Add timeout for go generate

This will prevent excessively long go generate runs from occuring in the Build and Push Binary and Container pipelines.
Timeout sends a list of exit codes we can expect if something goes wrong. Here they are used to help provide more information about the failure.
go generate doesn't support a timeout value directly.

Makefile

@@ -88,7 +88,7 @@ discoverycache:
 	$(MAKE) generate
 
 generate:
-	go generate ./...
+	hack/ci-utils/go_generate.sh
 
 generate-guardrails:
 	cd pkg/operator/controllers/guardrails/policies && ./scripts/generate.sh > /dev/null

hack/ci-utils/go_generate.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+
+set -o errexit
+
+# Variables checked for timeout values, defaults used if unset
+soft_timeout="${GO_GENERATE_SOFT_TIMEOUT:-2h}"
+hard_timeout="${GO_GENERATE_HARD_TIMEOUT:-2h}"
+
+if [[ -n $CI ]]; then
+    set -x
+fi
+
+
+declare timeout_exitcode go_generate
+# go generate doesn't support timeout itself, so --preserve-status wouldn't help us as it would simply be the status timeout sent to go.
+go_generate="go generate ./..."
+echo "Running ${go_generate} sending SIGTERM after ${soft_timeout} and SIGKILL after ${hard_timeout}"
+echo "${go_generate}"
+# shellcheck disable=SC2086
+timeout --foreground --kill-after="${hard_timeout}" -v -s SIGTERM "${soft_timeout}" ${go_generate}
+timeout_exitcode=$?
+
+# Capture expected exit codes
+case $timeout_exitcode in
+124)
+    echo "Command ${go_generate} timed out."
+    ;;
+125)
+    echo "The command \"timeout\" failed trying to run ${go_generate}. Note that ${go_generate} did not fail."
+    ;;
+126)
+    echo "Command found but cannot be invoked."
+    ;;
+127)
+    echo "Command not found recieved."
+    ;;
+137)
+    echo "timeout or command recieved kill signal 9) SIGKILL."
+    ;;
+-)
+    echo "Command go generate ./... exited with exit_code code ${-}."
+    ;;
+0)
+    echo "Command ${go_generate} completed successfully, exit code ${timeout_exitcode}."
+    ;;
+*)
+    echo "Unexpected error code received: ${timeout_exitcode}."
+    ;;
+esac
+
+exit "${timeout_exitcode}"