Introduced basic structure

providers/config.go

@@ -0,0 +1,100 @@
+package providers
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"githib.com/Theodor-Springmann-Stiftung/kgpz_web/helpers"
+	"github.com/kelseyhightower/envconfig"
+)
+
+// WARNING: this is not intended to be used in a multi-threaded environment
+// Instatiate this once on startup before any goroutines are started
+const (
+	DEFAULT_GIT_DIR = "data_git"
+	DEFAULT_GND_DIR = "cache_gnd"
+	DEFAULT_GEO_DIR = "cache_geo"
+)
+
+type ConfigProvider struct {
+	Files []string
+	*Config
+}
+
+type Config struct {
+	// At least one of these should be set
+	GitURL          string `json:"git_url" envconfig:"GIT_URL"`
+	GitBranch       string `json:"git_branch" envconfig:"GIT_BRANCH"`
+	FolderPath      string `json:"folder_path" envconfig:"FOLDER_PATH"`
+	GNDPath         string `json:"gnd_path" envconfig:"GND_PATH"`
+	GeoPath         string `json:"geo_path" envconfig:"GEO_PATH"`
+	WebHookEndpoint string `json:"webhook_endpoint" envconfig:"WEBHOOK_ENDPOINT"`
+	WebHookSecret   string `json:"webhook_secret" envconfig:"WEBHOOK_SECRET"`
+	Debug           bool   `json:"debug" envconfig:"DEBUG"`
+}
+
+func NewConfigProvider(files []string) *ConfigProvider {
+	return &ConfigProvider{Files: files}
+}
+
+func (c *ConfigProvider) Read() error {
+	c.Config = &Config{}
+	for _, file := range c.Files {
+		c.Config = readSettingsFile(c.Config, file)
+	}
+	c.Config = readSettingsEnv(c.Config)
+	c.Config = readDefaults(c.Config)
+	return nil
+}
+
+func (c *ConfigProvider) Validate() error {
+	if strings.TrimSpace(c.Config.FolderPath) == "" {
+		return fmt.Errorf("Folder path not set")
+	}
+	return nil
+}
+
+func readSettingsFile(cfg *Config, path string) *Config {
+	f, err := os.Open(path)
+	if err != nil {
+		fmt.Println("Error: ", err)
+		fmt.Println("Coudln't open ", path)
+		return cfg
+	}
+	defer f.Close()
+
+	dec := json.NewDecoder(f)
+	err = dec.Decode(cfg)
+	helpers.MaybePanic(err, "Error decoding config.json")
+
+	return cfg
+}
+
+func readSettingsEnv(cfg *Config) *Config {
+	_ = envconfig.Process("KGPZ", cfg)
+	return cfg
+}
+
+func readDefaults(cfg *Config) *Config {
+	if strings.TrimSpace(cfg.FolderPath) == "" {
+		cfg.FolderPath = DEFAULT_GIT_DIR
+	}
+
+	if strings.TrimSpace(cfg.GNDPath) == "" {
+		cfg.GNDPath = DEFAULT_GND_DIR
+	}
+
+	if strings.TrimSpace(cfg.GeoPath) == "" {
+		cfg.GeoPath = DEFAULT_GEO_DIR
+	}
+
+	return cfg
+}
+
+// Implement stringer
+func (c *Config) String() string {
+	return fmt.Sprintf("GitURL: %s\nGitBranch: %s\nFolderPath: %s\nGNDPath: %s\nGeoPath: %s\nWebHookEndpoint: %s\nWebHookSecret: %s\n",
+		c.GitURL, c.GitBranch, c.FolderPath, c.GNDPath, c.GeoPath, c.WebHookEndpoint, c.WebHookSecret)
+}