I am currentluy working on the AppConfig but don't know whether I should use a JSON schema validator or a lambda function as a validator. What is diffrenet between JSON schema and Lambda function? What benefit do they have?
I created a JSON schema and it's easy, but the file is large. I wonder if a lambda function could help and what the lambda function would look like.
The AppConfig JSON Schema Validator is a syntactic validation that allows you to check values in the JSON data itself. You can set constraints in your JSON Schema to check a value is not null, a number is within a certain range, a string has certain characters, etc.
The AppConfig Lambda Validator is more of a functional validation. Since Lambda allows you to do execute logic, you can use a Lambda Validator to run a query, do service discovery, or confirm the state of your resources before the new configuration data/feature flag is pushed out/deployed. A Lambda Validator will let you check pretty much anything. You can use a Lambda Validator to confirm syntactically the contents of the data too, but usually JSON Schema is better for that.
N.B.: I work on the AppConfig Team at AWS
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I am using a graphql API with AppSync that receives post requests from a lambda function that is triggered by AWS IoT with sensor data in the following JSON format:
{
"scoredata": {
"id": "240",
"distance": 124,
"timestamp": "09:21:11",
"Date": "04/16/2022"
}
}
The lambda function uses this JSON object to perform a post request on the graphql API, and AppSync puts this data in DynamoDB to be stored. My issue is that whenever I parse the JSON object within my lambda function to retrieve the id value, the id value does not match with the id value stored in DynamoDB; appsync is seemingly automatically generating an id.
Here is a screenshot of the request made to the graphql api from cloudwatch:
Here is what DynamoDB is storing:
I would like to know why the id in DynamoDB is shown as 964a3cb2-1d3d-4f1e-a94a-9e4640372963" when the post request id value is "240" and if there is anything I can do to fix this.
I can’t tell for certain but i’m guessing that dynamo db schema is autogenerating the id field on insert and using a uuid as the id type. An alternative would be to introduce a new property like score_id to store this extraneous id.
If you are using amplify most likely the request mapping templates you are generating automatically identify the "id" field as a unique identifier to be generated at runtime.
I recommend you to take a look at your VTL request template, you will most likely find something like this:
$util.qr($context.args.input.put("id", $util.defaultIfNull($ctx.args.input.id, $util.autoId())))
Surely the self-generated id comes from $util.autoId()
Probably some older version of Amplify could omit the verification $util.defaultIfNull($ctx.args.input.id,... and always overwrite the id by self-generating it.
I am trying to use the 'newUUID()' aws iot function in the AWS SiteWise service (as part of an alarm action) that returns a random 16-byte UUID to be stored as a partition key for a DynamoDb tables partition key column.
With reference to the attached screenshot, in the 'PartitionKeyValue' trying to
use the value returned by newUUID() function that will be passed to the DynamoDb as part of the action trigger.
Although this gives an error as follows:
"Invalid Request exception: Failed to parse expression due to: Invalid expression. Unrecognized function: newUUID".
I do understand the error, but not sure how can I solve this and use a random UUID generator. Kindly note that I do not want to use a timestamp, because there could be eventualities where multiple events get triggered at the same time and hence the same timestamp.
Any ideas that how can I use this function, or any other information that helps me achieve the above-mentioned.
The docs you refer to say that function is all lowercase newuuid().
Perhaps that will work, but I believe that function is only available in IoT Core SQL Statements. I think with event notifications, you only have these expressions to work with, which is not much. Essentially, you need to get what you need from the alarm event itself.
You may need the alarm event to invoke Lambda, rather than directly write to DynamoDB. Your Lambda function can create a UUID and write the alarm record to DynamoDB using the SDKs.
I am quite new to the CDK, but I'm adding a LogQueryWidget to my CloudWatch Dashboard through the CDK, and I need a way to add all LogGroups ending with a suffix to the query.
Is there a way to either loop through all existing LogGroups and finding the ones with the correct suffix, or a way to search through LogGroups.
const queryWidget = new LogQueryWidget({
title: "Error Rate",
logGroupNames: ['/aws/lambda/someLogGroup'],
view: LogQueryVisualizationType.TABLE,
queryLines: [
'fields #message',
'filter #message like /(?i)error/'
],
})
Is there anyway I can add it so logGroupNames contains all LogGroups that end with a specific suffix?
