config.go

/*
Copyright 2017 The Kubernetes Authors.

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 config knows how to read and parse config.yaml.
// It also implements an agent to read the secrets.
package config

import (
	"bytes"
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"text/template"
	"time"

	"github.com/ghodss/yaml"
	"github.com/sirupsen/logrus"
	cron "gopkg.in/robfig/cron.v2"
	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/util/sets"

	"k8s.io/test-infra/prow/config/org"
	"k8s.io/test-infra/prow/github"
	"k8s.io/test-infra/prow/kube"
	"k8s.io/test-infra/prow/pod-utils/decorate"
	"k8s.io/test-infra/prow/pod-utils/downwardapi"
)

// Config is a read-only snapshot of the config.
type Config struct {
	JobConfig
	ProwConfig
}

// JobConfig is config for all prow jobs
type JobConfig struct {
	// Presets apply to all job types.
	Presets []Preset `json:"presets,omitempty"`
	// Full repo name (such as "kubernetes/kubernetes") -> list of jobs.
	Presubmits  map[string][]Presubmit  `json:"presubmits,omitempty"`
	Postsubmits map[string][]Postsubmit `json:"postsubmits,omitempty"`

	// Periodics are not associated with any repo.
	Periodics []Periodic `json:"periodics,omitempty"`
}

// ProwConfig is config for all prow controllers
type ProwConfig struct {
	Tide             Tide                  `json:"tide,omitempty"`
	Plank            Plank                 `json:"plank,omitempty"`
	Sinker           Sinker                `json:"sinker,omitempty"`
	Deck             Deck                  `json:"deck,omitempty"`
	BranchProtection BranchProtection      `json:"branch-protection,omitempty"`
	Orgs             map[string]org.Config `json:"orgs,omitempty"`
	Gerrit           Gerrit                `json:"gerrit,omitempty"`

	// TODO: Move this out of the main config.
	JenkinsOperators []JenkinsOperator `json:"jenkins_operators,omitempty"`

	// ProwJobNamespace is the namespace in the cluster that prow
	// components will use for looking up ProwJobs. The namespace
	// needs to exist and will not be created by prow.
	// Defaults to "default".
	ProwJobNamespace string `json:"prowjob_namespace,omitempty"`
	// PodNamespace is the namespace in the cluster that prow
	// components will use for looking up Pods owned by ProwJobs.
	// The namespace needs to exist and will not be created by prow.
	// Defaults to "default".
	PodNamespace string `json:"pod_namespace,omitempty"`

	// LogLevel enables dynamically updating the log level of the
	// standard logger that is used by all prow components.
	//
	// Valid values:
	//
	// "debug", "info", "warn", "warning", "error", "fatal", "panic"
	//
	// Defaults to "info".
	LogLevel string `json:"log_level,omitempty"`

	// PushGateway is a prometheus push gateway.
	PushGateway PushGateway `json:"push_gateway,omitempty"`

	// OwnersDirBlacklist is used to configure which directories to ignore when
	// searching for OWNERS{,_ALIAS} files in a repo.
	OwnersDirBlacklist OwnersDirBlacklist `json:"owners_dir_blacklist,omitempty"`
}

// OwnersDirBlacklist is used to configure which directories to ignore when
// searching for OWNERS{,_ALIAS} files in a repo.
type OwnersDirBlacklist struct {
	// Repos configures a directory blacklist per repo (or org)
	Repos map[string][]string `json:"repos"`
	// Default configures a default blacklist for repos (or orgs) not
	// specifically configured
	Default []string `json:"default"`
}

// PushGateway is a prometheus push gateway.
type PushGateway struct {
	// Endpoint is the location of the prometheus pushgateway
	// where prow will push metrics to.
	Endpoint string `json:"endpoint,omitempty"`
	// IntervalString compiles into Interval at load time.
	IntervalString string `json:"interval,omitempty"`
	// Interval specifies how often prow will push metrics
	// to the pushgateway. Defaults to 1m.
	Interval time.Duration `json:"-"`
}

// Controller holds configuration applicable to all agent-specific
// prow controllers.
type Controller struct {
	// JobURLTemplateString compiles into JobURLTemplate at load time.
	JobURLTemplateString string `json:"job_url_template,omitempty"`
	// JobURLTemplate is compiled at load time from JobURLTemplateString. It
	// will be passed a kube.ProwJob and is used to set the URL for the
	// "Details" link on GitHub as well as the link from deck.
	JobURLTemplate *template.Template `json:"-"`

	// ReportTemplateString compiles into ReportTemplate at load time.
	ReportTemplateString string `json:"report_template,omitempty"`
	// ReportTemplate is compiled at load time from ReportTemplateString. It
	// will be passed a kube.ProwJob and can provide an optional blurb below
	// the test failures comment.
	ReportTemplate *template.Template `json:"-"`

