I am working on a project using AWS SAM local. I am invoking a function with
sam local invoke which successfully executes the function. The lambda function writes an image file into /tmp/image.png when the function is invoked. This writing operation happens in the environment of SAM local, the /tmp folder belongs to its docker environment.
Is there a way for me to access the files written into the /tmp folder while developing locally?
This apparently has been answered on their github:
Link
You create a /c/tmp directory and set the TMPDIR=/c/tmp environment variable while invoking.
echo '<!DOCTYPE html><html><head><title>HTML doc</title></head><body>Content<body></html>' | TMPDIR=/c/tmp sam local invoke "HtmlToPdfFunction"
Related
I try to run and test an AWS Lambda service written in Golang locally using SAM CLI. I have two problems:
The Lambda does not work locally if I use .zip files. When I deploy the code to AWS, it works without an issue, but if I try to run locally with .zip files, I get the following error:
A required privilege is not held by the client: 'handler' -> 'C:\Users\user\AppData\Local\Temp\tmpbvrpc0a9\bootstrap'
If I don't use .zip, then it works locally, but I still want to deploy as .zip and it is not feasible to change the template.yml every time I want to test locally
If I try to access AWS resources, I need to set the following environment variables:
AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEY
AWS_SESSION_TOKEN
However, if I set these variables in template.yml and then use sam local start-api --env-vars to fill them with the credentials, then the local environment works and can access AWS resources, but when I deploy the code to the real AWS, it gives an error, since these variables are reserved. I also tried to use different names for these variables, but then the local environment does not work, and also tried to omit these from template.yml and just use the local env-vars, but environment variables must be present in template.yml and cannot be created with env-vars, can only fill existing variables with values.
How can I make local env work but still be able to deploy to AWS?
For accessing AWS resources you need to look at IAM permissions rather than using programmatic access keys, check this document out for cloudformation.
To be clear virtually nothing deployed on AWS needs those keys, it's all about applying permissions to X(lambda, ec2 etc etc) - those keys are only really needed for the aws cli and some local envs like serverless and sam
The serverless framework now supports golang, if you're new I'd say give that a go while you get up to speed with IAM/Cloudformation.
I need to read a file in my lambda via sftp and save it locally for processing. The issue is that when running 'sam local' my lambda can only read from the local file system but not write to it.
Lambda functions can only write to a specific local area: /tmp
So that is the location you need to use if you want to write to a file.
See
Can I store a temp file on AWS Lambda Function?
https://aws.amazon.com/blogs/compute/choosing-between-aws-lambda-data-storage-options-in-web-apps/
The file system inside the container created by SAM when you run it locally is read-only.
I'm developing an application with micronaut using SAM CLI to deploy it on AWS Lambda. As I was including dependencies and developing new features, the function packages got bigger an bigger (now they are around 250MB). This makes deployment take a while.
On top of that every time I edit template.yaml and then run sam build && sam deploy to try a new configuration on S3, RDS, etc... I have to wait for gradle to build the function again (even though it's unchanged since the last deployment) and upload the whole package to S3.
As I'm trying to configure this application with many trials and errors on SAM, waiting for this process to complete just to get an error because of some misconfiguration is getting quite counterproductive.
Also my SAM s3 bcuket is at 10GB size after just a single day of work. This may get expensive on the long run.
Is there a way to avoid those gradle rebuilds and reuploads when teh function code is unchanged?
If you are only updating the template.yml file, you could copy the new version to ./.aws-sam/build folder and then run sam deploy
$ cp template.yml ./.aws-sam/build/template.yml
$ sam deploy
If you are editing a lambda you could try to update the function code by itself (after you create it in the template and deploy of course). That can be done via the AWS CLI update-function-code command:
rm index.zip
cd lambda
zip –X –r ../index.zip *
cd ..
aws lambda update-function-code --function-name MyLambdaFunction --zip-file fileb://index.zip
more info can be found here:
Alexa Blogs - Publishing Your Skill Code to Lambda via the Command Line Interface
AWS CLI Command Reference - lambda - update-function-code
my SAM s3 bcuket is at 10GB size
Heh. Yea start deleting stuff. Maybe you can write a script using aws s3?
So, I'm finally at the point where I can test my first Lambda function locally. As background, I've installed the AWS CLI under MacOS 10.14.2 (Mojave) and am able to access my AWS account. I've successfully zipped up my Lambda function and used 'aws lambda create-function' to deploy it.
I've installed aws-lambda-local (https://www.npmjs.com/package/aws-lambda-local) using 'npm install -g aws-lambda-local'.
But when I invoke the following from the Lambda function root:
lambda-local -l index.js -e event.json
I get the following error:
Invalid function name. It should be accessible from invocation place
Would someone please tell me why this is happening? I mean, the function name is most definitely valid.
Totally confused here!
According to the aws-lambda-local docs, there is no -l option. Use -f or --function to specify the file with the lambda function
I received following error in CloudWatch Logs after using AWS CodePipeline (AWS CodeBuild) to deploy my C# Lambda Function Code
Could not find the required 'MyAssembly.deps.json'.
This file should be present at the root of the deployment package.: LambdaException
The problem in my case was that the linux file permissions on files inside the Zip were set to 000; so when the zip was extracted by AWS Lambda; AWS Lambda did not have file permission to access the file MyAssembly.deps.json
I was using C# System.IO.Compression.ZipFile.CreateFromDirectory to author the zip file. I had to shell out to the native zip program to produce a zip file which worked.
Big thanks to https://forums.aws.amazon.com/message.jspa?messageID=856247
I know this is bit old question but writing answer for any user who are still facing the problem on windows system.
this is with dotnet core 3.1
The first command in package manager console to ensure the .deps.json included in publish files
dotnet publish /p:GenerateRuntimeConfigurationFiles=true
and than zip all files of publish folder in the same name of namespace folder. upload the zip file to AWS lambda using console.
worked.
If not than copy all project files ( not the published) in zip and upload to aws lambda.