WEBVTT 00:00.920 --> 00:05.910 -In this section, we will get introduced to the S3 service in AWS. 00:07.340 --> 00:10.120 S3 stands for Simple Storage Service. 00:11.400 --> 00:15.990 This service provides an infinitely scalable storage solution from AWS. 00:16.510 --> 00:20.220 It also offers high availability of data by storing it 00:20.250 --> 00:23.590 across multiple devices and availability zones in a region. 00:24.630 --> 00:26.790 S3 is an object based storage. 00:27.290 --> 00:31.250 It allows us to store objects or flat files, such as documents, 00:31.400 --> 00:34.050 images, and videos in the AWS cloud. 00:35.460 --> 00:39.380 This is equivalent to a file share storage, such as NFS, which 00:39.380 --> 00:42.770 is suitable to store flat files, but not suitable to install an 00:42.770 --> 00:44.730 operating system or databases. 00:46.210 --> 00:50.030 Data in S3 is stored in the form of an S3 bucket. 00:50.860 --> 00:53.920 A bucket can be considered to be a container or a directory 00:53.940 --> 00:55.410 which stores all your files. 00:55.960 --> 00:58.360 You can create as many of these buckets as you 00:58.360 --> 01:00.010 need in your AWS account. 01:01.390 --> 01:03.620 Everything within a bucket is an object. 01:04.400 --> 01:07.820 For example, let's consider a bucket called all-pets. 01:08.090 --> 01:11.240 Within this, we can have individual files such as a 01:11.240 --> 01:16.810 document called pets.json and image called dog and a cat video. 01:17.660 --> 01:21.190 Besides these, you can also have files within a folder such 01:21.190 --> 01:25.810 as the cat.jpg file under the pictures folder and a dog.mp4 01:25.810 --> 01:27.540 file inside the videos folder. 01:28.570 --> 01:31.360 Each of these items that you see here is an object. 01:31.970 --> 01:35.390 In the case of the file within a folder, the path 01:35.420 --> 01:38.760 of the file including the folder is also an object. 01:40.420 --> 01:44.360 AWS provides a simple web interface to create an S3 bucket 01:44.410 --> 01:45.900 via the Management Console. 01:47.330 --> 01:50.220 When creating a bucket in AWS, there are a couple of 01:50.240 --> 01:51.840 considerations to be followed. 01:52.730 --> 01:54.490 The bucket name must be unique. 01:55.050 --> 01:58.470 This is because when creating a bucket, AWS also 01:58.500 --> 02:00.280 creates a DNS name for it. 02:01.550 --> 02:05.340 This DNS name will be accessible from anywhere in the world. 02:05.980 --> 02:09.400 No two buckets, not even those which are created on different 02:09.400 --> 02:10.880 accounts, can have the same name. 02:12.360 --> 02:15.550 Secondly, the name should also be DNS-compliant. 02:15.960 --> 02:19.420 This means that there should not be any uppercases or underscores. 02:19.890 --> 02:24.290 The name should be between 3 to 63 characters long, and it 02:24.300 --> 02:25.990 should not end with a dash. 02:27.110 --> 02:30.860 The maximum size of a file that can be uploaded is 5 terabytes. 02:32.020 --> 02:34.630 Check out the reference documentation for the complete 02:34.630 --> 02:36.780 list of bucket naming restrictions. 02:37.950 --> 02:41.260 Once a bucket is created, it can be accessed via a unique 02:41.260 --> 02:43.240 DNS name that looks like this. 02:44.290 --> 02:48.010 For example, if we create a bucket called all-pets in 02:48.010 --> 02:52.420 the us-west-1 region, the web address for this bucket would be 02:52.710 --> 02:58.710 https://all-pets.us-west-1. amazonaws.com. 02:59.540 --> 03:03.210 The objects within this bucket can now be accessed using the bucket 03:03.210 --> 03:05.590 name and the object names like this. 03:06.760 --> 03:11.710 Any object in an S3 bucket consists of an object data and metadata. 03:12.580 --> 03:16.450 The data consists of a key, which is the actual name of the object, 03:16.770 --> 03:20.260 and a value, which is the actual data referenced by that object. 03:21.110 --> 03:24.220 Metadata are details about the object stored in a bucket. 03:24.850 --> 03:28.520 For example, the time when the object was created, the owner, 03:28.610 --> 03:30.510 the size of the object, et cetera. 03:32.150 --> 03:36.270 Just like IAM users, when a bucket is created and objects 03:36.280 --> 03:40.810 uploaded to it, by default, AWS provides it the least permissions. 03:41.650 --> 03:44.730 This means that by default, no one can access the objects 03:44.740 --> 03:47.410 in the bucket with the exception of the bucket owner. 03:48.630 --> 03:51.720 Access to the bucket and its objects are governed by bucket 03:51.750 --> 03:53.950 policies and access control lists. 03:55.100 --> 03:58.140 Bucket policies are permissions that are granted at a bucket 03:58.140 --> 04:02.070 level, and access control lists are more fine-grained access 04:02.070 --> 04:05.000 that can be used to define permissions at an object level. 04:06.280 --> 04:10.270 In this course, we will take a look at some of the basic bucket policies 04:10.280 --> 04:12.230 to govern access to S3 buckets. 04:13.320 --> 04:18.120 These will be used later in S3 with Terraform lecture and the S3 Lab. 04:19.200 --> 04:23.370 To allow the IAM user called Lucy to be able to retrieve all 04:23.380 --> 04:27.060 objects in the example bucket called all-pets, we can make use 04:27.080 --> 04:29.010 of a bucket policy like this. 04:30.620 --> 04:34.560 Just like IAM policies, bucket policies are JSON documents, 04:35.000 --> 04:38.180 and when they are attached to a bucket, they can either grant or 04:38.180 --> 04:39.950 revoke access at a bucket level. 04:41.080 --> 04:43.940 Finally, with the bucket policy, we can provide access 04:43.940 --> 04:47.550 to IAM users, groups, or even public access to our buckets. 04:48.210 --> 04:52.090 We can even grant access to users from other AWS accounts.