updated README

README.md

@@ -1,3 +1,59 @@
 # pkgstash
 
-A caching pacman mirror and aur build server.
+## A sparse caching pacman mirror
+
+Reduces external traffic in a local network with multiple arch linux systems with minimal config. It replicates the structure of a full mirror without downloading the whole mirror. Clients add this in mirrorlist and pacman just works. 
+
+## Install
+
+### From PKGBUILD
+
+Currently disributed as a binary. Download the PKGBUILD and pkgstash.install, use makepkg -i to install. See [Arch User Repository](https://wiki.archlinux.org/title/Arch_User_Repository) for more information.
+
+### From source
+
+clone the repo from repo root
+
+    go build ./cmd/server
+
+Binary is called pkgstash, sample config, env and service files are in deploy/
+### Configure and Start
+
+Edit `/etc/pkgstash/pkgstash.env` and change the token to a secure one. I used openssl like so:
+
+    openssl rand -base64 64
+
+```
+#/etc/pkgstash/pkgstash.env
+
+PKGSTASH_TOKEN=<paste secure token here>
+```
+
+start with the included systemd service
+
+    systemctl enable --now pkgstash.service
+
+    systemctl enable --now pkgstash-refresh.timer
+
+
+### Technical details
+
+1. Go as the language. It has most of the tools necessary for a http server ins the standard library and it's performant.
+2. Singleflight to prevent 2 clients from causing the server to fetch the same package more than once.
+3. Pkgs are written atomically to prevent serving partial files
+4. Use multiple mirrors for redundancy and spread the load out.
+5. Refresh the remote db files on a schedule to enable prefetching of cached pkgs.
+
+### Roadmap
+
+- Prefetch and cache cleanup
+- Streaming on cache misses
+- cli admin tool
+- Custom repo
+- Build server
+- Automate builds on updated aur pkgs
+    - Auto approve on version bump with not other changes in PKGSBUILD
+    - Notify if a build needs approval
+- Web admin interface
+
+