Add path patch to dockerfile

PR is open for a month now, so I've added it directly to the docker
image to stop waiting.
https://code.rocketnine.space/tslocum/twins/pulls/10

Dockerfile

@@ -4,9 +4,17 @@
 
 # Build
 FROM golang:1.16-alpine AS builder
-RUN apk add --no-cache openssl
-RUN go get -v code.rocketnine.space/tslocum/twins
+RUN apk add --no-cache openssl patch git
+WORKDIR /build
 COPY ./localhost.cnf /build/localhost.cnf
+RUN git clone https://code.rocketnine.space/tslocum/twins.git
+
+# Apply a needed patch
+COPY ./path-10.patch /build/path-10.patch
+RUN cd /build/twins && patch /build/path-10.patch
+
+RUN cd /build/twins && go build
+
 RUN openssl req \
   -x509 \
   -out /build/localhost.crt \
@@ -20,7 +28,7 @@ RUN openssl req \
 
 # Compress
 FROM gruebel/upx:latest as upx
-COPY --from=builder /go/bin/twins /app.org
+COPY --from=builder /build/twins/twins /app.org
 RUN upx --best --lzma -o /app /app.org
 
 # Final image

path-10.patch

@@ -0,0 +1,78 @@
+From bd0555069ede209f482a524a9a18fdc9a3f35183 Mon Sep 17 00:00:00 2001
+From: Aaron Fischer <mail@aaron-fischer.net>
+Date: Thu, 3 Jun 2021 23:47:46 +0200
+Subject: [PATCH 1/2] Strip path from root
+
+If there is a path (the URL path) specified under paths in the
+configuration, which points to a root (a physical folder on the
+filesystem), this path should not be attached to the root. This fix will
+do that. It strips the path from the root.
+
+Example configuration:
+
+hosts:
+  localhost:
+    paths:
+      -
+        path: /a
+        root: public/aroot
+      -
+        path: /
+        root: public
+
+Filesystem:
++ public
+  + index.gmi
+  + aroot
+    + index.gmi
+---
+ serve_https.go | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/serve_https.go b/serve_https.go
+index e227064..6ab3a41 100644
+--- a/serve_https.go
++++ b/serve_https.go
+@@ -80,7 +80,9 @@ func serveHTTPS(w http.ResponseWriter, r *http.Request) (int, int64, string) {
+ 						root += "/"
+ 					}
+ 
+-					requestSplit := strings.Split(r.URL.Path, "/")
++					// We remove the the path (specified in the config file) from the actual URL, so
++					// it will not prefixed two times to the root.
++					requestSplit := strings.Split(r.URL.Path[len(serve.Path)-1:], "/")
+ 
+ 					if !serve.SymLinks {
+ 						for i := 1; i < len(requestSplit); i++ {
+-- 
+2.32.0
+
+
+From 2257e0bcceb8dd2d3f471d679153cd08de4a7ef0 Mon Sep 17 00:00:00 2001
+From: Aaron Fischer <mail@aaron-fischer.net>
+Date: Mon, 7 Jun 2021 23:20:24 +0200
+Subject: [PATCH 2/2] Add some clarification for the paths arrangement
+
+---
+ CONFIGURATION.md | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/CONFIGURATION.md b/CONFIGURATION.md
+index 46c1987..471ca14 100644
+--- a/CONFIGURATION.md
++++ b/CONFIGURATION.md
+@@ -90,6 +90,11 @@ See [PROPOSALS.md](https://code.rocketnine.space/tslocum/twins/src/branch/master
+ 
+ ### Path
+ 
++Specify any number of paths, which will be checked against the request. The
++first match will be used to build the response. So keep in mind that the
++first path should be the most specific one and the last should be the least
++specific one, like `/`.
++
+ #### Resources
+ 
+ One resource must be defined for each path.
+-- 
+2.32.0
+