= AWS/LambdaExamples =
 * 2021 - Coursera course

 * Bash script to upload python lambda in zip file {{{
#!highlight bash
import boto3
import subprocess

client = boto3.client('lambda')
ROLE = 'arn:' + subprocess.getoutput('aws iam list-roles | grep role/lab4 | cut -f3- -d : | cut  --complement -c 44,45')
BUCKET = subprocess.getoutput('aws s3api list-buckets --query "Buckets[].Name" | grep s3bucket | tr -d "," | xargs')


response = client.create_function(
    FunctionName='get_reviews',
    Runtime='python3.8',
    Role=ROLE,
    Handler='get_reviews_code.lambda_handler',
    Code={
        'S3Bucket': BUCKET,
        'S3Key': 'get_reviews.zip'
    }
   
)

print ("DONE")
}}}

 * Python lambda example from course
   * APIGW setup, Integration mapping template, Content-Type application/json {{{
{

    "product_id_str": "$input.params().querystring.get('product_id')"

}
}}}
   * Test ApiGW Method Execution, "Query Strings  {get_reviews}" {{{
product_id=TESTID
}}}
   * API GW Integration response Header Mappings
    ||Response header || Mapping value	  ||
    ||Access-Control-Allow-Headers || 'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token' ||
    ||Access-Control-Allow-Methods || 'GET' ||
    ||Access-Control-Allow-Origin || '*' ||

   * Python lambda code {{{
#!highlight python
import boto3
import json
import re 

def lambda_handler(event, context):
    product_id_str = event['product_id_str']
    S3_BUCKET = 'aws-tc-largeobjects'
    S3_FILE = 'DEV-AWS-MO-Building_2.0/my_json_lines.jsonl'

    s3 = boto3.client('s3')

    r = s3.select_object_content(
            Bucket=S3_BUCKET,
            Key=S3_FILE,
            ExpressionType='SQL',
            Expression="select s.review_headline, s.review_body, s.star_rating from s3object[*] s where s.product_id = '" + product_id_str + "'",
            InputSerialization={'JSON': {"Type": "Lines"}},
            OutputSerialization={'JSON': {}}
    )
    
    all_reviews_list = []
    helper_format_str = ""
    for event in r['Payload']:
        if 'Records' in event:
            helper_format_str = event['Records']['Payload'].decode('utf-8')
            helper_format_str = helper_format_str.replace("review_headline", "review_headline_str").replace("review_body", "review_body_str")
            all_reviews_list = helper_format_str.splitlines()
            
    result_list = []
    for review_chunk in all_reviews_list:
        result_list.append(json.loads(review_chunk))
    
    return {
        "product_id_str" : product_id_str,
        "reviews_arr": result_list
    }
}}}

 * lambda python, checking and extracting info from Bearer token {{{
#!highlight python
import json
import base64

def lambda_handler(event, context):
    token_str = ""
    ipv4_str = ""
    decoded = {}
    return_me = {}
    name_str = ""
    extract_str = ""
    cell_str = ""
    return_me["message_str"] =  "Report processing, check your phone shortly"
    if "Authorization" in json.dumps(event):
        #i.e we are at the website and have a valid Bearer token passed
        token_str = event["params"]["header"]["Authorization"]
        extract_str = token_str.replace("Bearer ", "").strip().split(".")[1]
        extract_str += '=' * (-len(extract_str) % 4)
        decoded = json.loads(base64.b64decode(extract_str))
        cell_str = decoded["phone_number"]
        name_str = decoded["cognito:username"]
        ipv4_str = event["params"]["header"]["X-Forwarded-For"]
        return_me["cell_str"] = cell_str
        return_me["name_str"] = name_str
        return_me["name_str"] = decoded["cognito:username"]
        return_me["ipv4_str"] = ipv4_str
        return_me["message_str"] = "Report Processing"
    return return_me

}}}