	// MaxConcurrency is the maximum number of tests running concurrently that
	// will be allowed by the controller. 0 implies no limit.
	MaxConcurrency int `json:"max_concurrency,omitempty"`

	// MaxGoroutines is the maximum number of goroutines spawned inside the
	// controller to handle tests. Defaults to 20. Needs to be a positive
	// number.
	MaxGoroutines int `json:"max_goroutines,omitempty"`

	// AllowCancellations enables aborting presubmit jobs for commits that
	// have been superseded by newer commits in Github pull requests.
	AllowCancellations bool `json:"allow_cancellations,omitempty"`
}

// Plank is config for the plank controller.
type Plank struct {
	Controller `json:",inline"`
	// PodPendingTimeoutString compiles into PodPendingTimeout at load time.
	PodPendingTimeoutString string `json:"pod_pending_timeout,omitempty"`
	// PodPendingTimeout is after how long the controller will perform a garbage
	// collection on pending pods. Defaults to one day.
	PodPendingTimeout time.Duration `json:"-"`
	// DefaultDecorationConfig are defaults for shared fields for ProwJobs
	// that request to have their PodSpecs decorated
	DefaultDecorationConfig *kube.DecorationConfig `json:"default_decoration_config,omitempty"`
}

// Gerrit is config for the gerrit controller.
type Gerrit struct {
	// TickInterval is how often we do a sync with binded gerrit instance
	TickIntervalString string        `json:"tick_interval,omitempty"`
	TickInterval       time.Duration `json:"-"`
	// RateLimit defines how many changes to query per gerrit API call
	// default is 5
	RateLimit int `json:"ratelimit,omitempty"`
}

// JenkinsOperator is config for the jenkins-operator controller.
type JenkinsOperator struct {
	Controller `json:",inline"`
	// LabelSelectorString compiles into LabelSelector at load time.
	// If set, this option needs to match --label-selector used by
	// the desired jenkins-operator. This option is considered
	// invalid when provided with a single jenkins-operator config.
	//
	// For label selector syntax, see below:
	// https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
	LabelSelectorString string `json:"label_selector,omitempty"`
	// LabelSelector is used so different jenkins-operator replicas
	// can use their own configuration.
	LabelSelector labels.Selector `json:"-"`
}

// Sinker is config for the sinker controller.
type Sinker struct {
	// ResyncPeriodString compiles into ResyncPeriod at load time.
	ResyncPeriodString string `json:"resync_period,omitempty"`
	// ResyncPeriod is how often the controller will perform a garbage
	// collection. Defaults to one hour.
	ResyncPeriod time.Duration `json:"-"`
	// MaxProwJobAgeString compiles into MaxProwJobAge at load time.
	MaxProwJobAgeString string `json:"max_prowjob_age,omitempty"`
	// MaxProwJobAge is how old a ProwJob can be before it is garbage-collected.
	// Defaults to one week.
	MaxProwJobAge time.Duration `json:"-"`
	// MaxPodAgeString compiles into MaxPodAge at load time.
	MaxPodAgeString string `json:"max_pod_age,omitempty"`
	// MaxPodAge is how old a Pod can be before it is garbage-collected.
	// Defaults to one day.
	MaxPodAge time.Duration `json:"-"`
}

// Deck holds config for deck.
type Deck struct {
	// TideUpdatePeriodString compiles into TideUpdatePeriod at load time.
	TideUpdatePeriodString string `json:"tide_update_period,omitempty"`
	// TideUpdatePeriod specifies how often Deck will fetch status from Tide. Defaults to 10s.
	TideUpdatePeriod time.Duration `json:"-"`
	// HiddenRepos is a list of orgs and/or repos that should not be displayed by Deck.
	HiddenRepos []string `json:"hidden_repos,omitempty"`
	// ExternalAgentLogs ensures external agents can expose
	// their logs in prow.
	ExternalAgentLogs []ExternalAgentLog `json:"external_agent_logs,omitempty"`
	// Branding of the frontend
	Branding *Branding `json:"branding,omitempty"`
}

// ExternalAgentLog ensures an external agent like Jenkins can expose
// its logs in prow.
type ExternalAgentLog struct {
	// Agent is an external prow agent that supports exposing
	// logs via deck.
	Agent string `json:"agent,omitempty"`
	// SelectorString compiles into Selector at load time.
	SelectorString string `json:"selector,omitempty"`
	// Selector can be used in prow deployments where the workload has
	// been sharded between controllers of the same agent. For more info
	// see https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
	Selector labels.Selector `json:"-"`
	// URLTemplateString compiles into URLTemplate at load time.
	URLTemplateString string `json:"url_template,omitempty"`
	// URLTemplate is compiled at load time from URLTemplateString. It
	// will be passed a kube.ProwJob and the generated URL should provide
	// logs for the ProwJob.
	URLTemplate *template.Template `json:"-"`
}

