Developing cacheable PHP applications - PHP Barcelona 2019

See https://feryn.eu/speaking/developing-cacheable-php-applications/ for more information about this presentation.

Transcript

1. DEVELOPING CACHEABLE
   PHP APPLICATIONS
   Thijs Feryn
   

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2. Slow websites
   SUCK
   

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3. WEB PERFORMANCE IS AN
   ESSENTIAL PART OF THE
   USER EXPERIENCE
   

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4. SLOW ~ DOWN
   

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8. THROWING
   SERVERS
   AT THE PROBLEM
   

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9. MO' MONEY
   MO' SERVERS
   MO' PROBLEMS
   

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10. IDENTIFY SLOWEST PARTS
    

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11. OPTIMIZE
    

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12. AFTER A WHILE YOU HIT THE LIMITS
    

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13. CACHE
    

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14. HI, I'M THIJS
    

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15. I'M AN
    EVANGELIST
    AT
    

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18. 4,800,000 WEBSITES
    19% OF THE TOP 10K WEBSITES
    

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20. I'M @THIJSFERYN
    

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22. USER SERVER
    

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23. REVERSE CACHING PROXY
    

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24. USER PROXY SERVER
    

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27. HTTP CACHING MECHANISMS
    Expires: Sat, 23 July 2019 00:30:00 GMT
    Cache-control: public, max-age=3600,
    s-maxage=86400
    Cache-control: private, no-cache, no-store
    

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28. IN AN IDEAL WORLD
    

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29. ✓STATELESS
    ✓WELL-DEFINED TTL
    ✓CACHE / NO-CACHE PER RESOURCE
    ✓CACHE VARIATIONS
    ✓CONDITIONAL REQUESTS
    ✓PLACEHOLDERS FOR NON-CACHEABLE CONTENT
    ✓EDGE-SIDE LOGIC FOR PERSONALIZED CACHING
    IN AN IDEAL WORLD
    

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30. REALITY
    SUCKS
    

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32. FOR YOUR EYES ONLY
    NOT CACHED
    

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33. TIME TO LIVE
    

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34. CACHING PURGING LOGIC
    

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35. CACHE VARIATIONS
    

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36. LEGACY
    

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37. WHAT IF WE COULD
    DESIGN OUR
    SOFTWARE WITH
    HTTP CACHING IN
    MIND?
    

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38. CACHE-CONTROL
    

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39. Cache-Control: public, s-maxage=500
    

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40. namespace App\Controller;
    use Symfony\Component\HttpFoundation\Request;
    use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
    use Symfony\Bundle\FrameworkBundle\Controller\Controller;
    class DefaultController extends Controller
    {
    /**
    * @Route("/", name="home")
    */
    public function index()
    {
    return $this
    ->render('index.twig')
    ->setSharedMaxAge(500)
    ->setPublic();
    }
    }
    

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41. Cache-Control: private, no-store
    

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42. /**
    * @Route("/private", name="private")
    */
    public function private()
    {
    $response = $this
    ->render('private.twig')
    ->setPrivate();
    $response->headers->addCacheControlDirective('no-store');
    return $response;
    }
    

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43. CONDITIONAL
    REQUESTS
    

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44. ONLY FETCH PAYLOAD THAT HAS CHANGED
    

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45. HTTP/1.1 200 OK
    

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46. OTHERWISE:
    HTTP/1.1 304 NOT MODIFIED
    

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47. CONDITIONAL REQUESTS
    HTTP/1.1 200 OK
    Host: localhost
    Etag: 7c9d70604c6061da9bb9377d3f00eb27
    Content-type: text/html; charset=UTF-8
    Hello world output
    GET / HTTP/1.1
    Host: localhost
    

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48. CONDITIONAL REQUESTS
    HTTP/1.1 304 Not Modified
    Host: localhost
    Etag: 7c9d70604c6061da9bb9377d3f00eb27
    GET / HTTP/1.1
    Host: localhost
    If-None-Match: 7c9d70604c6061da9bb9377d3f00eb27
    

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49. CONDITIONAL REQUESTS
    HTTP/1.1 200 OK
    Host: localhost
    Last-Modified: Fri, 22 Jul 2016 10:11:16 GMT
    Content-type: text/html; charset=UTF-8
    Hello world output
    GET / HTTP/1.1
    Host: localhost
    

