Replace webhook build by agent construct

This will enable us to restart tests in future
and a void broken builds after restarting the server

Author: Lukas Matt

build.go

@@ -18,23 +18,282 @@
 package main
 
 import (
+  "fmt"
+  "net/http"
+  "strings"
+  "encoding/json"
+  "golang.org/x/oauth2"
+  "github.com/google/go-github/github"
+  "io/ioutil"
+  "context"
+  "time"
   "github.com/jinzhu/gorm"
+  _ "github.com/jinzhu/gorm/dialects/sqlite"
+)
+
+const (
+  STATUS_ERROR = "error"
+  STATUS_FAIL = "failure"
+  STATUS_PENDING = "pending"
+  STATUS_SUCCESS = "success"
+
+  BUILD_NOT_STARTED = 0
+  BUILD_PENDING = 1
+  BUILD_FINISHED = 2
 )
 
 type Build struct {
   gorm.Model
-  RepoID int
+  RepoID uint
   Matrix string
   TravisType string
   TravisRequestID int64
   TravisRepositoryID int64
   PRUser string
   PRRepo string
   PRSha string
+  Status int `gorm:"default:0"`
 
   Repo Repo
 }
 
+type Builds []Build
+
+type TravisStatus struct {
+  State string `json:"state"`
+  Builds []struct {
+    ID int64 `json:"id"`
+    State string `json:"state"`
+  } `json:"builds"`
+}
+
+type TravisRequest struct {
+  Type string `json:"@type"`
+  Request struct {
+    ID int64 `json:"id"`
+    Repository struct {
+      ID int64 `json:"id"`
+    } `json:"repository"`
+  } `json:"request"`
+}
+
+var (
+  travisTestEndpoint = "https://travis-ci.org/thefederationinfo/federation-tests/builds/%d"
+  travisTestDescription = "Continuous integration tests for the federation network"
+  travisTestContext = "Federation Suite"
+  travisEndpoint = "https://api.travis-ci.org/repo/"
+  travisSlug = "thefederationinfo%2Ffederation-tests"
+  travisRequests = travisEndpoint + travisSlug + "/requests"
+)
+
 func (build *Build) AfterFind(db *gorm.DB) error {
   return db.Model(build).Related(&build.Repo).Error
 }
+
+func BuildAgent() {
+  logger.Println("Started build agent")
+  db, err := gorm.Open(databaseDriver, databaseDSN)
+  if err != nil {
+    panic("failed to connect database")
+  }
+  defer db.Close()
+
+  for {
+    var builds Builds
+    err := db.Find(&builds).Error
+    if err != nil {
+      logger.Printf("Cannot fetch new builds: %+v\n", err)
+      continue
+    }
+    for _, build := range builds {
+      if build.Status == BUILD_NOT_STARTED {
+        build.Status = BUILD_PENDING
+        err = db.Save(&build).Error
+        if err != nil {
+          logger.Printf("#%d: cannot update status: %+v\n", build.ID, err)
+          continue
+        }
+        logger.Printf("#%d: starting new build\n", build.ID)
+        go build.Run(false)
+      }
+    }
+    time.Sleep(10 * time.Second)
+  }
+  logger.Println("Build agent died :S\n")
+}
+
+func (build *Build) Run(watch bool) {
+  db, err := gorm.Open(databaseDriver, databaseDSN)
+  if err != nil {
+    logger.Println(err)
+    return
+  }
+  defer db.Close()
+
+  ts := oauth2.StaticTokenSource(
+    &oauth2.Token{AccessToken: build.Repo.Token},
+  )
+  tc := oauth2.NewClient(context.Background(), ts)
+  client := github.NewClient(tc)
+
+  if !watch {
+    status := build.TriggerTravis()
+    logger.Printf("#%d: travis build triggered\n", build.ID)
+    build.UpdateStatus(client, status)
+    if status == STATUS_ERROR {
+      (*build).Status = BUILD_FINISHED
+      err := db.Save(&build).Error
+      if err != nil {
+        logger.Printf("#%d: cannot update status: %+v\n", build.ID, err)
+      }
+      return
+    }
+  }
+
+  var statusHref string
+  started := time.Now()
+  timeout := started.Add(-1 * time.Hour)
+  for {
+    status := build.FetchStatus()
+    logger.Printf("#%d: request status: %+v", build.ID, status)
+    if status.State == "finished" {
+      var failure bool
+      var passed int
+      for _, build := range status.Builds {
+        // canceled, passed, errored, started
+        switch build.State {
+        case "canceled":
+          fallthrough
+        case "errored":
+          fallthrough
+        case "failed":
+          failure = true
+        case "passed":
+          passed += 1
+        }
+      }
+      if failure {
+        build.UpdateStatus(client, STATUS_FAIL, statusHref)
