Persistent Cache

In order to exactly reconstruct a software appliance with the same exact version of packages. Kameleon offer the option of creating a persistent cache that will catch all the software packages during the building of the software appliance. Enabling other to reconstruct the same exact software appliance with the right package versions. Kameleon uses Polipo [1] which is a tiny and lightweight web proxy to cache most of the packages that comes form the network. First of all, you have to install Polipo on your system. If you are under a debian distribution you can install it using the package manager:

sudo apt-get install polipo

You can as well build it from sources and then specify the path of the generated binary using the option --polipo-path. Before using it you have to declare the variable proxy_cache, for example

  cmd: bash
  workdir: $${kameleon_cwd}

# Shell session that allows us to connect to the building machine in order to
# configure it and setup additional programs
ssh_config_file: $${kameleon_cwd}/ssh_config
  cmd: LC_ALL=POSIX ssh -F $${ssh_config_file} $${kameleon_recipe_name} -t /bin/bash
  workdir: /

To use, you just have to add the option --enable-cache as an argument of the build command. For example:

kameleon build my_recipe.yaml -b /tmp/kameleon/ --enable-cache

This will create a tar file in the build directory /tmp/kameleon called my_recipe-cache.tar. In order to use this generated cache file in another build, we have just to use the options --from-cache as follows:

kameleon build my_recipe.yaml -b /tmp/kameleon/ --from_cache /tmp/my_recipe-cache.tar