new feature: users are now able to provide more file types to convert by adding entries in their configuration file (#3)

* new feature: users are now able to provide more file types to convert by adding entries in their configuration file

* removing README blueprint: was not working correctly

* improving code coverage of config package

app/config/parser.go

@@ -0,0 +1,94 @@
+package config
+
+import (
+	"io/ioutil"
+
+	"gopkg.in/yaml.v2"
+)
+
+// ParseFile instantiates the application's configuration using the given YAML file.
+func ParseFile(configurationFilePath string) error {
+	fileConfig, err := readFile(configurationFilePath)
+	if err != nil {
+		return err
+	}
+
+	WithPort(fileConfig.Port)
+
+	if err := WithLogsLevel(fileConfig.Logs.Level); err != nil {
+		return err
+	}
+
+	if err := WithLogsFormatter(fileConfig.Logs.Formatter); err != nil {
+		return err
+	}
+
+	// handles merge command first...
+	cmd, err := NewCommand(fileConfig.Commands.Merge.Template, fileConfig.Commands.Merge.Timeout)
+	if err != nil {
+		return err
+	}
+
+	WithCommand(".pdf", cmd)
+
+	// ...then conversion commands!
+	for _, command := range fileConfig.Commands.Conversions {
+		cmd, err := NewCommand(command.Template, command.Timeout)
+		if err != nil {
+			return err
+		}
+
+		for _, ext := range command.Extensions {
+			if err := WithCommand(ext, cmd); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+type (
+	// fileConfig gathers all data coming from the configuration file gotenberg.yml.
+	fileConfig struct {
+		Port string `yaml:"port"`
+		Logs struct {
+			Level     string `yaml:"level"`
+			Formatter string `yaml:"formatter"`
+		} `yaml:"logs"`
+		Commands struct {
+			Merge       *mergeCommand        `yaml:"merge"`
+			Conversions []*conversionCommand `yaml:"conversions,omitempty"`
+		} `yaml:"commands"`
+	}
+
+	// mergeCommand gathers all data regarding the... merge command.
+	mergeCommand struct {
+		Template string `yaml:"template"`
+		Timeout  int    `yaml:"timeout"`
+	}
+
+	// conversionCommand gathers all data regarding a conversion command.
+	conversionCommand struct {
+		Template   string   `yaml:"template"`
+		Timeout    int      `yaml:"timeout"`
+		Extensions []string `yaml:"extensions"`
+	}
+)
+
+// readFile instantiates a fileConfig instance by reading
+// the given YAML file.
+func readFile(configurationFilePath string) (*fileConfig, error) {
+	c := &fileConfig{}
+
+	data, err := ioutil.ReadFile(configurationFilePath)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := yaml.Unmarshal(data, &c); err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}