// Branding holds branding configuration for deck.
type Branding struct {
	// Logo is the location of the logo that will be loaded in deck.
	Logo string `json:"logo,omitempty"`
	// Favicon is the location of the favicon that will be loaded in deck.
	Favicon string `json:"favicon,omitempty"`
	// BackgroundColor is the color of the background.
	BackgroundColor string `json:"background_color,omitempty"`
	// HeaderColor is the color of the header.
	HeaderColor string `json:"header_color,omitempty"`
}

// Load loads and parses the config at path.
func Load(prowConfig, jobConfig string) (c *Config, err error) {
	// we never want config loading to take down the prow components
	defer func() {
		if r := recover(); r != nil {
			c, err = nil, fmt.Errorf("panic loading config: %v", r)
		}
	}()
	c, err = loadConfig(prowConfig, jobConfig)
	if err != nil {
		return nil, err
	}
	if err := c.finalizeJobConfig(); err != nil {
		return nil, err
	}
	if err := c.validateJobConfig(); err != nil {
		return nil, err
	}
	return c, nil
}

// loadConfig loads one or multiple config files and returns a config object.
func loadConfig(prowConfig, jobConfig string) (*Config, error) {
	stat, err := os.Stat(prowConfig)
	if err != nil {
		return nil, err
	}

	if stat.IsDir() {
		return nil, fmt.Errorf("prowConfig cannot be a dir - %s", prowConfig)
	}

	var nc Config
	if err := yamlToConfig(prowConfig, &nc); err != nil {
		return nil, err
	}
	if err := parseProwConfig(&nc); err != nil {
		return nil, err
	}

	// TODO(krzyzacy): temporary allow empty jobconfig
	//                 also temporary allow job config in prow config
	if jobConfig == "" {
		return &nc, nil
	}

	stat, err = os.Stat(jobConfig)
	if err != nil {
		return nil, err
	}

	if !stat.IsDir() {
		// still support a single file
		var jc JobConfig
		if err := yamlToConfig(jobConfig, &jc); err != nil {
			return nil, err
		}
		if err := nc.mergeJobConfig(jc); err != nil {
			return nil, err
		}
		return &nc, nil
	}

	// we need to ensure all config files have unique basenames,
	// since updateconfig plugin will use basename as a key in the configmap
	uniqueBasenames := sets.String{}

	err = filepath.Walk(jobConfig, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			logrus.WithError(err).Errorf("walking path %q.", path)
			// bad file should not stop us from parsing the directory
			return nil
		}

		if strings.HasPrefix(info.Name(), "..") {
			// kubernetes volumes also include files we
			// should not look be looking into for keys
			if info.IsDir() {
				return filepath.SkipDir
			}
			return nil
		}

		if filepath.Ext(path) != ".yaml" {
			return nil
		}

		if info.IsDir() {
			return nil
		}

		base := filepath.Base(path)
		if uniqueBasenames.Has(base) {
			return fmt.Errorf("duplicated basename is not allowed: %s", base)
		}
		uniqueBasenames.Insert(base)

		var subConfig JobConfig
		if err := yamlToConfig(path, &subConfig); err != nil {
			return err
		}
		return nc.mergeJobConfig(subConfig)
	})

	if err != nil {
		return nil, err
	}

	return &nc, nil
}

// LoadSecrets loads multiple paths of secrets and add them in a map.
func LoadSecrets(paths []string) (map[string][]byte, error) {
	secretsMap := make(map[string][]byte, len(paths))

	for _, path := range paths {
		secretValue, err := LoadSingleSecret(path)
		if err != nil {
			return nil, err
		}
		secretsMap[path] = secretValue
	}
	return secretsMap, nil
}

// LoadSingleSecret reads and returns the value of a single file.
func LoadSingleSecret(path string) ([]byte, error) {
	b, err := ioutil.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("error reading %s: %v", path, err)
	}
	return bytes.TrimSpace(b), nil
}

// yamlToConfig converts a yaml file into a Config object
func yamlToConfig(path string, nc interface{}) error {
	b, err := ioutil.ReadFile(path)
	if err != nil {
		return fmt.Errorf("error reading %s: %v", path, err)
	}
	if err := yaml.Unmarshal(b, nc); err != nil {
		return fmt.Errorf("error unmarshaling %s: %v", path, err)
	}
	return nil
}

// mergeConfig merges two JobConfig together
// It will try to merge:
//	- Presubmits
//	- Postsubmits
// 	- Periodics
//	- PodPresets
func (c *Config) mergeJobConfig(jc JobConfig) error {
	// Merge everything
	// *** Presets ***
	c.Presets = append(c.Presets, jc.Presets...)

