set env variables to execute commands

before executing any action we need to update the environment variables
PODMAN_CONNECTIONS_CONF, PODMAN_DATA_DIR and PODMAN_RUNTIME_DIR to
define a specific location where to store macadam data. This way we
prevent to write macadam stuff within podman-related folders

Signed-off-by: lstocchi <[email protected]>

Author: lstocchi

cmd/macadam/root.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/cfergeau/macadam/cmd/macadam/registry"
 	"github.com/cfergeau/macadam/pkg/cmdline"
+	"github.com/cfergeau/macadam/pkg/env"
 	"github.com/containers/podman/v5/libpod/define"
 	"github.com/spf13/cobra"
 )
@@ -52,6 +53,7 @@ var (
 		TraverseChildren:      true,
 		Version:               cmdline.Version(),
 		DisableFlagsInUseLine: true,
+		PersistentPreRunE:     machinePreRunE,
 	}
 
 	defaultLogLevel = "warn"
@@ -82,3 +84,7 @@ func Execute() {
 
 	os.Exit(registry.GetExitCode())
 }
+
+func machinePreRunE(c *cobra.Command, args []string) error {
+	return env.SetupEnvironment()
+}

pkg/config/config.go

@@ -0,0 +1,29 @@
+//go:build !windows
+
+package config
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/containers/storage/pkg/unshare"
+)
+
+// _configPath is the path to the macadam/machines.conf
+// inside a given config directory.
+const _configPath = "macadam/machines.conf"
+
+// userConfigPath returns the path to the users local config that is
+// not shared with other users. It uses $XDG_CONFIG_HOME/containers...
+// if set or $HOME/.config/containers... if not.
+func UserConfigPath() (string, error) {
+	if configHome := os.Getenv("XDG_CONFIG_HOME"); configHome != "" {
+		return filepath.Join(configHome, _configPath), nil
+	}
+	home, err := unshare.HomeDir()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(home, _configPath), nil
+}

pkg/config/config_windows.go

@@ -0,0 +1,17 @@
+//go:build windows
+
+package config
+
+import "os"
+
+const (
+	// _configPath is the path to the macadam/machines.conf
+	// inside a given config directory.
+	_configPath = "\\macadam\\machines.conf"
+)
+
+// userConfigPath returns the path to the users local config that is
+// not shared with other users. It uses $APPDATA/containers...
+func UserConfigPath() (string, error) {
+	return os.Getenv("APPDATA") + _configPath, nil
+}

pkg/env/env.go

@@ -0,0 +1,41 @@
+package env
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/cfergeau/macadam/pkg/config"
+)
+
+const connectionsFile = "macadam-connections.json"
+
+func SetupEnvironment() error {
+	path, err := config.UserConfigPath()
+	if err != nil {
+		return err
+	}
+
+	connsFile := filepath.Join(filepath.Dir(path), connectionsFile)
+	// set the path used for storing connection of macadam vms
+	err = os.Setenv("PODMAN_CONNECTIONS_CONF", connsFile)
+	if err != nil {
+		return err
+	}
+
+	// set the directory used when calculating the data and config paths
+	// config -> <configHome>/containers/macadam/machine (configHome changes based on the OS used e.g. configHome == /home/user/.config)
+	// data -> <dataHome>/containers/macadam/machine (dataHome changes based on the OS used e.g. dataHome == /home/user/.local/share)
+	err = os.Setenv("PODMAN_DATA_DIR", filepath.Join("macadam", "machine"))
+	if err != nil {
+		return err
+	}
+
+	// set the directory to be used when calculating runtime path
+	// run -> <runHome>/macadam (runHome changes based on the OS used e.g. runHome == /run)
+	err = os.Setenv("PODMAN_RUNTIME_DIR", "macadam")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}