88 lines
2.1 KiB
Go
88 lines
2.1 KiB
Go
// Copyright (C) 2022 Mya Pitzeruse
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// The MIT License (MIT)
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package catalog
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import (
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"bytes"
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_ "embed"
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"encoding/json"
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"flag"
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"html/template"
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"io"
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"log"
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"net/http"
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"os"
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"time"
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"code.pitz.tech/mya/emc/catalog/service"
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)
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//go:embed index.html.tpl
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var catalog string
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var funcs = map[string]any{
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"mod": func(mod, v int) int { return v % mod },
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"eq": func(exp, act int) bool { return exp == act },
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}
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// Spec defines the requirements for hosting a catalog.
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type Spec struct {
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Services []service.Spec
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}
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// Option defines an optional component of the spec.
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type Option func(spec *Spec)
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// Service registers a known service with the catalog.
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func Service(label string, options ...service.Option) Option {
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return func(spec *Spec) {
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spec.Services = append(spec.Services, service.New(label, options...))
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}
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}
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// Serve provides command line functionality for running the service catalog.
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func Serve(options ...Option) {
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addr := flag.String("bind_address", "127.0.0.1:8080", "the address the service should bind to when serving content")
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output := flag.String("output", "", "set to output the catalog to stdout (valid html, json)")
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flag.Parse()
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start := time.Now()
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spec := Spec{}
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for _, opt := range options {
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opt(&spec)
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}
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buffer := bytes.NewBuffer(nil)
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var err error
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switch {
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case output == nil || *output == "" || *output == "html":
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err = template.Must(template.New("catalog").Funcs(funcs).Parse(catalog)).Execute(buffer, spec)
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case *output == "json":
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err = json.NewEncoder(buffer).Encode(spec)
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}
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if err != nil {
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log.Fatal("failed to render output", err)
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}
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if output != nil && *output != "" {
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_, err = io.Copy(os.Stdout, bytes.NewReader(buffer.Bytes()))
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if err != nil {
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log.Fatal("failed to write buffer to stdout", err)
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}
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} else {
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http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
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http.ServeContent(w, r, "", start, bytes.NewReader(buffer.Bytes()))
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})
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log.Printf("serving on %s\n", *addr)
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err = http.ListenAndServe(*addr, http.DefaultServeMux)
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if err != nil {
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log.Fatal("failed to serve content", err)
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}
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}
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}
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