config.go

// Copyright (c) 2021 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file
//
// 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.

package promtail

import (
	"fmt"

	extensionsv1alpha1 "github.com/gardener/gardener/pkg/apis/extensions/v1alpha1"
	"github.com/gardener/gardener/pkg/operation/botanist/component/extensions/operatingsystemconfig/original/components"
	"github.com/gardener/gardener/pkg/utils"
	"gopkg.in/yaml.v3"
	"k8s.io/utils/pointer"
)

const setActiveJournalFileScript = `#!/bin/bash
PERSISTANT_JOURNAL_FILE=/var/log/journal
TEMP_JOURNAL_FILE=/run/log/journal
if [ ! -d "$PERSISTANT_JOURNAL_FILE" ] && [ -d "$TEMP_JOURNAL_FILE" ]; then
	sed -i -e "s|$PERSISTANT_JOURNAL_FILE|$TEMP_JOURNAL_FILE|g" ` + PathPromtailConfig + `
fi`

type config struct {
	Server        server        `yaml:"server"`
	Client        client        `yaml:"client"`
	Positions     positions     `yaml:"positions"`
	ScrapeConfigs scrapeConfigs `yaml:"scrape_configs"`
}

type server struct {
	LogLevel       string `yaml:"log_level,omitempty"`
	HTTPListenPort int    `yaml:"http_listen_port,omitempty"`
}

type client struct {
	Url             string    `yaml:"url"`
	BearerTokenFile string    `yaml:"bearer_token_file"`
	TLSConfig       tlsConfig `yaml:"tls_config"`
}

type tlsConfig struct {
	CAFile     string `yaml:"ca_file,omitempty"`
	ServerName string `yaml:"server_name,omitempty"`
}

type positions struct {
	Filename string `yaml:"filename,omitempty"`
}

type job map[string]interface{}
type scrapeConfigs []job

var defaultConfig = config{
	Server: server{
		LogLevel:       "info",
		HTTPListenPort: PromtailServerPort,
	},
	Client: client{
		Url:             "http://localhost:3100/loki/api/v1/push",
		BearerTokenFile: PathPromtailAuthToken,
		TLSConfig: tlsConfig{
			CAFile: PathPromtailCACert,
		},
	},
	Positions: positions{
		Filename: PromtailPositionFile,
	},
	ScrapeConfigs: scrapeConfigs{
		{
			"job_name": "journal",
			"journal": map[string]interface{}{
				"json":    false,
				"max_age": "12h",
				"path":    "/var/log/journal",
				"labels": map[string]interface{}{
					"job": "systemd-journal",
				},
			},
			"relabel_configs": []map[string]interface{}{
				{
					"source_labels": []string{"__journal__hostname"},
					"regex":         "^localhost$",
					"action":        "drop",
				},
				{
					"source_labels": []string{"__journal__systemd_unit"},
					"target_label":  "unit",
				},
				{
					"source_labels": []string{"__journal__hostname"},
					"target_label":  "nodename",
				},
				{
					"source_labels": []string{"__journal_syslog_identifier"},
					"target_label":  "syslog_identifier",
				},
			},
		},
	},
}

func getPromtailConfiguration(ctx components.Context) (config, error) {
	if ctx.LokiIngress == "" {
		return config{}, fmt.Errorf("loki ingress url is misssing for %s", ctx.ClusterDomain)
	}
	conf := defaultConfig
	conf.Client.Url = "https://" + ctx.LokiIngress + "/loki/api/v1/push"
	conf.Client.TLSConfig.ServerName = ctx.LokiIngress
	return conf, nil
}

func getPromtailConfigurationFile(ctx components.Context) (*extensionsv1alpha1.File, error) {
	conf, err := getPromtailConfiguration(ctx)
	if err != nil {
		return nil, err
	}

	configYaml, err := yaml.Marshal(&conf)
	if err != nil {
		return nil, err
	}

	return &extensionsv1alpha1.File{
		Path:        PathPromtailConfig,
		Permissions: pointer.Int32Ptr(0644),
		Content: extensionsv1alpha1.FileContent{
			Inline: &extensionsv1alpha1.FileContentInline{
				Encoding: "b64",
				Data:     utils.EncodeBase64(configYaml),
			},
		},
	}, nil
}

func getPromtailAuthTokenFile(ctx components.Context) *extensionsv1alpha1.File {
	if len(ctx.PromtailRBACAuthToken) == 0 {
		return nil
	}
	return &extensionsv1alpha1.File{
		Path:        PathPromtailAuthToken,
		Permissions: pointer.Int32Ptr(0644),
		Content: extensionsv1alpha1.FileContent{
			Inline: &extensionsv1alpha1.FileContentInline{
				Encoding: "b64",
				Data:     utils.EncodeBase64([]byte(ctx.PromtailRBACAuthToken)),
			},
		},
	}
}

func getPromtailCAFile(ctx components.Context) *extensionsv1alpha1.File {
	var cABundle []byte
	if ctx.CABundle != nil {
		cABundle = []byte(*ctx.CABundle)
	}
	return &extensionsv1alpha1.File{
		Path:        PathPromtailCACert,
		Permissions: pointer.Int32Ptr(0644),
		Content: extensionsv1alpha1.FileContent{
			Inline: &extensionsv1alpha1.FileContentInline{
				Encoding: "b64",
				Data:     utils.EncodeBase64(cABundle),
			},
		},
	}
}

func setActiveJournalFile(ctx components.Context) *extensionsv1alpha1.File {
	return &extensionsv1alpha1.File{
		Path:        PathSetActiveJournalFileScript,
		Permissions: pointer.Int32Ptr(0644),
		Content: extensionsv1alpha1.FileContent{
			Inline: &extensionsv1alpha1.FileContentInline{
				Encoding: "b64",
				Data:     utils.EncodeBase64([]byte(setActiveJournalFileScript)),
			},
		},
	}
}

func getPromtailUnit(execStartPre, execStartPreConfig, execStart string) *extensionsv1alpha1.Unit {
	return &extensionsv1alpha1.Unit{
		Name:    UnitName,
		Command: pointer.StringPtr("start"),
		Enable:  pointer.BoolPtr(true),
		Content: pointer.StringPtr(`[Unit]
Description=promtail daemon
Documentation=https://grafana.com/docs/loki/latest/clients/promtail/
[Install]
WantedBy=multi-user.target
[Service]
CPUAccounting=yes
MemoryAccounting=yes
CPUQuota=3%
CPUQuotaPeriodSec=1000ms
MemoryMin=29M
MemoryHigh=400M
MemoryMax=800M
MemorySwapMax=0
Restart=always
RestartSec=5
EnvironmentFile=/etc/environment
ExecStartPre=` + execStartPre + `
ExecStartPre=` + execStartPreConfig + `
ExecStart=` + execStart),
	}
}