1 00:00:00,000 --> 00:00:10,933 Hi, Let us understand how to use variables, as we discussed in the earlier lecture, whenever I wanted 2 00:00:10,933 --> 00:00:15,533 to inject a value within a with block, which is out of its scope 3 00:00:15,533 --> 00:00:23,199 I need to use the variable. The same way within the range looping if I wanted to assign or process any 4 00:00:23,200 --> 00:00:28,900 specific element then I need to assign it to variable and process it within the block. 5 00:00:28,900 --> 00:00:33,800 For that, I need to assign a value into a variable. 6 00:00:33,800 --> 00:00:40,833 The syntax for that is the name of the variable with a dollar sign and the special assignment operator 7 00:00:40,833 --> 00:00:43,799 that we will be using is := 8 00:00:43,800 --> 00:00:49,266 And then the value that we are reading from the template or a literal value. 9 00:00:49,266 --> 00:00:52,932 Let's go ahead and do a small demo and get better understanding. 10 00:00:52,933 --> 00:00:59,066 Let me modify the template. 11 00:00:59,066 --> 00:01:03,432 Within the template, I'm going to add few lines. 12 00:01:03,433 --> 00:01:08,399 So what I'm doing over here, I do have a with block and outside the block 13 00:01:08,400 --> 00:01:15,266 I'm reading the release name and assigning in to a variable called relname. 14 00:01:15,266 --> 00:01:21,899 And that is starting with the dollar sign that is the syntax and the operated to assign the value is := 15 00:01:21,900 --> 00:01:26,666 And this particular variable can be accessed across the template and within the with block 16 00:01:26,666 --> 00:01:32,999 I am going to read that specific variable that is dollar or relname and print it with the 17 00:01:33,000 --> 00:01:39,300 key release. Earlier when we are accessing this particular value release.name 18 00:01:39,300 --> 00:01:42,200 That is the builtin object I was not able to read. 19 00:01:42,200 --> 00:01:50,700 Now what I am doing, I am assigning it to a variable and that variable will have the scope across the template. 20 00:01:50,700 --> 00:01:55,966 And over here I have added a dash in the beginning as well as in the end, because it's not going to 21 00:01:55,966 --> 00:02:03,199 print anything and if I doesn't provide this particular dash, it's going to add a new line character. 22 00:02:03,200 --> 00:02:07,566 And there will be a new line or empty line within that YAML file. 23 00:02:07,566 --> 00:02:11,866 Even though that is valid, that's not recommended. 24 00:02:11,866 --> 00:02:16,799 So let me go ahead and save this particular file and execute it. 25 00:02:16,800 --> 00:02:22,766 So the execution I'm going to do using a dry run. 26 00:02:22,766 --> 00:02:24,699 It's able to print the release name. 27 00:02:24,700 --> 00:02:29,566 That's the name that I provided as a part of the dry run statement. 28 00:02:29,566 --> 00:02:34,966 And there is no new line character where we are reading or assigning the variable. 29 00:02:34,966 --> 00:02:38,832 All other lines within the with block is same as we had earlier. 30 00:02:38,833 --> 00:02:41,399 And this is a proof where 31 00:02:41,400 --> 00:02:47,266 We can assign a builtin object into a variable and read it within the with block. 32 00:02:47,266 --> 00:02:49,466 Now let us see another demo where 33 00:02:49,466 --> 00:02:55,132 I'm going to assign an element within the range into a variable and read it within the range block. 34 00:02:55,133 --> 00:03:02,133 So within the template let me go ahead and edit the template. 35 00:03:02,133 --> 00:03:13,633 I'm going to remove these lines and add a range block. 36 00:03:13,633 --> 00:03:15,399 So within the range, what I'm doing 37 00:03:15,400 --> 00:03:21,966 I'm assigning that specific element that is values.langused as a part of topping 38 00:03:21,966 --> 00:03:23,599 And I'm going to have the index 39 00:03:23,600 --> 00:03:30,566 index of the element will be getting assigned to this, and I will printing both the index and the 40 00:03:30,566 --> 00:03:34,566 individual element that is being read within the collection. 41 00:03:34,566 --> 00:03:40,366 So I I'll be having key as the index and value as the actual element within the collection. 42 00:03:40,366 --> 00:03:44,599 And this particular collection already we do have within the values file 43 00:03:44,600 --> 00:03:47,100 Anyway we can go ahead and verify once. 44 00:03:47,100 --> 00:03:49,066 So we do have langused. 45 00:03:49,066 --> 00:03:52,332 And I do have a collection of values. 46 00:03:52,333 --> 00:03:55,866 Now I'm going to do a dry run. 47 00:03:55,866 --> 00:03:59,499 So I'm getting the index and the actual value. 48 00:03:59,500 --> 00:04:03,800 This is one another way of reading the variable and as a part of the variable 49 00:04:03,800 --> 00:04:06,600 another important thing to understand is the dollar. 50 00:04:06,600 --> 00:04:08,233 That's a global variable 51 00:04:08,233 --> 00:04:11,999 And this particular variable will always point to the root context. 52 00:04:12,000 --> 00:04:16,233 So I can access the global objects using the variable dollar. 53 00:04:16,233 --> 00:04:21,599 Let us see some demo about dollar variable as well. 54 00:04:21,600 --> 00:04:24,333 I'm going to edit this particular file. 55 00:04:24,333 --> 00:04:28,433 Let me go ahead and add few labels to this. 56 00:04:28,433 --> 00:04:32,866 So as a part of the label let me delete these 57 00:04:32,866 --> 00:04:38,999 So here I am adding the value by accessing the global variable dollar. 58 00:04:39,000 --> 00:04:40,766 So that will have the root context. 59 00:04:40,766 --> 00:04:42,566 So I can access the global object. 60 00:04:42,566 --> 00:04:49,399 Here I am accessing the global object, chart.name, chart.version, release details as well as the 61 00:04:49,400 --> 00:04:58,100 chart appversion. Let me go ahead and execute this particular chart and for almost all the demo 62 00:04:58,100 --> 00:05:03,466 I'm using the dry run because there is no need to go ahead and deploy. If a dry run is good definitely 63 00:05:03,466 --> 00:05:09,799 it will get deployed into the kubernetes cluster. Once we learn each and every individual concept, we can consolidate 64 00:05:09,800 --> 00:05:14,100 everything together and release them into the kubernetes cluster. 65 00:05:14,100 --> 00:05:17,966 I'm going to do a dry run of the chart mychart. 66 00:05:17,966 --> 00:05:21,932 So I'm able to get the chart releases and release 67 00:05:21,933 --> 00:05:26,833 Name, the version of the helm that we're using and what it is managed by 68 00:05:26,833 --> 00:05:30,966 That is the release service all the information we're able to get. 69 00:05:30,966 --> 00:05:33,332 So in a quick summary we learnt three major concepts. 70 00:05:33,333 --> 00:05:40,433 That is, how to inject a variable into a with block and how to assign a individual element of a 71 00:05:40,433 --> 00:05:47,799 range and access the individual element and its index within the range looping and how to access the 72 00:05:47,800 --> 00:05:51,733 global variable dollar and use the global objects.