1 files changed, 165 insertions, 0 deletions
diff --git a/modules/caddyhttp/starlarkmw/internal/lib/module.go b/modules/caddyhttp/starlarkmw/internal/lib/module.go
new file mode 100644
index 0000000..a7164cd
--- /dev/null
+++ b/modules/caddyhttp/starlarkmw/internal/lib/module.go
@@ -0,0 +1,165 @@
+package lib
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+
+	"github.com/caddyserver/caddy/v2"
+	"go.starlark.net/starlark"
+)
+
+// ResponderModule represents a module that satisfies the caddyhttp handler.
+type ResponderModule struct {
+	Name     string
+	Cfg      json.RawMessage
+	Instance caddyhttp.Handler
+}
+
+func (r ResponderModule) Freeze()               {}
+func (r ResponderModule) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: responder module") }
+func (r ResponderModule) String() string        { return "responder module" }
+func (r ResponderModule) Type() string          { return "responder module" }
+func (r ResponderModule) Truth() starlark.Bool  { return true }
+
+// Middleware represents a module that satisfies the starlark Value interface.
+type Middleware struct {
+	Name     string
+	Cfg      json.RawMessage
+	Instance caddyhttp.MiddlewareHandler
+}
+
+func (r Middleware) Freeze()               {}
+func (r Middleware) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: middleware") }
+func (r Middleware) String() string        { return "middleware" }
+func (r Middleware) Type() string          { return "middleware" }
+func (r Middleware) Truth() starlark.Bool  { return true }
+
+// LoadMiddleware represents the method exposed to starlark to load a Caddy module.
+type LoadMiddleware struct {
+	Middleware Middleware
+	Ctx        caddy.Context
+}
+
+func (r LoadMiddleware) Freeze()               {}
+func (r LoadMiddleware) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: loadMiddleware") }
+func (r LoadMiddleware) String() string        { return "loadMiddleware" }
+func (r LoadMiddleware) Type() string          { return "function: loadMiddleware" }
+func (r LoadMiddleware) Truth() starlark.Bool  { return true }
+
+// Run is the method bound to the starlark loadMiddleware function.
+func (r *LoadMiddleware) Run(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+	var name string
+	var cfg *starlark.Dict
+	err := starlark.UnpackPositionalArgs(fn.Name(), args, kwargs, 2, &name, &cfg)
+	if err != nil {
+		return starlark.None, fmt.Errorf("unpacking arguments: %v", err.Error())
+	}
+
+	js := json.RawMessage(cfg.String())
+
+	if strings.Index(name, "http.handlers.") == -1 {
+		name = fmt.Sprintf("http.handlers.%s", name)
+	}
+
+	inst, err := r.Ctx.LoadModule(name, js)
+	if err != nil {
+		return starlark.None, err
+	}
+
+	mid, ok := inst.(caddyhttp.MiddlewareHandler)
+	if !ok {
+		return starlark.None, fmt.Errorf("could not assert as middleware handler")
+	}
+
+	m := Middleware{
+		Name:     name,
+		Cfg:      js,
+		Instance: mid,
+	}
+
+	r.Middleware = m
+
+	return m, nil
+}
+
+// LoadResponder represents the method exposed to starlark to load a Caddy middleware responder.
+type LoadResponder struct {
+	Module ResponderModule
+	Ctx    caddy.Context
+}
+
+func (r LoadResponder) Freeze()               {}
+func (r LoadResponder) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: loadModule") }
+func (r LoadResponder) String() string        { return "loadModule" }
+func (r LoadResponder) Type() string          { return "function: loadModule" }
+func (r LoadResponder) Truth() starlark.Bool  { return true }
+
+// Run is the method bound to the starlark loadResponder function.
+func (r *LoadResponder) Run(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+	var name string
+	var cfg *starlark.Dict
+	err := starlark.UnpackPositionalArgs(fn.Name(), args, kwargs, 2, &name, &cfg)
+	if err != nil {
+		return starlark.None, fmt.Errorf("unpacking arguments: %v", err.Error())
+	}
+
+	js := json.RawMessage(cfg.String())
+
+	if strings.Index(name, "http.handlers.") == -1 {
+		name = fmt.Sprintf("http.handlers.%s", name)
+	}
+
+	inst, err := r.Ctx.LoadModule(name, js)
+	if err != nil {
+		return starlark.None, err
+	}
+
+	res, ok := inst.(caddyhttp.Handler)
+	if !ok {
+		return starlark.None, fmt.Errorf("could not assert as responder")
+	}
+
+	m := ResponderModule{
+		Name:     name,
+		Cfg:      js,
+		Instance: res,
+	}
+
+	r.Module = m
+
+	return m, nil
+}
+
+// Execute represents the method exposed to starlark to build a middleware chain.
+type Execute struct {
+	Modules []Middleware
+}
+
+func (r Execute) Freeze()               {}
+func (r Execute) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: execute") }
+func (r Execute) String() string        { return "execute" }
+func (r Execute) Type() string          { return "function: execute" }
+func (r Execute) Truth() starlark.Bool  { return true }
+
+// Run is the method bound to the starlark execute function.
+func (r *Execute) Run(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+	var mids *starlark.List
+	err := starlark.UnpackPositionalArgs(fn.Name(), args, kwargs, 1, &mids)
+	if err != nil {
+		return starlark.None, fmt.Errorf("unpacking arguments: %v", err.Error())
+	}
+
+	for i := 0; i < mids.Len(); i++ {
+		val, ok := mids.Index(i).(Middleware)
+		if !ok {
+			return starlark.None, fmt.Errorf("cannot get module from execute")
+		}
+
+		r.Modules = append(r.Modules, val)
+	}
+
+	return starlark.None, nil
+}