traefik/pkg/plugins/builder.go
2021-11-09 14:30:09 +01:00

131 lines
3.7 KiB
Go

package plugins
import (
"context"
"fmt"
"net/http"
"os"
"github.com/traefik/yaegi/interp"
"github.com/traefik/yaegi/stdlib"
)
// Constructor creates a plugin handler.
type Constructor func(context.Context, http.Handler) (http.Handler, error)
// pluginContext The static part of a plugin configuration.
type pluginContext struct {
// GoPath plugin's GOPATH
GoPath string `json:"goPath,omitempty" toml:"goPath,omitempty" yaml:"goPath,omitempty"`
// Import plugin's import/package
Import string `json:"import,omitempty" toml:"import,omitempty" yaml:"import,omitempty"`
// BasePkg plugin's base package name (optional)
BasePkg string `json:"basePkg,omitempty" toml:"basePkg,omitempty" yaml:"basePkg,omitempty"`
interpreter *interp.Interpreter
}
// Builder is a plugin builder.
type Builder struct {
middlewareDescriptors map[string]pluginContext
providerDescriptors map[string]pluginContext
}
// NewBuilder creates a new Builder.
func NewBuilder(client *Client, plugins map[string]Descriptor, localPlugins map[string]LocalDescriptor) (*Builder, error) {
pb := &Builder{
middlewareDescriptors: map[string]pluginContext{},
providerDescriptors: map[string]pluginContext{},
}
for pName, desc := range plugins {
manifest, err := client.ReadManifest(desc.ModuleName)
if err != nil {
_ = client.ResetAll()
return nil, fmt.Errorf("%s: failed to read manifest: %w", desc.ModuleName, err)
}
i := interp.New(interp.Options{GoPath: client.GoPath(), Env: os.Environ()})
err = i.Use(stdlib.Symbols)
if err != nil {
return nil, fmt.Errorf("%s: failed to load symbols: %w", desc.ModuleName, err)
}
err = i.Use(ppSymbols())
if err != nil {
return nil, fmt.Errorf("%s: failed to load provider symbols: %w", desc.ModuleName, err)
}
_, err = i.Eval(fmt.Sprintf(`import "%s"`, manifest.Import))
if err != nil {
return nil, fmt.Errorf("%s: failed to import plugin code %q: %w", desc.ModuleName, manifest.Import, err)
}
switch manifest.Type {
case "middleware":
pb.middlewareDescriptors[pName] = pluginContext{
interpreter: i,
GoPath: client.GoPath(),
Import: manifest.Import,
BasePkg: manifest.BasePkg,
}
case "provider":
pb.providerDescriptors[pName] = pluginContext{
interpreter: i,
GoPath: client.GoPath(),
Import: manifest.Import,
BasePkg: manifest.BasePkg,
}
default:
return nil, fmt.Errorf("unknow plugin type: %s", manifest.Type)
}
}
for pName, desc := range localPlugins {
manifest, err := ReadManifest(localGoPath, desc.ModuleName)
if err != nil {
return nil, fmt.Errorf("%s: failed to read manifest: %w", desc.ModuleName, err)
}
i := interp.New(interp.Options{GoPath: localGoPath, Env: os.Environ()})
err = i.Use(stdlib.Symbols)
if err != nil {
return nil, fmt.Errorf("%s: failed to load symbols: %w", desc.ModuleName, err)
}
err = i.Use(ppSymbols())
if err != nil {
return nil, fmt.Errorf("%s: failed to load provider symbols: %w", desc.ModuleName, err)
}
_, err = i.Eval(fmt.Sprintf(`import "%s"`, manifest.Import))
if err != nil {
return nil, fmt.Errorf("%s: failed to import plugin code %q: %w", desc.ModuleName, manifest.Import, err)
}
switch manifest.Type {
case "middleware":
pb.middlewareDescriptors[pName] = pluginContext{
interpreter: i,
GoPath: localGoPath,
Import: manifest.Import,
BasePkg: manifest.BasePkg,
}
case "provider":
pb.providerDescriptors[pName] = pluginContext{
interpreter: i,
GoPath: localGoPath,
Import: manifest.Import,
BasePkg: manifest.BasePkg,
}
default:
return nil, fmt.Errorf("unknow plugin type: %s", manifest.Type)
}
}
return pb, nil
}