Update landing request API for use in GatewayAPI demonstrations where multiple services are involved #5
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…al landing request microservice mode, controlled by environment variables Signed-off-by: Jef Spaleta <[email protected]>
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If this were targeted for use in production environments, I would probably scrutinize this a bit more just given the nature of relaying requests to a third party, however given this is primarily used as a demo tool this is probably fine. I'd prefer an approval from someone actually familiar with this code.
| Build and push to a registry with `make publish`. You can specify the image tag with the env var `IMAGE` (defaults to `cilium/starwars`). | ||
| Build and push to a registry with `make publish`. You can specify the image tag with the env var `IMAGE` (defaults to `cilium/starwars`) | ||
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| ## Set custom landing response msg |
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For clarity in this readme it might be nice to have an H2 something like "Runtime env vars", to distinguish from the "Build and publish" section that mentions setting a build-time env var
| if err != nil { | ||
| fmt.Printf("client: error making http request: %s\n", err) | ||
| return operations.NewPostRequestLandingServiceUnavailable().WithPayload( | ||
| "Request Forward to " + landingRequestURL + " Failed\nUnknon Request Error") |
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| "Request Forward to " + landingRequestURL + " Failed\nUnknon Request Error") | |
| "Request Forward to " + landingRequestURL + " Failed\nUnknown Request Error") |
| return operations.NewPostRequestLandingOK().WithPayload("Ship landed\n") | ||
| var landingRequestURL, ok = os.LookupEnv("LANDING_REQUEST_URL") | ||
| if !ok { | ||
| return operations.NewPostRequestLandingOK().WithPayload(landingResponse() + "\n") |
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I would have landingResponse() include the terminating \n. It already returns one of them, might as well add all of them in one place
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Also - and this is really not a big deal especially since it's demo code - for readability I'd have split this out into a named function, rather than have quite so many if / else indents. But really not a big deal
This implements two features exposed as optional environment variables that helped me extend the existing starwars tutorial into more complicated demo service environments using Ingress and GatewayAPI without needing additional images.
Here's what is implemented:
LANDING_RESPONSE_MSG
This environment variable allows the default landing request response to be replaced on a service backend basis. This is very useful to communicate back to the curl client which cluster service backend you are actually talking with while making a series of changes to ingress or gatewayAPI rules as part of a guided walkthrough.
LANDING_REQUEST_URL
This environment variable allows starwars image based service to call a separate landing request service URL when a landing request is made. I used this to create thin multi-team microservice configuration involving multiple services using the same starwars image.
I used these environment variables in my gateway API/ingress demos at SCALE conference, to show some 'interesting' starwars themed examples that extend the death star service example. I'm hoping to build a documented example(s) for Cilium docs along the same lines, but first I'd like to get the official starwars service docker image updated with these optional capability so I can use the official images in the deployment manifests I write-up.