feat(netemx): implement subset of the OONI API (ooni#1203)

This diff implements the subset of the OONI API required for testing Web
Connectivity LTE using netemx.

Diff adapted from: ooni#1185.

Reference issue: ooni/probe#2461.

---------

Co-authored-by: kelmenhorst <k.elmenhorst@mailbox.org>

internal/netemx/ooapi.go

@@ -0,0 +1,50 @@
+package netemx
+
+import (
+ "encoding/json"
+ "net/http"
+
+ "github.com/ooni/probe-cli/v3/internal/model"
+ "github.com/ooni/probe-cli/v3/internal/runtimex"
+)
+
+// OOAPIHandler is an [http.Handler] implementing the OONI API.
+type OOAPIHandler struct{}
+
+var _ http.Handler = &OOAPIHandler{}
+
+// ServeHTTP implements [http.Handler].
+func (p *OOAPIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ switch {
+ case r.URL.Path == "/api/v1/test-helpers" && r.Method == http.MethodGet:
+ p.getApiV1TestHelpers(w, r)
+
+ default:
+ w.WriteHeader(http.StatusNotFound)
+ }
+}
+
+func (p *OOAPIHandler) getApiV1TestHelpers(w http.ResponseWriter, r *http.Request) {
+ resp := map[string][]model.OOAPIService{
+ "web-connectivity": {
+ {
+ Address: "https://2.th.ooni.org",
+ Type: "https",
+ },
+ {
+ Address: "https://3.th.ooni.org",
+ Type: "https",
+ },
+ {
+ Address: "https://0.th.ooni.org",
+ Type: "https",
+ },
+ {
+ Address: "https://1.th.ooni.org",
+ Type: "https",
+ },
+ },
+ }
+ w.Header().Add("Content-Type", "application/json")
+ w.Write(runtimex.Try1(json.Marshal(resp)))
+}

internal/netemx/ooapi_test.go

@@ -0,0 +1,55 @@
+package netemx
+
+import (
+ "io"
+ "net/http"
+ "net/http/httptest"
+ "net/url"
+ "testing"
+
+ "github.com/google/go-cmp/cmp"
+ "github.com/ooni/probe-cli/v3/internal/runtimex"
+)
+
+func TestOOAPIHandler(t *testing.T) {
+ handler := &OOAPIHandler{}
+ server := httptest.NewServer(handler)
+ defer server.Close()
+
+ t.Run("for /api/v1/test-helpers with method GET", func(t *testing.T) {
+ URL := runtimex.Try1(url.Parse(server.URL))
+ URL.Path = "/api/v1/test-helpers"
+ resp, err := http.Get(URL.String())
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer resp.Body.Close()
+ if resp.StatusCode != http.StatusOK {
+ t.Fatal("unexpected status code", resp.StatusCode)
+ }
+ body, err := io.ReadAll(resp.Body)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ expectedBody := `{"web-connectivity":[{"address":"https://2.th.ooni.org","type":"https"},{"address":"https://3.th.ooni.org","type":"https"},{"address":"https://0.th.ooni.org","type":"https"},{"address":"https://1.th.ooni.org","type":"https"}]}`
+
+ t.Log(string(body))
+ if diff := cmp.Diff([]byte(expectedBody), body); diff != "" {
+ t.Fatal(diff)
+ }
+ })
+
+ t.Run("for unsupported URL path", func(t *testing.T) {
+ URL := runtimex.Try1(url.Parse(server.URL))
+ URL.Path = "/antani"
+ resp, err := http.Get(URL.String())
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer resp.Body.Close()
+ if resp.StatusCode != http.StatusNotFound {
+ t.Fatal("unexpected status code", resp.StatusCode)
+ }
+ })
+}

script/nocopyreadall.bash

@@ -2,6 +2,12 @@
 set -euo pipefail
 exitcode=0
 for file in $(find . -type f -name \*.go); do
+ if [ "$file" = "./internal/netemx/ooapi_test.go" ]; then
+ # We're allowed to use ReadAll and Copy in this file because
+ # it's code that we only use for testing purposes.
+ continue
+ fi
+
  if [ "$file" = "./internal/netxlite/iox.go" ]; then
  # We're allowed to use ReadAll and Copy in this file to
  # implement safer wrappers for these functions.