we could have some parameters,

62
00:02:53,087 --> 00:02:54,190
‫but I'm actually going to remove

63
00:02:54,190 --> 00:02:56,460
‫these parameters to make it very simple.

64
00:02:56,460 --> 00:02:58,192
‫And so we have the first resource which

65
00:02:58,192 --> 00:03:01,072
‫is the helloworldpython3, the type of it

66
00:03:01,072 --> 00:03:05,792
‫is a serverless function, and this is a sam-specific type

67
00:03:05,792 --> 00:03:08,883
‫of resource, and we can look at properties.

68
00:03:08,883 --> 00:03:11,043
‫Properties is that our lambda function

69
00:03:11,043 --> 00:03:13,392
‫is going to have a handler.

70
00:03:13,392 --> 00:03:14,630
‫Now the handler should be

71
00:03:14,630 --> 00:03:17,443
‫the file name dot the function name.

72
00:03:17,443 --> 00:03:21,621
‫Turns out that our file name is app.py, not lambda_function.

73
00:03:21,621 --> 00:03:23,991
‫So I'll just change this to app.

74
00:03:23,991 --> 00:03:27,334
‫And within our app, the py, the first function we define,

75
00:03:27,334 --> 00:03:31,043
‫is lambda_handler, so I'll keep app.lambda_handler.

76
00:03:31,043 --> 00:03:35,203
‫The runtime is python3.6, and the code is not

77
00:03:35,203 --> 00:03:37,781
‫in this directory, it is in the source directory,

78
00:03:37,781 --> 00:03:40,803
‫so I'll just have source as the CodeUri.

79
00:03:40,803 --> 00:03:44,771
‫CodeUri indicates locally where the code is.

80
00:03:44,771 --> 00:03:47,875
‫For me it is in the source directory.

81
00:03:47,875 --> 00:03:51,123
‫Now the description is that it's our starter AWS function.

82
00:03:51,123 --> 00:03:52,403
‫We can define the memory size straight

83
00:03:52,403 --> 00:03:55,519
‫from our parameters, so can we for the timeouts.

84
00:03:55,519 --> 00:03:57,377
‫And for the policies, I need to remove

85
00:03:57,377 --> 00:03:59,618
‫this because it is not useful right now.

86
00:03:59,618 --> 00:04:03,026
‫So here is our most simple file

87
00:04:03,026 --> 00:04:05,948
‫for sam, it looks pretty simple.

88
00:04:05,948 --> 00:04:08,748
‫We have a template, an app.py, and then we need

89
00:04:08,748 --> 00:04:12,612
‫to deploy it, which I will do in the next lecture.