I have a rails 3.2 server, Android App, our own API and AWS Cognito. Our backend is using PostgreSQL. How do I save the datasets created in cognito sync to our database? Should I listen for the callback of cognito sync's success then save the data using our API? or should I use the aws-sdk at the rails server to get the dataset? I don't want the android app to talk directly to RDS and S3.
I think you could use Cognito Events for that: You can set up an Amazon Lambda function that will trigger every time a dataset is updated so you can implement your own logic there.
Cognito Streams would also work, and might be faster because it's async: it makes every dataset update be written to a Kinesis stream, and then you can make your backend consume from that stream.
Updated as above link was not working.
https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-events.html
https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-streams.html
AWS AppSync simplifies application development by letting you create a flexible API to securely access, manipulate, and combine data from one or more data sources. AppSync is a managed service that uses GraphQL to make it easy for applications to get exactly the data they need.
If you're new to Amazon Cognito Sync, use AWS AppSync. Like Amazon
Cognito Sync, AWS AppSync is a service for synchronizing application
data across devices.
A single GraphQL API to deliver private and public data. Private data requires authenticated access using authorization mechanisms such as IAM, Amazon Cognito User Pools, and OIDC. Public data does not require authenticated access and is delivered through authorization mechanisms such as API Keys.
https://aws.amazon.com//appsync/
You can use aws-amplify to sync
https://aws-amplify.github.io/docs/js/api
https://forums.aws.amazon.com/message.jspa?messageID=918861
https://aws.amazon.com/blogs/mobile/using-multiple-authorization-types-with-aws-appsync-graphql-apis/
https://medium.com/open-graphql/authenticating-an-aws-appsync-graphql-api-with-auth0-48835691810a
https://hackernoon.com/aws-appsync-queries-and-mutations-with-lambda-2aee303c66b0
Related
I'm trying to create an external API using AWS API Gateway that will give users access to data stored in multiple databases. The APIs will mostly be accessed through scripts rather than through a web UI.
Are there any AWS services I can use to manage user access to my API?
I've read a little bit about Amazon Cognito and OAuth 2 but at a glance it seems like those might be more targeted towards cases with a UI for users to interact with. Is there a way to create and manage API keys with AWS?
Thanks in advance for your help!
You can use API Gateway Lambda Authorizer to write your custom login integration. For example a lambda that check in one Database if the user:password (passed as authorization header) exists in table in DynamoDB or SQL.
I've built an application which is connected with Amazon Cognito to take the sign in and sign-ups of users. Currently, application support three different subscriptions (Free, Basic, Premium). If the user signs in for basic Subscriptions, I want to give them least access to DynamoDB for download the parts of applications which is required to run the application service.
How to connect DynamoDB with Cognito directly
I am not sure, what's the best approach to follow this scenario?
(Please note- this is not a mobile-based application, so do not give suggestion to use AWS Amplify or relatable services)
When I was first learning about Cognito, I had made the same set of assumptions you are currently making. I knew that User Pools could act as my application's user directory, and Identity Pools would magically unlock all my authorization needs. I was mistaken :)
At the risk of oversimplifying, AWS Cognito exists to answer two questions:
Who are you? (authentication)
What can you do? (authorization)
Cognito addresses these concerns with two distinct offerings: User Pools (authentication) and Identity Pools (authorization).
At a high level, User Pools let you handle user registration, authentication, account recovery, and supports authentication with third-party identity providers like Facebook, Google, etc. Sounds like you might have this part figured out.
Cognito Identity Pools, on the other hand, provides a way to authorize users to use various AWS services. You can think of it as a vending machine for handing out AWS credentials. For example, if you needed to give your users access to upload a file to an S3 bucket or to invoke an endpoint in API Gateway, you could do so with an Identity Pool. You can even allow item-level access to DynamoDB based on an Amazon Cognito ID. However, this might not work the way you expect since your application users are probably not directly connecting to DynamoDB.
In most web/mobile applications, users are not connecting directly to DynamoDB. Instead, they are interacting with a web/mobile app that communicates to the back-end of your application via an API. That API would then communicate with DynamoDB. If your stack is in AWS, the path may look something like this:
Client (web/mobile app) <-> API Gateway <-> Lambda <-> DynamoDB
In this architecture, your users would authenticate via Cognito. Cognito would then authorize the user to make calls to API Gateway. API Gateway would execute your lambda, which would then interact with DynamoDB. The "user" of DynamoDB in this example is your Lambda, not the user of your application.
That last bit is important, so I'll repeat it: Unless your users are directly connecting to DynamoDB (not recommended), they are not the "user" operating on DynamoDb. Therefore, restricting DynamoDB access based on a user's Cognito ID is not going to be an option for you.
So, what can you do? Your application needs to provide the business logic around what effect your users can have on DynamoDB. Perhaps free users have read-only access to a specific partition, while premium users can modify the same partition. That logic has to be handled directly by you.
I know you said you weren't looking for Amplify suggestions since your application is not mobile-based. However, Amplify offers SDKs that aren't specific to mobile development. The folks at Serverless have made a fantastic tutorial on building a full-stack serverless web app, which includes a very readable chapter on serverless auth with Cognito. They use Amplify in a web app to integrate with Cognito, S3, and API Gateway. If that's something you are trying to do, I'd recommend checking it out.