	// validate no duplicated presets
	validLabels := map[string]string{}
	for _, preset := range c.Presets {
		for label, val := range preset.Labels {
			if _, ok := validLabels[label]; ok {
				return fmt.Errorf("duplicated preset label : %s", label)
			}
			validLabels[label] = val
		}
	}

	// *** Periodics ***
	c.Periodics = append(c.Periodics, jc.Periodics...)

	// *** Presubmits ***
	if c.Presubmits == nil {
		c.Presubmits = make(map[string][]Presubmit)
	}
	for repo, jobs := range jc.Presubmits {
		c.Presubmits[repo] = append(c.Presubmits[repo], jobs...)
	}

	// *** Postsubmits ***
	if c.Postsubmits == nil {
		c.Postsubmits = make(map[string][]Postsubmit)
	}
	for repo, jobs := range jc.Postsubmits {
		c.Postsubmits[repo] = append(c.Postsubmits[repo], jobs...)
	}

	return nil
}

func setPresubmitDecorationDefaults(c *Config, ps *Presubmit) {
	if ps.Decorate {
		ps.DecorationConfig = setDecorationDefaults(ps.DecorationConfig, c.Plank.DefaultDecorationConfig)
	}

	for i := range ps.RunAfterSuccess {
		setPresubmitDecorationDefaults(c, &ps.RunAfterSuccess[i])
	}
}

func setPostsubmitDecorationDefaults(c *Config, ps *Postsubmit) {
	if ps.Decorate {
		ps.DecorationConfig = setDecorationDefaults(ps.DecorationConfig, c.Plank.DefaultDecorationConfig)
	}

	for i := range ps.RunAfterSuccess {
		setPostsubmitDecorationDefaults(c, &ps.RunAfterSuccess[i])
	}
}

func setPeriodicDecorationDefaults(c *Config, ps *Periodic) {
	if ps.Decorate {
		ps.DecorationConfig = setDecorationDefaults(ps.DecorationConfig, c.Plank.DefaultDecorationConfig)
	}

	for i := range ps.RunAfterSuccess {
		setPeriodicDecorationDefaults(c, &ps.RunAfterSuccess[i])
	}
}

// finalizeJobConfig mutates and fixes entries for jobspecs
func (c *Config) finalizeJobConfig() error {
	if c.decorationRequested() {
		if c.Plank.DefaultDecorationConfig == nil {
			return errors.New("no default decoration config provided for plank")
		}
		if c.Plank.DefaultDecorationConfig.UtilityImages == nil {
			return errors.New("no default decoration image pull specs provided for plank")
		}
		if c.Plank.DefaultDecorationConfig.GCSConfiguration == nil {
			return errors.New("no default GCS decoration config provided for plank")
		}
		if c.Plank.DefaultDecorationConfig.GCSCredentialsSecret == "" {
			return errors.New("no default GCS credentials secret provided for plank")
		}

		for _, vs := range c.Presubmits {
			for i := range vs {
				setPresubmitDecorationDefaults(c, &vs[i])
			}
		}

		for _, js := range c.Postsubmits {
			for i := range js {
				setPostsubmitDecorationDefaults(c, &js[i])
			}
		}

		for i := range c.Periodics {
			setPeriodicDecorationDefaults(c, &c.Periodics[i])
		}
	}

	// Ensure that regexes are valid.
	for _, vs := range c.Presubmits {
		if err := SetPresubmitRegexes(vs); err != nil {
			return fmt.Errorf("could not set regex: %v", err)
		}
	}
	for _, js := range c.Postsubmits {
		if err := SetPostsubmitRegexes(js); err != nil {
			return fmt.Errorf("could not set regex: %v", err)
		}
	}

	for _, v := range c.AllPresubmits(nil) {
		if err := resolvePresets(v.Name, v.Labels, v.Spec, c.Presets); err != nil {
			return err
		}
	}

	for _, v := range c.AllPostsubmits(nil) {
		if err := resolvePresets(v.Name, v.Labels, v.Spec, c.Presets); err != nil {
			return err
		}
	}

	for _, v := range c.AllPeriodics() {
		if err := resolvePresets(v.Name, v.Labels, v.Spec, c.Presets); err != nil {
			return err
		}
	}

	return nil
}

// validateJobConfig validates if all the jobspecs/presets are valid
// if you are mutating the jobs, please add it to finalizeJobConfig above
func (c *Config) validateJobConfig() error {
	type orgRepoJobName struct {
		orgRepo, jobName string
	}

	// Validate presubmits.
	// Checking that no duplicate job in prow config exists on the same org / repo / branch.
	validPresubmits := map[orgRepoJobName][]Presubmit{}
	for repo, jobs := range c.Presubmits {
		for _, job := range listPresubmits(jobs) {
			repoJobName := orgRepoJobName{repo, job.Name}
			for _, existingJob := range validPresubmits[repoJobName] {
				if existingJob.Brancher.Intersects(job.Brancher) {
					return fmt.Errorf("duplicated presubmit job: %s", job.Name)
				}
			}
			validPresubmits[repoJobName] = append(validPresubmits[repoJobName], job)
		}
	}

	for _, v := range c.AllPresubmits(nil) {
		if err := validateAgent(v.Name, v.Agent, v.Spec, v.DecorationConfig); err != nil {
			return err
		}
		// Ensure max_concurrency is non-negative.
		if v.MaxConcurrency < 0 {
			return fmt.Errorf("job %s jas invalid max_concurrency (%d), it needs to be a non-negative number", v.Name, v.MaxConcurrency)
		}
		if err := validatePodSpec(v.Name, kube.PresubmitJob, v.Spec); err != nil {
			return err
		}
		if err := validateLabels(v.Name, v.Labels); err != nil {
			return err
		}
		if err := validateTriggering(v); err != nil {
			return err
		}
	}

	// Validate postsubmits.
	// Checking that no duplicate job in prow config exists on the same org / repo / branch.
	validPostsubmits := map[orgRepoJobName][]Postsubmit{}
	for repo, jobs := range c.Postsubmits {
		for _, job := range listPostsubmits(jobs) {
			repoJobName := orgRepoJobName{repo, job.Name}
			for _, existingJob := range validPostsubmits[repoJobName] {
				if existingJob.Brancher.Intersects(job.Brancher) {
					return fmt.Errorf("duplicated postsubmit job: %s", job.Name)
				}
			}
			validPostsubmits[repoJobName] = append(validPostsubmits[repoJobName], job)
		}
	}

	for _, j := range c.AllPostsubmits(nil) {
		if err := validateAgent(j.Name, j.Agent, j.Spec, j.DecorationConfig); err != nil {
			return err
		}
		// Ensure max_concurrency is non-negative.
		if j.MaxConcurrency < 0 {
			return fmt.Errorf("job %s jas invalid max_concurrency (%d), it needs to be a non-negative number", j.Name, j.MaxConcurrency)
		}
		if err := validatePodSpec(j.Name, kube.PostsubmitJob, j.Spec); err != nil {
			return err
		}
		if err := validateLabels(j.Name, j.Labels); err != nil {
			return err
		}
	}

	// validate no duplicated periodics
	validPeriodics := sets.NewString()
	// Ensure that the periodic durations are valid and specs exist.
	for _, p := range c.AllPeriodics() {
		if validPeriodics.Has(p.Name) {
			return fmt.Errorf("duplicated periodic job : %s", p.Name)
		}
		validPeriodics.Insert(p.Name)
		if err := validateAgent(p.Name, p.Agent, p.Spec, p.DecorationConfig); err != nil {
			return err
		}
		if err := validatePodSpec(p.Name, kube.PeriodicJob, p.Spec); err != nil {
			return err
		}
		if err := validateLabels(p.Name, p.Labels); err != nil {
			return err
		}
	}
	// Set the interval on the periodic jobs. It doesn't make sense to do this
	// for child jobs.
	for j, p := range c.Periodics {
		if p.Cron != "" && p.Interval != "" {
			return fmt.Errorf("cron and interval cannot be both set in periodic %s", p.Name)
		} else if p.Cron == "" && p.Interval == "" {
			return fmt.Errorf("cron and interval cannot be both empty in periodic %s", p.Name)
		} else if p.Cron != "" {
			if _, err := cron.Parse(p.Cron); err != nil {
				return fmt.Errorf("invalid cron string %s in periodic %s: %v", p.Cron, p.Name, err)
			}
		} else {
			d, err := time.ParseDuration(c.Periodics[j].Interval)
			if err != nil {
				return fmt.Errorf("cannot parse duration for %s: %v", c.Periodics[j].Name, err)
			}
			c.Periodics[j].interval = d
		}
	}

	return nil
}

func parseProwConfig(c *Config) error {
	if err := ValidateController(&c.Plank.Controller); err != nil {
		return fmt.Errorf("validating plank config: %v", err)
	}

	if c.Plank.PodPendingTimeoutString == "" {
		c.Plank.PodPendingTimeout = 24 * time.Hour
	} else {
		podPendingTimeout, err := time.ParseDuration(c.Plank.PodPendingTimeoutString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for plank.pod_pending_timeout: %v", err)
		}
		c.Plank.PodPendingTimeout = podPendingTimeout
	}

	if c.Gerrit.TickIntervalString == "" {
		c.Gerrit.TickInterval = time.Minute
	} else {
		tickInterval, err := time.ParseDuration(c.Gerrit.TickIntervalString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for c.gerrit.tick_interval: %v", err)
		}
		c.Gerrit.TickInterval = tickInterval
	}

