I have several AWS SAM templates for the same project, where the lambdas use Python 3.8, partly for different environments, and partly to try out new things, and I use -t my-template.yaml to specify which template to use.
I build using the regular sam build -t my-template.yaml && sam deploy -t my-template.yaml.
Problem: the requirements.txt file seems to be respected in the build step appears to be ignored by the deploy step.
.aws-sam/build/MyFunction contains the requirements:
$ ls
app.py
certifi-2020.12.5.dist-info
chardet-4.0.0.dist-info
idna-2.10.dist-info
pymysql
rds_config.py
requests-2.25.1.dist-info
urllib3
certifi
chardet
idna
__init__.py
PyMySQL-1.0.2.dist-info
requests
requirements.txt
urllib3-1.26.3.dist-info
But when running in the cloud, the lambda fails with an exception saying that pymysql is not found, and when I check the function in the AWS UI, there are no requirements included (eg. no PyMySQL-1.0.2.dist-info).
I noticed that if I don't use the -t flag on sam deploy and just have the default template.yaml file there, then the requirements appear to be included correctly, and the lambda runs successfully.
What may I be doing wrong?
requirements.txt contents:
$ cat requirements.txt
requests
pymysql
SAM version:
$ sam --version
SAM CLI, version 1.18.1
OS:
$ cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
....
The solution was to use:
sam build -t my-template.yaml
But then do:
sam deploy
without adding -t my-template.yaml again
Answer from the ticket below:
What you are doing is telling sam deploy to use the "source template" which points to non-built functions. Instead, if you drop the -t from the sam deploy command, SAM CLI will pick up the built template from .aws-sam/build/template.yaml which will have all the dependencies "installed".
https://github.com/aws/serverless-application-model/issues/1927