commit 6a7461454c28557deca70abe4795e7be2d0d1341
Author: Alexander "PapaTutuWawa <papatutuwawa@polynom.me>
Date:   Sun Dec 31 13:26:56 2023 +0100

    Initial commit

diff --git a/dns.go b/dns.go
new file mode 100644
index 0000000..32eaba5
--- /dev/null
+++ b/dns.go
@@ -0,0 +1,25 @@
+package main
+
+import (
+	"net"
+	"time"
+
+	"github.com/patrickmn/go-cache"
+)
+
+var (
+	cnameCache = cache.New(1 * time.Hour, 1 * time.Hour)
+)
+
+func lookupCNAME(domain string) (string, error) {
+	cname, found := cnameCache.Get(domain)
+	if found {
+		return cname.(string), nil
+	}
+
+	cname, err := net.LookupCNAME(domain)
+	if err == nil {
+		return cname.(string), nil
+	}
+	return "", err
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..5845f58
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,21 @@
+module paptutuwawa/rio
+
+go 1.20
+
+require (
+	code.gitea.io/sdk/gitea v0.17.0
+	github.com/patrickmn/go-cache v2.1.0+incompatible
+	github.com/sirupsen/logrus v1.9.3
+	github.com/urfave/cli/v2 v2.27.1
+)
+
+require (
+	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
+	github.com/davidmz/go-pageant v1.0.2 // indirect
+	github.com/go-fed/httpsig v1.1.0 // indirect
+	github.com/hashicorp/go-version v1.5.0 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
+	golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e // indirect
+	golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..43c4b76
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,48 @@
+code.gitea.io/sdk/gitea v0.17.0 h1:8JPBss4+Jf7AE1YcfyiGrngTXE8dFSG3si/bypsTH34=
+code.gitea.io/sdk/gitea v0.17.0/go.mod h1:ndkDk99BnfiUCCYEUhpNzi0lpmApXlwRFqClBlOlEBg=
+github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davidmz/go-pageant v1.0.2 h1:bPblRCh5jGU+Uptpz6LgMZGD5hJoOt7otgT454WvHn0=
+github.com/davidmz/go-pageant v1.0.2/go.mod h1:P2EDDnMqIwG5Rrp05dTRITj9z2zpGcD9efWSkTNKLIE=
+github.com/go-fed/httpsig v1.1.0 h1:9M+hb0jkEICD8/cAiNqEB66R87tTINszBRTjwjQzWcI=
+github.com/go-fed/httpsig v1.1.0/go.mod h1:RCMrTZvN1bJYtofsG4rd5NaO5obxQ5xBkdiS7xsT7bM=
+github.com/hashicorp/go-version v1.5.0 h1:O293SZ2Eg+AAYijkVK3jR786Am1bhDEh2GHT0tIVE5E=
+github.com/hashicorp/go-version v1.5.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/urfave/cli/v2 v2.27.1 h1:8xSQ6szndafKVRmfyeUMxkNUJQMjL1F2zmsZ+qHpfho=
+github.com/urfave/cli/v2 v2.27.1/go.mod h1:8qnjx1vcq5s2/wpsqoZFndg2CE5tNFyrTvS6SinrnYQ=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20210513164829-c07d793c2f9a/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
+golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e h1:T8NU3HyQ8ClP4SEE+KbFlg6n0NhuTsN4MyznaarGsZM=
+golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..65a2530
--- /dev/null
+++ b/main.go
@@ -0,0 +1,138 @@
+package main
+
+import (
+	"os"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+
+	"code.gitea.io/sdk/gitea"
+	"github.com/urfave/cli/v2"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	//PagesBranch "pages"
+	// TODO: Change back for testing
+	PagesBranch = "main"
+)
+
+func handleSubdomain(domain string, cname string, path string, giteaClient *gitea.Client, w http.ResponseWriter) {
+	hostParts := strings.Split(domain, ".")
