From 2cbea02b3a1f9e7023d0be271b45488b8ae4aeb2 Mon Sep 17 00:00:00 2001
From: Alex Denes <caskd@redxen.eu>
Date: Wed, 16 Oct 2024 19:45:48 +0000
Subject: [PATCH] Inital commit

---
 go.mod  |  3 +++
 main.go | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 go.mod
 create mode 100644 main.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..f36b84f
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module git.redxen.eu/caskd/postgres-seeder
+
+go 1.22.7
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..bd85957
--- /dev/null
+++ b/main.go
@@ -0,0 +1,74 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+)
+
+func main() {
+	var (
+		pairs     = make(map[string]([]string))
+		databases = make(map[string]interface{})
+		l         = log.New(os.Stderr, "postgres-seeder: ", log.Lmsgprefix|log.LUTC)
+		err       error
+
+		hbastr, initstr string
+		hba, init       *os.File
+		hbabuf, initbuf strings.Builder
+	)
+
+	flag.StringVar(&hbastr, "hbafile", "pg_hba.conf", "Host-Based authentication file output")
+	flag.StringVar(&initstr, "init", "init.sql", "SQL command list file output")
+	flag.Parse()
+
+	if hba, err = os.Create(hbastr); err != nil {
+		l.Fatalf("Cannot create or truncate HBA file %s: %s\n", hbastr, err)
+	}
+	defer hba.Close()
+
+	if init, err = os.Create(initstr); err != nil {
+		l.Fatalf("Cannot create or truncate init file %s: %s\n", initstr, err)
+	}
+	defer init.Close()
+
+	for _, v := range flag.Args() {
+		tok := strings.Split(v, "/")
+		if len(tok) != 2 {
+			l.Fatalln("Incorrect token count")
+		}
+		var (
+			user = tok[0]
+			db   = tok[1]
+			v    []string
+		)
+
+		v, _ = pairs[user]
+		pairs[user] = append(v, db)
+
+		databases[db] = nil
+	}
+
+	hbabuf.WriteString("local\tall\tpostgres\ttrust\n")
+
+	for d := range databases {
+		initbuf.WriteString(fmt.Sprintf("CREATE DATABASE %s;\n", d))
+	}
+
+	for u, v := range pairs {
+		initbuf.WriteString(fmt.Sprintf("CREATE USER %s LOGIN;\n", u))
+		for _, d := range v {
+			initbuf.WriteString(fmt.Sprintf("GRANT ALL PRIVILEGES ON DATABASE %s TO %s;\n", d, u))
+			hbabuf.WriteString(fmt.Sprintf("hostssl\t%s\t%s\tall\tcert\tclientcert=verify-full\n", u, d))
+		}
+	}
+
+	if _, err = hba.WriteString(hbabuf.String()); err != nil {
+		l.Fatalf("Failed to write to HBA: %s\n", err)
+	}
+	if _, err = init.WriteString(initbuf.String()); err != nil {
+		l.Fatalf("Failed to write to init: %s\n", err)
+	}
+}