initial commitHEADmaster

3 files changed, 196 insertions, 0 deletions

diff --git a/src/app.go b/src/app.go
new file mode 100644
index 0000000..0581bfb
--- /dev/null
+++ b/src/app.go
@@ -0,0 +1,50 @@
+package main
+
+import (
+	"app/common"
+	"app/jobCheckin"
+	"log"
+	"net/http"
+	"os"
+)
+
+func pingHandler(w http.ResponseWriter, r *http.Request) {
+	common.JsonRespond(&w, http.StatusOK, "pong")
+	return
+}
+
+func main() {
+	// define urls being served
+	pingEndpoint := "ping"
+	checkinEndpoint := "check-in"
+
+	// create mux
+	mux := http.NewServeMux()
+
+	// define handlers for endpoints here
+	mux.HandleFunc("/"+pingEndpoint, pingHandler)
+	mux.HandleFunc("/"+pingEndpoint+"/", pingHandler)
+
+	// check-in handled by jobCheckin package
+	jobCheckinHandler := jobCheckin.MakeHTTPHandler(checkinEndpoint)
+	mux.Handle("/"+checkinEndpoint, jobCheckinHandler)
+	mux.Handle("/"+checkinEndpoint+"/", jobCheckinHandler)
+
+	// add more routes... eg. /foo handled by foo package
+	// ...
+
+	log.Println("Starting Restful services...")
+	log.Println("Using port:", os.Getenv("HTTP_LISTEN_PORT"))
+
+	// start listening
+	err := http.ListenAndServe(":"+os.Getenv("HTTP_LISTEN_PORT"), mux)
+	log.Print(err)
+	errorHandler(err)
+}
+
+func errorHandler(err error) {
+	if err != nil {
+		log.Println(err)
+		os.Exit(1)
+	}
+}
diff --git a/src/common/common.go b/src/common/common.go
new file mode 100644
index 0000000..3e50632
--- /dev/null
+++ b/src/common/common.go
@@ -0,0 +1,32 @@
+// ONLY PUT FUNCTIONS / VARS THAT WILL BE USED BY MANY PACKAGES
+package common
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/gorilla/mux"
+	"log"
+	"net/http"
+)
+
+// Every respose MUST be a single string.
+type response struct {
+	Mssg string
+}
+
+// Builds and write json response given http status code, and message.
+func JsonRespond(w *http.ResponseWriter, rc int, body string) {
+	res1D := &response{Mssg: body}
+	res1B, _ := json.Marshal(res1D)
+	(*w).WriteHeader(rc)
+	log.Printf("RC: %d | Message: %s", rc, body)
+	fmt.Fprintln(*w, string(res1B))
+}
+
+// Assign a handler function to an endpoint.
+func MakeHTTPHandler(route string, h http.HandlerFunc) http.Handler {
+	r := mux.NewRouter()
+	r.HandleFunc("/"+route, h)
+	r.HandleFunc("/"+route+"/", h)
+	return r
+}
diff --git a/src/jobCheckin/jobCheckin.go b/src/jobCheckin/jobCheckin.go
new file mode 100644
index 0000000..0a1dd1b
--- /dev/null
+++ b/src/jobCheckin/jobCheckin.go
@@ -0,0 +1,114 @@
+package jobCheckin
+
+import (
+	"app/common"
+	"encoding/json"
+	client "github.com/influxdata/influxdb1-client/v2"
+	"log"
+	"net/http"
+	"os"
+	"regexp"
+	"strings"
+)
+
+type Job struct {
+	Source string
+}
+
+// Validates the incomming request and writes an appropriate response.
+// 405: when not POST request
+// 401: when body is not given, or 'source' field missing
+// 500: failed to complete
+// 202: successfully complete
+func jobCheckinHandler(w http.ResponseWriter, r *http.Request) {
+	log.Println("New request ===== ")
+
+	if r.Method != "POST" {
+		common.JsonRespond(&w, http.StatusMethodNotAllowed, "This end-point only accepts POST requests.")
+		return
+	}
+
+	var j Job
+	err := json.NewDecoder(r.Body).Decode(&j)
+	if err != nil {
+		common.JsonRespond(&w, http.StatusBadRequest, err.Error())
+		return
+	}
+	if j.Source == "" {
+		common.JsonRespond(&w, http.StatusBadRequest, "no 'source' field in body. Try sending a json such as {'source': 'job_name'} in the body.")
+		return
+	}
+	log.Println("source:", j.Source)
+
+	measurement, err := chekinJob(j.Source)
+	if err != nil {
+		common.JsonRespond(&w, http.StatusInternalServerError, "Error while writing to Influx.")
+		return
+	}
+
+	common.JsonRespond(&w, http.StatusAccepted, measurement)
+	return
+}
+
+// Write job check-in to influx.
+func chekinJob(jobName string) (string, error) {
+	jobNameClean, err := sanitizeJobName(jobName)
+	if err != nil {
+		return "", err
+	}
+
+	// Make client
+	c, err := client.NewHTTPClient(client.HTTPConfig{
+		Addr: "http://" + os.Getenv("INFLUX_HOST") + ":" + os.Getenv("INFLUX_PORT"),
+	})
+	if err != nil {
+		return "", err
+	}
+	defer c.Close()
+
+	// Create a new point batch
+	bp, _ := client.NewBatchPoints(client.BatchPointsConfig{
+		Database:        os.Getenv("INFLUX_DB"),
+		Precision:       "s",
+		RetentionPolicy: os.Getenv("INFLUX_RP"),
+	})
+
+	measurement := jobNameClean + "_checkins"
+	// Create a point and add to batch
+	tags := map[string]string{}
+	fields := map[string]interface{}{"check-in": 1}
+	pt, err := client.NewPoint(measurement, tags, fields)
+	if err != nil {
+		return "", err
+	}
+	bp.AddPoint(pt)
+
+	// Write the batch
+	err = c.Write(bp)
+	if err != nil {
+		return "", err
+	}
+	return measurement, nil
+}
+
+// Sanitize jobname - we only want letters, numbers, and underscores
+func sanitizeJobName(jobName string) (string, error) {
+	// remove any non-alphanumeric chars, and non-space chars
+	reg1, err := regexp.Compile("[^ _a-zA-Z0-9]+")
+	if err != nil {
+		return "", nil
+	}
+	jobName = reg1.ReplaceAllString(jobName, "")
+	// replace spaces with _
+	reg2, err := regexp.Compile("[ ]+")
+	if err != nil {
+		return "", nil
+	}
+	jobName = reg2.ReplaceAllString(jobName, "_")
+	return strings.ToLower(jobName), nil
+}
+
+// Every new endpoint/package MUST implement this function like so...
+func MakeHTTPHandler(endpoint string) http.Handler {
+	return common.MakeHTTPHandler(endpoint, jobCheckinHandler)
+}