Merge branch 'master' of gitlab.mi.hdm-stuttgart.de:goik/GoikLectures

Doc/Common/glossary.xml

@@ -558,6 +558,16 @@
       </glossdef>
     </glossentry>
 
+    <glossentry xml:id="glo_NIC">
+      <glossterm>NIC</glossterm>
+
+      <glossdef>
+        <para><link
+        xlink:href="https://en.wikipedia.org/wiki/Network_interface_controller">Network
+        Interface Controller</link></para>
+      </glossdef>
+    </glossentry>
+
     <glossentry xml:id="glo_OO">
       <glossterm><acronym>OO</acronym></glossterm>
 
@@ -703,6 +713,14 @@
       </glossdef>
     </glossentry>
 
+    <glossentry xml:id="glo_SNI">
+      <glossterm><acronym>SNI</acronym></glossterm>
+
+      <glossdef>
+        <para>Server Name Indication</para>
+      </glossdef>
+    </glossentry>
+
     <glossentry xml:id="glo_SNMP">
       <glossterm><acronym>SNMP</acronym></glossterm>
 
@@ -887,9 +905,20 @@
       <glossterm><acronym>TLS</acronym></glossterm>
 
       <glossdef>
-        <para><link
-        xlink:href="https://en.wikipedia.org/wiki/Transport_Layer_Security">Transport
-        Layer Security</link></para>
+        <para>Transport Layer Security</para>
+
+        <itemizedlist>
+          <listitem>
+            <para><link
+            xlink:href="https://en.wikipedia.org/wiki/Transport_Layer_Security">Wikipedia</link></para>
+          </listitem>
+
+          <listitem>
+            <para><link
+            xlink:href="https://www.globalsign.com/en/blog/ssl-vs-tls-difference">TLS
+            <abbrev>vs.</abbrev> SSL</link> distinction</para>
+          </listitem>
+        </itemizedlist>
       </glossdef>
     </glossentry>
 

Doc/Sd1/languageFundamentals.xml

@@ -1739,10 +1739,9 @@ velocity = (short) measure; // Explicit double to short conversion</programlisti
             <programlisting language="java">int i = -21;
 double d = i;</programlisting>
 
-            <para>This snippet shows perfectly correct <xref
-            linkend="glo_Java"/> code. However <xref
-            linkend="sd1_fig_typeSafety"/> suggests we should not be allowed
-            to assign an <code language="java"
+            <para>This snippet shows correct <xref linkend="glo_Java"/> code.
+            However <xref linkend="sd1_fig_typeSafety"/> suggests we should
+            not be allowed to assign an <code language="java"
             xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
             to a <code language="java"
             xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
@@ -1766,48 +1765,70 @@ int i = d; // Error: Incompatible types</programlisting>
 
               <listitem>
                 <para>Whats the ratio behind this design decision? Hint: What
-                would happen for larger <code>double</code> values?</para>
+                would happen for larger <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
+                values?</para>
               </listitem>
             </orderedlist>
           </question>
 
           <answer>
-            <para>The first code snippet uses the <emphasis
-            role="bold">widening conversion</emphasis>: When assigning <code
-            language="java">d = i</code> the <xref linkend="glo_Java"/>
-            compiler implicitly converts a four byte <code language="java"
-            xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
-            into an eight byte <code language="java"
-            xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
-            value.</para>
+            <orderedlist>
+              <listitem>
+                <para>The first code snippet uses the <emphasis
+                role="bold">widening conversion</emphasis>: When assigning
+                <code language="java">d = i</code> the <xref
+                linkend="glo_Java"/> compiler implicitly converts a four byte
+                <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
+                into an eight byte <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
+                value.</para>
 
-            <para>Turning a double into an int is more cumbersome: The
-            expression <code language="java">i = 3.5</code> could be evaluated
-            by agreeing on a specific rounding prescription. But what about i
-            = 3457357385783573478955345.45? A <xref linkend="glo_Java"/> <code
-            language="java"
-            xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>'s
-            maximum value is <inlineequation>
-                <m:math display="inline">
-                  <m:mrow>
-                    <m:msup>
-                      <m:mi>2</m:mi>
+                <para>In contrast there is no automated narrowing from <code
+                language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
+                to <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
+                hence causing a compile time error.</para>
+              </listitem>
 
