Question

我正在AWS中构建一个应用程序，其中要编写许多Lambda函数-它们全部将通过运行以下代码来创建要查询的数据库实例：

mydb = mysql.connector.connect(
host="endpoint.rds.amazonaws.com",
user="user",
passwd="password",
database="dbname"
)

现在，我不想在每个Lambda函数中都明确包含此代码-我宁愿将其放在其他地方（在Layer或单独的Lambda函数中），以便可以简单地完成此操作通过这样的东西：

mydb = ConnectToDB()

关于如何执行此操作的任何想法？

Answer 1

解决了！我创建了一个名为DBConnections.py的python文件，其中包含以下功能-并将其包含在我的AWS Lambda Layer的部署包中。

SELECT I.MEDICATION_ID, M.MEDICATION_NAME, SUM(I.STOCK_LEVEL) AS STOCK_LEVEL,
       SUBSTR(M.MEDICATION_DESC,1,20) "Medication Description", M.MANUFACTURER, M.PACK_SIZE
  FROM INVENTORY I
  JOIN MEDICATION M ON M.MEDICATION_ID = I.MEDICATION_ID
 GROUP BY I.MEDICATION_ID, M.MEDICATION_NAME, SUBSTR(M.MEDICATION_DESC,1,20),
          M.MANUFACTURER, M.PACK_SIZE;

部署后，我唯一要做的就是：

def Connect():

mydb = mysql.connector.connect(
host="endpoint.amazonaws.com",
user="user",
passwd="password",
database="mydbname"
)

return mydb

Voilà。

Answer 2

您有一个正确的想法，假设您使用的是python，我会创建一个类似于以下内容的图层包：

library(ggplot2)
library(scales)

df = data.frame("No" = seq_len(20),
                "Perc" = c(72.0, 12.7273,
                           8.72727, rep(0.363636, 17)),
                "Codon" = as.factor(c("ATA","ATG","GTG", "ATG",
                                      rep("GTG",5), rep("ATA",6),
                                      rep("ATG",5))))

breaks <- unique(c(seq(0,1,by = 0.1), 
    seq(1,10, 1), seq(10,100, 10)))
labs = c("","0.1",rep("",8),"1", 
    rep("",8), "10", rep("",8), "100")

gg  <- ggplot(data = df, aes(x = No, y = Perc, fill = Codon))
gg + geom_bar(stat = "identity") + 
coord_flip(ylim = c(0.1,100)) + scale_x_reverse() +
    scale_y_continuous(
        trans = pseudo_log_trans(base = 10),
        breaks = breaks, position = "right",
        labels = labs)

其中mysql包括mysql软件包，而myPackage.py包括以下内容的某些变体：

python/
    myPackage.py
    mysql/

然后使用此脚本在lambda中创建一个图层：

import mysql

def ConnectToDB(**kwargs):
      return mysql.connector.connect(
                host=kwargs.get("YOUR_ENDPOINT"),
                user=kwargs.get("YOUR_USER"),
                passwd=kwargs.get("YOUR_PASSWORD"),
                database=kwargs.get("YOUR_DBNAME")
          )

然后您可以将图层与lambda函数关联，并使用以下语法将包导入lambda中：

#!/bin/bash

#Required variables
LAYER_NAME="YOUR_LAYER_NAME"
LAYER_DESCRIPTION="YOUR_LAYER_DESCRIPTION"
LAYER_RUNTIMES="python3.6 python3.7"
S3_BUCKET="YOUR_S3_BUCKET"

#Zip Package Files
zip -r ${LAYER_NAME}.zip .
echo "Zipped ${LAYER_NAME}"

#Upload Package to Lambda
aws s3 cp ./${LAYER_NAME}.zip s3://${S3_BUCKET}

#Create new layer
aws lambda publish-layer-version --layer-name ${LAYER_NAME} --description "${LAYER_DESCRIPTION}" --content S3Bucket=${S3_BUCKET},S3Key=${LAYER_NAME}.zip --compatible-runtimes ${LAYER_RUNTIMES}

#Cleanup zip files
rm ${LAYER_NAME}.zip

如何在AWS Lambda中抽象数据库连接？

2 个答案: