Document upcoming operation mechanism

Eventually this chunk of README should be inside the code instead. Also,
preliminary scaffold for wgconfig parser and serialiser

README.md

@@ -29,12 +29,27 @@ The primary scenario this tool is going to be used for is to manage machines usi
 
 ## Server
 
-The "server" manages a WireGuard interface, ~~treating a WireGuard configuration file as a database~~ (TODO). It assumes this interface and configuration exists. It only adds new peers to the configuration file and interface, and does not delete existing configuration. 
+The "server" manages a WireGuard interface, treating a WireGuard configuration file as a database. It assumes this interface and configuration exists. 
 
 ```
 wireguard-negotiator server --endpoint wireguard-endpoint:port
 ```
 
+1. On start:
+   1. Read and apply WireGuard configuration file if `--apply-on-start` is set (Equivalent to wg setconf)
+   2. Read from interface PublicKey and ListenPort
+   3. Read from interface all IPNets
+2. On request:
+   1. Check if PublicKey is already configured in a Peer or pending
+   2. Assign first/random available IP for every interface IPNet
+      1. Unavailable is any existing interface IPNets, Peer AllowedIPs and pending IPs
+   3. Gate requests
+   4. Switch rejected
+      1. If rejected, remove from pending
+   5. Apply Config with ReplacePeers false and new Peer
+   6. Save Device into WireGuard configuration file (Almost equivalent to wg showconf)
+   7. Return PeerConfigResponse
+
 It can generate an Ansible inventory on the same system. This reads off the same WireGuard configuration file as a database.
 
 ```
@@ -45,7 +60,7 @@ The "server" exposes the HTTP server with the following endpoints:
 
 ### `POST /request`
 
-Request for the assignment of an IP address and accepted as a peer. This blocks until the server has finished configuring the peer, therefore the client SHOULD NOT timeout. 
+Request for the assignment of an IP address and accepted as a peer. This blocks until the server has finished configuring the peer.
 
 #### Request Body
 

cmd/server.go

@@ -35,7 +35,7 @@ var CmdServer = &cli.Command{
 			Aliases:     []string{"c"},
 			Value:       "",
 			DefaultText: "/etc/wireguard/<interface>.conf",
-			Usage:       "Path to the existing WireGuard configuration file",
+			Usage:       "Path to the existing WireGuard configuration file. WARNING: wireguard-negotiator will remove any comments in the file",
 		},
 		&cli.StringFlag{
 			Name:     "endpoint",

go.mod

@@ -3,6 +3,7 @@ module github.com/serverwentdown/wireguard-negotiator
 go 1.13
 
 require (
+	github.com/google/go-cmp v0.3.1
 	github.com/urfave/cli/v2 v2.0.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20191219145116-fa6499c8e75f
 	gopkg.in/ini.v1 v1.51.0

go.sum

@@ -2,6 +2,7 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d h1:U+s90UTSYgptZMwQh2aRr3LuazLJIa+Pg3Kc1ylSYVY=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/jsimonetti/rtnetlink v0.0.0-20190606172950-9527aa82566a/go.mod h1:Oz+70psSo5OFh8DBl0Zv2ACw7Esh6pPUphlvZG9x7uw=
 github.com/mdlayher/genetlink v0.0.0-20191205172946-651acf4b47ef/go.mod h1:0rJ0h4itni50A86M2kHcgS85ttZazNt7a8H2a2cw0Gc=

lib/wgconfig.go

@@ -1,7 +1,14 @@
 package lib
 
 import (
-//"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+	"io"
+
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 )
 
 // ReadConfig is yet another INI-like configuration file parser, but for WireGuard
+func ReadConfig(r io.Reader) (wgtypes.Config, error) {
+	tmp := make([]byte, 1000)
+	r.Read(tmp)
+	return wgtypes.Config{}, nil
+}

lib/wgconfig_test.go

@@ -1,8 +1,14 @@
 package lib
 
-import "testing"
+import (
+	"strings"
+	"testing"
 
-var testGoodConfiguration1 = `
+	"github.com/google/go-cmp/cmp"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+const testGoodConfig1 = `
 # Test = Example comment
 
 [Interface]
@@ -18,6 +24,15 @@ AllowedIPs = 192.168.10.40/32, 2001:470:ed5d:a::28/128
 PublicKey = wXU+vSTdEoIwSi+Tmv35SCOFg17wCAwnmYxeQPpbzDg=
 `
 
-func TestReadConfig(t *testing.T) {
+var testGoodConfig1Want = wgtypes.Config{}
 
+func TestReadConfig1(t *testing.T) {
+	buf := strings.NewReader(testGoodConfig1)
+	got, err := ReadConfig(buf)
+	if err != nil {
+		t.Fatalf("config read failed: %w", err)
+	}
+	if diff := cmp.Diff(testGoodConfig1Want, got); diff != "" {
+		t.Fatalf("returned config is not what is wanted: \n%s", diff)
+	}
 }