-                      <m:mi>31</m:mi>
-                    </m:msup>
+              <listitem>
+                <para>Turning a <code language="java">double</code> into an
+                <code language="java">int</code> is more cumbersome: The
+                expression e.g. <code language="java">i = 3.5</code> could be
+                evaluated by agreeing on a specific rounding prescription. But
+                what about e.g. i = 3457357385783573478955345.45 ? A <xref
+                linkend="glo_Java"/> <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>'s
+                maximum value is <inlineequation>
+                    <m:math display="inline">
+                      <m:mrow>
+                        <m:msup>
+                          <m:mi>2</m:mi>
 
-                    <m:mo>-</m:mo>
+                          <m:mi>31</m:mi>
+                        </m:msup>
 
-                    <m:mi>1</m:mi>
-                  </m:mrow>
-                </m:math>
-              </inlineequation>exceeding the former <code language="java"
-            xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
-            value.</para>
+                        <m:mo>-</m:mo>
 
-            <para>Conclusion: <xref linkend="glo_Java"/> disallows double to
-            int assignments unless using a so called cast (explicit type
-            conversion):</para>
+                        <m:mi>1</m:mi>
+                      </m:mrow>
+                    </m:math>
+                  </inlineequation>unable to accommodate the <code
+                language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
+                value in question by far.</para>
+
+                <para>Conclusion: <xref linkend="glo_Java"/> disallows <code
+                language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
+                to <code language="java"
+                xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
+                assignments unless using a so called cast (explicit type
+                conversion):</para>
+              </listitem>
+            </orderedlist>
 
             <para>Caveats using explicit casts:</para>
 
@@ -1824,8 +1845,8 @@ System.out.println("Result: " + i);</programlisting></td>
                 </informaltable>
 
                 <para>Notice the result of 2 rather than 3 as you might have
-                expected assuming some common rounding convention. This does
-                not happen unless you explicitly use methods like e.g.
+                expected assuming common rounding convention rules. Rounding
+                does not happen unless you explicitly use methods like e.g.
                 <methodname
                 xlink:href="https://docs.oracle.com/javase/10/docs/api/java/lang/Math.html#round(double)">Math.round()</methodname>.</para>
               </listitem>
@@ -1842,8 +1863,8 @@ System.out.println("Result: " + i);</programlisting></td>
                 </informaltable>
 
                 <para>This truncation of 3 billion to 2147483647 is due to the
-                latter being the largest possible <code
-                language="java">int</code> value to je represented in <xref
+                latter value being the largest possible <code
+                language="java">int</code> value to be represented in <xref
                 linkend="glo_Java"/>.</para>
               </listitem>
             </orderedlist>

Doc/Sdi/apache.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <chapter version="5.1" xml:id="sdiApache"
-         xmlns="http://docbook.org/ns/docbook"
+	annotations="slide"
+	xmlns="http://docbook.org/ns/docbook"
          xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xila="http://www.w3.org/2001/XInclude/local-attributes"
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xmlns:svg="http://www.w3.org/2000/svg"
          xmlns:ns="http://docbook.org/ns/transclusion"
@@ -13,29 +15,198 @@
   <section xml:id="sdiApachePrelim">
     <title>Preliminaries</title>
 
