With Tencent cloud cloud function to achieve a minimalist API Gateway
Intro
Micro-letter domain name applet requires the record, but no servers continent, and I think the record somewhat cumbersome at first to do a little applet want to give up, and later learned that Tencent cloud cloud function, so use Tencent cloud cloud function implements a simple API gateway to call the real address through the cloud API function, thereby to circumvent the problem of domain name for the record.
Introduction to Cloud function
Tencent and so on function (Serverless Cloud Function, SCF) is Tencent cloud for businesses and developers No server execution environment to help you run the code without the need to purchase and manage server, is a real-time file processing and data processing and other scenes ideal computing platform. You simply write the conditions using SCF platform supported language core code and set the code running, elasticity can safely run code on Tencent cloud infrastructure.
Changes computing resources
With the development of cloud services, computing resources, highly abstract, Tencent cloud offers from physical servers to the cloud across a variety of functions and level of abstraction of computing resources for users to choose.
- Blackstone physical servers: the physical machine extension units. User computing entity wholly owned by the whole resource, the best security.
- Cloud server (CVM): cloud server expansion unit, virtualized hardware devices. Users and other tenants to share physical machine resources, CVM can still configure their own indicators of relative and iterative deployment easier.
- Containers: to serve as an extension unit, virtualized operating system. Test and production environments exactly the same, testing and deployment very easy.
- Cloud function: The function expansion unit, virtualized run-time environment (Runtime). Is the smallest unit of existing computing resources, it has a fully automated, one-click deploy, highly scalable and other characteristics, is a lightweight service deployment very good choice.
Overview serverless
No server (Serverless) is not that there is no server, means that when you use Serverless, you do not care about the underlying resources, without having to log server and optimization server, just focus on the core code snippet, you can skip the complicated, tedious the basic work. The core code snippet entirely by an event or request triggers, parallel platform automatically adjust resources according to the service request. Serverless have virtually unlimited expansion capability, idle, do not run any resources. Stateless code runs, you can easily achieve rapid iteration, speed deployment.
More Description Reference official documents
Tencent cloud functions currently free credit can be used, not the application, which can be enough:
I'm just a demo of this feature, the amount should be sufficient for free, use the minimum memory configuration to run properly properly month no problem, there will be time left.
60 * 60 * 24 * 31 = 2,678,400 < 3,200,000
Create a cloud function
Create a cloud function:
Provides a number of default templates, you can create according to their own needs, I choose here empty functions, select the operating environment is nodejs 8.9, then the next step can
If your method is relatively simple and can be edited directly and then complete a good, if more complex, then you can complete the first, well then updates your local editor.
Use
Cloud Gateway API function Source: https://github.com/WeihanLi/ActivityReservation/tree/dev/ActivityReservation.Clients/ReservationApiFunction
Cloud function update
Modify the index.tsfile to be forwarded address
Execute in the directory tsc, js generated after compilation
To perform under the dist directory npm install, install dependencies, currently used only one got, if you use something else please package.jsonadd a file, or performnpm install <package-name> --save
After packing the contents of the dist directory under the zip, you can then upload to the console Tencent cloud
Note that the archive can not contain dist directory, open the archive after the code is
dist.zip
- -- node_modules
- -- httpRequester.js
- -- index.js
- -- packages.json
- Configuration Trigger:
There will be created after creating the API Gateway in the API Gateway trigger a service, and will get the address of an access
We visit the following path to access to our api, and examples:
This request will be forwarded to the actual https://reservation.weihanli.xyz/api/notice
Use this address in the request interface address applet on it, thus temporarily bypass the applet server domain name for the record ~~
The principle
Forwards the request to implement a simple API Gateway
Implementation issues encountered in the process
unable to verify the first certificate
This is the problem https request a certificate of verification, reference StackOverflow https://stackoverflow.com/questions/31673587/error-unable-to-verify-the-first-certificate-in-nodejs/32440021
By setting up an environment variable NODE_TLS_REJECT_UNAUTHORIZED=0to solve
Access api 404
After the visit, by looking at the log, the output of address discovery request, request the path is with the function name, so the function name can be removed
if ((<string>event.path).startsWith('/reservationWxAppGateway')) {
event.path = (<string>event.path).replace('/reservationWxAppGateway', '');
}Later found in the eventparameters, there are two event.requestContext.pathto represent the cloud function path, this path is the real path to remove the request
if((<string>event.path).startsWith(`${event.requestContext.path}`)){
event.path = (<string>event.path).replace(`${event.requestContext.path}`, '');
}Forward the request header
When forwarding the request header, hostrequest header can not pass, I pass headers when the hostrequest is set to headundefined
headers["host"]= undefined;