Use Go modules when generating code

We used to use `dep` to download "k8s.io/code-generator" and call it within the vendor directory. Go does not provide a way to do that with a single module, so follow the lead of "sigs.k8s.io/kubebuilder" and install the binary using another, temporary module when it's not already on the PATH. Issue: [ch9453] See: c8f13d3

Author: cbandy

Makefile

@@ -245,8 +245,7 @@ release: linuxpgo macpgo winpgo
 cp $(PGOROOT)/examples/pgo-bash-completion $(RELTMPDIR)
 tar czvf $(RELFILE) -C $(RELTMPDIR) .
 
-update-codegen:
-$(PGOROOT)/hack/update-codegen.sh
+generate: generate-client
 
-verify-codegen:
-$(PGOROOT)/hack/verify-codegen.sh
+generate-client:
+./hack/generate-clientset.sh

docs/content/contributing/developer-setup.md

@@ -62,16 +62,12 @@ Code generation is leveraged to generate the clients and informers utilized to i
 various [Custom Resources](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/)
 (e.g. `pgclusters`) comprising the PostgreSQL Operator declarative API. Code generation is provided
 by the [Kubernetes code-generator project](https://github.com/kubernetes/code-generator),
-and the following two `Make` targets are included within the PostgreSQL Operator project to both
-determine if any generated code within the project requires an update, and then update that code
+and the following Make target is included within the PostgreSQL Operator project to update that code
 as needed:
 
 ```bash
-# Check to see if an update to generated code is needed:
-make verify-codegen
-
 # Update any generated code:
-make update-codegen
+make generate
 ```
 
 Therefore, in the event that a Custom Resource defined within the PostgreSQL Operator API

hack/generate-clientset.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+# Copyright 2020 Crunchy Data Solutions, Inc.
+# 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.
+
+set -eu
+
+# Find the Go install path.
+[ "${GOBIN:-}" ] || GOBIN="$(go env GOBIN)"
+[ "${GOBIN:-}" ] || GOBIN="$(go env GOPATH)/bin"
+
+# Create and cleanup a temporary directory.
+DIR="$(mktemp -d)"
+trap "rm -rf '$DIR'" EXIT
+
+# Find `client-gen` on the current PATH or install it to the Go install path.
+tool="$(command -v client-gen || true)"
+[ -n "$tool" ] || tool="$GOBIN/client-gen"
+[ -x "$tool" ] || ( cd "$DIR" && go mod init tmp && go get 'k8s.io/code-generator/cmd/client-gen@v0.17.9' )
+
+# Generate ./pkg/generated/clientset/versioned from objects defined in ./pkg/apis/crunchydata.com/...
+
+target_directory='pkg/generated/clientset'
+target_package="$(go list -m)/${target_directory}"
+
+"$tool" \
+--clientset-name='versioned' \
+--go-header-file='hack/boilerplate.go.txt' \
+--input-base='' --input="$(go list ./pkg/apis/crunchydata.com/... | paste -sd, -)" \
+--output-base="$DIR" --output-package="$target_package" \
+
+[ ! -d "$target_directory" ] || rm -r "$target_directory"
+mv "${DIR}/${target_package}" "${target_directory}"