fix: Traefik does not allow go modules; use structure impose by GOPATH

Dockerfile

@@ -11,12 +11,12 @@ RUN curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/i
 # Install Yaegi (go interpreter used by Traefik)
 RUN curl -sfL https://raw.githubusercontent.com/traefik/yaegi/master/install.sh | bash -s -- -b $(go env GOPATH)/bin ${YAEGI_VERSION}
 
-WORKDIR /home/traefik_request_id
+WORKDIR /go/src/github.com/ZeroGachis/traefik-request-id
 
 COPY ./ ./
 
 RUN \
-    go env -w GOPATH=/home/traefik_request_id/go && \
+    go env -w GOPATH=/go && \
     go mod tidy && \
     go mod download && \
     go mod vendor

docker-compose.yml

@@ -3,6 +3,6 @@ services:
     build:
       context: .
     tty: true
-    working_dir: /home/traefik_request_id
+    working_dir: /go/src/github.com/ZeroGachis/traefik-request-id
     volumes:
-      - .:/home/traefik_request_id
+      - .:/go/src/github.com/ZeroGachis/traefik-request-id

requestid_test.go

@@ -1,19 +1,21 @@
-package requestid
+package requestid_test
 
 import (
 	"context"
 	"net/http"
 	"net/http/httptest"
 	"testing"
+
+	plugin "github.com/ZeroGachis/traefik-request-id"
 )
 
 func TestAddRequestIdInHeaderIfNoneExist(t *testing.T) {
-	cfg := CreateConfig()
+	cfg := plugin.CreateConfig()
 
 	ctx := context.Background()
 	next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {})
 
-	handler, err := New(ctx, next, cfg, "sw-request-id-plugin")
+	handler, err := plugin.New(ctx, next, cfg, "sw-request-id-plugin")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -34,12 +36,12 @@ func TestAddRequestIdInHeaderIfNoneExist(t *testing.T) {
 }
 
 func TestKeepRequestIdInHeaderIfOneExist(t *testing.T) {
-	cfg := CreateConfig()
+	cfg := plugin.CreateConfig()
 
 	ctx := context.Background()
 	next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {})
 
-	handler, err := New(ctx, next, cfg, "sw-request-id-plugin")
+	handler, err := plugin.New(ctx, next, cfg, "sw-request-id-plugin")
 	if err != nil {
 		t.Fatal(err)
 	}