So the System VM is "built" from two sources. 1) https://github.com/apache/cloudstack/tree/master/tools/appliance/definitions/systemvmtemplate This defines what is actually built and is distributed as the SystemVM Template. You MUST use it if you change the packages included in the SystemVM template or change the core components in any way. Changing anything here REQUIRES a new SystemVM template to be distributed for that change to be used.
2) https://github.com/apache/cloudstack/tree/master/systemvm/patches/debian This defines the systemvm.iso which is loaded into the System VM template after the system vm is deployed. This basically defines configuration which can be changed without requiring a new System VM template. This section does not handle installation of packages and such, instead it handles System VM configuration and functionality. So if settings files need to be changed (for say something like VPN) or if the way we handle IP address changes, etc... That is all handled from here. The systemvm.iso is generated by the management server (i think) and is pushed to the system vm after the system vm boots and the configuration which cloudstack manages is handled through this code. Is that clear? Let me know if you have more questions. I have had to do a bunch of stuff in this recently for some of the networking issues we have had as well as the StrongSwan VPN implementation (which changed both places). Using StrongSwan as an example: I had to modify (1) in order to remove the OpenSwan package installation and add the StrongSwan package installation. I had to modify (2) in order to change the configuration of the VPN in order to handle things the way that StrongSwan needed things done. So the changes to things like the `ipsec` command are handled in (2) because those are configuration changes and not package changes. Is that clearer? *Will STEVENS* Lead Developer <https://goo.gl/NYZ8KK> On Fri, Feb 17, 2017 at 11:18 AM, David Mabry <dma...@ena.com> wrote: > Hello everyone, > > I’m looking at making some changes to the system vm, but I have found that > there looks like there are 2 different places in the code that “build” the > systemvm. There is there is https://github.com/apache/cloudstack/tree/ > 13bfdd71e6fffff52d2f613a802b3d16c9b40af7/systemvm/patches/debian, which > looks like it might be the “old” way and there is > https://github.com/apache/cloudstack/tree/87ef8137534fa798101f65c6691fcf > 71513ac978/tools/appliance/definitions/systemvmtemplate, which looks like > it might be the “new” way. If I wanted to make changes to how the systemvm > is built which place should I modify? I assume that I should modify the > build scripts in the “new” location, but I thought I would ask here first > just to be sure. > > --Mabry >