+	username := hostParts[0]
+
+	// Strip the leading /
+	if path[:1] == "/" {
+		path = path[1:]
+	}
+
+	_, path, err := RepoFromPath(
+		username,
+		domain,
+		cname,
+		path,
+		giteaClient,
+		
+	)
+	if err != nil {
+		log.Errorf("Failed to get repo: %s", err)
+		w.WriteHeader(404)
+		return
+	}
+
+	serveFile(username, path, giteaClient, w)
+}
+
+func Handler(pagesDomain string, giteaClient *gitea.Client) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		w.Header().Set("Server", "rio")
+
+		if strings.HasSuffix(req.Host, pagesDomain){
+			log.Debug("Domain can be directly handled")
+			handleSubdomain(req.Host, "", req.URL.Path, giteaClient, w)
+			return
+		}
+		
+		cname, err := lookupCNAME(req.Host)
+		if err != nil {
+			log.Warningf("CNAME request failed, we don't handle %s", req.Host)
+			w.WriteHeader(400)
+			return
+		}
+		log.Debugf("Got CNAME %s", cname)
+
+		if strings.HasSuffix(cname, pagesDomain) {
+			log.Debugf("%s is alias of %s", req.Host, cname)
+			handleSubdomain(cname, cname, req.URL.Path, giteaClient, w)
+			return
+		}
+
+		log.Errorf("Not handling %s", req.Host)
+		w.WriteHeader(404)
+	}
+}
+
+func runServer(ctx *cli.Context) error {
+	giteaUrl := ctx.String("gitea-url")
+	addr := ctx.String("listen-host") + ":" + ctx.String("listen-port")
+	domain := ctx.String("pages-domain")
+
+	log.SetLevel(log.DebugLevel)
+	httpClient := http.Client{Timeout: 10 * time.Second}
+	client, err := gitea.NewClient(
+		giteaUrl,
+		gitea.SetHTTPClient(&httpClient),
+		gitea.SetToken(""),
+		gitea.SetUserAgent("rio"),
+	)
+
+	listener, err := net.Listen("tcp", addr)
+	if err != nil {
+		fmt.Errorf("Failed to create listener: %v", err)
+		return err
+	}
+	if err := http.Serve(listener, Handler(domain, client)); err != nil {
+		fmt.Printf("Listening failed")
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+	app := &cli.App{
+		Action: runServer,
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name: "gitea-url",
+				Usage: "The (HTTPS) URL to the serving Gitea instance",
+				EnvVars: []string{"GITEA_URL"},
+				Required: true,
+			},
+			&cli.StringFlag{
+				Name: "listen-host",
+				Usage: "The host to listen on",
+				EnvVars: []string{"HOST"},
+				Value: "127.0.0.1",
+			},
+			&cli.StringFlag{
+				Name: "listen-port",
+				Usage: "The port to listen on",
+				EnvVars: []string{"PORT"},
+				Value: "8888",
+			},
+			&cli.StringFlag{
+				Name: "pages-domain",
+				Usage: "The domain on which the server is reachable",
+				EnvVars: []string{"PAGES_DOMAIN"},
+				Required: true,
+			},
+		},
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Fatalf("Failed to run app: %s", err)
+	}
+}
diff --git a/pages.go b/pages.go
new file mode 100644
index 0000000..1bbb920
--- /dev/null
+++ b/pages.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"mime"
+	"net/http"
+	"strings"
+	"time"
+
+	"code.gitea.io/sdk/gitea"
+	"github.com/patrickmn/go-cache"
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	pageCache = cache.New(6 * time.Hour, 1 * time.Hour)
+)
+
+type PageContentCache struct {
+	Content []byte
+	mimeType string
+}
+
+func makePageContentCacheEntry(username, path string) string {
+	return username + ":" + path
+}
+
+func serveFile(username string, path string, giteaClient *gitea.Client, w http.ResponseWriter) {
+	// Provide a default
+	if path == "" {
+		path = "/index.html"
+	}
+
+	// Strip away a starting / as it messes with Gitea
+	if path[:1] == "/" {
+		path = path[1:]
+	}
+
+	key := makePageContentCacheEntry(username, path)
+	entry, found := pageCache.Get(key)
+	var content []byte
+	var mimeType string
+	if found {
+		log.Debugf("Returning %s from cache", path)
+		content = entry.(PageContentCache).Content
+		mimeType = entry.(PageContentCache).mimeType
+	} else {
+		content, _, err := giteaClient.GetFile(username, "pages", PagesBranch, path, false)
+		if err != nil {
+			log.Errorf("Failed to get file %s (%s)", path, err)
+			w.WriteHeader(404)
+			return
+		}
+
+		pathParts := strings.Split(path, ".")
