misc/package/WebAppGallery/parameters.xml

<parameters>
  <!-- Application install path -->
  <parameter
    name="Application Path"
    description="Full site path where you would like to install your application (for example, Default Web Site/piwik)."
    defaultValue="Default Web Site/piwik"
    tags="iisapp">
    <parameterEntry
      type="ProviderPath"
      scope="iisapp"
      match="piwik"
    />
  </parameter>

  <!-- Set access control list -->
  <parameter
    name="SetAclParameterTree"
    description="Sets the ACL on the Installation tree"
    defaultValue="{Application Path}"
    tags="Hidden">
    <parameterEntry
      type="ProviderPath"
      scope="setAcl"
      match="piwik"
      />
  </parameter>

  <!-- Database server name -->
  <parameter
    name="DbServer"
    description="This is usually localhost, 127.0.0.1, or a host name provided by the hosting provider."
    defaultValue="localhost"
    tags="MySQL,dbServer">
    <parameterEntry
      type="TextFile"
      scope="install.sql"
      match="PlaceholderForServer"
    />
  </parameter>
  <parameter
    name="Automatic Database Server PHP File"
    defaultValue="host = &quot;{DbServer}&quot;"
    tags="Hidden,MySQL">
    <parameterEntry
      type="TextFile"
      scope="config\\config.ini.php"
      match="host\s*=\s*&quot;([^&quot;]*)&quot;"
    />
  </parameter>

   <!-- Database name -->
  <parameter
    name="DbName"
    description="Database Name may be a combination of lower case letters, numerals and/or underscore (_), but must start with a letter."
    defaultValue="piwik"
    tags="MySQL,dbName">
    <parameterValidation
      type="RegularExpression"
      validationString="^\w{1,16}$"
    />
    <parameterEntry
      type="TextFile"
      scope="install.sql"
      match="PlaceholderForDbName"
    />
  </parameter>
  <parameter
    name="Automatic Database Name PHP File"
    defaultValue="dbname = &quot;{DbName}&quot;"
    tags="Hidden,MySQL">
    <parameterEntry
      type="TextFile"
      scope="config\\config.ini.php"
      match="dbname\s*=\s*&quot;([^&quot;]*)&quot;"
    />
  </parameter>

  <!-- Database user name -->
  <parameter
    name="DbUsername"
    description="Username to access your database"
    defaultValue="piwikuser"
    tags="MySQL,DbUsername">
    <parameterValidation
      type="RegularExpression"
      validationString="^\w{1,16}$"
    />
    <parameterEntry
      type="TextFile"
      scope="install.sql"
      match="PlaceholderForDbUsername"
    />
  </parameter>
  <parameter
    name="Automatic Database Username PHP File"
    defaultValue="username = &quot;{DbUsername}&quot;"
    tags="Hidden,MySQL">
    <parameterEntry
      type="TextFile"
      scope="config\\config.ini.php"
      match="username\s*=\s*&quot;([^&quot;]*)&quot;"
    />
  </parameter>

  <!-- Database user password -->
  <parameter
    name="DbPassword"
    description="Minimum 4 characters and maximum 20 characters"
    tags="New,Password,MySQL,DbUserPassword">
    <parameterValidation
      type="RegularExpression"
      validationString=".{4,20}"
    />
    <parameterEntry
      type="TextFile"
      scope="install.sql"
      match="PlaceholderForDbPassword"
    />
  </parameter>
  <parameter
    name="Automatic Database Password PHP File"
    defaultValue="password = &quot;{DbPassword}&quot;"
    tags="Hidden,MySQL">
    <parameterEntry
      type="TextFile"
      scope="config\\config.ini.php"
      match="password\s*=\s*&quot;([^&quot;]{6,20})&quot;"
    />
  </parameter>

  <!-- Database admin user name -->
  <parameter
    name="DbAdminUsername"
    description="This can be the default MySQL username root, a username provided by your hosting provider, or one that your created in setting up your database server."
    defaultValue="root"
    tags="MySQL,DbAdminUsername">
  </parameter>

  <!-- Database admin user password -->
  <parameter
    name="DbAdminPassword"
    description="Password for the database administrator account. Required for site security. This may be predefined by your hosting provider."
    tags="Password,MySQL,DbAdminPassword">
  </parameter>

  <!-- Execute install.sql -->
  <parameter
    name="Connection String"
    description="Automatically sets the connection string for the connection request."
    defaultValue="Server={DbServer};Database={DbName};uid={DbAdminUsername};Pwd={DbAdminPassword};"
    tags="Hidden,MySQLConnectionString,Validate,MySQL">
    <parameterEntry
      type="ProviderPath"
      scope="dbmysql"
      match="install.sql$"
    />
  </parameter>

  <!-- Database adapter -->
  <parameter
    name="Automatic Database adapter"
    defaultValue="adapter = &quot;PDO_MYSQL&quot;"
    tags="Hidden,MySQL,NoStore">
    <parameterEntry
      type="TextFile"
      scope="config\\config.ini.php"
      match="adapter\s*=\s*[^\r\n]*"
    />
  </parameter>
</parameters>