Revision as of 21:47, 11 November 2012

This page is for describing functional requirements of the bake tool for ns-3.16 and for future releases.

Broad functional goals

1. Enable a more distributed package environment for ns-3 third-party developers.

1.1 Split out some of existing ns-3-dev into a smaller "core" and additional "extensions". This should reduce build time for users.

1.2 Provide straightforward way for a third-party developer to maintain their own ns-3 extension and make it available to ns-3 users.

2. Provide a tool for developers to manage multiple builds.

3. Start to provide access to INRIA's Direct Code Execution (DCE) environment

ns-3.16 goals

Below are proposed goals for ns-3.16.

1. bake.py provides existing download.py and build.py with no change of functionality

1.1 For ns-3-dev (after merge):

 hg clone http://code.nsnam.org/ns-3-allinone
 cd ns-3-allinone
 ./bake.py configure -e ns-3-dev
 ./bake.py download
 ./bake.py build

alternative: the "install" command will "download" then "build"

 hg clone http://code.nsnam.org/ns-3-allinone
 cd ns-3-allinone
 ./bake.py configure -e ns-3-dev
 ./bake.py install

1.2 For ns-3.16:

 tar xjf ns-allinone-3.16.tar.bz2
 cd ns-allinone-3.16
 ./bake.py configure -e ns-3.16
 ./bake.py build

1.3 existing download.py and build.py

We keep existing download.py and build.py files, but they print out a backward-compatibility warning and call the equivalent bake commands; e.g.

 cd ns-allinone-3.16
 ./build.py
  "Warning:  build.py is deprecated, please use './bake.py configure -e ns-3.16 && ./bake.py build' instead.

2. different levels of verbosity show different amount of build information

 ./bake.py install 

yields something sparse, such as

 >> Downloading ns-3-dev
 >> Download ns-3-dev - OK 
 >> Building ns-3-dev
 >> Built ns-3-dev - OK
   

while this:

 ./bake.py install -vv

yields the full build output (full waf configure and build information).

3. Managing ns-3 versions

4. Managing debug, optimized, and static builds

5. Passing configure options to bake, especially ns-3 ones such as --disable-python

6. cleaning the directory

'./bake.py clean' will remove the build/ directory and any build artifacts and configuration information; './bake.py distclean' will perform a clean and also remove source/

7. Configuration manipulation

-d and -e behavior

8. Show behavior

bake.py shows available packages, whether they are enabled, and their dependencies; e.g.:

./bake.py show --enabled
 module: click (enabled)
   No dependencies!
 module: openflow-ns3 (enabled)
   No dependencies!
 module: gccxml-ns3 (enabled)
   No dependencies!
 module: nsc (enabled)
   No dependencies!
 module: qt4 (enabled)
   No dependencies!
 module: pygccxml (enabled)
   depends on:
      gccxml-ns3 (optional:True)
 module: net_anim (enabled)
   depends on:
      qt4 (optional:True)
 module: pybindgen (enabled)
   depends on:
      pygccxml (optional:True)
 module: ns-3-dev (enabled)
   depends on:
      net_anim (optional:True)
      nsc (optional:True)
      pybindgen (optional:True)
      click (optional:True)
      openflow-ns3 (optional:True)

In the example above, the gccxml-ns3 dependency is shown for pygccxml. It is out of scope for bake.py to manage package dependencies for some of these (e.g. showing "scons" as a dependency for nsc). However, it would be nice if, during the course of the build, if a package configure bails out, that "bake.py build" reports this to a user in a nice way so the user can try to find/install the missing package.

The user can check the missing dependencies by calling:

./bake.py check
 > Python - Ok
 > Mercurial - Ok
 > CVS - Ok
 > Bazaar - Ok
 > Tar tool - Ok
 > Unzip tool - Ok
 > Unrar tool - Ok
 > GIT - is missing
 > Make - Ok
 > cMake - Ok
 > path tool - Ok
 > Autotools - Ok

Perhaps an enhancement to the above would be to show the "build" and "install" status of each.

Users should be able to disable (in a sticky way) a package they are not interested in; e.g.:

 ./bake.py configure -d netanim

would result in netanim being "(disabled)". Either of the following would restore netanim:

 ./bake.py reconfigure  (or some other way to get back to defaults)
 ./bake.py configure -e netanim

9. Other behavior

- bake.py does not rebuild things unnecessarily - bake.py handles control-C to abort the build

10. bake.py handling of ns-3 enabled_modules

11. DCE

bake.py provides access to ns-3 DCE with at least one well-documented example (iperf? quagga?) of how to use real application code within an ns-3 program. Perhaps we focus on user-mode applications for ns-3.16 and kernel-mode for the next release.

12. external module

(defer) bake.py allows at least one "external" ns-3-based module to be downloaded and built with ns-3. For example, assume there is an external routing protocol module (ns-3-bgp); we may need to make one of these up for the sake of providing an example.

For ns-3-bgp to build, it needs to link to ns-3 libraries. So, there needs to be some install step in bake to install to a well-known place in the allinone directory, or in the system.

For a user program in ns-3.16/scratch to use ns-3-bgp, it needs to be able to find the library and headers. So, the install step on ns-3-bgp should leave the installation in a well-known place by ns-3's waf.

So, the goal here would be:

 ./bake.py configure -e ns-3-bgp
 ./bake.py download
 ./bake.py build       # builds ns-3, then builds ns-3-bgp
 ./bake.py install     # installs both (does install have to happen before ns-3-bgp build?)

Then, user program in ns-3.16/scratch/ can include the module without specifying the full path to ns-3-bgp; i.e., waf may need to become smarter to find these headers and libraries.

Beyond ns-3.16

To be determined.