Show a warning when using wrong executable

This commit updates the 'wdcli' command to show a warning when using the
wrong executable.

env/constants.go

@@ -0,0 +1,36 @@
+package env
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/fsx"
+)
+
+// Executable is the name of the 'wdcli' executable.
+// It should be located inside the deployment directory.
+const Executable = "wdcli"
+
+// ExecutablePath returns the path to the executable of this distillery.
+func (dis *Distillery) ExecutablePath() string {
+	return filepath.Join(dis.Config.DeployRoot, Executable)
+}
+
+// UsingDistilleryExecutable checks if the current process
+func (dis *Distillery) UsingDistilleryExecutable() bool {
+	exe, err := os.Executable()
+	if err != nil {
+		return false
+	}
+	return fsx.SameFile(exe, dis.ExecutablePath())
+}
+
+// Config file is the name of the config file.
+// It should be located inside the deployment directory.
+const ConfigFile = ".env"
+
+// ConfigFilePath returns the path to the configuration file of this distillery.
+// TODO: This should be moved to the Config struct.
+func (dis *Distillery) ConfigFilePath() string {
+	return filepath.Join(dis.Config.DeployRoot, ConfigFile)
+}

env/distillery.go

@@ -54,7 +54,7 @@ func NewDistillery(params Params, req Requirements) (env *Distillery, err error)
 	env = &Distillery{}
 
 	// if we don't need to load the config, there is nothing to do
-	if !req.NeedsConfig {
+	if !req.NeedsDistillery {
 		return
 	}
 

env/params.go

@@ -20,7 +20,7 @@ func (params Params) ConfigFilePath() string {
 	if params.BaseDirectory == "" {
 		return ""
 	}
-	return filepath.Join(params.BaseDirectory, ".env")
+	return filepath.Join(params.BaseDirectory, ConfigFile)
 }
 
 var errUnableToLoadParams = exit.Error{

env/requirements.go

@@ -6,7 +6,8 @@ import (
 )
 
 type Requirements struct {
-	NeedsConfig bool
+	// Do we need an installed distillery?
+	NeedsDistillery bool
 }
 
 // AllowsFlag checks if the provided flag may be passed to fullfill this requirement