Allow to specify daily time periods without chaos

README.md

@@ -31,8 +31,7 @@ INFO[4804] Killing pod chaoskube/nginx-701339712-51nt8
 ...
 ```
 
-`chaoskube` allows to filter target pods by namespaces, labels and annotations.
-[See below](#filtering-targets) for details.
+`chaoskube` allows to filter target pods [by namespaces, labels and annotations](#filtering-targets) as well as [exclude certain weekdays or times of day](#limit-the-chaos) from chaos.
 
 ## How
 
@@ -139,21 +138,26 @@ spec:
       ...
 ```
 
-## Limiting the Chaos
+## Limit the Chaos
 
-You can limit the time when chaos is introduced. To turn on this feature, add a comma-separated list of abbreviated weekdays via the `--excluded-weekdays` option and specify a `--timezone` in which to interpret those weekdays. Use `UTC`, `Local` or pick a timezone name from the [(IANA) tz database](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). If you're testing `chaoskube` from your local machine then `Local` makes the most sense. Once you deploy `chaoskube` to your cluster you should deploy it with a specific timezone, e.g. where most of your team members are living, so that both your team and `chaoskube` have a common understanding when a particular weekday begins and ends. If your team is spread across multiple time zones it's probably best to pick `UTC` which is also the default. Picking the wrong timezone shifts the meaning of, e.g., Saturday by a couple of hours between you and the server.
+You can limit the time when chaos is introduced by weekdays, time periods of a day or both.
+
+Add a comma-separated list of abbreviated weekdays via the `--excluded-weekdays` options and/or a comma-separated list of time periods via the `--excluded-times-of-day` option and specify a `--timezone` by which to interpret them.
+
+Use `UTC`, `Local` or pick a timezone name from the [(IANA) tz database](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). If you're testing `chaoskube` from your local machine then `Local` makes the most sense. Once you deploy `chaoskube` to your cluster you should deploy it with a specific timezone, e.g. where most of your team members are living, so that both your team and `chaoskube` have a common understanding when a particular weekday begins and ends, for instance. If your team is spread across multiple time zones it's probably best to pick `UTC` which is also the default. Picking the wrong timezone shifts the meaning of a particular weekday by a couple of hours between you and the server.
 
 ## Flags
 
-| Option                | Description                                                          | Default                |
-|-----------------------|----------------------------------------------------------------------|------------------------|
-| `--interval`          | interval between pod terminations                                    | 10m                    |
-| `--labels`            | label selector to filter pods by                                     | (matches everything)   |
-| `--annotations`       | annotation selector to filter pods by                                | (matches everything)   |
-| `--namespaces`        | namespace selector to filter pods by                                 | (all namespaces)       |
-| `--excluded-weekdays` | weekdays when chaos is to be suspended, e.g. "Sat,Sun"               | (no weekday excluded)  |
-| `--timezone`          | timezone from tz database, e.g. "America/New_York", "UTC" or "Local" | (UTC)                  |
-| `--dry-run`           | don't kill pods, only log what would have been done                  | true                   |
+| Option                    | Description                                                          | Default                    |
+|---------------------------|----------------------------------------------------------------------|----------------------------|
+| `--interval`              | interval between pod terminations                                    | 10m                        |
+| `--labels`                | label selector to filter pods by                                     | (matches everything)       |
+| `--annotations`           | annotation selector to filter pods by                                | (matches everything)       |
+| `--namespaces`            | namespace selector to filter pods by                                 | (all namespaces)           |
+| `--excluded-weekdays`     | weekdays when chaos is to be suspended, e.g. "Sat,Sun"               | (no weekday excluded)      |
+| `--excluded-times-of-day` | times of day when chaos is to be suspended, e.g. "22:00-08:00"       | (no times of day excluded) |
+| `--timezone`              | timezone from tz database, e.g. "America/New_York", "UTC" or "Local" | (UTC)                      |
+| `--dry-run`               | don't kill pods, only log what would have been done                  | true                       |
 
 ## Contributing
 

chaoskube/chaoskube.go

@@ -13,6 +13,8 @@ import (
 	"k8s.io/apimachinery/pkg/selection"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/pkg/api/v1"
+
+	"github.com/linki/chaoskube/util"
 )
 
 // Chaoskube represents an instance of chaoskube
@@ -27,6 +29,8 @@ type Chaoskube struct {
 	Namespaces labels.Selector
 	// a list of weekdays when termination is suspended
 	ExcludedWeekdays []time.Weekday
+	// a list of time periods of a day when termination is suspended
+	ExcludedTimesOfDay []util.TimePeriod
 	// the timezone to apply when detecting the current weekday
 	Timezone *time.Location
 	// an instance of logrus.StdLogger to write log messages to
@@ -48,23 +52,27 @@ var msgVictimNotFound = "No victim could be found. If that's surprising double-c
 // msgWeekdayExcluded is the log message when termination is suspended due to the weekday filter
 var msgWeekdayExcluded = "This day of the week is excluded from chaos."
 
+// msgTimeOfDayExcluded is the log message when termination is suspended due to the time of day filter
+var msgTimeOfDayExcluded = "This time of day is excluded from chaos."
+
 // New returns a new instance of Chaoskube. It expects a kubernetes client, a
 // label, annotation and/or namespace selector to reduce the amount of affected
 // pods as well as whether to enable dryRun mode and a seed to seed the randomizer
 // with. You can also provide a list of weekdays and corresponding time zone when
 // chaoskube should be inactive.
-func New(client kubernetes.Interface, labels, annotations, namespaces labels.Selector, excludedWeekdays []time.Weekday, timezone *time.Location, logger log.StdLogger, dryRun bool, seed int64) *Chaoskube {
+func New(client kubernetes.Interface, labels, annotations, namespaces labels.Selector, excludedWeekdays []time.Weekday, excludedTimesOfDay []util.TimePeriod, timezone *time.Location, logger log.StdLogger, dryRun bool, seed int64) *Chaoskube {
 	c := &Chaoskube{
-		Client:           client,
-		Labels:           labels,
-		Annotations:      annotations,
-		Namespaces:       namespaces,
-		ExcludedWeekdays: excludedWeekdays,
-		Timezone:         timezone,
-		Logger:           logger,
-		DryRun:           dryRun,
-		Seed:             seed,
-		Now:              time.Now,
+		Client:             client,
+		Labels:             labels,
+		Annotations:        annotations,
+		Namespaces:         namespaces,
+		ExcludedWeekdays:   excludedWeekdays,
+		ExcludedTimesOfDay: excludedTimesOfDay,
+		Timezone:           timezone,
+		Logger:             logger,
+		DryRun:             dryRun,
+		Seed:               seed,
+		Now:                time.Now,
 	}
 
 	rand.Seed(c.Seed)
@@ -131,6 +139,13 @@ func (c *Chaoskube) TerminateVictim() error {
 		}
 	}
 
+	for _, tp := range c.ExcludedTimesOfDay {
+		if tp.Includes(c.Now().In(c.Timezone)) {
+			c.Logger.Printf(msgTimeOfDayExcluded)
+			return nil
+		}
+	}
+
 	victim, err := c.Victim()
 	if err == ErrPodNotFound {
 		c.Logger.Printf(msgVictimNotFound)