bouncer/internal/proxy/director/layer/rewriter/layer.go
William Petit fea0610346
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Cadoles/bouncer/pipeline/pr-develop This commit looks good
feat: reusable rule engine to prevent memory reallocation
2024-09-24 18:45:34 +02:00

116 lines
3.1 KiB
Go

package rewriter
import (
"net/http"
proxy "forge.cadoles.com/Cadoles/go-proxy"
"forge.cadoles.com/Cadoles/go-proxy/wildcard"
"forge.cadoles.com/cadoles/bouncer/internal/proxy/director"
"forge.cadoles.com/cadoles/bouncer/internal/proxy/director/layer/util"
"forge.cadoles.com/cadoles/bouncer/internal/rule"
ruleHTTP "forge.cadoles.com/cadoles/bouncer/internal/rule/http"
"forge.cadoles.com/cadoles/bouncer/internal/store"
"github.com/pkg/errors"
"gitlab.com/wpetit/goweb/logger"
)
const LayerType store.LayerType = "rewriter"
type Layer struct {
requestRuleEngine *util.RevisionedRuleEngine[*RequestVars, *LayerOptions]
responseRuleEngine *util.RevisionedRuleEngine[*ResponseVars, *LayerOptions]
}
func (l *Layer) LayerType() store.LayerType {
return LayerType
}
func (l *Layer) Middleware(layer *store.Layer) proxy.Middleware {
return func(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
options, err := fromStoreOptions(layer.Options)
if err != nil {
logger.Error(ctx, "could not parse layer options", logger.E(errors.WithStack(err)))
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
matches := wildcard.MatchAny(r.URL.String(), options.MatchURLs...)
if !matches {
next.ServeHTTP(w, r)
return
}
if err := l.applyRequestRules(ctx, r, layer.Revision, options); err != nil {
logger.Error(ctx, "could not apply request rules", logger.E(errors.WithStack(err)))
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
next.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
}
// ResponseTransformer implements director.ResponseTransformerLayer.
func (l *Layer) ResponseTransformer(layer *store.Layer) proxy.ResponseTransformer {
return func(r *http.Response) error {
options, err := fromStoreOptions(layer.Options)
if err != nil {
return errors.WithStack(err)
}
matches := wildcard.MatchAny(r.Request.URL.String(), options.MatchURLs...)
if !matches {
return nil
}
ctx := r.Request.Context()
if err := l.applyResponseRules(ctx, r, layer.Revision, options); err != nil {
return errors.WithStack(err)
}
return nil
}
}
func New(funcs ...OptionFunc) *Layer {
return &Layer{
requestRuleEngine: util.NewRevisionedRuleEngine(func(options *LayerOptions) (*rule.Engine[*RequestVars], error) {
engine, err := rule.NewEngine[*RequestVars](
rule.WithRules(options.Rules.Request...),
ruleHTTP.WithRequestFuncs(),
)
if err != nil {
return nil, errors.WithStack(err)
}
return engine, nil
}),
responseRuleEngine: util.NewRevisionedRuleEngine(func(options *LayerOptions) (*rule.Engine[*ResponseVars], error) {
engine, err := rule.NewEngine[*ResponseVars](
rule.WithRules(options.Rules.Response...),
ruleHTTP.WithResponseFuncs(),
)
if err != nil {
return nil, errors.WithStack(err)
}
return engine, nil
}),
}
}
var (
_ director.MiddlewareLayer = &Layer{}
_ director.ResponseTransformerLayer = &Layer{}
)