fix go build with sqlite

Dockerfile

@@ -3,8 +3,8 @@ FROM golang:1.25-alpine AS builder
 
 WORKDIR /app
 
-# Install git if needed for go mod
+# Install git, gcc, musl-dev, and sqlite-dev for go mod and CGO
-RUN apk add --no-cache git
+RUN apk add --no-cache git gcc musl-dev sqlite-dev
 
 # Copy go mod and sum files
 COPY go.mod go.sum ./
@@ -15,6 +15,9 @@ RUN go mod download
 COPY main.go .
 COPY internal ./internal
 
+# Enable CGO for go-sqlite3
+ENV CGO_ENABLED=1
+
 RUN go build -o main .
 
 FROM alpine:latest

go.mod

@@ -3,6 +3,7 @@ module gemini_site
 go 1.25.0
 
 require (
-	git.travisshears.com/travisshears/gemlog-cli v1.0.1
+	git.travisshears.com/travisshears/gemlog-cli v1.1.0
 	github.com/kulak/gemini v1.2.2
+	github.com/mattn/go-sqlite3 v1.14.32
 )

go.sum

@@ -1,9 +1,11 @@
-git.travisshears.com/travisshears/gemlog-cli v1.0.1 h1:0AcFwrnukwcWHuePEROG3WDSGbcE8WoFvJTQxrTaszc=
+git.travisshears.com/travisshears/gemlog-cli v1.1.0 h1:iFMIeYyzPvoUw2sQqGg8PTejCcKxgmhjy5HqpVo3Ag8=
-git.travisshears.com/travisshears/gemlog-cli v1.0.1/go.mod h1:N6l94N174EhDOIHU0/RlJ0PWrxB0BMa0W6LcpgAtvCE=
+git.travisshears.com/travisshears/gemlog-cli v1.1.0/go.mod h1:N6l94N174EhDOIHU0/RlJ0PWrxB0BMa0W6LcpgAtvCE=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/kulak/gemini v1.2.2 h1:wPFOAFFdOf9ZaHcpMwTq1xYUWxmyV3h0uQl0OXCGa+A=
 github.com/kulak/gemini v1.2.2/go.mod h1:8yiD7yhLkUGvOpdvgd/0nKQD2I0ChIAKD3yHuT13R5k=
+github.com/mattn/go-sqlite3 v1.14.32 h1:JD12Ag3oLy1zQA+BNn74xRgaBbdhbNIDYvQUEuuErjs=
+github.com/mattn/go-sqlite3 v1.14.32/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

