runner-controller: do not delete runner if it is busy (#103)

Currently, after refreshing the token, the controller re-creates the runner with the new token. This results in jobs being interrupted. This PR makes sure the pod is not restarted if it is busy.

Closes #74

github/fake/runners.go

@@ -0,0 +1,74 @@
+package fake
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+
+	"github.com/google/go-github/v32/github"
+	"github.com/gorilla/mux"
+)
+
+type RunnersList struct {
+	runners []*github.Runner
+}
+
+func NewRunnersList() *RunnersList {
+	return &RunnersList{
+		runners: make([]*github.Runner, 0),
+	}
+}
+
+func (r *RunnersList) Add(runner *github.Runner) {
+	if !exists(r.runners, runner) {
+		r.runners = append(r.runners, runner)
+	}
+}
+
+func (r *RunnersList) GetServer() *httptest.Server {
+	router := mux.NewRouter()
+
+	router.Handle("/repos/{owner}/{repo}/actions/runners", r.handleList())
+	router.Handle("/repos/{owner}/{repo}/actions/runners/{id}", r.handleRemove())
+	router.Handle("/orgs/{org}/actions/runners", r.handleList())
+	router.Handle("/orgs/{org}/actions/runners/{id}", r.handleRemove())
+
+	return httptest.NewServer(router)
+}
+
+func (r *RunnersList) handleList() http.HandlerFunc {
+	return func(w http.ResponseWriter, res *http.Request) {
+		j, err := json.Marshal(github.Runners{
+			TotalCount: len(r.runners),
+			Runners:    r.runners,
+		})
+		if err != nil {
+			panic(err)
+		}
+
+		w.WriteHeader(http.StatusOK)
+		w.Write(j)
+	}
+}
+
+func (r *RunnersList) handleRemove() http.HandlerFunc {
+	return func(w http.ResponseWriter, res *http.Request) {
+		vars := mux.Vars(res)
+		for i, runner := range r.runners {
+			if runner.ID != nil && vars["id"] == strconv.FormatInt(*runner.ID, 10) {
+				r.runners = append(r.runners[:i], r.runners[i+1:]...)
+			}
+		}
+		w.WriteHeader(http.StatusOK)
+	}
+}
+
+func exists(runners []*github.Runner, runner *github.Runner) bool {
+	for _, r := range runners {
+		if *r.Name == *runner.Name {
+			return true
+		}
+	}
+	return false
+}