Add code to generate openapi specs

Some of the modern Kubernetes clients use clients generated from a
swagger.json

kubernetes-client/javascript uses kubernetes-client/gen which uses
OpenApiTools/openapi-generator and kubernetes/kubernetes/api/openapi-spec/swagger.json

There are open/closed/rotten/ignored issues all over the place about
making these easier to use with CRDs.

Wrongly closed issue on kubernetes-client/javascript: kubernetes-client/javascript#341
Open issue on kubernetes-client/gen: kubernetes-client/gen#121

It seems like kubernetes/kube-openapi is one of the repos working on
solving the main part of this problem, generating the Go code to make
it easy to generate a swagger.json

I found the following Argo code via the following issue:

kubernetes/kube-openapi#13

https://github.com/argoproj/argo/blob/master/hack/gen-openapi-spec/main.go
https://github.com/argoproj/argo/blob/master/pkg/apis/workflow/v1alpha1/openapi_generated.go#L14:6
https://github.com/kubernetes/kube-openapi/blob/master/cmd/openapi-gen/openapi-gen.go

So I'm working on adding similar stuff to Shipper.

gen-openapi-spec uses the generated openapi_generated.go module that is
generated via the openapi-gen command.

The following commit adds the code to generate openapi_generated.go

Signed-off-by: William Stewart <zoidbergwill@gmail.com>

hack/update-openapigen.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+# PROJECT_ROOT=$(cd $(dirname "$0")/.. ; pwd)
+# CODEGEN_PKG=${PROJECT_ROOT}/vendor/k8s.io/kube-openapi
+# VERSION="v1alpha1"
+# 
+# go run ${CODEGEN_PKG}/cmd/openapi-gen/openapi-gen.go \
+#   --go-header-file ${PROJECT_ROOT}/hack/custom-boilerplate.go.txt \
+#   --input-dirs github.com/bookingcom/shipper/pkg/apis/workflow/${VERSION} \
+#   --output-package github.com/argoproj/argo/pkg/apis/workflow/${VERSION} \
+#   --report-filename pkg/apis/api-rules/violation_exceptions.list \
+#   $@
+# PROJECT_ROOT=$(cd $(dirname "$0")/.. ; pwd)
+# CODEGEN_PKG=${PROJECT_ROOT}/vendor/k8s.io/kube-openapi
+VERSION="v1alpha1"
+
+go run $GOPATH/src/k8s.io/kube-openapi/cmd/openapi-gen/openapi-gen.go \
+  --input-dirs github.com/bookingcom/shipper/pkg/apis/shipper/${VERSION} \
+  --output-package github.com/bookingcom/shipper/pkg/apis/shipper/${VERSION} \
+  --report-filename pkg/apis/api-rules/violation_exceptions.list
+  $@
+

pkg/apis/api-rules/violation_exceptions.list

@@ -0,0 +1,32 @@
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ApplicationList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ApplicationStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ApplicationStatus,History
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,CapacityTargetList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,CapacityTargetSpec,Clusters
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,CapacityTargetStatus,Clusters
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityReport,Breakdown
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityReportBreakdown,Containers
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityReportContainerBreakdown,States
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityStatus,Reports
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterCapacityStatus,SadPods
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterInstallationStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterRequirements,Capabilities
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterRequirements,Regions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterSpec,Capabilities
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ClusterTrafficStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,InstallationTargetList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,InstallationTargetSpec,Clusters
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,InstallationTargetStatus,Clusters
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,PodStatus,Containers
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,PodStatus,InitContainers
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ReleaseList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ReleaseStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,ReleaseStrategyStatus,Conditions
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,RolloutBlockList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,RolloutStrategy,Steps
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,TrafficTargetList,Items
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,TrafficTargetSpec,Clusters
+API rule violation: list_type_missing,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,TrafficTargetStatus,Clusters
+API rule violation: names_match,github.com/bookingcom/shipper/pkg/apis/shipper/v1alpha1,Chart,RepoURL

pkg/apis/shipper/v1alpha1/doc.go

@@ -1,4 +1,5 @@
 // +k8s:deepcopy-gen=package,register
+// +k8s:openapi-gen=true
 
 // Package v1alpha1 is the v1alpha1 version of the API.
 // +groupName=shipper.booking.com