Ubuntu (Windows Subsystem for Linux) Apache2 Configuration Overview

So Apache2 running on Ubuntu running on Windows Subsystem for Linux (WSL) on Windows 10 has a different configuration from other Apache2 installs. So there is a mismatch between documentation, if for example one is following Dedoimedo's Apache Web server Complete Guide. The config details are hiding in plain sight on the default index page that appears after a fresh install. Because we are meant to replace that page I am keeping a copy here.

Configuration Overview

Ubuntu's Apache2 default configuration is different from the upstream default configuration, and split into several files optimized for interaction with Ubuntu tools. The configuration system is fully documented in /usr/share/doc/apache2/README.Debian.gz. Refer to this for the full documentation. Documentation for the web server itself can be found by accessing the manual if the apache2-doc package was installed on this server.

The configuration layout for an Apache2 web server installation on Ubuntu systems is as follows:

/etc/apache2/
|-- apache2.conf
|       `--  ports.conf
|-- mods-enabled
|       |-- *.load
|       `-- *.conf
|-- conf-enabled
|       `-- *.conf
|-- sites-enabled
|       `-- *.conf
          

• apache2.conf is the main configuration file. It puts the pieces together by including all remaining configuration files when starting up the web server.
• ports.conf is always included from the main configuration file. It is used to determine the listening ports for incoming connections, and this file can be customized anytime.
• Configuration files in the mods-enabled/, conf-enabled/ and sites-enabled/ directories contain particular configuration snippets which manage modules, global configuration fragments, or virtual host configurations, respectively.
• They are activated by symlinking available configuration files from their respective *-available/ counterparts. These should be managed by using our helpers a2enmod, a2dismod, a2ensite, a2dissite, and a2enconf, a2disconf . See their respective man pages for detailed information.
• The binary is called apache2. Due to the use of environment variables, in the default configuration, apache2 needs to be started/stopped with /etc/init.d/apache2 or apache2ctl. Calling /usr/bin/apache2 directly will not work with the default configuration.

Document Roots

By default, Ubuntu does not allow access through the web browser to any file apart of those located in /var/www, public_html directories (when enabled) and /usr/share (for web applications). If your site is using a web document root located elsewhere (such as in /srv) you may need to whitelist your document root directory in /etc/apache2/apache2.conf.

The default Ubuntu document root is /var/www/html. You can make your own virtual hosts under /var/www. This is different to previous releases which provides better security out of the box.

Ubuntu on WSL piping output to the host OS's drives - convert LFs to CRLFs

So continuing on the Ubuntu theme. I need to configure Apache. So I am not used to Linux because it has been a dozen years ago since I trained for certification on Linux. I still want to use my favourite Windows apps not mention the windowed environment; it takes a while to acclimatise to console culture. Specifically, whilst poking around the Linux file system, I need to find a way to pipe output of a command to a file on the host OS’s drive and then handle the line feed issue.

In Linux line feeds are one character ASC 10, whilst in Windows line feeds are in fact two, ASC 13 + ASC 10. If you don’t believe me then in VBA Immediate window try ?ASC(MID$(vbNewLine,1,1)) and then ?ASC(MID$(vbNewLine,2,1)) .

So in the Linux console a typical command would be sudo find / -name apache2.conf &> /mnt/n/findapache.txt which searches for Apache2 configuration file (it’s not where my Apache book says it should be!). The above command pipes output both stdout and stderr (hence “&>”) to /mnt/n which is where my N: drive is mounted into the unified Linux file system.

So here is some code to process the line feeds

Option Explicit

'* Tools->References->Microsoft Scripting Runtime

Sub Test()
    'ConvertLinuxLineFeedsToWindowsCRAndLineFeeds "n:\findapache.txt"
    ConvertLinuxLineFeedsToWindowsCRAndLineFeeds "n:\apache2.conf"
End Sub

Sub ConvertLinuxLineFeedsToWindowsCRAndLineFeeds(ByVal sLinuxFile As String, _
                        Optional ByVal sWindowsFile As String)

    sWindowsFile = Trim(sWindowsFile)
    If LenB(sWindowsFile) = 0 Then
        Dim vSplit As Variant
        vSplit = VBA.Split(sLinuxFile, ".")
        
        Dim lCount As Long
        lCount = UBound(vSplit)
        ReDim Preserve vSplit(0 To lCount + 1)
        vSplit(lCount + 1) = vSplit(lCount)
        vSplit(lCount) = "winLfCr"
        
        sWindowsFile = VBA.Join(vSplit, ".")
    
    End If

    Dim oFSO As New Scripting.FileSystemObject
    
    
    Debug.Assert oFSO.FileExists(sLinuxFile)
    Dim oTxtIn As Scripting.TextStream
    Set oTxtIn = oFSO.OpenTextFile(sLinuxFile)

    Dim oTxtOut As Scripting.TextStream
    Set oTxtOut = oFSO.CreateTextFile(sWindowsFile)

    While Not oTxtIn.AtEndOfStream
        Dim sLine As String
        sLine = oTxtIn.ReadLine
        Debug.Print sLine
        
        oTxtOut.WriteLine sLine
        
    Wend
    
    oTxtOut.Close
    oTxtIn.Close
    
    Set oTxtOut = Nothing
    Set oTxtIn = Nothing

End Sub

Now one can use Notepad to view the contents. Without the windows line feeds the whole file looks like it has no line breaks!