internal/guestbook/guestbook.go

@@ -0,0 +1,255 @@
+package guestbook
+
+import (
+	"crypto/sha256"
+	"crypto/x509"
+	"database/sql"
+	"encoding/hex"
+	"fmt"
+	"log/slog"
+	"os"
+	"strings"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+
+	gemini "github.com/kulak/gemini"
+)
+
+const adminUserId = "6a1171c755cbde90373bee2ac08c6aa4607ecf8ed3f50c55cf76c6a0e27dfa5c"
+
+type GuestBook struct {
+	db *sql.DB
+}
+
+func NewGuestBook(db *sql.DB) *GuestBook {
+	err := initDB(db)
+	if err != nil {
+		slog.Error("Error migrating sqlite database", "error", err)
+		panic(err)
+	}
+	return &GuestBook{
+		db,
+	}
+}
+
+func initDB(db *sql.DB) error {
+	_, err := db.Exec(`
+		CREATE TABLE IF NOT EXISTS guestbook (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			name TEXT NOT NULL,
+			user_id INTEGER NOT NULL,
+			approved BOOLEAN NOT NULL,
+			message TEXT NOT NULL,
+			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+		)
+	`)
+	return err
+}
+
+func (book *GuestBook) HandleRequest(w gemini.ResponseWriter, req *gemini.Request) {
+	path := req.URL.Path
+
+	switch {
+	case path == "/guestbook" || path == "/guestbook/":
+		book.serveIndex(w, req)
+	case path == "/guestbook/new":
+		book.serveNewEntry(w, req)
+	case path == "/guestbook/admin":
+		book.serveAdmin(w, req)
+	case strings.HasPrefix(path, "/guestbook/approve"):
+		book.serveApprove(w, req)
+	case strings.HasPrefix(path, "/guestbook/delete"):
+		book.serveDelete(w, req)
+	default:
+		w.WriteStatusMsg(gemini.StatusNotFound, "Page not found")
+	}
+}
+
+func UserIDFromCert(cert *x509.Certificate) (string, error) {
+	pubKeyBytes, err := x509.MarshalPKIXPublicKey(cert.PublicKey)
+	if err != nil {
+		return "", err
+	}
+	hash := sha256.Sum256(pubKeyBytes)
+	return hex.EncodeToString(hash[:]), nil
+}
+
+func (book *GuestBook) serveDelete(w gemini.ResponseWriter, req *gemini.Request) {
+	if req.Certificate() == nil {
+		w.WriteStatusMsg(gemini.StatusCertRequired, "Authentication Required")
+		return
+	}
+	userId, err := UserIDFromCert(req.Certificate())
+	if err != nil {
+		slog.Error("Error creating user id from cert", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error generating user ID")
+		return
+	}
+	if userId != adminUserId {
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Permission denied")
+		return
+	}
+	entryId := req.URL.Query().Get("id")
+	slog.Info("Deleting", "userId", userId, "entryId", entryId)
+	_, err = book.db.Exec("DELETE FROM guestbook WHERE id = ?", entryId)
+	if err != nil {
+		slog.Error("Error deleting guestbook entry", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error deleting guestbook entry")
+		return
+	}
+	book.serveAdmin(w, req)
+}
+
+func (book *GuestBook) serveApprove(w gemini.ResponseWriter, req *gemini.Request) {
+	if req.Certificate() == nil {
+		w.WriteStatusMsg(gemini.StatusCertRequired, "Authentication Required")
+		return
+	}
+	userId, err := UserIDFromCert(req.Certificate())
+	if err != nil {
+		slog.Error("Error creating user id from cert", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error generating user ID")
+		return
+	}
+	if userId != adminUserId {
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Permission denied")
+		return
+	}
+	entryId := req.URL.Query().Get("id")
+	slog.Info("Approving", "userId", userId, "entryId", entryId)
+	_, err = book.db.Exec("UPDATE guestbook SET approved = true WHERE id = ?", entryId)
+	if err != nil {
+		slog.Error("Error approving guestbook entry", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error approving guestbook entry")
+		return
+	}
+	book.serveAdmin(w, req)
+}
+
+func (book *GuestBook) serveNewEntry(w gemini.ResponseWriter, req *gemini.Request) {
+	if req.Certificate() == nil {
+		w.WriteStatusMsg(gemini.StatusCertRequired, "Authentication Required")
+		return
+	}
+	if req.URL.RawQuery == "" {
+		w.WriteStatusMsg(gemini.StatusPlainInput, "Your guestbook entry:")
+		return
+	}
+	// w.WriteStatusMsg(gemini.StatusSuccess, "text/gemini")
+	name := req.Certificate().Subject.CommonName
+	userId, err := UserIDFromCert(req.Certificate())
+	slog.Info("User ID created", "user_id", userId)
+	if err != nil {
+		slog.Error("Error creating user id from cert", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error generating user ID")
+		return
+	}
+	txt := req.URL.RawQuery
+	_, err = book.db.Exec("INSERT INTO guestbook(name, user_id, approved, message) VALUES(?, ?, ?, ?)", name, userId, false, txt)
+	if err != nil {
+		slog.Error("Error writing to database", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error writing to database")
+		return
+	}
+	w.WriteStatusMsg(gemini.StatusSuccess, "text/gemini")
+	var content strings.Builder
+	content.WriteString("# Success!\n")
+	content.WriteString("Your entry was added to the guestbook\n\n")
+	content.WriteString(fmt.Sprintf("username: %s\nentry:\n> %s\n\n", name, txt))
+	content.WriteString("For now since the entry has not been approved it will appear in the list with xxxxx in place of chars.\n")
+	content.WriteString("\n\n=> /guestbook Back to guestbook")
+	w.WriteBody([]byte(content.String()))
+}
+
+func (book *GuestBook) serveIndex(w gemini.ResponseWriter, req *gemini.Request) {
+	w.WriteStatusMsg(gemini.StatusSuccess, "text/gemini")
+	var content strings.Builder
+	page, err := os.ReadFile("./pages/guestbook.gmi")
+	if err != nil {
+		slog.Error("Problem reading guestbook.gmi", "error", err)
+		return
+	}
+	content.Write(page)
+	content.WriteString("\n")
+
+	rows, err := book.db.Query("SELECT id, name, approved, created_at, message FROM guestbook ORDER BY created_at DESC")
+	if err != nil {
+		slog.Error("Error querying database", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error writing to database")
+		return
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var id int
+		var name string
+		var approved bool
+		var createdAt time.Time
+		var message string
+		rows.Scan(&id, &name, &approved, &createdAt, &message)
+		if !approved {
+			// Overwrite all non-space characters in message with "x"
+			masked := []rune(message)
+			for i, c := range masked {
+				if c != ' ' {
+					masked[i] = 'x'
+				}
+			}
+			message = string(masked)
+		}
+		content.WriteString(fmt.Sprintf("%s :: %s\n> %s\n", createdAt.Format("2006-01-02"), name, message))
+		content.WriteString("\n")
+	}
+	defer rows.Close()
+
+	content.WriteString("=> / Back to home\n")
+	w.WriteBody([]byte(content.String()))
+}
+
+func (book *GuestBook) serveAdmin(w gemini.ResponseWriter, req *gemini.Request) {
+	if req.Certificate() == nil {
+		w.WriteStatusMsg(gemini.StatusCertRequired, "Authentication Required")
+		return
+	}
+	w.WriteStatusMsg(gemini.StatusSuccess, "text/gemini")
+
+	userId, err := UserIDFromCert(req.Certificate())
+	if err != nil {
+		slog.Error("Error creating user id from cert", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error generating user ID")
+		return
+	}
+	if userId != adminUserId {
+		w.WriteStatusMsg(gemini.StatusBadRequest, "UserId != adminUserId")
+		return
+	}
+
+	var content strings.Builder
+	rows, err := book.db.Query("SELECT id, user_id, name, approved, created_at, message FROM guestbook ORDER BY created_at DESC")
+	if err != nil {
+		slog.Error("Error querying database", "error", err)
+		w.WriteStatusMsg(gemini.StatusGeneralPermFail, "Error writing to database")
+		return
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var id int
+		var userId string
+		var name string
+		var approved bool
+		var createdAt time.Time
+		var message string
+		rows.Scan(&id, &userId, &name, &approved, &createdAt, &message)
+		content.WriteString(fmt.Sprintf("%s :: %s\n> %s\n", createdAt.Format("2006-01-02"), name, message))
+		if !approved {
+			content.WriteString(fmt.Sprintf("=> /guestbook/approve?id=%d Approve\n", id))
+		}
+		content.WriteString(fmt.Sprintf("=> /guestbook/delete?id=%d Delete\n", id))
+		content.WriteString("\n")
+	}
+	defer rows.Close()
+
+	content.WriteString("=> /guestbook Back to guesbook\n")
+	content.WriteString("=> / Back to home\n")
+	w.WriteBody([]byte(content.String()))
+}

