loncom/build/readme.html - view

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Wed Jan 17 13:43:26 2001 UTC (23 years, 11 months ago) by harris41
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very small fixes to HTML structure code -Scott

<HTML> <HEAD> <META NAME="GENERATOR" CONTENT="Scott Harrison and Emacs Version 3.14159265358979"> <TITLE>LON-CAPA Software Developer Instructions</TITLE> </HEAD> <BODY> <H1>LON-CAPA Software Developer Instructions</H1> <BR><I>Written by Scott Harrison, January 17, 2001</I> <BR><I>Last updated, January 17, 2001</I> <OL> <LI><A HREF="#Using_CVS">Using CVS</A> <UL> <LI><A HREF="#cvslog">Logging in and out (cvs login; cvs logout)</A> <LI><A HREF="#cvsget">Getting files (cvs update -d)</A> <LI><A HREF="#cvsupdate">Updating files (cvs update -d)</A> <LI><A HREF="#cvssave">Saving files (cvs commit)</A> <LI><A HREF="#cvsadd">Adding files (cvs add)</A> <LI><A HREF="#cvsadddir">Adding directories (cvs add/import)</A> <LI><A HREF="#cvsnotsure">What to do when you're not sure about your files (cvs update)</A> </UL> <LI><A HREF="#makeHTML">Viewing the software (make HTML)</A> <LI><A HREF="#makebuild">Compiling the software (make build)</A> <LI><A HREF="#loncapafiles">Adding/removing files from the LON-CAPA installation (doc/loncapafiles/loncapafiles.html)</A> <LI><A HREF="#configversusnonconfig">Configurable files versus non-configurable files</A> <LI><A HREF="#makeinstall">Updating the non-configurable files on your machine (make install)</A> <LI><A HREF="#makeconfiginstall">Updating the configurable files on your machine (make configinstall)</A> <LI><A HREF="#makeRPM">Building RPMs (make RPM)</A> </OL> <OL> <A NAME="Using_CVS"> <LI><H2>Using CVS</H2> <UL> <LI><A NAME="cvslog"> <H3>Using CVS: Logging in and out (cvs login; cvs logout)</H3> <LI><A NAME="cvsget"> <H3>Using CVS: Getting files (cvs update -d)</H3> <LI><A NAME="cvsupdate"> <H3>Using CVS: Updating files (cvs update -d)</H3> <LI><A NAME="cvssave"> <H3>Using CVS: Saving files (cvs commit)</H3> <LI><A NAME="cvsadd"> <H3>Using CVS: Adding files (cvs add)</H3> <LI><A NAME="cvsadddir"> <H3>Using CVS: Adding directories (cvs add/import)</H3> <LI><A NAME="cvsnotsure"> <H3>Using CVS: What to do when you're not sure about your files (cvs update)</H3> </UL> <LI><A NAME="makeHTML"> <H2>Viewing the software (make HTML)</H2> <STRONG>Commands</STRONG> <FONT COLOR="#008800"> <PRE> cd loncom/build rm -Rf HTML <I>(or alternatively, "make clean")</I> make HTML cd HTML <I>(look at the index.html file with a web browser such as Netscape)</I> </PRE> </FONT> <STRONG>General description of what happens</STRONG> <P> This is the actual make target code. <FONT COLOR="#880000"> <PRE>  HTML: install -d HTML cp ../../doc/loncapafiles/*.gif HTML perl parse.pl ../../doc/loncapafiles/loncapafiles.html HTML > HTML/index.html  </PRE> </FONT> What basically happens is that specially marked-up data in the LON-CAPA cvs repository file <TT>doc/loncapafiles.html</TT> is parsed into a more viewable format by <TT>loncom/build/parse.pl</TT>. The resulting file gives a very well organized view of all the files, directories, links, ownerships, permissions, and brief documentation of what each file does. </P> <LI><A NAME="makebuild"> <H2>Compiling the software (make build)</H2> <STRONG>Commands</STRONG> <FONT COLOR="#008800"> <PRE> cd loncom/build make build </PRE> </FONT> <STRONG>General description of what happens</STRONG> <P> This is the actual make target code. <FONT COLOR="#880000"> <PRE>  build: perl parse.pl ../../doc/loncapafiles/loncapafiles.html build > Makefile.build make -f Makefile.build all  </PRE> </FONT> <TT>loncom/build/parse.pl</TT> reads in all the build information out of <TT>doc/loncapafiles/loncapafiles.html</TT>. A new Makefile named <TT>loncom/build/Makefile.build</TT> is dynamically constructed. This dynamically generated Makefile is then run to build/compile all the software targets from source. This currently takes 10 minutes (depends on the speed of the machine you compile with). </P> <STRONG>Example</STRONG> <P> Here is information for one file <TT>tth.so</TT> provided in <TT>doc/loncapafiles/loncapafiles.html</TT>. <FONT COLOR="#330066"> <PRE> <BR><METAGROUP> <BR><LONCAPA