89 lines
3.0 KiB
Go
89 lines
3.0 KiB
Go
package dist
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//go:generate env GO111MODULE=on go run github.com/kevinburke/go-bindata/go-bindata -o dist_gen.go -ignore 'map|go' -tags assets -pkg dist ../../ui/build/...
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import (
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"fmt"
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"net/http"
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"github.com/elazarl/go-bindata-assetfs"
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)
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// DebugAssets serves assets via a specified directory
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type DebugAssets struct {
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Dir string // Dir is a directory location of asset files
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Default string // Default is the file to serve if file is not found.
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}
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// Handler is an http.FileServer for the Dir
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func (d *DebugAssets) Handler() http.Handler {
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return http.FileServer(NewDir(d.Dir, d.Default))
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}
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// BindataAssets serves assets from go-bindata, but, also serves Default if assent doesn't exist
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// This is to support single-page react-apps with its own router.
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type BindataAssets struct {
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Prefix string // Prefix is prepended to the http file request
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Default string // Default is the file to serve if the file is not found
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DefaultContentType string // DefaultContentType is the content type of the default file
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}
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// Handler serves go-bindata using a go-bindata-assetfs façade
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func (b *BindataAssets) Handler() http.Handler {
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return b
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}
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// addCacheHeaders requests an hour of Cache-Control and sets an ETag based on file size and modtime
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func (b *BindataAssets) addCacheHeaders(filename string, w http.ResponseWriter) error {
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w.Header().Add("Cache-Control", "public, max-age=3600")
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fi, err := AssetInfo(filename)
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if err != nil {
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return err
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}
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hour, minute, second := fi.ModTime().Clock()
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etag := fmt.Sprintf(`"%d%d%d%d%d"`, fi.Size(), fi.ModTime().Day(), hour, minute, second)
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w.Header().Set("ETag", etag)
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return nil
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}
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// ServeHTTP wraps http.FileServer by returning a default asset if the asset
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// doesn't exist. This supports single-page react-apps with its own
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// built-in router. Additionally, we override the content-type if the
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// Default file is used.
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func (b *BindataAssets) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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// def wraps the assets to return the default file if the file doesn't exist
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def := func(name string) ([]byte, error) {
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// If the named asset exists, then return it directly.
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octets, err := Asset(name)
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if err != nil {
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// If this is at / then we just error out so we can return a Directory
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// This directory will then be redirected by go to the /index.html
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if name == b.Prefix {
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return nil, err
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}
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// If this is anything other than slash, we just return the default
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// asset. This default asset will handle the routing.
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// Additionally, because we know we are returning the default asset,
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// we need to set the default asset's content-type.
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w.Header().Set("Content-Type", b.DefaultContentType)
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if err := b.addCacheHeaders(b.Default, w); err != nil {
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return nil, err
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}
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return Asset(b.Default)
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}
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if err := b.addCacheHeaders(name, w); err != nil {
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return nil, err
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}
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return octets, nil
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}
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var dir http.FileSystem = &assetfs.AssetFS{
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Asset: def,
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AssetDir: AssetDir,
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AssetInfo: AssetInfo,
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Prefix: b.Prefix,
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}
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http.FileServer(dir).ServeHTTP(w, r)
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}
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