	if c.Gerrit.RateLimit == 0 {
		c.Gerrit.RateLimit = 5
	}

	for i := range c.JenkinsOperators {
		if err := ValidateController(&c.JenkinsOperators[i].Controller); err != nil {
			return fmt.Errorf("validating jenkins_operators config: %v", err)
		}
		sel, err := labels.Parse(c.JenkinsOperators[i].LabelSelectorString)
		if err != nil {
			return fmt.Errorf("invalid jenkins_operators.label_selector option: %v", err)
		}
		c.JenkinsOperators[i].LabelSelector = sel
		// TODO: Invalidate overlapping selectors more
		if len(c.JenkinsOperators) > 1 && c.JenkinsOperators[i].LabelSelectorString == "" {
			return errors.New("selector overlap: cannot use an empty label_selector with multiple selectors")
		}
		if len(c.JenkinsOperators) == 1 && c.JenkinsOperators[0].LabelSelectorString != "" {
			return errors.New("label_selector is invalid when used for a single jenkins-operator")
		}
	}

	for i, agentToTmpl := range c.Deck.ExternalAgentLogs {
		urlTemplate, err := template.New(agentToTmpl.Agent).Parse(agentToTmpl.URLTemplateString)
		if err != nil {
			return fmt.Errorf("parsing template for agent %q: %v", agentToTmpl.Agent, err)
		}
		c.Deck.ExternalAgentLogs[i].URLTemplate = urlTemplate
		// we need to validate selectors used by deck since these are not
		// sent to the api server.
		s, err := labels.Parse(c.Deck.ExternalAgentLogs[i].SelectorString)
		if err != nil {
			return fmt.Errorf("error parsing selector %q: %v", c.Deck.ExternalAgentLogs[i].SelectorString, err)
		}
		c.Deck.ExternalAgentLogs[i].Selector = s
	}

	if c.Deck.TideUpdatePeriodString == "" {
		c.Deck.TideUpdatePeriod = time.Second * 10
	} else {
		period, err := time.ParseDuration(c.Deck.TideUpdatePeriodString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for deck.tide_update_period: %v", err)
		}
		c.Deck.TideUpdatePeriod = period
	}

	if c.PushGateway.IntervalString == "" {
		c.PushGateway.Interval = time.Minute
	} else {
		interval, err := time.ParseDuration(c.PushGateway.IntervalString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for push_gateway.interval: %v", err)
		}
		c.PushGateway.Interval = interval
	}

	if c.Sinker.ResyncPeriodString == "" {
		c.Sinker.ResyncPeriod = time.Hour
	} else {
		resyncPeriod, err := time.ParseDuration(c.Sinker.ResyncPeriodString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for sinker.resync_period: %v", err)
		}
		c.Sinker.ResyncPeriod = resyncPeriod
	}

	if c.Sinker.MaxProwJobAgeString == "" {
		c.Sinker.MaxProwJobAge = 7 * 24 * time.Hour
	} else {
		maxProwJobAge, err := time.ParseDuration(c.Sinker.MaxProwJobAgeString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for max_prowjob_age: %v", err)
		}
		c.Sinker.MaxProwJobAge = maxProwJobAge
	}

	if c.Sinker.MaxPodAgeString == "" {
		c.Sinker.MaxPodAge = 24 * time.Hour
	} else {
		maxPodAge, err := time.ParseDuration(c.Sinker.MaxPodAgeString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for max_pod_age: %v", err)
		}
		c.Sinker.MaxPodAge = maxPodAge
	}

	if c.Tide.SyncPeriodString == "" {
		c.Tide.SyncPeriod = time.Minute
	} else {
		period, err := time.ParseDuration(c.Tide.SyncPeriodString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for tide.sync_period: %v", err)
		}
		c.Tide.SyncPeriod = period
	}
	if c.Tide.StatusUpdatePeriodString == "" {
		c.Tide.StatusUpdatePeriod = c.Tide.SyncPeriod
	} else {
		period, err := time.ParseDuration(c.Tide.StatusUpdatePeriodString)
		if err != nil {
			return fmt.Errorf("cannot parse duration for tide.status_update_period: %v", err)
		}
		c.Tide.StatusUpdatePeriod = period
	}

	if c.Tide.MaxGoroutines == 0 {
		c.Tide.MaxGoroutines = 20
	}
	if c.Tide.MaxGoroutines <= 0 {
		return fmt.Errorf("tide has invalid max_goroutines (%d), it needs to be a positive number", c.Tide.MaxGoroutines)
	}

