From d4bd6e92a5fc05f3931bde7566da445861ea38f4 Mon Sep 17 00:00:00 2001
From: shokara <shokara@8f5ca974-a7f8-e144-9f80-d41d5039c194>
Date: Sat, 25 Dec 2021 03:42:55 +0000
Subject: [PATCH] use environment variables instead of hardcoding values

git-svn-id: file:///srv/svn/repo/tokiko/trunk@11 8f5ca974-a7f8-e144-9f80-d41d5039c194
---
 .gitignore |  2 --
 Gophermap  |  4 ++++
 README     |  7 +++++++
 main.go    | 55 +++++++++++++++++++++++++++++++++++++++++++-----------
 4 files changed, 55 insertions(+), 13 deletions(-)
 delete mode 100644 .gitignore
 create mode 100644 Gophermap

diff --git a/.gitignore b/.gitignore
deleted file mode 100644
index 4026300..0000000
--- a/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-Gophermap
-test-gopher
diff --git a/Gophermap b/Gophermap
new file mode 100644
index 0000000..43bf7b5
--- /dev/null
+++ b/Gophermap
@@ -0,0 +1,4 @@
+iIf you see this, then thomomys is probably running! If you are the
+isysadmin running thomomys and were expecting something else, try
+isetting the GOPHER_DIR environment variable to a directory containing
+ithe gopherhole. See the README for more details.
diff --git a/README b/README
index 02d6bef..24dc037 100644
--- a/README
+++ b/README
@@ -1,3 +1,10 @@
 Thomomys
 ========
 A simple gopher daemon written in Golang.
+
+Environment Variables
+---------------------
+GOPHER_IP	= IP address for Thomomys to listen on
+GOPHER_PORT	= Port for Thomomys to listen on
+GOPHER_HOSTNAME	= Default hostname that gets printed for links
+GOPHER_DIR	= Root directory that gets served
diff --git a/main.go b/main.go
index de813ff..2cd7398 100644
--- a/main.go
+++ b/main.go
@@ -10,10 +10,12 @@ import (
 	"strings"
 )
 
-const HOST = "0.0.0.0"
-const PORT = "7070"
-const HOSTNAME = "demiurge.shoko.home"
-const DIR = "/home/kou/src/gopherhole"
+var (
+	ADDR_IP string
+	ADDR_PORT string
+	HOSTNAME string
+	SRVDIR string
+)
 
 func formatLine(line string) string {
 	trimmed := strings.TrimRight(line, "\r\n")
@@ -22,9 +24,9 @@ func formatLine(line string) string {
 	if len(splitted) == 3 {
 		return line
 	} else if len(splitted) == 2 {
-		line += "\t" + HOSTNAME + "\t" + PORT
+		line += "\t" + HOSTNAME + "\t" + ADDR_PORT
 	} else if len(splitted) == 1 {
-		line += "\tErr\t" + HOSTNAME + "\t" + PORT
+		line += "\tErr\t" + HOSTNAME + "\t" + ADDR_PORT
 	}
 
 	return line + "\n"
@@ -66,7 +68,6 @@ func printFile(c net.Conn, path string) {
 		}
 	}()
 
-	// 1024 bytes or 1K for buffer
 	const bufSz = 1024
 	b := make([]byte, bufSz)
 
@@ -119,12 +120,44 @@ func connHandle(c net.Conn) {
 }
 
 func main() {
-	const ADDR = HOST + ":" + PORT
-	log.Printf("Starting thomomys on %s\n", ADDR)
+	// set default values if environment variables aren't set
+	ADDR_IP = os.Getenv("GOPHER_IP")
+	if len(ADDR_IP) == 0 {
+		ADDR_IP = "0.0.0.0"
+		log.Printf("$GOPHER_IP is not set. Falling back to %s.\n", ADDR_IP)
+	}
 
-	os.Chdir(DIR)
+	ADDR_PORT = os.Getenv("GOPHER_PORT")
+	if len(ADDR_PORT) == 0 {
+		ADDR_PORT = "70"
+		log.Printf("$GOPHER_PORT is not set. Falling back to port %s.\n", ADDR_PORT)
+	}
 
-	l, err := net.Listen("tcp", ADDR)
+	HOSTNAME = os.Getenv("GOPHER_HOSTNAME")
+	if len(HOSTNAME) == 0 {
+		log.Println("$GOPHER_HOSTNAME is not set. Falling back to system hostname.")
+
+		value, err := os.Hostname()
+		if err != nil {
+			log.Fatal(err)
+			return
+		}
+
+		HOSTNAME = value
+	}
+
+	SRVDIR = os.Getenv("GOPHER_DIR")
+	if len(SRVDIR) == 0 {
+		SRVDIR = "."
+		log.Println("$GOPHER_DIR is not set. Falling back to current directory.")
+	}
+
+	LISTEN_ADDR := ADDR_IP + ":" + ADDR_PORT
+	log.Printf("Starting thomomys on %s\n", LISTEN_ADDR)
+
+	os.Chdir(SRVDIR)
+
+	l, err := net.Listen("tcp", LISTEN_ADDR)
 	if err != nil {
 		log.Fatal(err)
 		return