internal/guestbook/handler.go

@@ -0,0 +1,17 @@
+package guestbook
+
+import (
+	"database/sql"
+
+	gemini "github.com/kulak/gemini"
+)
+
+// Handler interface for microblog functionality
+type Handler interface {
+	HandleRequest(w gemini.ResponseWriter, req *gemini.Request)
+}
+
+// NewHandler creates a new microblog handler
+func NewHandler(db *sql.DB) Handler {
+	return NewGuestBook(db)
+}

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"database/sql"
 	"errors"
 	"flag"
 	"fmt"
@@ -10,7 +11,10 @@ import (
 	"strings"
 	"time"
 
+	_ "github.com/mattn/go-sqlite3"
+
 	gemlog "gemini_site/internal/gemlog"
+	"gemini_site/internal/guestbook"
 	microblog "gemini_site/internal/microblog"
 	"gemini_site/internal/pocketbase"
 
@@ -18,8 +22,9 @@ import (
 )
 
 type MainHandler struct {
-	blog   microblog.Handler
+	blog      microblog.Handler
-	gemlog gemlog.Handler
+	gemlog    gemlog.Handler
+	guestbook guestbook.Handler
 }
 
 func (h MainHandler) ServeGemini(w gemini.ResponseWriter, req *gemini.Request) {
@@ -28,14 +33,17 @@ func (h MainHandler) ServeGemini(w gemini.ResponseWriter, req *gemini.Request) {
 		"user", strings.Join(userName(req), " "))
 
