postgres-operator/run_operator_locally.sh

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#!/usr/bin/env bash
#
# Deploy a Postgres Operator to a minikube aka local Kubernetes cluster
# Optionally re-build the operator binary beforehand to test local changes
# Known limitations:
# 1) minikube provides a single node K8s cluster. That is, you will not be able test functions like pod
# migration between multiple nodes locally
# 2) this script configures the operator via configmap, not the operator CRD
# enable unofficial bash strict mode
set -o errexit
set -o nounset
set -o pipefail
IFS=$'\n\t'
readonly PATH_TO_LOCAL_OPERATOR_MANIFEST="/tmp/local-postgres-operator-manifest.yaml"
readonly PATH_TO_PORT_FORWARED_KUBECTL_PID="/tmp/kubectl-port-forward.pid"
readonly PATH_TO_THE_PG_CLUSTER_MANIFEST="/tmp/minimal-postgres-manifest.yaml"
readonly LOCAL_PORT="8080"
readonly OPERATOR_PORT="8080"
# minikube needs time to create resources,
# so the script retries actions until all the resources become available
function retry(){
local -r retry_cmd="$1"
local -r retry_msg="$2"
# Time out after three minutes.
for i in {1..60}; do
if eval "$retry_cmd"; then
return 0
fi
echo "$retry_msg"
sleep 3
done
>2& echo "The command $retry_cmd timed out"
return 1
}
function display_help(){
echo "Usage: $0 [ -r | --rebuild-operator ] [ -h | --help ] [ -n | --deploy-new-operator-image ] [ -t | --deploy-pg-to-namespace-test ]"
}
function clean_up(){
echo "==== CLEAN UP PREVIOUS RUN ==== "
local status
status=$(minikube status --format "{{.Host}}" || true)
if [[ "$status" = "Running" ]] || [[ "$status" = "Stopped" ]]; then
echo "Delete the existing local cluster so that we can cleanly apply resources from scratch..."
minikube delete
fi
if [[ -e "$PATH_TO_LOCAL_OPERATOR_MANIFEST" ]]; then
rm -v "$PATH_TO_LOCAL_OPERATOR_MANIFEST"
fi
# the kubectl process does the port-forwarding between operator and local ports
# we restart the process to bind to the same port again (see end of script)
if [[ -e "$PATH_TO_PORT_FORWARED_KUBECTL_PID" ]]; then
local pid
pid=$( < "$PATH_TO_PORT_FORWARED_KUBECTL_PID")
# the process dies if a minikube stops between two invocations of the script
if kill "$pid" > /dev/null 2>&1; then
echo "Kill the kubectl process responsible for port forwarding for minikube so that we can re-use the same ports for forwarding later..."
fi
rm -v "$PATH_TO_PORT_FORWARED_KUBECTL_PID"
fi
}
function start_minikube(){
echo "==== START MINIKUBE ===="
echo "May take a few minutes ..."
minikube start
kubectl config set-context minikube
echo "==== MINIKUBE STATUS ===="
minikube status
echo ""
}
function build_operator_binary(){
# redirecting stderr greatly reduces non-informative output during normal builds
echo "Build operator binary (stderr redirected to /dev/null)..."
make clean deps local test > /dev/null 2>&1
}
function deploy_self_built_image() {
echo "==== DEPLOY CUSTOM OPERATOR IMAGE ==== "
build_operator_binary
# the fastest way to run a docker image locally is to reuse the docker from minikube
# set docker env vars so that docker can talk to the Docker daemon inside the minikube
eval $(minikube docker-env)
# image tag consists of a git tag or a unique commit prefix
# and the "-dev" suffix if there are uncommited changes in the working dir
local -x TAG
TAG=$(git describe --tags --always --dirty="-dev")
readonly TAG
# build the image
make docker > /dev/null 2>&1
# update the tag in the postgres operator conf
# since the image with this tag already exists on the machine,
# docker should not attempt to fetch it from the registry due to imagePullPolicy
sed -e "s/\(image\:.*\:\).*$/\1$TAG/; s/smoke-tested-//" manifests/postgres-operator.yaml > "$PATH_TO_LOCAL_OPERATOR_MANIFEST"
retry "kubectl apply -f \"$PATH_TO_LOCAL_OPERATOR_MANIFEST\"" "attempt to create $PATH_TO_LOCAL_OPERATOR_MANIFEST resource"
}
function start_operator(){
echo "==== START OPERATOR ===="
echo "Certain operations may be retried multiple times..."