-    <para>The following documentation will be helpful:</para>
-
-    <itemizedlist>
-      <listitem>
-        <para><link xlink:href="https://httpd.apache.org/docs/2.4">Apache HTTP
-        Server Version 2.4 Documentation</link></para>
-      </listitem>
-    </itemizedlist>
-
-    <tip>
-      <para>Whenever searching for <productname>Apache</productname> related
-      configuration hints always include <quote>2.4</quote> in your query
-      string: The configuration file syntax has changed considerably in
-      comparison to <productname>Apache</productname> 2.2.</para>
-    </tip>
+    <figure xml:id="sdi_webserver_documentation">
+      <title>External documentation</title>
+
+      <itemizedlist>
+        <listitem>
+          <para><link xlink:href="https://httpd.apache.org/docs/2.4">Apache
+          HTTP Server Version 2.4 Documentation</link></para>
+        </listitem>
+      </itemizedlist>
+
+      <tip>
+        <para>Whenever searching for <productname>Apache</productname> related
+        documentation <emphasis>always</emphasis> include <quote>2.4</quote>
+        in your query: Configuration file syntax changed considerably with
+        respect to <productname>Apache</productname> version 2.2.</para>
+      </tip>
+    </figure>
+
+    <figure xml:id="sdi_webserver_uri2fs">
+      <title>URI to filesystem mapping</title>
+
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="Ref/Webserver/assetMapping.multi.svg"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
+
+    <figure xml:id="sdi_webserver_virtualHostPrinciple">
+      <title>Virtual hosting</title>
+
+      <itemizedlist>
+        <listitem>
+          <para>One physical host system</para>
+        </listitem>
+
+        <listitem>
+          <para>Serving multiple sites e.g.:</para>
+
+          <itemizedlist>
+            <listitem>
+              <para><uri>https://www.foo.org</uri></para>
+            </listitem>
+
+            <listitem>
+              <para><uri>https://www.second.org</uri></para>
+            </listitem>
+          </itemizedlist>
+        </listitem>
+      </itemizedlist>
+    </figure>
+
+    <figure xml:id="sdi_webserver_virtualHostImplementations">
+      <title>Implementing virtual hosting</title>
+
+      <orderedlist>
+        <listitem>
+          <para>Port based virtual hosting</para>
+        </listitem>
+
+        <listitem>
+          <para>IP based virtual hosting</para>
+        </listitem>
+
+        <listitem>
+          <para>Name based virtual hosting</para>
+
+          <para>Typically using <emphasis role="red">S</emphasis>erver
+          <emphasis role="red">N</emphasis>ame <emphasis
+          role="red">I</emphasis>ndication (<xref linkend="glo_SNI"/>)</para>
+        </listitem>
+      </orderedlist>
+    </figure>
+
+    <figure xml:id="sdi_webserver_IpBasedVhost">
+      <title>IP based virtual hosting</title>
+
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="Ref/Webserver/ipBasedVirtual.multi.svg"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
+
+    <figure xml:id="sdi_webserver_IpBasedVhostProCons">
+      <title>IP based, pros / cons</title>
+
+      <itemizedlist>
+        <listitem>
+          <para>Host system: One IP per site to serve</para>
+        </listitem>
+
+        <listitem>
+          <para>Pro: <xref linkend="glo_TLS"/> handshake without <xref
+          linkend="glo_SNI"/>.</para>
+
+          <para>Supporting older clients.</para>
+        </listitem>
+
+        <listitem>
+          <para>Downside:</para>
+
+          <itemizedlist>
+            <listitem>
+              <para>IP address waste</para>
+            </listitem>
+
+            <listitem>
+              <para>Host system <xref linkend="glo_NIC"/> configuration
+              required</para>
+            </listitem>
+          </itemizedlist>
+        </listitem>
+      </itemizedlist>
+    </figure>
+
+    <figure xml:id="sdi_webserver_NameBasedVhost">
+      <title>Name based virtual hosting</title>
+
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="Ref/Webserver/nameBasedVirtual.multi.svg"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
+
+    <figure xml:id="sdi_webserver_NameBasedVhostProCons">
+      <title>Name based, pros / cons</title>
+
+      <itemizedlist>
+        <listitem>
+          <para>Host system: Common IP address</para>
+        </listitem>
+
+        <listitem>
+          <para>Pro</para>
+
+          <itemizedlist>
+            <listitem>
+              <para>IP address waste</para>
+            </listitem>
+
+            <listitem>
+              <para>Host system <xref linkend="glo_NIC"/> configuration
+              required</para>
+            </listitem>
+          </itemizedlist>
+        </listitem>
+
+        <listitem>
+          <para>Cons: Excluding older non <xref linkend="glo_SNI"/> supporting
+          clients.</para>
+
+          <para>(Internet Explorer on <productname>Windows XP</productname>,
+          Android below V. 2.3)</para>
+        </listitem>
+
+        <listitem>
+          <para><xref linkend="glo_SNI"/> allows for eavesdropping requested
+          site's name.</para>
+        </listitem>
+      </itemizedlist>
+    </figure>
+
+    <figure xml:id="sdi_webserver_ldapAuth">
+      <title><xref linkend="glo_LDAP"/> backed authentication</title>
+
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="Ref/Webserver/ldapAuth.multi.svg"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
+
+    <figure xml:id="sdi_webserver_phpFpm">
+      <title><abbrev>PHP</abbrev> <abbrev>FPM</abbrev> server</title>
+
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="Ref/Webserver/phpFpm.multi.svg"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
   </section>
 
   <section xml:id="sdiApacheExercise">
     <title>Exercises</title>
 
     <para>The Apache web server <package>apache2</package> software package
-    may have already been installed depending on other exercises (<xref
-    linkend="glo_LDAP"/> administration frontend?):</para>
+    may have already been installed depending on other exercises
+    <abbrev>e.g.</abbrev> <xref linkend="glo_LDAP"/> administration
+    frontend:</para>
 
     <screen>aptitude install apache2</screen>