 	// Check if this is a blog request
-	if strings.HasPrefix(req.URL.Path, "/microblog") {
+	switch {
+	case strings.HasPrefix(req.URL.Path, "/microblog"):
 		h.blog.HandleBlogRequest(w, req)
 		return
-	}
 
-	if strings.HasPrefix(req.URL.Path, "/gemlog") {
+	case strings.HasPrefix(req.URL.Path, "/gemlog"):
 		h.gemlog.HandleRequest(w, req)
 		return
+	case strings.HasPrefix(req.URL.Path, "/guestbook"):
+		h.guestbook.HandleRequest(w, req)
+		return
 	}
 
 	switch req.URL.Path {
@@ -102,6 +110,16 @@ func main() {
 		Level: slog.LevelInfo,
 	}))
 	slog.SetDefault(logger)
+	// Setup DB
+	sqlitePath := os.Getenv("SQLITE_PATH")
+	if sqlitePath == "" {
+		panic("SQLITE_PATH environment variable must be set and non-empty")
+	}
+	db, err := sql.Open("sqlite3", sqlitePath)
+	if err != nil {
+		panic(err)
+	}
+	defer db.Close()
 
 	slog.Info("Starting gemini server")
 	var host, cert, key string
@@ -112,11 +130,12 @@ func main() {
 
 	pbClient := pocketbase.NewPocketBaseClient()
 	handler := MainHandler{
-		blog:   microblog.NewHandler(pbClient),
+		blog:      microblog.NewHandler(pbClient),
-		gemlog: gemlog.NewHandler(),
+		gemlog:    gemlog.NewHandler(),
+		guestbook: guestbook.NewGuestBook(db),
 	}
 
-	err := gemini.ListenAndServe(host, cert, key, gemini.TrapPanic(handler.ServeGemini))
+	err = gemini.ListenAndServe(host, cert, key, gemini.TrapPanic(handler.ServeGemini))
 	if err != nil {
 		slog.Error("server failed to start", "error", err)
 		os.Exit(1)

pages/guestbook.gmi

@@ -0,0 +1,13 @@
+# Guestbook
+
+A place to leave messages.
+
+Hey gemspace! Thanks for visiting my capsule. Why not leave a message?
+
+=> /guestbook/new Sign the guestbook
+=> /guestbook/admin Admin
+
+
+Messages like "xxxxx xxxx" mean they are awaiting my approval. Once approved, the actual text will be rendered.
+
+------------------------

pages/home.gmi

@@ -11,7 +11,11 @@
 
 Hello, World!
 
-Welcome to my Gemini capsule. This capsule is in very early stages of development. Mostly a proof of concept at this point. I plan to add more features like a gemlog soon. Looking forward to writing and interacting with folks in gemspace.
+Welcome to my Gemini capsule. Est 2025.09.
+
+This capsule is my playground for experimenting with text based content and interacting with folks in gemspace.
+
+Want to get in touch? Shoot me an email at t [at] travisshears.com
 
 My personal website:
 => https://travisshears.com
@@ -21,17 +25,24 @@ So far I've joined the following communities here in gemspace:
 ## Capsule Features
 
 => /gemlog Gemlog - Gemini exclusive blog
+=> /guestbook Guestbook - Open guestbook for visitors to sign
 => /microblog Microblog - Aggregation of all my microblog posts
 
 ## Site updates
 
-== 06.10.2025 ==
+== 2025.10.07 ==
 
-Added gemlog!
+Added Guestbook!
 
-=> /gemlog
+=> /guestbook Sign it now
 
-== 29.09.2025 ==
+== 2025.10.06 ==
+
+Added Gemlog!
+
+=> /gemlog Check it out
+
+== 2025.09.29 ==
 
 Added microblog feature rendering my nostr post feed. Nice to have a dynamic source of content in this capsule to keep it fresh between updates.
 
@@ -39,7 +50,7 @@ Ideas for next features:
 * Guestbook backed by sqlite. Would be fun to playout sqlite and golang. Could also be intresting to do a telegram notification.
 * Code block rendering from my git hosting
 
-== 26.09.2025 ==
+== 2025.09.26 ==
 
 Initial deployment
 Took quite some tinkering to get everything working, but it's finally up and running! If you are reading this then I got the following architecture working: