Fissile has experimental support for generating Kubernetes resource definitions. It will create one workload (deployment, stateful set, or job) per defined instance group, and any associated services (and volume claims) required.
Currently, the resource definitions generated assumes you have a StorageClass
named persistent. This is used to support persistent volume claims used for
ephemeral local storage. A second StorageClass named shared is used for
shared volumes; it must support ReadWriteMany.
Kubernetes resource definitions may be created via the subcommand
fissile build kube. Please refer to the generated documentation for
available arguments.
There are three workload types that fissile will emit:
Fissile emits a Job for BOSH tasks (such as running smoke tests). They are
generated in the bosh-tasks/ subdirectory, as it's likely that you do not want
to run them to deploy the cluster. For example, the
Cloud Foundry Acceptance Tests are destructive and is not suitable to run on a
cluster that is needed for other purposes.
Fissile emits a StatefulSet under two circumstances.
Any self-clustering instance groups (i.e. any group with the clustered tag)
will be a StatefulSet, in order for each pod to be addressable (so
that they can talk to each other). For example, a doppler group would
fall under this category.
Secondly, any instance groups tagged as indexed. An example of such would be
the CF instance group nats. These are groups which require load balancing and
need a 0-based, incremented index. To support this fissile creates a
public service (of type LoadBalancer) for indexed groups, providing a
single point of access to the pods for the group.
Note that both clustered and indexed instance groups can take advantage of
volume claim templates for local storage.
Attention: The automatic emission of StatefulSet for instance groups which have volume specifications has been removed. All instance groups now have to be explicitly tagged as described above.
All instance groups without the above constraints will be generated as deployments.
Each instance group may have attached services generated as necessary. There are three general conditions:
- Each StatefulSet will have a headless service (e.g.
nats-set); this is used to manage the StatefulSet (a Kubernetes requirement), and to allow discovery of pods within a instance group via DNS. - A instance group may have a service for its public ports, if any port is public.
- A instance group may have a service for its private ports, if any ports are defined. Public ports will also be listed to ease communication across instance groups (not having to use different names depending on whether a port is public).