WEBVTT 00:00.810 --> 00:01.643 Narrator: In last section, 00:01.643 --> 00:04.530 we learned about the importance of the - IT flag. 00:04.530 --> 00:05.363 In this section, 00:05.363 --> 00:06.930 I wanna tell you about one last use 00:06.930 --> 00:08.640 of the docker exec command. 00:08.640 --> 00:11.130 And this use of it is probably going to be the most common 00:11.130 --> 00:12.360 that you're going to be making use of 00:12.360 --> 00:14.580 on your own personal projects. 00:14.580 --> 00:16.830 A very common thing that you're going to want to do 00:16.830 --> 00:19.770 when you are using docker, is to get shell access 00:19.770 --> 00:22.219 or terminal access to your running container. 00:22.219 --> 00:25.770 In other words, you are going to want to run commands inside 00:25.770 --> 00:28.320 of your container without having to rerun, 00:28.320 --> 00:30.450 docker exec, docker exec, docker exec 00:30.450 --> 00:32.250 again and again all day. 00:32.250 --> 00:34.470 So in this section, I'm gonna show you how you can open up 00:34.470 --> 00:37.488 a shell right terminal in the context of your 00:37.488 --> 00:39.600 running container. 00:39.600 --> 00:41.220 So, here's what we're gonna do. 00:41.220 --> 00:44.220 I'm gonna flip back over to my terminal. 00:44.220 --> 00:45.930 I'm gonna verify that I'm still running. 00:45.930 --> 00:48.000 That red is container. 00:48.000 --> 00:50.335 I'm gonna open up a second terminal window 00:50.335 --> 00:51.990 inside of here. 00:51.990 --> 00:56.080 I'm going to run docker PS and get my container ID 00:57.690 --> 01:02.220 and then I'm going to run docker exec - IT. 01:02.220 --> 01:03.930 I'll put the container ID in. 01:03.930 --> 01:06.750 And then here's the magic I'm gonna put in SH. 01:06.750 --> 01:10.050 And we'll talk about what SH is in just a second. 01:10.050 --> 01:11.730 I'm gonna run that command and you'll see that 01:11.730 --> 01:13.890 I get the little # over here. 01:13.890 --> 01:14.760 Once I'm in here, 01:14.760 --> 01:17.190 I can now start to type out typical commands 01:17.190 --> 01:19.500 that I would expect to be able to run in a 01:19.500 --> 01:20.970 Unix environment. 01:20.970 --> 01:22.110 So for example, 01:22.110 --> 01:25.860 I could change my directory to my home directory, 01:25.860 --> 01:27.930 I could list out the files and folders inside there, 01:27.930 --> 01:29.040 nothing there right now. 01:29.040 --> 01:31.989 Let's try going back to the root directory of \ 01:31.989 --> 01:33.990 and then if I do an LS 01:33.990 --> 01:38.310 I'll see all the root files and folders of the container. 01:38.310 --> 01:40.890 I could execute commands like echo hi\\there. 01:40.890 --> 01:42.835 I can export variables, 01:42.835 --> 01:44.250 environment variables like 01:44.250 --> 01:47.760 export b = 5, and then echo that. 01:47.760 --> 01:49.320 So essentially when I make use 01:49.320 --> 01:52.530 of this docker exec command with SH over here 01:52.530 --> 01:55.680 I get full terminal access inside the context 01:55.680 --> 01:56.513 of the container, 01:56.513 --> 01:59.340 which is extremely powerful for debugging. 01:59.340 --> 02:00.960 I could even do things like, say, 02:00.960 --> 02:02.910 run the docker CLI directly or something, 02:02.910 --> 02:05.850 not docker CLI, but red as CLI 02:05.850 --> 02:07.830 and that starts up, the red as CLI. 02:07.830 --> 02:09.210 And then when I'm all done 02:09.210 --> 02:10.390 I can hit control C 02:11.610 --> 02:13.500 and it looks like nothing's happening. 02:13.500 --> 02:14.730 So quick shortcut here. 02:14.730 --> 02:16.680 If you ever are in a container 02:16.680 --> 02:19.110 and it feels like you can't hit control C to exit 02:19.110 --> 02:20.793 you can always try hitting command D, or excuse me 02:20.793 --> 02:23.610 control D to get out as well. 02:23.610 --> 02:24.443 All right, so we'll, 02:24.443 --> 02:25.950 let's talk about what just happened there. 02:25.950 --> 02:27.270 So we ran docker exec, 02:27.270 --> 02:29.070 which we've seen several times before, 02:29.070 --> 02:31.260 and then we did SH. 02:31.260 --> 02:32.613 So what is SH? 02:33.450 --> 02:35.880 Well, SH is the name of a program 02:35.880 --> 02:38.550 and it's a program that is being executed inside 02:38.550 --> 02:39.960 of that container. 02:39.960 --> 02:43.260 SH is a command processor or a shell. 02:43.260 --> 02:45.930 It's something that allows us to type commands in 02:45.930 --> 02:49.080 and have them be executed inside that container. 02:49.080 --> 02:50.910 You are already making use 02:50.910 --> 02:54.570 of a program very much like SH on your own computer. 02:54.570 --> 02:56.100 Chances are if you're on Mac OS 02:56.100 --> 02:58.260 you are probably using something like Bash. 02:58.260 --> 02:59.093 If you're on Windows, 02:59.093 --> 03:00.210 you're probably using something like 03:00.210 --> 03:02.010 Git Bash or PowerShell. 03:02.010 --> 03:04.530 Me personally, I'm making use of Z Shell. 03:04.530 --> 03:06.983 These are all programs that allow you to type commands 03:06.983 --> 03:10.050 into your terminal and have them be executed. 03:10.050 --> 03:12.930 And so when we start up SH inside of our container 03:12.930 --> 03:15.660 that's just another command shell 03:15.660 --> 03:18.278 that we can use to execute commands. 03:18.278 --> 03:19.920 Traditionally, a lot 03:19.920 --> 03:21.660 of the different containers that you're going to be working 03:21.660 --> 03:25.080 with are probably going to have the SH command 03:25.080 --> 03:28.500 or excuse me, or excuse me, the SH program already included. 03:28.500 --> 03:30.060 Some more complete versions 03:30.060 --> 03:32.490 of containers or images are going to also have 03:32.490 --> 03:35.190 the Bash command processor as well. 03:35.190 --> 03:37.680 So in some cases, you can make use of Bash directly. 03:37.680 --> 03:39.840 In vast majority, you're probably going to 03:39.840 --> 03:41.700 be able to run the shell inside there 03:41.700 --> 03:44.673 to start up a command prompt and type in some commands. 03:45.840 --> 03:47.010 Okay, So again, I think 03:47.010 --> 03:50.940 that you're probably going to be using docker exec - IT 03:50.940 --> 03:54.060 with SH as the command very, very often 03:54.060 --> 03:56.820 when you start doing your own docker development. 03:56.820 --> 03:59.910 All right, so we've spoken a whole bunch around Docker CLI. 03:59.910 --> 04:01.290 Let's take one more break here. 04:01.290 --> 04:03.420 There's just one or two quick topics I wanna talk 04:03.420 --> 04:06.170 about and we'll start to move on to our next big topic.