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50. CONDITIONAL REQUESTS
    HTTP/1.1 304 Not Modified
    Host: localhost
    Last-Modified: Fri, 22 Jul 2016 10:11:16 GMT
    GET / HTTP/1.1
    Host: localhost
    If-Last-Modified: Fri, 22 Jul 2016 10:11:16 GMT
    

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51. VARNISH SUPPORTS
    CONDITIONAL REQUESTS
    FOR CLIENTS & BACKENDS
    

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52. AND WILL SERVE STALE DATA
    WHILE IT ASYNCHRONOUSLY
    REVALIDATES CONTENT
    

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53. Cache-Control: public, max-age=100,
    s-maxage=500, stale-while-revalidate=20
    

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54. QUICKLY
    

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55. EARLY
    

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56. Store &
    retrieve
    Etag
    

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57. namespace App\EventListener;
    use Symfony\Component\HttpFoundation\Response;
    use Symfony\Component\HttpFoundation\Request;
    use Symfony\Component\HttpKernel\Event\GetResponseEvent;
    use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
    use SymfonyBundles\RedisBundle\Redis\Client as RedisClient;
    class ConditionalRequestListener
    {
    protected $redis;
    public function __construct(RedisClient $redis)
    {
    $this->redis = $redis;
    }
    protected function isModified(Request $request, $etag)
    {
    if ($etags = $request->getETags()) {
    return in_array($etag, $etags) || in_array('*', $etags);
    }
    return true;
    }
    ...
    src/EventListener/ConditionalRequestListener.php
    

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58. {
    $this->redis = $redis;
    }
    protected function isModified(Request $request, $etag)
    {
    if ($etags = $request->getETags()) {
    return in_array($etag, $etags) || in_array('*', $etags);
    }
    return true;
    }
    public function onKernelRequest(GetResponseEvent $event)
    {
    $request = $event->getRequest();
    $etag = $this->redis->get('etag:'.md5($request->getUri()));
    if(!$this->isModified($request,$etag)) {
    $event->setResponse(Response::create('Not Modified',Response::HTTP_NOT_MODIFIED));
    }
    }
    public function onKernelResponse(FilterResponseEvent $event)
    {
    $response = $event->getResponse();
    $request = $event->getRequest();
    $etag = md5($response->getContent());
    $response->setEtag($etag);
    if($this->isModified($request,$etag)) {
    $this->redis->set('etag:'.md5($request->getUri()),$etag);
    }
    }
    }
    src/EventListener/ConditionalRequestListener.php
    

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59. CONTENT COMPOSITION
    & PLACEHOLDERS
    

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61. NO CACHE
    

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62. PLACEHOLDERS
    

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63. SEPARATE
    HTTP REQUEST
    

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64. AJAX
    

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65. ✓CLIENT-SIDE
    ✓COMMON KNOWLEDGE
    ✓PARALLEL PROCESSING
    ✓GRACEFUL
    DEGRADATION
    -PROCESSED BY THE
    BROWSER
    -EXTRA ROUNDTRIPS
    -SOMEWHAT SLOWER
    AJAX
    

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66. EDGE-SIDE INCLUDES ESI
    

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67. 
    

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68. ESI
    ✓ PLACEHOLDER
    ✓ PARSED BY VARNISH
    ✓ OUTPUT IS A COMPOSITION OF BLOCKS
    ✓ STATE PER BLOCK
    ✓ TTL PER BLOCK
    

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69. VARNISH Surrogate-Capability: key="ESI/1.0"
    Surrogate-Control: content="ESI/1.0"
    
    BACKEND
    Parse ESI placeholders
    VARNISH
    

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70. WRITE SOME VCL CODE
    FOR AUTOMATIC ESI DETECTION
    

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71. sub vcl_recv {
    set req.http.Surrogate-Capability = "key=ESI/1.0";
    }
    sub vcl_backend_response {
    if (beresp.http.Surrogate-Control ~ "ESI/1.0") {
    unset beresp.http.Surrogate-Control;
    set beresp.do_esi = true;
    }
    }
    