Well, I have a web page (PHP) that is running on-premise and it's accessed from different countries. I would like to catch some data and store it somewhere. I can handle internally with the team the data and the format of the file to catch the info. But we would like to get leverage of AWS to store it in S3. So we notice that we need an intermedium layer to avoid use AWS credentials required for S3.
as this page is on the internet and it's consumed by a user thru web for sure we don't want to include anything for credentials embedded in the site. So likely Kinesis data firehose as consumer role could just catch the data send by our page and then internally store it in S3.
Question
I see that exist an SDK for Kinesis but it requires AWS credentials. We really need a kind of link where we need the data produced and AWS handles the rest. But I don't know why I require to set up AWS credentials using the SDK. Does it mean then that our website will load and live with our credentials? I don't feel this approach secure. I appreciate the comments.
You can use API Gateway Kinesis Proxy to avoid using credentials or even aws-sdk in your webpages.
https://docs.aws.amazon.com/apigateway/latest/developerguide/integrating-api-with-aws-services-kinesis.html
This way you don't need to expose any credentials and control permissions with a role.
If you are worried about having a security issue and if the users are authenticated, you can use custom authorizers to authorize the url.
https://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html
If it is public facing, then just the above integration should work.
Hope it helps.
I want to use Cognito for authentification and s3 to store files (images) for a new app (ionic 3). But AWS isn't simple to use and as soon as I start doing something, I need to read another doc somewhere and end up with 15 tabs of documentation open. With twice as many questions.
Do I need a server (nodejs on EC2), lambda (??) or everything can be serverless (direct access to Cognito and s3)? I wish to implement a subscription system at some point.
The user should have access to a list of images (like an infographic) only if he is subscribed. The app is aimed to be deployed on Play store and iOS.
Does the user (mail/password) exist ?
Is he subscribed (monthly) ?
access to the database (read-only)
Based on the app features that you provided, you can use the following:
AWS Cognito for user authentication
AWS API Gateway and AWS Lambda for your backend REST (or GraphQL) API
AWS DynamoDB for database (or Amazon RDS if you want to use an SQL database)
AWS S3 for image storage
If your app is really basic, I think you can even skip 2 and 3.
So since parse is shutting down we are moving our website / mobile app that we've been developing to AWS. We are primarily going to use the following services:
SNS, SES, Dynamo, S3, Lambda.
Now I am still a bit confused on:
what cognito is used for? Do we really need cognito to authenticate users and use DynamoDB, S3, SNS ? Or can we just use specific APIs for each of these services and connect directly (using Js SDK)?
If we do have to use cognito how do we save local data i.e logged in user/ identity? is that what cognito sync is for or do we have to use cookies ?
In summary why do I need cognito when I can directly connect to DynamoDB using the JavaScript SDK?!
Thank you in Advance.
Amazon Cognito can be decomposed in two sub-services: Amazon Cognito Identity and Amazon Cognito Sync.
Think of the former as an authentication service and a credentials provider. The latter is just a service to store user data and keep it synchronized between multiple devices.
What is the purpose of Amazon Cognito Identity?
Suppose that you have a table in DynamoDB. Let's say that you have a web application that will store an item on that table.
You can create an user in IAM, embed the credential information on the web application, and then put the item on the table using the AWS SDK.
There are three things going on here:
The credentials are embedded in the application
The credentials do not expire.
Every user in your application has the same access rights on your table
This may be fine for some applications, but Amazon Cognito Identity offers a solution to these common problems.
Let me explain Cognito Identity's workflow:
An user registers an account on your application, sending all the information (username, password, other data...) to your server.
The server stores the user in some back-end database (it could be a DynamoDB table) and creates a new identity on the Cognito service. This identity is then mapped to this user.
The user can now login into your application. The user logins and sends username and password to your server. (This process could be done automatically after account registration)
The server checks the username and password against your back-end database. If everything is right, then the server makes a request to Amazon Cognito for a temporary access token.
The web application receives the token and makes a request to Amazon Cognito (using that access token) to get the user credentials. These credentials are basically a temporary IAM user that was created specifically for this user. It will have an expiration (usually an hour).
The web application uses these credentials to make operations on AWS, such as putting an item on a DynamoDB table, or calling a Lambda.
When the credentials expire, the user must re-login into the application. This might be done automatically or not, depending on your application's requirements.
On the Amazon Cognito dashboard, you can configure roles and policies for your "identities" (an user in Cognito). This way you can specify which services it can access. It even allows you to create access roles for your users (Admin users may be able to access some services that normal users should not).
I should also note that Amazon Cognito can be easily adapted to support Facebook / Google+ / Amazon accounts, which will be mapped to the same identity, so the user can login via multiple sources.
What is the purpose of Amazon Cognito Sync?
Consider it like a DynamoDB table where you store information for a specific user. These information is shared between multiple devices and is always synchronized. This means that when a web application updates an user value, then the mobile application will automatically reflect this change.
There is a limit on how much user data you can store (I don't remember now), so it's not something you would use to persist information (such as an user password), but rather a mean to share information.