pkg/controller/kibana/initcontainer/fs_scripts.go

// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
// or more contributor license agreements. Licensed under the Elastic License 2.0;
// you may not use this file except in compliance with the Elastic License 2.0.

package initcontainer

import (
	"bytes"
	"text/template"

	"github.com/elastic/cloud-on-k8s/v3/pkg/controller/kibana/volume"
)

const (
	KibanaInitScriptConfigKey = "init.sh"
)

// templateParams are the parameters used in the initFSScriptTemplate template.
type templateParams struct {
	// ContainerPluginsMountPath is the mount path for plugins
	// within the Kibana container.
	ContainerPluginsMountPath string
	// InitContainerPluginsMountPath is the mount path for plugins
	// within the init container.
	InitContainerPluginsMountPath string
}

var initFsScriptTemplate = template.Must(template.New("").Parse(
	`#!/usr/bin/env bash
set -eux

# compute time in seconds since the given start time
function duration() {
	local start=$1
	end=$(date +%s)
	echo $((end-start))
}

#######################
# Plugins persistence #
#######################

init_plugins_copied_flag={{.InitContainerPluginsMountPath}}/elastic-internal-init-plugins.ok

# Persist the content of plugins/ to a volume, so installed
# plugins files can to be used by the Kibana container.
mv_start=$(date +%s)
if [[ ! -f "${init_plugins_copied_flag}" ]]; then
	if [[ -z "$(ls -A {{.ContainerPluginsMountPath}})" ]]; then
		echo "Empty dir {{.ContainerPluginsMountPath}}"
	else
		echo "Copying {{.ContainerPluginsMountPath}}/* to {{.InitContainerPluginsMountPath}}/"
		# Use "yes" and "-f" as we want the init container to be idempotent and not to fail when executed more than once.
		yes | cp -avf {{.ContainerPluginsMountPath}}/* {{.InitContainerPluginsMountPath}}/
	fi
fi
touch "${init_plugins_copied_flag}"
echo "Files copy duration: $(duration $mv_start) sec."

init_config_initialized_flag=` + volume.InitContainerConfigVolumeMountPath + `/elastic-internal-init-config.ok

if [[ -f "${init_config_initialized_flag}" ]]; then
	echo "Kibana configuration already initialized."
	exit 0
fi

echo "Setup Kibana configuration"

ln -sf ` + volume.InternalConfigVolumeMountPath + `/* ` + volume.InitContainerConfigVolumeMountPath + `/

touch "${init_config_initialized_flag}"
echo "Kibana configuration successfully prepared."
`))

// renderScriptTemplate renders initFsScriptTemplate using the given TemplateParams
func renderScriptTemplate(params templateParams) (string, error) {
	tplBuffer := bytes.Buffer{}
	if err := initFsScriptTemplate.Execute(&tplBuffer, params); err != nil {
		return "", err
	}
	return tplBuffer.String(), nil
}