In this section, we will create a user pool by using CLI commands:

1. Generate the input JSON template, using the generate-cli-skeleton option:

aws cognito-idp create-user-pool 
    --pool-name my-pool-from-cli 
    --generate-cli-skeleton

This command will return a template with all of the supported properties for the create-user-pool sub-command, in the correct JSON format. 

2. Fill in the properties that are required within the JSON file, and remove the properties that are not required:
   1. Start the JSON file, specifying a name by using the PoolName property:

{
  "PoolName": "MyFirstUserPool",

2. 2. Under the Policies section, we will define the password policy, using the PasswordPolicy sub-property:

"Policies": {
  "PasswordPolicy": {
    "MinimumLength": 8,
    "RequireUppercase": true,
    "RequireLowercase": true,
    "RequireNumbers": true,
    "RequireSymbols": true
  }
},

3. 3. Define AutoVerifiedAttributes and AliasAttributes, as follows:

"AutoVerifiedAttributes": [
  "email"
],
"AliasAttributes": [
  "email"
],

Refer to the How it works... section for more details.

1. 4. Define an email verification message and an email verification subject:

"EmailVerificationMessage": "Your verification code from MyApp is {####}.",
"EmailVerificationSubject": "Your verification code from MyApp",

1. 5. Define a tag by using the UserPoolTags property, as follows:

"UserPoolTags": {
  "Team": "Dev"
},

1. 6. Define the AdminCreateUserConfig property, as follows:

"AdminCreateUserConfig": {
  "AllowAdminCreateUserOnly": false,
  "UnusedAccountValidityDays": 7,
  "InviteMessageTemplate": {
    "EmailMessage": "Your username for MyApp is {username} and password is {####}.",
    "EmailSubject": "Your temporary password for MyApp"
  }
}

The AllowAdminCreateOnly property, if set to true, restricts creating accounts to administrators. We will set it to false, as we will be doing user sign-up with this user pool in a later recipe. The complete JSON file is available in the code files.

3. Execute the aws congnito-idp create-user-pool command, specifying this JSON file:

aws cognito-idp create-user-pool 
    --cli-input-json file://resources/create-user-pool-cli-input.json 
    --profile admin

Note the user-pool-id, for use in future commands.

We can verify user-pool-created by using the describe-user-pool sub-command:

aws cognito-idp describe-user-pool 
    --user-pool-id us-east-1_u0YJPtdpv 
    --profile admin

Remember to replace the user-pool-id value with our user-pool-id from the previous command. The describe-user-pool sub-command returns the current properties of the user-pool.