camper/pkg/http/request.go

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Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
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/*
* SPDX-FileCopyrightText: 2023 jordi fita mas <jfita@peritasoft.com>
* SPDX-License-Identifier: AGPL-3.0-only
*/
package http
import (
"net"
"net/http"
"path"
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
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"strings"
)
func RemoteAddr(r *http.Request) string {
address, _, _ := net.SplitHostPort(r.RemoteAddr)
if address != "localhost" && address != "127.0.0.1" && address != "::1" {
return address
}
forwarded := r.Header.Get("X-Forwarded-For")
if forwarded == "" {
return address
}
ips := strings.Split(forwarded, ", ")
forwarded = ips[0]
if forwarded == "" {
return address
}
return forwarded
}
func ShiftPath(p string) (head, tail string) {
p = path.Clean("/" + p)
if i := strings.IndexByte(p[1:], '/') + 1; i <= 0 {
return p[1:], "/"
} else {
return p[1:i], p[i:]
}
}
Add the company’s slug in the URL before company-dependent handlers I really doubt that they are going to use more than a single company, but the application is based on Numerus, that **does** have multiple company, and followed the same architecture and philosophy: use the URL to choose the company to manage, even if the user has a single company. The reason i use the slug instead of the ID is because i do not want to make the ID public in case the application is really used by employees of many unrelated companies: they need not need to guess how many companies there are based on the ID. I validate this slug to be a valid UUID instead of relaying on the query’s empty result because casting a string with a malformed value to UUID results in an error other than data not found. Not with that select, but it would fail with a function parameter, and i want to add that UUID check to all functions that do use slugs. I based uuid.Valid function on Parse() from Google’s uuid package[0] instead of using regular expression, as it was my first idea, because that function is an order of magnitude faster in benchmarks: goos: linux goarch: amd64 pkg: dev.tandem.ws/tandem/numerus/pkg cpu: Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz BenchmarkValidUuid-4 36946050 29.37 ns/op BenchmarkValidUuid_Re-4 3633169 306.70 ns/op The regular expression used for the benchmark was: var re = regexp.MustCompile("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12}$") And the input parameter for both functions was the following valid UUID, because most of the time the passed UUID will be valid: "f47ac10b-58cc-0372-8567-0e02b2c3d479" I did not use the uuid package as is, even though it is in Debian’s repository, because i only need to check whether the value is valid, not convert it to a byte array. As far as i know, that package can not do that. Adding the Company struct into auth was not my intention, as it makes little sense name-wise, but i need to have the Company when rendering templates and the company package has templates to render, thus using the company package for the Company struct would create a dependency loop between template and company. I’ve chosen the auth package only because User is also there; User and Company are very much related in this application, but not enough to include the company inside the user, or vice versa, as the User comes from the cookie while the company from the URL. Finally, had to move methodNotAllowed to the http package, as an exported function, because it is used now from other packages, namely campsite. [0]: https://github.com/google/uuid
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func MethodNotAllowed(w http.ResponseWriter, _ *http.Request, allowed ...string) {
w.Header().Set("Allow", strings.Join(allowed, ", "))
http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
}