+        (*build).Status = BUILD_FINISHED
+        err := db.Save(&build).Error
+        if err != nil {
+          logger.Printf("#%d: cannot update status: %+v\n", build.ID, err)
+        }
+        break
+      } else if len(status.Builds) == passed {
+        build.UpdateStatus(client, STATUS_SUCCESS, statusHref)
+        (*build).Status = BUILD_FINISHED
+        err := db.Save(&build).Error
+        if err != nil {
+          logger.Printf("#%d: cannot update status: %+v\n", build.ID, err)
+        }
+        break
+      }
+      // update the status line in the PR once
+      if len(status.Builds) > 0 && statusHref == "" {
+        statusHref = fmt.Sprintf(travisTestEndpoint, status.Builds[0].ID)
+        build.UpdateStatus(client, STATUS_PENDING, statusHref)
+      }
+    }
+
+    if time.Now().Before(timeout) {
+      build.UpdateStatus(client, STATUS_ERROR, statusHref)
+      logger.Printf("#%d: Timeout..\n", build.ID)
+      (*build).Status = BUILD_FINISHED
+      err := db.Save(&build).Error
+      if err != nil {
+        logger.Printf("#%d: cannot update status: %+v\n", build.ID, err)
+      }
+      break
+    }
+    time.Sleep(1 * time.Minute)
+  }
+  logger.Printf("#%d: Travis build finished\n", build.ID)
+}
+
+func (build *Build) TriggerTravis() string {
+  var requestJson = `{"request":{"branch":"continuous_integration","config":{"env":{"matrix":[%s]}}}}`
+  resp, err := build.fetch("POST", travisRequests,
+    fmt.Sprintf(requestJson, build.Matrix))
+  if err != nil {
+    fmt.Println("#%d: Cannot create request: %+v", build.ID, err)
+    return STATUS_ERROR
+  }
+  defer resp.Body.Close()
+
+  b, err := ioutil.ReadAll(resp.Body)
+  if err != nil {
+    fmt.Println("#%d: Cannot read status body: %+v", build.ID, err)
+    return STATUS_ERROR
+  }
+
+  var request TravisRequest
+  err = json.Unmarshal(b, &request)
+  if err != nil {
+    fmt.Println("#%d: Cannot unmarshal body: %+v <> %s", build.ID, err, string(b))
+    return STATUS_ERROR
+  }
+
+  build.TravisType = request.Type
+  build.TravisRequestID = request.Request.ID
+  build.TravisRepositoryID = request.Request.Repository.ID
+
+  return STATUS_PENDING
+}
+
+func (build *Build) UpdateStatus(client *github.Client, params... string) {
+  if len(params) <= 0 {
+    panic("state is mandatory")
+  }
+
+  repoStatus := github.RepoStatus{
+    State: &params[0],
+    Description: &travisTestDescription,
+    Context: &travisTestContext,
+  }
+  if len(params) >= 2 {
+    repoStatus.TargetURL = &params[1]
+  }
+  if _, _, err := client.Repositories.CreateStatus(context.Background(),
+  build.PRUser, build.PRRepo, build.PRSha, &repoStatus); err != nil {
+    fmt.Println("#%d: Cannot update status: %+v", build.ID, err)
+  }
+}
+
+func (build *Build) FetchStatus() (status TravisStatus) {
+  resp, err := build.fetch("GET", fmt.Sprintf(
+    "%s%d%s%d", travisEndpoint, build.TravisRepositoryID,
+    "/request/", build.TravisRequestID), "")
+  if err != nil {
+    logger.Printf("#%d: Cannot fetch build status: %+v\n", build.ID, err)
+    return
+  }
+  defer resp.Body.Close()
+
+  b, err := ioutil.ReadAll(resp.Body)
+  if err != nil {
+    logger.Printf("#%d: Cannot read status body: %+v\n", build.ID, err)
+    return
+  }
+
+  err = json.Unmarshal(b, &status)
+  if err != nil {
+    logger.Printf("#%d: Cannot unmarshal body: %+v <> %s\n", build.ID, err, string(b))
+    return
+  }
+  return
+}
+
+func (build *Build) fetch(method, url, body string) (*http.Response, error) {
+  req, err := http.NewRequest(method, url, strings.NewReader(body))
+  if err != nil {
+    return nil, err
+  }
+  req.Header.Set("Content-Type", "application/json")
+  req.Header.Set("Accept", "application/json")
+  req.Header.Set("Travis-API-Version", "3")
+  req.Header.Set("Authorization", "token " + travisToken)
+
+  client := &http.Client{}
+  return client.Do(req)
+}

server.go

@@ -85,6 +85,9 @@ func main() {
     return
   }
 
+  // start build agent
+  go BuildAgent()
+
   http.HandleFunc("/", frontend)
   http.HandleFunc("/auth", authentication)
   http.HandleFunc("/hook", webhook)