stoplight.ino

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClientSecure.h>
#include <ArduinoJson.h>

// WiFi access data
const char *ssid = "WIFI_SSID";
const char *password = "WIFI_PASSWORD";

// Private token of your Gitlab user
const char *private_token = "GITLAB_PRIVATE_TOKEN";

// Gitlab HTTPS certificate SHA-1 fingerprint
const char *https_fingerprint = "F3 85 85 A1 04 F3 77 26 CF CC E5 CE E2 23 ED 63 A1 8F 54 DC";

// Replace <PROJECT_ID> with your Gitlab project ID (the unique number)
const char *url_pipeline = "https://gitlab.com/api/v4/projects/<PROJECT_ID>/pipelines?ref=master&per_page=1";

// LED output mapping
const int LED_RED = 5;    // D1
const int LED_YELLOW = 4; // D2
const int LED_GREEN = 15; // D8

// How often to poll for updates
const int updateDelayMillis = 5000;

// How long to wait for response until switching to "error"
const int updateTimeoutMillis = 20000;


long lastUpdateMillis = 0;

enum PipelineState
{
  SUCCESS,
  RUNNING_TESTED,
  RUNNING,
  FAILED,
  UNKNOWN,
  ERROR
};

PipelineState currentState = UNKNOWN;

void setup()
{
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  
  // turn off onboard blue LED!
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);

  Serial.begin(115200);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // LED test
  Serial.println("Testing LEDs...");
  currentState = SUCCESS;
  lastUpdateMillis = millis();
  loop();
  delay(3000);
  currentState = RUNNING;
  lastUpdateMillis = millis();
  loop();
  delay(3000);
  currentState = FAILED;
  lastUpdateMillis = millis();
  loop();
  delay(3000);

  Serial.println("Starting.");
  currentState = UNKNOWN;
}

void loop()
{
  switch (currentState)
  {
  case UNKNOWN: // blink yellow
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    delay(1000);
    digitalWrite(LED_YELLOW, LOW);
    break;

  case ERROR: // blink red
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, LOW);
    digitalWrite(LED_RED, HIGH);
    delay(1000);
    digitalWrite(LED_RED, LOW);
    break;

  case SUCCESS: // green
    digitalWrite(LED_GREEN, HIGH);
    digitalWrite(LED_YELLOW, LOW);
    digitalWrite(LED_RED, LOW);
    break;

  case FAILED: // red
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, LOW);
    digitalWrite(LED_RED, HIGH);
    break;

  case RUNNING: // yellow
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_RED, LOW);
    break;

  case RUNNING_TESTED: // green + yellow
    digitalWrite(LED_GREEN, HIGH);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_RED, LOW);
    break;
  }

  delay(1000);
  update();
}

void update()
{
  if (millis() <= (lastUpdateMillis + updateDelayMillis))
    return;

  if (WiFi.status() == WL_CONNECTED)
  {
    Serial.print("Updating pipeline status... ");

    HTTPClient http;
    http.setTimeout(updateTimeoutMillis);
    http.begin(url_pipeline, https_fingerprint);
    http.addHeader("PRIVATE-TOKEN", private_token);

    int returnCode = http.GET();
    if (returnCode != 200)
    {
      Serial.print("ERROR: ");
      Serial.print(returnCode);
      Serial.print(" (");
      Serial.print(http.errorToString(returnCode));
      Serial.print("): ");
      Serial.print(http.getString());

      currentState = ERROR;
    }
    else
    {
      Serial.print("update retrieved. ");

      DynamicJsonDocument doc(http.getSize());
      deserializeJson(doc, http.getString());

      const char *pipelineStatus = doc[0]["status"];
      Serial.print("Pipeline status: ");
      Serial.print(pipelineStatus);

      if (strcmp(pipelineStatus, "success") == 0)
      {
        currentState = SUCCESS;
      }
      else if (strcmp(pipelineStatus, "failed") == 0)
      {
        currentState = FAILED;
      }
      else if (strcmp(pipelineStatus, "running") == 0)
      {
        currentState = RUNNING;
      }
      else if (strcmp(pipelineStatus, "scheduled") == 0)
      {
        currentState = RUNNING_TESTED;
      }
      else
      {
        currentState = UNKNOWN;
      }
    }
    Serial.println("");
  }
  lastUpdateMillis = millis();
}