Add missing ExternalAPIs

internal/shared/config/config.go

@@ -17,6 +17,7 @@ type Config struct {
 	Metrics              *MetricsConfig              `mapstructure:"metrics"`
 	Assets               *AssetsConfig               `mapstructure:"assets"`
 	DelegationTransition *DelegationTransitionConfig `mapstructure:"delegation-transition"`
+	ExternalAPIs         *ExternalAPIsConfig         `mapstructure:"external_apis"`
 }
 
 func (cfg *Config) Validate() error {

internal/shared/config/external_apis.go

@@ -0,0 +1,49 @@
+package config
+
+import (
+	"fmt"
+	"time"
+)
+
+type ExternalAPIsConfig struct {
+	CoinMarketCap *CoinMarketCapConfig `mapstructure:"coinmarketcap"`
+}
+
+type CoinMarketCapConfig struct {
+	APIKey   string        `mapstructure:"api_key"`
+	BaseURL  string        `mapstructure:"base_url"`
+	Timeout  time.Duration `mapstructure:"timeout"`
+	CacheTTL time.Duration `mapstructure:"cache_ttl"`
+}
+
+func (cfg *ExternalAPIsConfig) Validate() error {
+	if cfg.CoinMarketCap == nil {
+		return fmt.Errorf("missing coinmarketcap config")
+	}
+
+	if err := cfg.CoinMarketCap.Validate(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (cfg *CoinMarketCapConfig) Validate() error {
+	if cfg.APIKey == "" {
+		return fmt.Errorf("missing coinmarketcap api key")
+	}
+
+	if cfg.BaseURL == "" {
+		return fmt.Errorf("missing coinmarketcap base url")
+	}
+
+	if cfg.Timeout <= 0 {
+		return fmt.Errorf("invalid coinmarketcap timeout")
+	}
+
+	if cfg.CacheTTL <= 0 {
+		return fmt.Errorf("invalid coinmarketcap cache ttl")
+	}
+
+	return nil
+}