Add 'dis' component

This commit adds a new 'dis' component to the distillery that serves a
list of all known instances for the moment.

env/component_dis.go

@@ -0,0 +1,47 @@
+package env
+
+import (
+	"github.com/FAU-CDI/wisski-distillery/core"
+	"github.com/FAU-CDI/wisski-distillery/internal/stack"
+)
+
+// DisComponent represents the 'dis' layer belonging to a distillery
+type DisComponent struct {
+	dis *Distillery
+}
+
+// Dis returns the DisComponent belonging to this distillery
+func (dis *Distillery) Dis() DisComponent {
+	return DisComponent{dis: dis}
+}
+
+func (DisComponent) Name() string {
+	return "dis"
+}
+
+func (dis DisComponent) Stack() stack.Installable {
+	return dis.dis.makeComponentStack(dis, stack.Installable{
+		EnvFileContext: map[string]string{
+			"VIRTUAL_HOST":      dis.dis.DefaultVirtualHost(),
+			"LETSENCRYPT_HOST":  dis.dis.DefaultLetsencryptHost(),
+			"LETSENCRYPT_EMAIL": dis.dis.Config.CertbotEmail,
+
+			"CONFIG_PATH": dis.dis.Config.ConfigPath,
+			"DEPLOY_ROOT": dis.dis.Config.DeployRoot,
+
+			"GLOBAL_AUTHORIZED_KEYS_FILE": dis.dis.Config.GlobalAuthorizedKeysFile,
+			"SELF_OVERRIDES_FILE":         dis.dis.Config.SelfOverridesFile,
+		},
+		CopyContextFiles: []string{core.Executable},
+	})
+}
+
+func (dis DisComponent) Context(parent stack.InstallationContext) stack.InstallationContext {
+	return stack.InstallationContext{
+		core.Executable: dis.dis.CurrentExecutable(),
+	}
+}
+
+func (dis DisComponent) Path() string {
+	return dis.Stack().Dir
+}