TYPE=LOCATION DIST="redhat6.2" SOURCE="loncom/modules/TexConvert/tthperl/tth.so" TARGET="usr/lib/perl5/site_perl/5.005/tth.so" CATEGORY="system file"> <BR><DESCRIPTION> <BR>shared library file for dynamic loading and unloading of TeX-to-HTML functionality <BR></DESCRIPTION> <BR><BUILD> <BR>loncom/modules/TexConvert/tthperl/commands <BR></BUILD> <BR><DEPENDENCIES> <BR>../tthdynamic/tthfunc.c <BR>../ttmdynamic/ttmfunc.c <BR></DEPENDENCIES> </PRE> </FONT> <TT>loncom/build/parse.pl</TT> sees the <B>BUILD</B> tags and sets up a dynamic file <TT>Makefile.build</TT> to run the command inside the <B>BUILD</B> tags (currently, <B>DEPENDENCIES</B> is not used for anything besides documentation). </P> <P> Here is an example of a dynamically generated <TT>Makefile.build</TT> that builds two LON-CAPA files (one of which is <TT>tth.so</TT>). <FONT COLOR="#330066"> <PRE> all: ../homework/caparesponse/capa.so ../modules/TexConvert/tthperl/tth.so ../homework/caparesponse/capa.so: ../homework/caparesponse/caparesponse.c ../ho mework/caparesponse/caparesponse.pm alwaysrun cd ../homework/caparesponse/; sh ./commands ../modules/TexConvert/tthperl/tth.so: ../modules/TexConvert/tthperl/../tthdynam ic/tthfunc.c ../modules/TexConvert/tthperl/../ttmdynamic/ttmfunc.c cd ../modules/TexConvert/tthperl/; sh ./commands alwaysrun: </PRE> </FONT> </P> <LI><A NAME="loncapafiles"> <H2>Adding/removing files from the LON-CAPA installation (doc/loncapafiles/loncapafiles.html)</H2> <STRONG>To add and remove (and alter)</STRONG> <P> All that you have to do to alter the behavior of the installation is edit a single file (<TT>doc/loncapafiles/loncapafiles.html</TT>). Adding, removing, and altering files requires proper attention to the syntax of file format of course. </P> <STRONG>File Format</STRONG> <P> The preceding <A HREF=#"makebuild">"make build"</A> documentation gives an example <B>METAGROUP</B> entry describing one particular file. All data within <TT>loncapafiles.html</TT> is specified according to markup tags. The format and syntax of <TT>loncapafiles.html</TT> is currently best described by the HTML documentation code at the beginning of loncapafiles.html (as well as, by example, seeing how various information is coded). All in all, the syntax is quite simple. </P> <STRONG>Philosophy and notes (the thing nobody reads)</STRONG> <P> Packaging the software from CVS onto a machine file system requires many things: <UL> <LI>documenting every component of the software, <LI>handling CVS <U>source</U> to file system <U>target</U> information <LI>handling (according to a hierarchical scheme of grouping) file ownership and permissions, <LI>handling (according to a hierarchical scheme of grouping) directory ownership and permissions, <LI>handling symbolic links <LI>providing for multiple options of installation targets (RedHat versus Debian for instance), <LI>providing for different file ownerships and permissions to apply to the same file, <LI>allowing system software documentation to be automatically generated (see information on <A HREF="#makeHTML">"make html"</A>), <LI>providing information in an easily adjustable form as new demands are made on the software packaging system, <LI>providing software package information (for RPM), <LI>having information in a format that allows for troubleshooting the current status of the machine file system, <LI>allow for changes to the structure of the CVS repository, <LI>and something that is simple enough for any one to immediately work with, without having to learn specifics (or hidden traps) of complicated Makefile's or a new macro language (m4?). </UL> </P> <P> I looked into, and tried, different ways of accomplishing the above including automake and recursive make. The automake system seemed quite complicated (and needlessly so in terms of this project since, by and large, it works to coordinate many different types of build/compilation parameters whereas we are more concerned with installation parameters). Recursive make has significant deficiencies in the sense that not all the information is kept in one place, and there are significant levels of dependency between all the things that must be done to keep software packaging up to date. A particularly convincing article I found when looking into much of this was <A HREF="http://www.pcug.org.au/~millerp/rmch/recu-make-cons-harm.html"> "Recursive Make Considered Harmful" by Peter Miller</A>. Complicating matters was, at the time, it was unclear as to what categories of software files we had, and whether or not the directory structure of CVS would remain constant. With an ever-developing directory structure to CVS, I preferred to organize the information on a per-file basis as opposed to a per-directory basis (although there is a successful implementation of a standard big Makefile in <TT>loncom/Makefile</TT>). Additionally, a standard big Makefile assumes certain "normalcy" to the directory structure of different potential operating system directories (RedHat vs. Debian). </P> <P> If you take time to look at loncapafiles.html (and perhaps run the <A HREF="#makeHTML">make HTML</A> command) you will find that the organizing information according to the markup syntax in <TT>loncapafiles.html</TT> is simple. Simple is good. </P> <P> <TT>loncom/build/parse.pl</TT> is the script (invoked automatically by the various targets in <TT>loncom/build/Makefile</TT>) that reads <TT>doc/loncapafiles/loncapafiles.html</TT>. <TT>parse.pl</TT> is capable of reading and returning different types of information from <TT>loncapafiles.html</TT> depending on how <TT>parse.pl</TT> is invoked. <TT>parse.pl</TT> has yet to have introduced new sources of error, and has been tested in quite a number of ways. As with any parser however, I remain paranoid. </P> <P> My regrets with the current system is that <TT>parse.pl</TT> is slow (can take 1 minute to run) and includes a few tidbits of code, specific to the make process, that probably should be in <TT>loncom/build/Makefile</TT>. Additionally, <TT>loncapafiles.html</TT> should have a DTD and all those other good SGML-ish things (and parsing should be done with a real SGML-derived parser). </P> <P> On the plus side, the <TT>parse.pl</TT>-<TT>loncapafiles.html</TT> combination has been working very efficiently and error-free. </P> <LI><A NAME="configversusnonconfig"> <H2>Configurable files versus non-configurable files</H2> <STRONG>Machine-specific information is the difference</STRONG> <P> The current list of configurable files for the LON-CAPA system is /etc/httpd/access.conf, /etc/smb.conf, /etc/ntp.conf, /etc/krb.conf, /etc/atalk/config, /etc/ntp/step-tickers, /home/httpd/html/res/adm/includes/copyright.tab, /home/httpd/html/res/adm/includes/un_keyword.tab, /home/httpd/hosts.tab, and /home/httpd/spare.tab. </P> <P> All of these configurable files contain machine-specific information. For instance, the LON-CAPA system relies on unique host IDs such as msua3, s1, s2, msul1, and 103a1 (specified as a "PerlSetVar lonHostID" field within /etc/httpd/access.conf). Non-configurable files simply do NOT have machine-specific information. <STRONG>The impact on updating software</STRONG> <P> What this means in terms of software updating is that <UL> <LI>non-configurable files can be simply overwritten with newer versions (without "anything" else to worry about), <LI>and configurable files must follow these steps to be safely overwritten <OL> <LI>have their machine specific information saved, <LI>be overwritten, and then <LI>have their machine specific information restored. </OL> </UL> </P> <LI><A NAME="makeinstall"> <H2>Updating the non-configurable files on your machine (make install)</H2> <STRONG>Commands</STRONG> <FONT COLOR="#008800"> <PRE> cd loncom/build make install </PRE> </FONT> <STRONG>General description of what happens</STRONG> <P> This is the actual make target code. <FONT COLOR="#880000"> <PRE>  install: build perl parse.pl ../../doc/loncapafiles/loncapafiles.html install > Makefil e.install make -f Makefile.install SOURCE="../.." TARGET="" directories make -f Makefile.install SOURCE="../.." TARGET="" files make -f Makefile.install SOURCE="../.." TARGET="" links  </PRE> </FONT> For safety reasons (so as to not mess up a machine's configuration), configuration files are NOT installed during this step. This means that files such as /etc/httpd/access.conf, /etc/smb.conf, /etc/atalk/config, /home/httpd/html/res/adm/includes/copyright.tab, and /home/httpd/spare.tab are not overwritten, but remain as old, non-updated copies. (To automatically update these files and save/restore their encoded machine configuration, you must run "make configinstall"). </P> <LI><A NAME="makeconfiginstall"> <H2>Updating the configurable files on your machine (make configinstall)</H2> <STRONG>Commands</STRONG> <FONT COLOR="#008800"> <PRE> cd loncom/build make configinstall </PRE> </FONT> <STRONG>General description of what happens</STRONG> <P> This is the actual make target code. <FONT COLOR="#880000"> <PRE>  configinstall: # there is a dependency on having directories in place, but oh well... perl parse.pl ../../doc/loncapafiles/loncapafiles.html configinstall > Makefile.configinstall make -f Makefile.configinstall SOURCE="../.." TARGET="" configfiles perl loncaparestoreconfigurations lasttimestamp make -f Makefile.configinstall TARGET="" configpermissions  </PRE> </FONT> Configuration files are installed during this step. This means that files such as /etc/httpd/access.conf, /etc/smb.conf, /etc/atalk/config, /home/httpd/html/res/adm/includes/copyright.tab, and /home/httpd/spare.tab are overwritten. Before being overwritten, a backup copy is made though. Information is read out of these backup copies and restored to the new files by the <TT>loncaparestoreconfigurations</TT> script. To ensure that new file permissions and ownerships are installed, a final set of <TT>chown</TT> and <TT>chmod</TT> commands are called upon all the configuration files. </P> <STRONG>For the truly paranoid</STRONG> <P> If you are truly paranoid, you can just make the <TT>Makefile.configinstall</TT> file and then save, copy, and restore all the configuration values yourself. <TT>loncaparestoreconfigurations</TT> is pretty smart though, has yet to fail, and besides, a backup copy is always made (time-stamped so that backup copies are not overwritten). </P> <LI><A NAME="makeRPM"> <H2>Building RPMs (make RPM)</H2> <STRONG>Commands</STRONG> <FONT COLOR="#008800"> <PRE> cd loncom/build rm -Rf BinaryRootL <I>(or alternatively, "make clean")</I> make RPM <I>(to subsequently install, you can type commands like "rpm -Uvh --force LON-CAPA-base-3.1-1.i386.rpm") </PRE> </FONT> </P> <STRONG>WARNING!!!!!!!!!!!!!!</STRONG> <P> Never never never never never manually install the LON-CAPA-setup-3.1-1.i386.rpm. This RPM is meant to only be installed by the CD installation process (it wipes out the existing /etc/passwd file). </P> <STRONG>Configuration files</STRONG> <P> Configuration files are automatically saved with the file suffix ".rpmsave". So <TT>/etc/httpd/conf/access.conf</TT> is saved as <TT>/etc/httpd/conf/access.conf.rpmsave</TT>. You can restore the machine-specific configuration information by running the <TT>/usr/sbin/loncaparestoreconfigurations</TT>. However, a <B>warning</B> is important here. If you install an RPM twice without restoring your configuration, you will overwrite the ".rpmsave" files. </P> <STRONG>General description of what happens</STRONG> <P> This is the actual make target code. <FONT COLOR="#880000"> <PRE>  RPM: BinaryRoot cat base_file_list.txt | perl make_rpm.pl base 3.1 '' '' BinaryRoot cat setup_file_list.txt | perl make_rpm.pl setup 3.1 '' '' BinaryRoot BinaryRoot: perl parse.pl ../../doc/loncapafiles/loncapafiles.html BinaryRoot  </PRE> </FONT> A <TT>BinaryRoot</TT> directory is generated that reflects the locations, ownerships, permissions, and contents for all the CVS source files, compiled binaries, directories, and links as they should eventually occur on the '/' filesystem location. </P> <P> <TT>loncom/build/make_rpm.pl</TT> is robust (tested over the span of months) and, unlike other automated RPM-builders, cleanly builds new RPMs without any after-effect of temporary files left on the system. (On the negative side, there are a number of LON-CAPA specific customizations inside make_rpm.pl which, for the sake of reusability, should eventually be removed). Two new RPMs are generated: LON-CAPA-base-3.1-1.i386 and LON-CAPA-setup-3.1-1.i386.rpm (again, never manually install LON-CAPA-setup-3.1-1.i386.rpm). </P> </OL> </BODY> </HTML>