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72. EDGE SIDE INCLUDES
    ✓ SERVER-SIDE
    ✓ STANDARDIZED
    ✓ PROCESSED ON THE
    “EDGE”, NOT IN THE
    BROWSER
    ✓ GENERALLY FASTER
    - SEQUENTIAL
    (ONLY PARALLEL IN ENTERPRISE VERSION)
    - ONE FAILS, ALL FAIL
    - LIMITED IMPLEMENTATION
    IN VARNISH
    

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73. ESI VS AJAX
    

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74. COMPOSITION AT THE VIEW LAYER
    

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75. /**
    * @Route("/", name="home")
    */
    public function index()
    {
    return $this
    ->render('index.twig')
    ->setPublic()
    ->setSharedMaxAge(500);
    }
    /**
    * @Route("/header", name="header")
    */
    public function header()
    {
    $response = $this
    ->render('header.twig')
    ->setPrivate();
    $response->headers->addCacheControlDirective('no-store');
    return $response;
    }
    /**
    * @Route("/footer", name="footer")
    */
    public function footer()
    {
    $response = $this->render('footer.twig');
    $response
    ->setSharedMaxAge(500)
    ->setPublic();
    return $response;
    }
    /**
    * @Route("/nav", name="nav")
    */
    public function nav()
    {
    $response = $this->render('nav.twig');
    $response
    ->setVary('X-Login',false)
    ->setSharedMaxAge(500)
    ->setPublic();
    return $response;
    }
    Controller
    action per
    fragment
    

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76. 
    {{ include('header.twig') }}
    
    
    {{ include('nav.twig') }}
    
    
    {% block content %}{% endblock %}
    
    
    {{ include('footer.twig') }}
    
    
    {{ render_esi(url('header')) }}
    
    
    {{ render_esi(url('nav')) }}
    
    
    {% block content %}{% endblock %}
    
    
    {{ render_esi(url('footer')) }}
    
    

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77. 
    
    
    
    
    
    
    
    An example page Rendered at 2017-05-17 16:57:14
    
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris consequat orci eget libero
    sollicitudin,…
    
    
    
    
    

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78. CACHE VARIATIONS
    

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79. HOW DO YOU IDENTIFY AN
    OBJECT IN CACHE?
    

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80. THE URL IDENTIFIES
    THE OBJECT IN CACHE
    

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81. WHAT IF THE CONTENT
    OF A URL VARIES
    BASED ON THE VALUE
    OF A REQUEST
    HEADER?
    

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82. CACHE VARIATIONS
    HTTP/1.1 200 OK
    Host: localhost
    Content-Language: en
    Content-type: text/html; charset=UTF-8
    Hello world output
    GET / HTTP/1.1
    Host: localhost
    Accept-Language: en, nl, de
    

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83. Vary: Accept-Language
    Request
    header
    value
    Response
    header
    

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84. WHAT IF YOU CAN'T
    LEVERAGE HTTP?
    

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85. WRITE VCL CODE
    

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86. sub vcl_recv {
    if (req.url ~ "^/status\.php$" ||
    req.url ~ "^/update\.php$" ||
    req.url ~ "^/admin$" ||
    req.url ~ "^/admin/.*$" ||
    req.url ~ "^/flag/.*$" ||
    req.url ~ "^.*/ajax/.*$" ||
    req.url ~ "^.*/ahah/.*$") {
    return (pass);
    }
    }
    URL
    BLACKLIST
    EXAMPLE
    

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87. sub vcl_recv {
    if (req.http.Cookie) {
    set req.http.Cookie = ";" + req.http.Cookie;
    set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
    set req.http.Cookie = regsuball(req.http.Cookie,
    ";(SESS[a-z0-9]+|SSESS[a-z0-9]+|NO_CACHE)=", "; \1=");
    set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
    set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
    if (req.http.Cookie == "") {
    unset req.http.Cookie;
    }
    else {
    return (pass);
    }
    }
    }
    ONLY
    KEEP CERTAIN
    COOKIES
    

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88. NON-CACHEABLE ROUTES WILL STILL BE A
    TARGET FOR LOAD/LATENCY
    

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89. CACHING PERSONALIZED DATA
    

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90. DECISION MAKING AT THE EDGE
    

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91. SYNTHETIC HTTP
    HTTP OUTPUT THAT
    DIDN'T ORIGINATE FROM
    THE BACKEND SERVER
    

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92. {USERNAME: "THIJS"}
    GENERATED IN VCL
    BASED ON REDIS DATA
    

