Move to yaml-based configuration

This commit updates the configuration to be yaml-based and updates the
configuration to read in a yaml file.

internal/config/paths.go

@@ -0,0 +1,52 @@
+package config
+
+import (
+	"path/filepath"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/bootstrap"
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
+)
+
+type PathsConfig struct {
+	// Several docker-compose files are created to manage global services and the system itself.
+	// On top of this all real-system space will be created under this directory.
+	Root string `yaml:"root" default:"/var/www/deploy" validate:"directory"`
+
+	// You can override individual URLS in the homepage
+	// Do this by adding URLs (without trailing '/'s) into a JSON file
+	OverridesJSON string `yaml:"overrides" validate:"file"`
+
+	// You can block specific prefixes from being picked up by the resolver.
+	// Do this by adding one prefix per file.
+	ResolverBlocks string `yaml:"blocks" validate:"file"`
+}
+
+// RuntimeDir returns the path to the runtime directory
+func (pcfg PathsConfig) RuntimeDir() string {
+	return filepath.Join(pcfg.Root, "runtime")
+}
+
+// ExecutablePath returns the path to the executable of this distillery.
+func (pcfg PathsConfig) ExecutablePath() string {
+	return filepath.Join(pcfg.Root, bootstrap.Executable)
+}
+
+// UsingDistilleryExecutable checks if the current process is using the distillery executable
+func (pcfg PathsConfig) UsingDistilleryExecutable(env environment.Environment) bool {
+	exe, err := env.Executable()
+	if err != nil {
+		return false
+	}
+	return fsx.SameFile(env, exe, pcfg.ExecutablePath())
+}
+
+// CurrentExecutable returns the path to the current executable being used.
+// When it does not exist, falls back to the default executable.
+func (pcfg PathsConfig) CurrentExecutable(env environment.Environment) string {
+	exe, err := env.Executable()
+	if err != nil || !fsx.IsFile(env, exe) {
+		return pcfg.ExecutablePath()
+	}
+	return exe
+}