I am attempting to access system parameters from a Lambda developed using C#
I have added the required lambda layer as per https://docs.aws.amazon.com/systems-manager/latest/userguide/ps-integration-lambda-extensions.html#ps-integration-lambda-extensions-sample-commands
The lambda execution role has the following in the IAM definition (???????? replacing actual account id)
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"ssm:*"
],
"Resource": "arn:aws:ssm:*:???????????:parameter/*"
}
]
}
As per the AWS page reference above I made a HTTP GET request to http://localhost:2773/systemsmanager/parameters/get/?name=/ClinMod/SyncfusionKey&version=1
This is failing with the following response
{
"Version": "1.1",
"Content": {
"Headers": [
{
"Key": "Content-Type",
"Value": [
"text/plain"
]
},
{
"Key": "Content-Length",
"Value": [
"31"
]
}
]
},
"StatusCode": 401,
"ReasonPhrase": "Unauthorized",
"Headers": [
{
"Key": "X-Amzn-Errortype",
"Value": [
"AccessDeniedException"
]
},
{
"Key": "Date",
"Value": [
"Thu, 01 Dec 2022 12:16:59 GMT"
]
}
],
"TrailingHeaders": [],
"RequestMessage": {
"Version": "1.1",
"VersionPolicy": 0,
"Content": null,
"Method": {
"Method": "GET"
},
"RequestUri": "http://localhost:2773/systemsmanager/parameters/get/?name=/ClinMod/SyncfusionKey&version=1",
"Headers": [],
"Properties": {},
"Options": {}
},
"IsSuccessStatusCode": false
}
Any clues where I am going wrong?
After a discussion on an AWS forum, it looks like the issue was that I was not setting a required header of the HTTP GET request.
For this to work, it needs the X-Aws-Parameters-Secrets-Token header set with the AWS_SESSION_TOKEN.
Once I did this it worked fine.