	for name, method := range c.Tide.MergeType {
		if method != github.MergeMerge &&
			method != github.MergeRebase &&
			method != github.MergeSquash {
			return fmt.Errorf("merge type %q for %s is not a valid type", method, name)
		}
	}

	for i, tq := range c.Tide.Queries {
		if err := tq.Validate(); err != nil {
			return fmt.Errorf("tide query (index %d) is invalid: %v", i, err)
		}
	}

	if c.ProwJobNamespace == "" {
		c.ProwJobNamespace = "default"
	}
	if c.PodNamespace == "" {
		c.PodNamespace = "default"
	}

	if c.LogLevel == "" {
		c.LogLevel = "info"
	}
	lvl, err := logrus.ParseLevel(c.LogLevel)
	if err != nil {
		return err
	}
	logrus.SetLevel(lvl)

	return nil
}

func (c *JobConfig) decorationRequested() bool {
	for _, vs := range c.Presubmits {
		for i := range vs {
			if vs[i].Decorate {
				return true
			}
		}
	}

	for _, js := range c.Postsubmits {
		for i := range js {
			if js[i].Decorate {
				return true
			}
		}
	}

	for i := range c.Periodics {
		if c.Periodics[i].Decorate {
			return true
		}
	}

	return false
}

func setDecorationDefaults(provided, defaults *kube.DecorationConfig) *kube.DecorationConfig {
	merged := &kube.DecorationConfig{}
	if provided != nil {
		merged = provided
	}

	if merged.Timeout == 0 {
		merged.Timeout = defaults.Timeout
	}
	if merged.GracePeriod == 0 {
		merged.GracePeriod = defaults.GracePeriod
	}
	if merged.UtilityImages == nil {
		merged.UtilityImages = defaults.UtilityImages
	}
	if merged.GCSConfiguration == nil {
		merged.GCSConfiguration = defaults.GCSConfiguration
	}
	if merged.GCSCredentialsSecret == "" {
		merged.GCSCredentialsSecret = defaults.GCSCredentialsSecret
	}
	if len(merged.SSHKeySecrets) == 0 {
		merged.SSHKeySecrets = defaults.SSHKeySecrets
	}

	return merged
}

func validateLabels(name string, labels map[string]string) error {
	for label := range labels {
		for _, prowLabel := range decorate.Labels() {
			if label == prowLabel {
				return fmt.Errorf("job %s attempted to set Prow-controlled label %s to %s", name, label, labels[label])
			}
		}
	}
	return nil
}

func validateAgent(name, agent string, spec *v1.PodSpec, config *kube.DecorationConfig) error {
	// Ensure that k8s jobs have a pod spec.
	if agent == string(kube.KubernetesAgent) && spec == nil {
		return fmt.Errorf("job %s has no spec", name)
	}
	// Only k8s jobs can be decorated
	if agent != string(kube.KubernetesAgent) && config != nil {
		return fmt.Errorf("job %s configured PodSpec decoration but is not a Kubernetes job", name)
	}
	// Jobs asking for decoration should provide config
	if agent == string(kube.KubernetesAgent) && config != nil {
		if config.UtilityImages == nil {
			return fmt.Errorf("job %s does not configure pod utility images but asks for decoration", name)
		}
		if config.GCSConfiguration == nil || config.GCSCredentialsSecret == "" {
			return fmt.Errorf("job %s does not configure GCS uploads but asks for decoration", name)
		}
	}
	// Ensure agent is a known value.
	if agent != string(kube.KubernetesAgent) && agent != string(kube.JenkinsAgent) && agent != string(kube.BuildAgent) {
		return fmt.Errorf("job %s has invalid agent (%s), it needs to be one of the following: %s %s %s",
			name, agent, kube.KubernetesAgent, kube.JenkinsAgent, kube.BuildAgent)
	}
	return nil
}

func resolvePresets(name string, labels map[string]string, spec *v1.PodSpec, presets []Preset) error {
	for _, preset := range presets {
		if err := mergePreset(preset, labels, spec); err != nil {
			return fmt.Errorf("job %s failed to merge presets: %v", name, err)
		}
	}

	return nil
}

func validatePodSpec(name string, jobType kube.ProwJobType, spec *v1.PodSpec) error {
	if spec == nil {
		return nil
	}

	if len(spec.InitContainers) != 0 {
		return fmt.Errorf("job %s specified init containers, which is not allowed", name)
	}

	if len(spec.Containers) != 1 {
		return fmt.Errorf("job %s specified %d containers when only one is allowed", name, len(spec.Containers))
	}

	for _, env := range spec.Containers[0].Env {
		for _, prowEnv := range downwardapi.EnvForType(jobType) {
			if env.Name == prowEnv {
				return fmt.Errorf("job %s attempted to set Prow-controlled environment variable %s to %s on test container", name, env.Name, env.Value)
			}
		}
	}

