Boxes

Stacki enables you to create a box which is a composition of pallets and (optionally) carts. The contents of a box is the entire set of RPMs and configuration scripts that are available to a backend host when it installs.

The default box consists of the stacki and os pallets (and no carts). The os pallet is a stripped down version of CentOS. These two pallets are the minimum pallets required to install a backend host. Backend hosts are assigned the default box automatically.

Different backend hosts can be assigned to different boxes which gives you a great deal of latitude when deciding what software stacks should go on which backend hosts.

A few examples of the utility of boxes:

• Maintaining different versions of the OS: If you want CentOS 6.6 on one set of backend hosts and CentOS 6.7 on another set of backend hosts. You can download the 6.7 CentOS ISOs, add them to the frontend (with stack add pallet), create a new box with the CentOS 6.7 pallet, then assign backend hosts to the new box.

• Maintaining updates: Pallets can be created by mirroring any publicly available repo (or subscribed repo if using RHEL). Adding an updates pallet to any box will make the updated RPMs to hosts via yum.

• Maintaining dev/test/production environments: Again, having created dev, test, and production boxes with the appropriate pallets, assign machines to each of those boxes. Install/reinstall the machines. When you want to promote machines to a new environment, reassign the machine's box and reinstall.

Create a new box

This example will create a new box that incorporates RHEL 6.7 instead of CentOS 6.7. Then we'll then assign a machine to the new box.

List boxes:

# stack list box

Which returns:

NAME     OS     PALLETS                   CARTS
default: redhat stacki-3.0-6.x CentOS-6.7 -----

In the above output, the default box contains two pallets (stacki version 3.0-6.x and CentOS version 6.7) and it contains no carts (denoted by -----).

Let's look at all the available pallets:

# stack list pallet

Which outputs:

NAME    VERSION RELEASE ARCH   OS     BOXES  
os:     6.7     6.x     x86_64 redhat -------
stacki: 3.0     6.x     x86_64 redhat default
CentOS: 6.7     ------- x86_64 redhat default

We see we have CentOS version 6.7 avaiable. Now we'll add RHEL 6.7 to the list of available pallets:

# stack add pallet rhel-server-6.7-x86_64-dvd.iso

And now the output of stack list pallet shows:

NAME    VERSION RELEASE ARCH   OS     BOXES  
os:     6.7     6.x     x86_64 redhat -------
stacki: 3.0     6.x     x86_64 redhat default
CentOS: 6.7     ------- x86_64 redhat default
RHEL:   6.7     ------- x86_64 redhat -------

The RHEL pallet is not associated with any box.

We'll add a new box and call it dev:

# stack add box dev

Now stack list box shows the new box dev with no pallets and no carts associated with it:

NAME     OS     PALLETS                   CARTS
default: redhat stacki-3.0-6.x CentOS-6.7 -----
dev:     redhat ------------------------- -----

Let's associate the RHEL and stacki pallets with the dev box:

# stack enable pallet RHEL box=dev
# stack enable pallet stacki box=dev

And now stack list box shows:

NAME     OS     PALLETS                   CARTS
default: redhat stacki-3.0-6.x CentOS-6.7 -----
dev:     redhat stacki-3.0-6.x RHEL-6.7   -----

We see that the dev box contains the RHEL and stacki pallets.

Now let's assign a backend host to the dev box. First, let's look at what the backend hosts are currently set to:

# stack list host
HOST     RACK RANK CPUS APPLIANCE BOX     RUNACTION INSTALLACTION
node203: 0    0    1    frontend  default os        install     
node214: 0    22   2    backend   default os        install    
node213: 0    23   2    backend   default os        install   

We see that backend hosts node213 and node214 are both associated with the default box.

Let's associate node214 with the new dev box:

# stack set host box node214 box=dev

Now stack list host shows that node214 is associated with the dev box:

HOST     RACK RANK CPUS APPLIANCE BOX     RUNACTION INSTALLACTION
node203: 0    0    1    frontend  default os        install     
node214: 0    22   2    backend   dev     os        install    
node213: 0    23   2    backend   default os        install   

The next time node214 is installed, it will have the packages from the RHEL pallet (repository) at its disposal rather than the CentOS packages.

Removing a Box

To remove a box, do the following:

Reset the backend nodes to a valid box:

# stack set host box node214 box=default

Remove the box dev and verify it is gone:

# stack remove box dev
# stack list box

Which shows that we only now have the default box defined:

NAME     OS     PALLETS                   CARTS
default: redhat stacki-3.0-6.x CentOS-6.7 -----