+		ext := pathParts[len(pathParts) - 1]
+		mimeType := mime.TypeByExtension("." + ext)
+
+		pageCache.Set(
+			key,
+			PageContentCache{
+				content,
+				mimeType,
+			},
+			cache.DefaultExpiration,
+		)
+	}
+	
+	w.WriteHeader(200)
+	w.Header().Set("Content-Type", mimeType)
+	w.Write(content)
+}
diff --git a/repo.go b/repo.go
new file mode 100644
index 0000000..f689b09
--- /dev/null
+++ b/repo.go
@@ -0,0 +1,110 @@
+package main
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"code.gitea.io/sdk/gitea"
+	"github.com/patrickmn/go-cache"
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	pathCache = cache.New(1 * time.Hour, 1 * time.Hour)
+)
+
+
+type PageCacheEntry struct {
+	Repository *gitea.Repository
+	Path string
+}
+
+func makePageCacheKey(domain, path string) string {
+	return domain + "/" + path
+}
+
+func lookupRepositoryAndCache(username, reponame, host, domain, path, cname string, giteaClient *gitea.Client) (*gitea.Repository, error) {
+	log.Debugf("Looking up repository %s/%s", username, reponame)
+	repo, _, err := giteaClient.GetRepo(username, reponame)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the CNAME file matches
+	if cname != "" {
+		file, _, err := giteaClient.GetFile(
+			username,
+			repo.Name,
+			PagesBranch,
+			"CNAME",
+			false,
+		)
+		if err != nil {
+			log.Errorf("Could not verify CNAME of %s/%s: %v\n", username, repo.Name, err)
+			return nil, err
+		}
+
+		cnameContent := strings.Trim(
+			string(file[:]),
+			"\n",
+		)
+		if cnameContent != cname {
+			return nil, errors.New("CNAME mismatch")
+		}
+	}
+
+	// Cache data
+	cnameCache.Set(host, domain, cache.DefaultExpiration)
+	pathCache.Set(
+		makePageCacheKey(domain, path),
+		PageCacheEntry{
+			repo,
+			path,
+		},
+		cache.DefaultExpiration,
+	)
+	return repo, nil
+}
+
+func RepoFromPath(username, host, cname, path string, giteaClient *gitea.Client) (*gitea.Repository, string, error) {
+	domain := host
+
+	// Guess the repository
+	key := makePageCacheKey(domain, path)
+	entry, found := pathCache.Get(key)
+	if found {
+		pageEntry := entry.(PageCacheEntry)
+		return pageEntry.Repository, pageEntry.Path, nil
+	}
+
+	pathParts := strings.Split(path, "/")
+	if len(pathParts) > 1 {
+		log.Debugf("Trying repository %s", pathParts[0])
+		modifiedPath := strings.Join(pathParts[1:], "/")
+		repo, err := lookupRepositoryAndCache(
+			username,
+			pathParts[0],
+			host,
+			domain,
+			modifiedPath,
+			cname,
+			giteaClient,
+		)
+		if err == nil {
+			return repo, modifiedPath, nil
+		}
+	}
+
+	log.Debugf("Trying repository pages")
+	repo, err := lookupRepositoryAndCache(
+		username,
+		"pages",
+		host,
+		domain,
+		path,
+		cname,
+		giteaClient,
+	)
+	return repo, path, err
+}