Move code into new component package

This commit cleans up the resources in the 'embed' package, and instead
moves them into subpackages of a new 'compose' package. This makes sure
that '.env' templates and docker compose contexts are located in the
same location.

component/component.go

@@ -0,0 +1,61 @@
+// Package component holds the main abstraction for components.
+package component
+
+import (
+	"github.com/FAU-CDI/wisski-distillery/internal/config"
+	"github.com/FAU-CDI/wisski-distillery/internal/stack"
+)
+
+// Component represents a logical subsystem of the distillery.
+//
+// By convention these are defined within their corresponding subpackage.
+// This subpackage also contains all required resources.
+// Furthermore, a component is typically instantiated using a call on the ["distillery.Distillery"] struct.
+//
+// Each Component should make use of [ComponentBase] for sane defaults.
+//
+// For example, the web.Web component lives in the web package and can be created like:
+//
+//	var dis Distillery
+//  web := dis.Web()
+type Component interface {
+	// Name returns the name of this component.
+	// It should correspond to the appropriate subpackage.
+	Name() string
+
+	// Path returns the path this component is installed at.
+	// By convention it is /var/www/deploy/core/${Name()}
+	Path() string
+
+	// Stack can be used to gain access to the "docker compose" stack.
+	//
+	// This should internally call
+	Stack() stack.Installable
+
+	// Context returns a new InstallationContext to be used during installation from the command line.
+	// Typically this should just pass through the parent, but might perform other tasks.
+	Context(parent stack.InstallationContext) stack.InstallationContext
+}
+
+// ComponentBase implements base functionality for a component
+type ComponentBase struct {
+	Dir string // Dir is the directory this component lives in
+
+	Config *config.Config // Config is the configuration of the underlying distillery
+}
+
+// Path returns the path to this component
+func (cb ComponentBase) Path() string {
+	return cb.Dir
+}
+
+// Context passes through the parent context
+func (ComponentBase) Context(parent stack.InstallationContext) stack.InstallationContext {
+	return parent
+}
+
+// MakeStack registers the Installable as a stack
+func (cb ComponentBase) MakeStack(stack stack.Installable) stack.Installable {
+	stack.Dir = cb.Dir
+	return stack
+}