Introduce Cozystack API (#460)

Signed-off-by: Andrei Kvapil <kvapss@gmail.com>


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced a RESTful API for managing `Application` resources,
enabling CRUD operations with HelmRelease integration.
- Added validation functions for `Application` and `ApplicationSpec`,
laying the groundwork for future validation rules.
- Implemented configuration management for resources, allowing for
structured application and release settings.

- **Bug Fixes**
- Addressed API rule violations related to naming conventions and
missing types in the CozyStack API definitions.

- **Tests**
- Added comprehensive tests for round-trip functionality and version
compatibility within the Apps API server.

- **Documentation**
- Introduced documentation for the `v1alpha1` API version, including
licensing and code generation annotations.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Andrei Kvapil <kvapss@gmail.com>

api/api-rules/cozystack_api_violation_exceptions.list

@@ -0,0 +1,25 @@
+API rule violation: list_type_missing,github.com/aenix.io/cozystack/pkg/apis/apps/v1alpha1,ApplicationStatus,Conditions
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,Ref
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,Schema
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XEmbeddedResource
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XIntOrString
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XListMapKeys
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XListType
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XMapType
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XPreserveUnknownFields
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaProps,XValidations
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrArray,JSONSchemas
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrArray,Schema
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrBool,Allows
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrBool,Schema
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrStringArray,Property
+API rule violation: names_match,k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1,JSONSchemaPropsOrStringArray,Schema
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,APIResourceList,APIResources
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,Duration,Duration
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,InternalEvent,Object
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,InternalEvent,Type
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,MicroTime,Time
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,StatusCause,Type
+API rule violation: names_match,k8s.io/apimachinery/pkg/apis/meta/v1,Time,Time
+API rule violation: names_match,k8s.io/apimachinery/pkg/runtime,Unknown,ContentEncoding
+API rule violation: names_match,k8s.io/apimachinery/pkg/runtime,Unknown,ContentType

cmd/cozystack-api/main.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2024 The Cozystack Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"os"
+
+	"github.com/aenix.io/cozystack/pkg/cmd/server"
+	genericapiserver "k8s.io/apiserver/pkg/server"
+	"k8s.io/component-base/cli"
+)
+
+func main() {
+	ctx := genericapiserver.SetupSignalContext()
+	options := server.NewAppsServerOptions(os.Stdout, os.Stderr)
+	cmd := server.NewCommandStartAppsServer(ctx, options)
+	code := cli.Run(cmd)
+	os.Exit(code)
+}

go.mod

@@ -0,0 +1,113 @@
+// This is a generated file. Do not edit directly.
+
+module github.com/aenix.io/cozystack
+
+go 1.23.0
+
+require (
+	github.com/emicklei/go-restful/v3 v3.11.0
+	github.com/google/gofuzz v1.2.0
+	github.com/spf13/cobra v1.8.1
+	github.com/stretchr/testify v1.9.0
+	k8s.io/apiextensions-apiserver v0.31.2
+	k8s.io/apimachinery v0.31.2
+	k8s.io/apiserver v0.31.2
+	k8s.io/client-go v0.31.2
+	k8s.io/code-generator v0.31.2
+	k8s.io/component-base v0.31.2
+	k8s.io/kube-openapi v0.0.0-20240827152857-f7e401e7b4c2
+	k8s.io/utils v0.0.0-20240711033017-18e509b52bc8
+	sigs.k8s.io/structured-merge-diff/v4 v4.4.1
+)
+
+require (
+	github.com/NYTimes/gziphandler v1.1.1 // indirect
+	github.com/antlr4-go/antlr/v4 v4.13.0 // indirect
+	github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/blang/semver/v4 v4.0.0 // indirect
+	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/coreos/go-semver v0.3.1 // indirect
+	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/fluxcd/helm-controller/api v1.1.0 // indirect
+	github.com/fluxcd/pkg/apis/kustomize v1.6.1 // indirect
+	github.com/fluxcd/pkg/apis/meta v1.6.1 // indirect
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
+	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
+	github.com/go-logr/logr v1.4.2 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/go-openapi/jsonpointer v0.21.0 // indirect
+	github.com/go-openapi/jsonreference v0.20.2 // indirect
+	github.com/go-openapi/swag v0.23.0 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/google/cel-go v0.21.0 // indirect
+	github.com/google/gnostic-models v0.6.8 // indirect
+	github.com/google/go-cmp v0.6.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect
+	github.com/imdario/mergo v0.3.6 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/prometheus/client_golang v1.19.1 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/stoewer/go-strcase v1.3.0 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
+	go.etcd.io/etcd/api/v3 v3.5.16 // indirect
+	go.etcd.io/etcd/client/pkg/v3 v3.5.16 // indirect
+	go.etcd.io/etcd/client/v3 v3.5.16 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.53.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.53.0 // indirect
+	go.opentelemetry.io/otel v1.28.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.28.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.27.0 // indirect
+	go.opentelemetry.io/otel/metric v1.28.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.3.1 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	go.uber.org/zap v1.27.0 // indirect
+	golang.org/x/crypto v0.28.0 // indirect
+	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
+	golang.org/x/mod v0.21.0 // indirect
+	golang.org/x/net v0.30.0 // indirect
+	golang.org/x/oauth2 v0.23.0 // indirect
+	golang.org/x/sync v0.8.0 // indirect
+	golang.org/x/sys v0.26.0 // indirect
+	golang.org/x/term v0.25.0 // indirect
+	golang.org/x/text v0.19.0 // indirect
+	golang.org/x/time v0.7.0 // indirect
+	golang.org/x/tools v0.26.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240528184218-531527333157 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240701130421-f6361c86f094 // indirect
+	google.golang.org/grpc v1.65.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
+	gopkg.in/evanphx/json-patch.v4 v4.12.0 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/natefinch/lumberjack.v2 v2.2.1 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/api v0.31.2 // indirect
+	k8s.io/gengo/v2 v2.0.0-20240911193312-2b36238f13e9 // indirect
+	k8s.io/klog/v2 v2.130.1 // indirect
+	k8s.io/kms v0.31.2 // indirect
+	sigs.k8s.io/apiserver-network-proxy/konnectivity-client v0.31.0 // indirect
+	sigs.k8s.io/controller-runtime v0.19.0 // indirect
+	sigs.k8s.io/json v0.0.0-20241010143419-9aa6b5e7a4b3 // indirect
+	sigs.k8s.io/yaml v1.4.0 // indirect
+)