Scaffold tomswallapi control-plane service

internal/config/config.go

@@ -0,0 +1,69 @@
+// Package config loads tomswallapi runtime configuration from the environment.
+package config
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+)
+
+// Config holds all runtime configuration, sourced from environment variables.
+type Config struct {
+	ListenAddr string
+
+	DBHost     string
+	DBPort     string
+	DBUser     string
+	DBPassword string
+	DBName     string
+	DBSSLMode  string
+
+	// WriteToken guards all mutating API endpoints (used by the Terraform provider).
+	WriteToken string
+	// AgentToken guards the per-device config endpoint (used by tomswall agents).
+	AgentToken string
+
+	// IPLocateAPIKey is used to expand ASN address groups into prefixes.
+	IPLocateAPIKey string
+}
+
+// Load reads configuration from the environment, applying defaults.
+func Load() (*Config, error) {
+	c := &Config{
+		ListenAddr:     env("TOMSWALLAPI_LISTEN_ADDR", ":8000"),
+		DBHost:         env("TOMSWALLAPI_DB_HOST", "localhost"),
+		DBPort:         env("TOMSWALLAPI_DB_PORT", "5432"),
+		DBUser:         env("TOMSWALLAPI_DB_USER", "tomswallapi"),
+		DBPassword:     os.Getenv("TOMSWALLAPI_DB_PASSWORD"),
+		DBName:         env("TOMSWALLAPI_DB_NAME", "tomswallapi"),
+		DBSSLMode:      env("TOMSWALLAPI_DB_SSLMODE", "disable"),
+		WriteToken:     os.Getenv("TOMSWALLAPI_WRITE_TOKEN"),
+		AgentToken:     os.Getenv("TOMSWALLAPI_AGENT_TOKEN"),
+		IPLocateAPIKey: os.Getenv("TOMSWALLAPI_IPLOCATE_API_KEY"),
+	}
+	if c.DBName == "" {
+		return nil, fmt.Errorf("TOMSWALLAPI_DB_NAME must not be empty")
+	}
+	return c, nil
+}
+
+// DatabaseDSN builds a libpq-style connection string.
+func (c *Config) DatabaseDSN() string {
+	u := url.URL{
+		Scheme: "postgres",
+		User:   url.UserPassword(c.DBUser, c.DBPassword),
+		Host:   fmt.Sprintf("%s:%s", c.DBHost, c.DBPort),
+		Path:   c.DBName,
+	}
+	q := u.Query()
+	q.Set("sslmode", c.DBSSLMode)
+	u.RawQuery = q.Encode()
+	return u.String()
+}
+
+func env(key, def string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return def
+}