Copy-Paste anything you want, then get it from anywhere.

#include "FastLED.h"
#define NUM_LEDS 10                     // Number of LEDs used
#define PIN_LEDS 6                      // Pin used for LEDs data
#define SWITCH 4                        // Pin used for On/Off Switch
#define CONNECTED 2                     // Pin used for NAS connection feedback from RaspberryPi
CRGB leds[NUM_LEDS];

const int speedDelay = 50;
const int startupColorR = 0xFF;         // Start-up color, Red LED
const int startupColorG = 0xFF;         // Start-up color, Green LED
const int startupColorB = 0xFF;         // Start-up color, Blue LED
const int connectedColorR = 0xFF;       // Connected color, Red LED
const int connectedColorG = 0xFF;       // Connected color, Green LED
const int connectedColorB = 0xFF;       // Connected color, Blue LED
const float increment = 0.006;
const float brightness = 1.8*PI;        // Actual brightness used in functions; 1.5*PI is 0% and 2.5*PI is 100% brightness
int steps = 0;

void setup()
{
  FastLED.addLeds<WS2811, PIN_LEDS, GRB>(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);
  pinMode(SWITCH,INPUT);                // Input from selector switch
  pinMode(CONNECTED,INPUT);             // Input from RaspberryPi
  
  setAll(0x00, 0x00, 0x00);             // Starts with all turned off LEDs
}

void loop()
{
  if (digitalRead(SWITCH) == HIGH)
  {
    switch (steps)
    {
      case 0:       // STEP 1 : progressive start of the start-up color lighting
      {
        startLighting(startupColorR, startupColorG, startupColorB);
        delay(20*speedDelay); // 1s delay
        steps = 1;
        break;
      }
      case 1:       // STEP 2 : LEDs animation while RapberryPi Starts and connects to NAS server
      {
        if (digitalRead(CONNECTED) == LOW)
        {
          serverSearch(startupColorR, startupColorG, startupColorB, 10, true);
        }
        else
        {
          setAll(0x00,0x00,0x00);
          delay(20*speedDelay); // 1s delay
          steps = 2;
        }
        break;
      }
      case 2:       // STEP 3 : progressive start of the connected color lighting
      {
        if (digitalRead(CONNECTED) == HIGH)
        {
          startedLighting(connectedColorR, connectedColorG, connectedColorB);
          delay(20*speedDelay); // 1s delay
          steps = 3;
        }
        else
        {
          steps = 1;
        }
        break;
      }
      case 3:       // STEP 3 :steady connected color lighting while ready
      {
        if (digitalRead(CONNECTED) == HIGH)
        {
          steadyLighting(connectedColorR, connectedColorG, connectedColorB);
        }
        else
        {
          stopLighting(connectedColorR, connectedColorG, connectedColorB);
          delay(20*speedDelay); // 1s delay
          steps = 1;
        }
        break;
      }
    }
  }
  else
  {
    setAll(0x00, 0x00, 0x00);
    steps = 0;
  }
}

void setPixel(int Pixel, byte Red, byte Green, byte Blue)                   // Sets RGB colors to one LED from the strip
{
  leds[Pixel].r = Red;
  leds[Pixel].g = Green;
  leds[Pixel].b = Blue;
}

void setAll(byte Red, byte Green, byte Blue)                                // This function sets all LEDs in the strip to their RGB colors
{
  for(int i = 0; i < NUM_LEDS; i   )
  {
    setPixel(i, Red, Green, Blue); 
  }
  FastLED.show();
}

void startLighting(byte Red, byte Green, byte Blue)                         
{
  float r, g, b;
  for(float k = 1.5*PI; k < 2.3*PI; k=k increment)
  { 
    r = (sin(k)*127.5 127.5)/256.0*Red;
    g = (sin(k)*127.5 127.5)/256.0*Green;
    b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }
    delay(20*speedDelay); // 1s delay
    for(float k = 2.3*PI; k >= 1.5*PI; k=k-2*increment)
  { 
    r = (sin(k)*127.5 127.5)/256.0*Red;
    g = (sin(k)*127.5 127.5)/256.0*Green;
    b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }
}

void startedLighting(byte Red, byte Green, byte Blue)                         
{
  float r, g, b;
  for(float k = 1.5*PI; k < 2.3*PI; k=k increment)
  { 
    r = (sin(k)*127.5 127.5)/256.0*Red;
    g = (sin(k)*127.5 127.5)/256.0*Green;
    b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }
    delay(20*speedDelay); // 1s delay
    for(float k = 2.3*PI; k >= brightness; k=k-2*increment)
  { 
    r = (sin(k)*127.5 127.5)/256.0*Red;
    g = (sin(k)*127.5 127.5)/256.0*Green;
    b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }
}

void steadyLighting(byte Red, byte Green, byte Blue)                         
{
  float r, g, b;
  float k = brightness;
  r = (sin(k)*127.5 127.5)/256.0*Red;
  g = (sin(k)*127.5 127.5)/256.0*Green;
  b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }

void stopLighting(byte Red, byte Green, byte Blue)
{
  float r, g, b;
  for(float k = brightness; k >= 1.5*PI; k=k-2*increment)
  { 
    r = (sin(k)*127.5 127.5)/256.0*Red;
    g = (sin(k)*127.5 127.5)/256.0*Green;
    b = (sin(k)*127.5 127.5)/256.0*Blue;
    setAll(r, g, b);
    FastLED.show();
  }
}

void serverSearch(byte Red, byte Green, byte Blue, int Count, boolean OnlyOne)
{
  for(int i = 0; i < NUM_LEDS-3; i  )
  {
    setAll(0x00,0x00,0x00);
    for (int i = 0; i < Count; i  )
    {
      setPixel(random(NUM_LEDS),Red,Green,Blue);
      FastLED.show();
      delay(1.5*speedDelay);
      if(OnlyOne)
      { 
        setAll(0x00,0x00,0x00); 
      }
    }
  }
}