Ryan
0557635008
Add package declarations across the Go scaffold, YAML configuration loading and validation, and a minimal API entry point. Add development and production Compose files, a multi-stage Docker image, configuration template, and Make targets. Remove the directory scaffolding script.
85 lines
1.9 KiB
Go
85 lines
1.9 KiB
Go
package app
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import (
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"errors"
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"fmt"
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"os"
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"strings"
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"gopkg.in/yaml.v3"
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)
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const defaultConfigPath = "configs/config.example.yaml"
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// Config contains the settings required to start the application.
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type Config struct {
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Environment string `yaml:"environment"`
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HTTP HTTPConfig `yaml:"http"`
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Database DatabaseConfig `yaml:"database"`
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}
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type HTTPConfig struct {
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Address string `yaml:"address"`
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}
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type DatabaseConfig struct {
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URL string `yaml:"url"`
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}
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// LoadConfig reads configuration from YAML, applies environment overrides,
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// and validates the result. An empty path uses CONFIG_FILE when set.
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func LoadConfig(path string) (Config, error) {
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if path == "" {
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path = os.Getenv("CONFIG_FILE")
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}
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if path == "" {
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path = defaultConfigPath
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}
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contents, err := os.ReadFile(path)
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if err != nil {
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return Config{}, fmt.Errorf("read config %q: %w", path, err)
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}
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var config Config
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if err := yaml.Unmarshal(contents, &config); err != nil {
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return Config{}, fmt.Errorf("parse config %q: %w", path, err)
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}
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applyEnvironment(&config)
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if err := config.Validate(); err != nil {
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return Config{}, fmt.Errorf("validate config: %w", err)
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}
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return config, nil
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}
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func (config Config) Validate() error {
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var missing []string
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if strings.TrimSpace(config.Environment) == "" {
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missing = append(missing, "environment")
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}
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if strings.TrimSpace(config.HTTP.Address) == "" {
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missing = append(missing, "http.address")
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}
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if strings.TrimSpace(config.Database.URL) == "" {
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missing = append(missing, "database.url")
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}
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if len(missing) > 0 {
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return errors.New("missing required values: " + strings.Join(missing, ", "))
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}
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return nil
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}
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func applyEnvironment(config *Config) {
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if value := os.Getenv("APP_ENVIRONMENT"); value != "" {
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config.Environment = value
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}
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if value := os.Getenv("APP_HTTP_ADDRESS"); value != "" {
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config.HTTP.Address = value
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}
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if value := os.Getenv("APP_DATABASE_URL"); value != "" {
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config.Database.URL = value
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}
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}
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