Add cron scheduling of deletes (#14)

* Add deletionSchedule and fix bad metric

* Update Dockerfile and go.sum

Dockerfile

@@ -1,10 +1,9 @@
-FROM --platform=$BUILDPLATFORM golang:1.12
+FROM --platform=$BUILDPLATFORM golang:1.15
 
 ARG BUILDPLATFORM
 ARG TARGETARCH
 ARG TARGETOS
 
-ENV GO111MODULE=on
 WORKDIR /go/src/github.com/wish/nodereaper
 
 # Cache dependencies
@@ -20,7 +19,7 @@ RUN CGO_ENABLED=0 GOARCH=${TARGETARCH} GOOS=${TARGETOS} go build -o ./nodereaper
 # Build daemon
 RUN CGO_ENABLED=0 GOARCH=${TARGETARCH} GOOS=${TARGETOS} go build -o ./nodereaperd/nodereaperd -a -installsuffix cgo ./nodereaperd
 
-FROM alpine:3.7
+FROM alpine:3.13
 RUN apk --no-cache add ca-certificates
 WORKDIR /root/
 COPY --from=0 /go/src/github.com/wish/nodereaper/nodereaper/nodereaper /root/nodereaper

README.md

@@ -53,6 +53,7 @@ Setting Name | Type | Default | Description
 `deleteOldLaunchConfig` | `bool` | `false` | Whether to delete nodes with a different Launch Configuration than their group. With this set, `nodereaper` can perform the function of `kops rolling-update cluster` automatically after a change to configuration is made.
 `deletionAge` | `*time.Duration` | `nil` | If set, the controller will delete any node older than this value.
 `deletionAgeJitter` | `*time.Duration` | `nil` | If this is set, along with `deletionAge`, the controller will randomly delete nodes when their age is somewhere between `deletionAge` and `deletionAge + deletionAgeJitter`.
+`deletionSchedule` | `*cron.Schedule` | `nil` | A crontab schedule defining when, in UTC (**not local time!**), nodes can be deleted (ex. `weekends from 6 to 8 pm` -> `* 18-20 * * 0,6`)
 `startupGracePeriod` | `*time.Duration` | `nil` | Ignore nodes newer than this. Useful to allow time for new nodes to become `Ready`, schedule pods, etc before terminating more.
 `ignoreSelector` | `string` | `kubernetes.io/role=master` | Ignore any node that matches this label selector. Ignored nodes still count towards group size, but they will never be deleted.
 `ignore` | `bool` | `false` | Ignore every single node in the group (if specified per-group), or ignore every node in the cluster (if specified globally).

go.sum

@@ -241,6 +241,7 @@ github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190115171406-56726106282f h1:BVwpUVJDADN2ufcGik7W992pyps0wZ888b/y9GXcLTU=
 github.com/prometheus/client_model v0.0.0-20190115171406-56726106282f/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/client_model v0.2.0 h1:uq5h0d+GuxiXLJLNABMgp2qUWDPiLvgCzz2dUR+/W/M=
 github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
 github.com/prometheus/common v0.0.0-20181126121408-4724e9255275 h1:PnBWHBf+6L0jOqq0gIVUe6Yk0/QMZ640k6NvkxcBf+8=
 github.com/prometheus/common v0.0.0-20181126121408-4724e9255275/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=

pkg/config/dynamic.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/sirupsen/logrus"
+	"github.com/wish/nodereaper/pkg/cron"
 )
 
 var defaults map[string]string = map[string]string{
@@ -16,6 +17,7 @@ var defaults map[string]string = map[string]string{
 	"deleteOldLaunchConfig": "false",
 	"deletionAge":           "",
 	"deletionAgeJitter":     "",
+	"deletionSchedule":      "",
 	"startupGracePeriod":    "",
 	"ignoreSelector":        "kubernetes.io/role=master",
 	"ignore":                "false",
@@ -145,6 +147,23 @@ func (c *DynamicConfig) GetDuration(groupName, key string) *time.Duration {
 	panic("No default exists for setting " + key)
 }
 