	for _, mount := range spec.Containers[0].VolumeMounts {
		for _, prowMount := range decorate.VolumeMounts() {
			if mount.Name == prowMount {
				return fmt.Errorf("job %s attempted to mount a Prow-controlled volume mount %s on test container", name, mount.Name)
			}
		}
		for _, prowMountPath := range decorate.VolumeMountPaths() {
			if strings.HasPrefix(mount.MountPath, prowMountPath) || strings.HasPrefix(prowMountPath, mount.MountPath) {
				return fmt.Errorf("job %s mounts %s at %s, which would conflict with a Prow-controlled mount at %s", name, mount.Name, mount.MountPath, prowMountPath)
			}
		}
	}

	for _, volume := range spec.Volumes {
		for _, prowVolume := range decorate.VolumeMounts() {
			if volume.Name == prowVolume {
				return fmt.Errorf("job %s attempted to add a Prow-controlled volume %s", name, volume.Name)
			}
		}
	}

	return nil
}

func validateTriggering(job Presubmit) error {
	if job.AlwaysRun && job.RunIfChanged != "" {
		return fmt.Errorf("job %s is set to always run but also declares run_if_changed targets, which are mutually exclusive", job.Name)
	}

	if !job.SkipReport && job.Context == "" {
		return fmt.Errorf("job %s is set to report but has no context configured", job.Name)
	}

	return nil
}

// ValidateController validates the provided controller config.
func ValidateController(c *Controller) error {
	urlTmpl, err := template.New("JobURL").Parse(c.JobURLTemplateString)
	if err != nil {
		return fmt.Errorf("parsing template: %v", err)
	}
	c.JobURLTemplate = urlTmpl

	reportTmpl, err := template.New("Report").Parse(c.ReportTemplateString)
	if err != nil {
		return fmt.Errorf("parsing template: %v", err)
	}
	c.ReportTemplate = reportTmpl
	if c.MaxConcurrency < 0 {
		return fmt.Errorf("controller has invalid max_concurrency (%d), it needs to be a non-negative number", c.MaxConcurrency)
	}
	if c.MaxGoroutines == 0 {
		c.MaxGoroutines = 20
	}
	if c.MaxGoroutines <= 0 {
		return fmt.Errorf("controller has invalid max_goroutines (%d), it needs to be a positive number", c.MaxGoroutines)
	}
	return nil
}

// SetPresubmitRegexes compiles and validates all the regular expressions for
// the provided presubmits.
func SetPresubmitRegexes(js []Presubmit) error {
	for i, j := range js {
		if re, err := regexp.Compile(j.Trigger); err == nil {
			js[i].re = re
		} else {
			return fmt.Errorf("could not compile trigger regex for %s: %v", j.Name, err)
		}
		if !js[i].re.MatchString(j.RerunCommand) {
			return fmt.Errorf("for job %s, rerun command \"%s\" does not match trigger \"%s\"", j.Name, j.RerunCommand, j.Trigger)
		}
		if err := SetPresubmitRegexes(j.RunAfterSuccess); err != nil {
			return err
		}
		if j.RunIfChanged != "" {
			re, err := regexp.Compile(j.RunIfChanged)
			if err != nil {
				return fmt.Errorf("could not compile changes regex for %s: %v", j.Name, err)
			}
			js[i].reChanges = re
		}
		b, err := setBrancherRegexes(j.Brancher)
		if err != nil {
			return fmt.Errorf("could not set branch regexes for %s: %v", j.Name, err)
		}
		js[i].Brancher = b
	}
	return nil
}

// setBrancherRegexes compiles and validates all the regular expressions for
// the provided branch specifiers.
func setBrancherRegexes(br Brancher) (Brancher, error) {
	if len(br.Branches) > 0 {
		if re, err := regexp.Compile(strings.Join(br.Branches, `|`)); err == nil {
			br.re = re
		} else {
			return br, fmt.Errorf("could not compile positive branch regex: %v", err)
		}
	}
	if len(br.SkipBranches) > 0 {
		if re, err := regexp.Compile(strings.Join(br.SkipBranches, `|`)); err == nil {
			br.reSkip = re
		} else {
			return br, fmt.Errorf("could not compile negative branch regex: %v", err)
		}
	}
	return br, nil
}

// SetPostsubmitRegexes compiles and validates all the regular expressions for
// the provided postsubmits.
func SetPostsubmitRegexes(ps []Postsubmit) error {
	for i, j := range ps {
		b, err := setBrancherRegexes(j.Brancher)
		if err != nil {
			return fmt.Errorf("could not set branch regexes for %s: %v", j.Name, err)
		}
		ps[i].Brancher = b
		if err := SetPostsubmitRegexes(j.RunAfterSuccess); err != nil {
			return err
		}
	}
	return nil
}