You cannot do that dynamically (i.e. you can't make this work such that if you add a new LogGroup, the query automatically adjusts), without using something like AWS lambda that periodically updates your Log Query.
However, because CDK is just a code, there is nothing stopping you from making an AWS SDK API call inside the code to retrieve all the log groups (See https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/CloudWatchLogs.html#describeLogGroups-property) and then populate logGroupNames accordingly.
That way, when CDK compiles, it will make an API call to fetch LogGroups and then generated CloudFormation will contain the log groups you need. Note that this list will only be updated when you re-synthesize and re-deploy your stack.
Finally, note that there is a limit on how many Log Groups you can query with Log Insights (20 according to https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/AnalyzingLogData.html).
If you want to achieve this, you can create a custom resource using AwsCustomResource and AwsSdkCall classes to do the AWS SDK API call (as mentioned by #Tofig above) as part of the deployment. You can read data from the API call response as well and act on it as you want.
Is there a simple way to retrieve all items from a DynamoDB table using a mapping template in an API Gateway endpoint? I usually use a lambda to process the data before returning it but this is such a simple task that a Lambda seems like an overkill.
I have a table that contains data with the following format:
roleAttributeName roleHierarchyLevel roleIsActive roleName
"admin" 99 true "Admin"
"director" 90 true "Director"
"areaManager" 80 false "Area Manager"
I'm happy with getting the data, doesn't matter the representation as I can later transform it further down in my code.
I've been looking around but all tutorials explain how to get specific bits of data through queries and params like roles/{roleAttributeName} but I just want to hit roles/ and get all items.
All you need to do is
create a resource (without curly braces since we dont need a particular item)
create a get method
use Scan instead of Query in Action while configuring the integration request.
Configurations as follows :
enter image description here
now try test...you should get the response.
to try it out on postman deploy the api first and then use the provided link into postman followed by your resource name.
API Gateway allows you to Proxy DynamoDB as a service. Here you have an interesting tutorial on how to do it (you can ignore the part related to index to make it work).
To retrieve all the items from a table, you can use Scan as the action in API Gateway. Keep in mind that DynamoDB limits the query sizes to 1MB either for Scan and Query actions.
You can also limit your own query before it is automatically done by using the Limit parameter.
AWS DynamoDB Scan Reference
I'm a newbie rails programmer, and I have even less experience with all the AWS products. I'm trying to use lambda to subscribe to and consume an rss feed from youtube. I am able to send the subscription request just fine with HTTParty from my locally hosted rails app:
query = {'hub.mode':'subscribe', 'hub.verify':'sync', 'hub.topic': 'https://www.youtube.com/feeds/videos.xml?channel_id=CHANNELID', 'hub.callback':'API Endpoint for Lambda'}
subscribe = 'HTTParty.post(https://pubsubhubbub.appspot.com/subscribe, :query=>query)
and it will ping the lambda function with a get request. I know that I need to echo back a hub.challenge string, but I don't know how. The lambda event is empty, I didn't see anything useful in the context. I tried formatting the response in the API gateway but that didn't work either. So right now when I try to subscribe I get back a 'Challenge Mismatch' error.
I know this: https://pubsubhubbub.googlecode.come/git/pubsubhubbub-core-0.3.html#subscribing explains what I'm trying to do better than what I just did, and section 6.2.1 is where the breakdown is. How do I set up either the AWS Lambda function and/or the API Gateway to reflect back the 'hub.challenge' verification token string?
You need to use the parameter mapping functionality of API Gateway to map the parameters from the incoming query string to a parameter passed to your Lambda function. From the documentation link you provided, it looks like you'll at least need to map the hub.challenge query string parameter, but you may also need the other parameters (hub.mode, hub.topic, and hub.verify_token) depending on what validation logic (if any) that you're implementing.
The first step is to declare your query string parameters in the method request page. Once you have declared the parameters open the integration request page (where you specify which Lambda function API Gateway should call) and use the "+" icon to add a new template. In the template you will have to specify a content type (application/json), and then the body you want to send to Lambda. You can read both query string and header parameters using the params() function. In that input mapping field you are creating the event body that is posted to AWS Lambda. For example: { "challenge": "$input.params('hub.challenge')" }
Documentation for mapping query string parameters