+func (c *DynamicConfig) GetSchedule(groupName, key string) *cron.Schedule {
+	if groupSettings, ok := c.settings[groupName]; ok {
+		if setting, ok := groupSettings[key]; ok {
+			return parseSchedule(setting)
+		}
+	}
+	if globalSettings, ok := c.settings[""]; ok {
+		if setting, ok := globalSettings[key]; ok {
+			return parseSchedule(setting)
+		}
+	}
+	if defaultSetting, ok := defaults[key]; ok {
+		return parseSchedule(defaultSetting)
+	}
+	panic("No default exists for setting " + key)
+}
+
 func parseBool(s string) bool {
 	if s == "true" {
 		return true
@@ -164,3 +183,14 @@ func parseDuration(s string) *time.Duration {
 	}
 	return &d
 }
+
+func parseSchedule(s string) *cron.Schedule {
+	if s == "" {
+		return nil
+	}
+	p, err := cron.ParseStandard(s)
+	if err != nil {
+		panic(fmt.Sprintf("Schedule %v is not valid: %v", s, err))
+	}
+	return p
+}

pkg/cron/README.md

@@ -0,0 +1 @@
+Adapted from https://github.com/robfig/cron

pkg/cron/cron_test.go

@@ -0,0 +1,85 @@
+package cron
+
+import (
+	"testing"
+	"time"
+)
+
+type test struct {
+	t   time.Time
+	res bool
+}
+
+func TestHourDay(t *testing.T) {
+	s, err := ParseStandard("* 2-4 5-10 * *")
+	if err != nil {
+		t.Error(err)
+	}
+
+	tests := []test{
+		// Test day of month
+		{time.Date(2021, time.March, 4, 3, 0, 0, 0, time.UTC), false},
+		{time.Date(2021, time.March, 5, 3, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 6, 3, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 9, 3, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 10, 3, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 11, 3, 0, 0, 0, time.UTC), false},
+
+		// Test hour
+		{time.Date(2021, time.March, 5, 1, 0, 0, 0, time.UTC), false},
+		{time.Date(2021, time.March, 5, 2, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 5, 3, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 5, 4, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 5, 5, 0, 0, 0, time.UTC), false},
+
+		// Test minute/second
+		{time.Date(2021, time.March, 5, 1, 59, 59, 0, time.UTC), false},
+		{time.Date(2021, time.March, 5, 2, 0, 0, 0, time.UTC), true},
+	}
+
+	for _, test := range tests {
+		if s.Matches(test.t) != test.res {
+			t.Errorf("Failed testing date %s, got result %v, wanted %v", test.t, !test.res, test.res)
+		}
+	}
+}
+
+func TestWeekendNights(t *testing.T) {
+	// Weekends from 6 to 8 pm
+	s, err := ParseStandard("* 18-20 * * 0,6")
+	if err != nil {
+		t.Error(err)
+	}
+
+	tests := []test{
+		// Test day
+		{time.Date(2021, time.March, 5, 18, 0, 0, 0, time.UTC), false},
+		{time.Date(2021, time.March, 6, 18, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 7, 18, 0, 0, 0, time.UTC), true},
+		{time.Date(2021, time.March, 8, 18, 0, 0, 0, time.UTC), false},
+	}
+
+	for _, test := range tests {
+		if s.Matches(test.t) != test.res {
+			t.Errorf("Failed testing date %s, got result %v, wanted %v", test.t, !test.res, test.res)
+		}
+	}
+}
+
+func TestMinues(t *testing.T) {
+	// Weekends from 6 to 8 pm
+	s, err := ParseStandard("25-30 * * * *")
+	if err != nil {
+		t.Error(err)
+	}
+
+	tests := []test{
+		{time.Date(2021, time.January, 27, 20, 26, 19, 0, time.UTC), true},
+	}
+
+	for _, test := range tests {
+		if s.Matches(test.t) != test.res {
+			t.Errorf("Failed testing date %s, got result %v, wanted %v", test.t, !test.res, test.res)
+		}
+	}
+}