Add tests and end-to-end tests for websocket execution

For unit tests, this mocks the runners Execute method with a
customizable function that operates on the request, streams and exit
channel to simulate a real execution.

End-to-end tests are moved to the tests/e2e_tests folder. The tests
folder allows us to have shared helper functions for all tests in a
separate package (tests) that is not included in the non-test build.

This also adds one second of delay before each end-to-end test case by
using the TestSetup method of suite. By slowing down test execution,
this gives Nomad time to create new allocations when a test requested a
runner. Another solution could be to increase the scale of the job to
have enough allocations for all end-to-end tests.

Co-authored-by: Maximilian Paß <maximilian.pass@student.hpi.uni-potsdam.de>

tests/e2e/runners_test.go

@@ -0,0 +1,67 @@
+package e2e
+
+import (
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/api"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/api/dto"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/tests/e2e/helpers"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+func (suite *E2ETestSuite) TestProvideRunnerRoute() {
+	runnerRequestString, _ := json.Marshal(dto.RunnerRequest{})
+	reader := strings.NewReader(string(runnerRequestString))
+	resp, err := http.Post(helpers.BuildURL(api.RouteBase, api.RouteRunners), "application/json", reader)
+	suite.NoError(err)
+	suite.Equal(http.StatusOK, resp.StatusCode, "The response code should be ok")
+
+	runnerResponse := new(dto.RunnerResponse)
+	err = json.NewDecoder(resp.Body).Decode(runnerResponse)
+	suite.NoError(err)
+
+	suite.True(runnerResponse.Id != "", "The response contains a runner id")
+}
+
+func newRunnerId(t *testing.T) string {
+	runnerRequestString, _ := json.Marshal(dto.RunnerRequest{})
+	reader := strings.NewReader(string(runnerRequestString))
+	resp, err := http.Post(helpers.BuildURL(api.RouteBase, api.RouteRunners), "application/json", reader)
+	assert.NoError(t, err)
+	runnerResponse := new(dto.RunnerResponse)
+	_ = json.NewDecoder(resp.Body).Decode(runnerResponse)
+	return runnerResponse.Id
+}
+
+func (suite *E2ETestSuite) TestDeleteRunnerRoute() {
+	runnerId := newRunnerId(suite.T())
+	suite.NotEqual("", runnerId)
+
+	suite.Run("Deleting the runner returns NoContent", func() {
+		resp, err := httpDelete(helpers.BuildURL(api.RouteBase, api.RouteRunners, "/", runnerId), nil)
+		suite.NoError(err)
+		suite.Equal(http.StatusNoContent, resp.StatusCode)
+	})
+
+	suite.Run("Deleting it again returns NotFound", func() {
+		resp, err := httpDelete(helpers.BuildURL(api.RouteBase, api.RouteRunners, "/", runnerId), nil)
+		suite.NoError(err)
+		suite.Equal(http.StatusNotFound, resp.StatusCode)
+	})
+
+	suite.Run("Deleting non-existing runner returns NotFound", func() {
+		resp, err := httpDelete(helpers.BuildURL(api.RouteBase, api.RouteRunners, "/", "n0n-3x1st1ng-1d"), nil)
+		suite.NoError(err)
+		suite.Equal(http.StatusNotFound, resp.StatusCode)
+	})
+}
+
+// HttpDelete sends a Delete Http Request with body to the passed url.
+func httpDelete(url string, body io.Reader) (response *http.Response, err error) {
+	req, _ := http.NewRequest(http.MethodDelete, url, body)
+	client := &http.Client{}
+	return client.Do(req)
+}