To properly support the kubectl-slice use case the Artifact map needs to
write multiple files out to the filesystem. This needs to be dynamic in
the sense holos and the end user don't know what files the kubectl-slice
transformer is producing.
As a hack, which may actually turn out to be "good enough" this patch
makes the Slice transformer behave like so:
1. Execute kubectl-slice outputting to an empty temp directory.
2. Holos saves all files in this directory into the artifact map.
3. At the end of the Artifact pipeline, if the final artifact produced
ends in a /, then all keys in the artifact map having the prefix are
written to the output directory.
This should be sufficient for the use case, but we'll need to consider
how this transformer and apporach works when subsequent transformers are
used in the pipeline. I haven't thought deeply about it, but it should
ideally work pretty well if the tools involved truly only care about
directories and not the files within the directory.
Previously the BuildPlan pipeline didn't execute generators and
transformers concurrently. All steps were sequentially executed. Holos
was primarily concurrent by executing multiple BuildPlans at once.
This patch changes the Build implementation for each BuildPlan to
execute a GoRoutine pipeline. One producer fans out to a group of
routines each executing the pipeline for one artifact in the build plan.
The pipeline has 3 stages:
1: Fan-out to build each Generator concurrently.
2: Fan-in to build each Transformer sequentially.
3: Fan-out again to run each validator concurrently.
When the artifact pipelines return, the producer closes the tasks
channel causing the worker tasks to return.
Note the overall runtime for 8 BuildPlans is roughly equivalent to
previously at 160ms with --concurrency=8 on my M3 Max. I expect this to
perform better than previously when multiple artifacts are rendered for
each BuildPlan.
Show subcommand:
This is large change that accomplishes a number of goals. First, there
was no convenient way to show a build plan without using the debug logs
to indentify the tags to inject, then calling the cue command with the
right incantation to inspect the BuildPlan.
This patch addresses the problem by adding a `holos show buildplans`
command. The command loads the Platform spec from the platform
directory, then iterates over all Components to produce the BuildPlan.
This patch adds labels and annotations to the platform Components
collection in order to select and filter the output.
Result:
```
❯ holos show components --selector app.holos.run/cluster=local --format=yaml | head
kind: BuildPlan
apiversion: v1alpha5
metadata:
name: podinfo
spec:
artifacts:
- artifact: clusters/local/components/podinfo/podinfo.gen.yaml
generators:
- kind: Helm
output: helm.gen.yaml
```
---
Interface refactor:
This refactors the interface between the `holos` Go CLI layer and the
various core schema data structures. We now use a proper Go interface.
Concurrent execution over platform components has been improved to
accept a closure function so we can use the same interface method to
process the components. We use this to show each component and render
each component from different subcommands using the same interface
embedded in the builder.Platform struct.
The embedded interface allows us to easily swap in different versions,
e.g. v1beta1 and eventually v1. The number of interface methods are
quite small. 14 methods across 4 interfaces in holos/interface.go.
---
Remove old versions:
This patch removes support for versions prior to v1alpha5 in an effort
to clean up cruft.
holos.FilePath is intended for paths relative to the platform root
directory. We use the Artifact to store lots of stuff not related to
the platform root directory, for example kustomization.yaml in a temp
dir. Most entries are not relative to the platform root directory given
the implicit cfg.WriteTo prefix.
Previously:
could not run: could not build dev-join: could not get foo.yaml: not set at builder/v1alpha4/builder.go:180
This is confusing because set has nothing to do with the missing input
from the cue code the user writes.
Result:
could not run: could not build test-join: missing foo.yaml at builder/v1alpha4/builder.go:180
This is better because it at doesn't distract the user from the fact
they're missing a foo.yaml generator output to align with the
transformer input.
The code was inlined in a number of places, it makes sense to move it to
the interface. It'll also make it easier to test, we can provide a null
writer concrete value.
With this patch the first use case of CUE Resources + Kustomize is fully
working, artifacts are written into the deploy directory.
❯ holos render platform ./platforms/minimal
rendered namespaces for cluster local in 143.068583ms
rendered namespaces for cluster local in 143.861834ms
rendered namespaces for cluster local in 144.072666ms
rendered namespaces for cluster local in 144.219417ms
rendered platform in 144.326625ms
The output indicates we need to plumb the BuildPlan metadata.name from
the PlatfromSpec through to the render component command. This is
necessary so we can report the correct name instead of just the base
path.
This patch implements the v1alpha4 component rendering builder for a
component BuildPlan. We don't yet have the CUE definitions, so this
hasn't been end to end tested yet, the next step is defining the
generators and transforms in the core API BuildPlan.