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93. vcl 4.1;
    import cookieplus;
    import redis;
    import synthbackend;
    sub vcl_init
    {
    new db = redis.db(
    location="redis:6379",
    type=master,
    connection_timeout=500,
    shared_connections=false,
    max_connections=1);
    }
    sub vcl_recv
    {
    set req.http.X-Login = "false";
    set req.http.x-session = cookieplus.get("PHPSESSID","guest");
    if(req.http.x-session != "guest") {
    db.command("EXISTS");
    db.push("sf_s"+cookieplus.get("PHPSESSID"));
    db.execute();
    if(db.get_integer_reply() == 1) {
    set req.http.X-Login = "true";
    }
    }
    }
    SYNTHETIC HTTP
    

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94. sub vcl_backend_fetch
    {
    if(bereq.url == "/session") {
    if(bereq.http.X-Login != "true") {
    set bereq.backend = synthbackend.from_string("{}");
    return(fetch);
    }
    db.command("EVAL");
    db.push({"
    local session = redis.call('GET', KEYS[1])
    if session == nil then
    return '{}'
    end
    local result = string.gsub(session, '[%c]', '')
    local username = string.gsub(result,'.+Userusername\";s:[0-9]+:\"([^\"]+)\";.+','%1')
    if username == nil then
    return '{}'
    end
    return '{"username":"'.. username ..'"}'
    "});
    db.push(1);
    db.push("sf_s"+cookieplus.get("PHPSESSID"));
    db.execute();
    set bereq.backend = synthbackend.from_string(db.get_string_reply());
    }
    }
    sub vcl_backend_response
    {
    if(bereq.url == "/session") {
    set beresp.http.Content-Type = "application/json; charset=utf-8";
    set beresp.ttl = 3600s;
    set beresp.http.vary = "x-session";
    }
    }
    REDIS LUA
    CODE
    

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95. EDGESTASH
    VARNISH
    MODULE FOR MUSTACHE
    PROCESSING ON THE
    EDGE
    

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96. {{ USERNAME }}
    VARNISH
    MODULE FOR MUSTACHE
    PROCESSING ON THE
    EDGE
    REPLACES
    PLACEHOLDERS WITH JSON
    VALUES
    

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97. Surrogate-Control: edgestash="EDGESTASH/2.1"
    Link: ; rel=edgestash
    Welcome {{ username }}
    Welcome Thijs
    +
    =
    

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98. vcl 4.1;
    import edgestash;
    import std;
    backend default
    {
    .host = "1.1.1.1";
    }
    sub vcl_recv
    {
    set req.http.Surrogate-Capability={"edgestash="EDGESTASH/2.1""};
    }
    sub vcl_backend_response
    {
    if(beresp.http.Link) {
    std.collect(beresp.http.Link,",");
    }
    if(beresp.http.Link ~ "<([^>]+)>; rel=edgestash") {
    set beresp.http.x-edgestash-json-urls = regsuball(beresp.http.Link,"(?(?=<[^>]+>; rel=edgestash)<([^>]+)>;
    rel=edgestash|<([^>]+)>; rel=[a-z]+, )","\1");
    }
    if(beresp.http.Surrogate-Control) {
    std.collect(beresp.http.Surrogate-Control);
    }
    if(beresp.http.Surrogate-Control ~ {".*="EDGESTASH/2\.[0-9]+".*"}) {
    edgestash.parse_response();
    }
    }
    EDGESTASH
    

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99. sub vcl_deliver
    {
    if(edgestash.is_edgestash() && resp.http.x-edgestash-json-urls) {
    edgestash.add_json_url_csv(resp.http.x-edgestash-json-urls);
    edgestash.execute();
    }
    unset resp.http.Link;
    unset resp.http.x-edgestash-json-urls;
    unset resp.http.surrogate-control;
    }
    EDGESTASH
    

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101. COMPOSER REQUIRE THIJSFERYN/EDGESTASH-TWIG-BUNDLE
     

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102. {{ edgestash('username','/session') }}
     {{ username | edgestash('username','/session') }}
     

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104. 14 DAYS FREE TRIAL
     

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107. HTTPS://FERYN.EU
     HTTPS://TWITTER.COM/THIJSFERYN
     HTTPS://INSTAGRAM.COM/THIJSFERYN
     

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