#require no-chg

  $ send() {
  >   hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT/
  > }

  $ hg init server
  $ hg -R server serve -p $HGPORT -d --pid-file hg.pid
  $ cat hg.pid > $DAEMON_PIDS

Request to /api fails unless web.apiserver is enabled

  $ get-with-headers.py $LOCALIP:$HGPORT api
  400 no such method: api
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>$TESTTMP/server: error</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="https://mercurial-scm.org/">
  <img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog">log</a></li>
  <li><a href="/graph">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  
  <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
  <h3>error</h3>
  
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
  <div id="hint">Find changesets by keywords (author, files, the commit message), revision
  number or hash, or <a href="/help/revsets">revset expression</a>.</div>
  </form>
  
  <div class="description">
  <p>
  An error occurred while processing your request:
  </p>
  <p>
  no such method: api
  </p>
  </div>
  </div>
  </div>
  
  
  
  </body>
  </html>
  
  [1]

  $ get-with-headers.py $LOCALIP:$HGPORT api/
  400 no such method: api
  
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
  <head>
  <link rel="icon" href="/static/hgicon.png" type="image/png" />
  <meta name="robots" content="index, nofollow" />
  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
  <script type="text/javascript" src="/static/mercurial.js"></script>
  
  <title>$TESTTMP/server: error</title>
  </head>
  <body>
  
  <div class="container">
  <div class="menu">
  <div class="logo">
  <a href="https://mercurial-scm.org/">
  <img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
  </div>
  <ul>
  <li><a href="/shortlog">log</a></li>
  <li><a href="/graph">graph</a></li>
  <li><a href="/tags">tags</a></li>
  <li><a href="/bookmarks">bookmarks</a></li>
  <li><a href="/branches">branches</a></li>
  </ul>
  <ul>
  <li><a href="/help">help</a></li>
  </ul>
  </div>
  
  <div class="main">
  
  <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
  <h3>error</h3>
  
  
  <form class="search" action="/log">
  
  <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
  <div id="hint">Find changesets by keywords (author, files, the commit message), revision
  number or hash, or <a href="/help/revsets">revset expression</a>.</div>
  </form>
  
  <div class="description">
  <p>
  An error occurred while processing your request:
  </p>
  <p>
  no such method: api
  </p>
  </div>
  </div>
  </div>
  
  
  
  </body>
  </html>
  
  [1]

Restart server with support for API server

  $ killdaemons.py
  $ cat > server/.hg/hgrc << EOF
  > [experimental]
  > web.apiserver = true
  > EOF

  $ hg -R server serve -p $HGPORT -d --pid-file hg.pid
  $ cat hg.pid > $DAEMON_PIDS

/api lists available APIs (empty since none are available by default)

  $ send << EOF
  > httprequest GET api
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 200 OK\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 100\r\n
  s>     \r\n
  s>     APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
  s>     \n
  s>     (no available APIs)\n

  $ send << EOF
  > httprequest GET api/
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api/ HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 200 OK\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 100\r\n
  s>     \r\n
  s>     APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
  s>     \n
  s>     (no available APIs)\n

Accessing an unknown API yields a 404

  $ send << EOF
  > httprequest GET api/unknown
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api/unknown HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 404 Not Found\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 33\r\n
  s>     \r\n
  s>     Unknown API: unknown\n
  s>     Known APIs: 

Accessing a known but not enabled API yields a different error

  $ send << EOF
  > httprequest GET api/exp-http-v2-0003
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api/exp-http-v2-0003 HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 404 Not Found\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 33\r\n
  s>     \r\n
  s>     API exp-http-v2-0003 not enabled\n

Restart server with support for HTTP v2 API

  $ killdaemons.py
  $ cat > server/.hg/hgrc << EOF
  > [experimental]
  > web.apiserver = true
  > web.api.http-v2 = true
  > EOF

  $ hg -R server serve -p $HGPORT -d --pid-file hg.pid
  $ cat hg.pid > $DAEMON_PIDS

/api lists the HTTP v2 protocol as available

  $ send << EOF
  > httprequest GET api
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 200 OK\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 96\r\n
  s>     \r\n
  s>     APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
  s>     \n
  s>     exp-http-v2-0003

  $ send << EOF
  > httprequest GET api/
  >     user-agent: test
  > EOF
  using raw connection to peer
  s> setsockopt(6, 1, 1) -> None (?)
  s>     GET /api/ HTTP/1.1\r\n
  s>     Accept-Encoding: identity\r\n
  s>     user-agent: test\r\n
  s>     host: $LOCALIP:$HGPORT\r\n (glob)
  s>     \r\n
  s> makefile('rb', None)
  s>     HTTP/1.1 200 OK\r\n
  s>     Server: testing stub value\r\n
  s>     Date: $HTTP_DATE$\r\n
  s>     Content-Type: text/plain\r\n
  s>     Content-Length: 96\r\n
  s>     \r\n
  s>     APIs can be accessed at /api/<name>, where <name> can be one of the following:\n
  s>     \n
  s>     exp-http-v2-0003