# the order of resource initialization is significant
local file
for file in "configmap.yaml" "operator-service-account-rbac.yaml"
do
retry "kubectl create -f manifests/\"$file\"" "attempt to create $file resource"
done
cp manifests/postgres-operator.yaml $PATH_TO_LOCAL_OPERATOR_MANIFEST
if [[ "$should_build_custom_operator" = true ]]; then # set in main()
deploy_self_built_image
else
retry "kubectl create -f ${PATH_TO_LOCAL_OPERATOR_MANIFEST}" "attempt to create ${PATH_TO_LOCAL_OPERATOR_MANIFEST} resource"
fi
local -r msg="Wait for the postgresql custom resource definition to register..."
local -r cmd="kubectl get crd | grep --quiet 'postgresqls.acid.zalan.do'"
retry "$cmd" "$msg "
}
function forward_ports(){
echo "==== FORWARD OPERATOR PORT $OPERATOR_PORT TO LOCAL PORT $LOCAL_PORT ===="
local operator_pod
operator_pod=$(kubectl get pod -l name=postgres-operator -o jsonpath={.items..metadata.name})
# Spawn `kubectl port-forward` in the background to keep current terminal
# responsive. Hide stdout because otherwise there is a note about each TCP
# connection. Do not hide stderr so port-forward setup errors can be
# debugged. Sometimes the port-forward setup fails because expected k8s
# state isn't achieved yet. Try to detect that case and then run the
# command again (in a finite loop).
for _attempt in {1..20}; do
# Delay between retry attempts. First attempt should already be
# delayed.
echo "soon: invoke kubectl port-forward command (attempt $_attempt)"
sleep 5
# With the --pod-running-timeout=4s argument the process is expected
# to terminate within about that time if the pod isn't ready yet.
kubectl port-forward --pod-running-timeout=4s "$operator_pod" "$LOCAL_PORT":"$OPERATOR_PORT" 1> /dev/null &
_kubectl_pid=$!
_pf_success=true
# A successful `kubectl port-forward` setup can pragmatically be
# detected with a time-based criterion: it is a long-running process if
# successfully set up. If it does not terminate within deadline then
# consider the setup successful. Overall, observe the process for
# roughly 7 seconds. If it terminates before that it's certainly an
# error. If it did not terminate within that time frame then consider
# setup successful.
for ib in {1..7}; do
sleep 1
# Portable and non-blocking test: is process still running?
if kill -s 0 -- "${_kubectl_pid}" >/dev/null 2>&1; then
echo "port-forward process is still running"
else
# port-forward process seems to have terminated, reap zombie
set +e
# `wait` is now expected to be non-blocking, and exits with the
# exit code of pid (first arg).
wait $_kubectl_pid
_kubectl_rc=$?
set -e
echo "port-forward process terminated with exit code ${_kubectl_rc}"
_pf_success=false
break
fi
done
if [ ${_pf_success} = true ]; then
echo "port-forward setup seems successful. leave retry loop."
break
fi
done
if [ "${_pf_success}" = false ]; then
echo "port-forward setup failed after retrying. exit."
exit 1
fi
echo "${_kubectl_pid}" > "$PATH_TO_PORT_FORWARED_KUBECTL_PID"
}
function check_health(){
echo "==== RUN HEALTH CHECK ==== "
local -r check_cmd="curl --location --silent --output /dev/null http://127.0.0.1:$LOCAL_PORT/clusters"
local -r check_msg="Wait for port forwarding to take effect"
echo "Command for checking: $check_cmd"
if retry "$check_cmd" "$check_msg"; then
echo "==== SUCCESS: OPERATOR IS RUNNING ==== "
echo "To stop it cleanly, run 'minikube delete'"
else
>2& echo "==== FAILURE: OPERATOR DID NOT START OR PORT FORWARDING DID NOT WORK"
exit 1
fi
}
function submit_postgresql_manifest(){
echo "==== SUBMIT MINIMAL POSTGRES MANIFEST ==== "
local namespace="default"
cp manifests/minimal-postgres-manifest.yaml $PATH_TO_THE_PG_CLUSTER_MANIFEST
if $should_deploy_pg_to_namespace_test; then
kubectl create namespace test
namespace="test"
sed --in-place 's/namespace: default/namespace: test/' $PATH_TO_THE_PG_CLUSTER_MANIFEST
fi
kubectl create -f $PATH_TO_THE_PG_CLUSTER_MANIFEST
echo "The operator will create the PG cluster with minimal manifest $PATH_TO_THE_PG_CLUSTER_MANIFEST in the ${namespace} namespace"
}
function main(){
if ! [[ $(basename "$PWD") == "postgres-operator" ]]; then
echo "Please execute the script only from the root directory of the Postgres Operator repo."
exit 1
fi
trap "echo 'If you observe issues with minikube VM not starting/not proceeding, consider deleting the .minikube dir and/or rebooting before re-running the script'" EXIT
local should_build_custom_operator=false
local should_deploy_pg_to_namespace_test=false
local should_replace_operator_image=false
while true
do
# if the 1st param is unset, use the empty string as a default value
case "${1:-}" in
-h | --help)
display_help
exit 0
;;
-r | --rebuild-operator) # with minikube restart
should_build_custom_operator=true
break
;;
-n | --deploy-new-operator-image) # without minikube restart that takes minutes
should_replace_operator_image=true
break
;;
-t | --deploy-pg-to-namespace-test) # to test multi-namespace support locally
should_deploy_pg_to_namespace_test=true
break
;;
*) break
;;
esac
done
if ${should_replace_operator_image}; then
deploy_self_built_image
exit 0
fi
clean_up
start_minikube
start_operator
submit_postgresql_manifest
forward_ports
check_health
exit 0
}
main "$@"