Initial version

.gitignore

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+backoff

README.md

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+# Luzifer / backoff
+
+`backoff` is a small CLI util wrapping [`github.com/Luzifer/go_helpers/v2/backoff`](https://pkg.go.dev/github.com/Luzifer/go_helpers/v2@v2.20.0/backoff) to be used in shell scripts
+
+## Usage
+
+```console
+# backoff --help
+Usage of backoff:
+      --log-level string              Log level (debug, info, warn, error, fatal) (default "info")
+      --max-iteration-time duration   How long to wait at most between iterations (default 1m0s)
+  -i, --max-iterations uint           Maximum number of retries (0 = infinite)
+  -t, --max-total-time duration       Deadline for overall executions (0 = infinite)
+      --min-iteration-time duration   How long to wait before first retry (default 100ms)
+      --mulitplier float              Mulitplier to apply to the wait-time after each retry (1.0 = constant backoff) (default 1.5)
+      --stdin                         Pass stdin to command, to do so stdin will be fully buffered to memory before starting the command, enabling without input wil hang forever
+      --version                       Prints current version and exits
+
+# backoff -i 10 --log-level=debug -- false
+time="2023-07-22T14:38:28+02:00" level=debug msg="starting execution" try=1
+time="2023-07-22T14:38:28+02:00" level=debug msg="starting execution" try=2
+time="2023-07-22T14:38:28+02:00" level=debug msg="starting execution" try=3
+time="2023-07-22T14:38:28+02:00" level=debug msg="starting execution" try=4
+time="2023-07-22T14:38:28+02:00" level=debug msg="starting execution" try=5
+time="2023-07-22T14:38:29+02:00" level=debug msg="starting execution" try=6
+time="2023-07-22T14:38:30+02:00" level=debug msg="starting execution" try=7
+time="2023-07-22T14:38:31+02:00" level=debug msg="starting execution" try=8
+time="2023-07-22T14:38:33+02:00" level=debug msg="starting execution" try=9
+time="2023-07-22T14:38:35+02:00" level=debug msg="starting execution" try=10
+time="2023-07-22T14:38:35+02:00" level=fatal msg="retrying command" error="Maximum iterations reached: executing command: exit status 1"
+```

go.mod

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+module git.luzifer.io/luzifer/backoff
+
+go 1.20
+
+require (
+	github.com/Luzifer/go_helpers/v2 v2.20.0
+	github.com/Luzifer/rconfig/v2 v2.4.0
+	github.com/pkg/errors v0.9.1
+	github.com/sirupsen/logrus v1.9.3
+)
+
+require (
+	github.com/kr/pretty v0.3.1 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/sys v0.9.0 // indirect
+	gopkg.in/validator.v2 v2.0.0-20210331031555-b37d688a7fb0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)

go.sum

@@ -0,0 +1,37 @@
+github.com/Luzifer/go_helpers/v2 v2.20.0 h1:OyCUs7TFGwfJpGqD21KEKKOXy92jetw2l7dlmG7HZnA=
+github.com/Luzifer/go_helpers/v2 v2.20.0/go.mod h1:KPGjImwm51SmOTZMd9XUsT241gHYJuEyLrS/omQ4/Dw=
+github.com/Luzifer/rconfig/v2 v2.4.0 h1:MAdymTlExAZ8mx5VG8xOFAtFQSpWBipKYQHPOmYTn9o=
+github.com/Luzifer/rconfig/v2 v2.4.0/go.mod h1:hWF3ZVSusbYlg5bEvCwalEyUSY+0JPJWUiIu7rBmav8=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
+golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/validator.v2 v2.0.0-20210331031555-b37d688a7fb0 h1:EFLtLCwd8tGN+r/ePz3cvRtdsfYNhDEdt/vp6qsT+0A=
+gopkg.in/validator.v2 v2.0.0-20210331031555-b37d688a7fb0/go.mod h1:o4V0GXN9/CAmCsvJ0oXYZvrZOe7syiDZSN1GWGZTGzc=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

main.go

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+package main
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"os/exec"
+	"strconv"
+	"time"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+
+	"github.com/Luzifer/go_helpers/v2/backoff"
+	"github.com/Luzifer/rconfig/v2"
+)
+
+var (
+	cfg = struct {
+		LogLevel         string        `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
+		MaxIterations    uint64        `flag:"max-iterations,i" vardefault:"maxIterations" description:"Maximum number of retries (0 = infinite)"`
+		MaxIterationTime time.Duration `flag:"max-iteration-time" vardefault:"maxIterationTime" description:"How long to wait at most between iterations"`
+		MaxTotalTime     time.Duration `flag:"max-total-time,t" vardefault:"maxTotalTime" description:"Deadline for overall executions (0 = infinite)"`
+		MinIterationTime time.Duration `flag:"min-iteration-time" vardefault:"minIterationTime" description:"How long to wait before first retry"`
+		Multiplier       float64       `flag:"mulitplier" vardefault:"mulitplier" description:"Mulitplier to apply to the wait-time after each retry (1.0 = constant backoff)"`
+		Stdin            bool          `flag:"stdin" default:"false" description:"Pass stdin to command, to do so stdin will be fully buffered to memory before starting the command, enabling without input wil hang forever"`
+		VersionAndExit   bool          `flag:"version" default:"false" description:"Prints current version and exits"`
+	}{}
+
+	version = "dev"
+)
+
+func initApp() error {
+	rconfig.SetVariableDefaults(map[string]string{
+		"maxIterations":    strconv.FormatUint(backoff.DefaultMaxIterations, 10),
+		"maxIterationTime": backoff.DefaultMaxIterationTime.String(),
+		"maxTotalTime":     backoff.DefaultMaxTotalTime.String(),
+		"minIterationTime": backoff.DefaultMinIterationTime.String(),
+		"mulitplier":       strconv.FormatFloat(backoff.DefaultMultipler, 'f', -1, 64),
+	})
+	rconfig.AutoEnv(true)
+	if err := rconfig.ParseAndValidate(&cfg); err != nil {
+		return errors.Wrap(err, "parsing cli options")
+	}
+
+	l, err := logrus.ParseLevel(cfg.LogLevel)
+	if err != nil {
+		return errors.Wrap(err, "parsing log-level")
+	}
+	logrus.SetLevel(l)
+
+	return nil
+}
+
+func main() {
+	var err error
+	if err = initApp(); err != nil {
+		logrus.WithError(err).Fatal("initializing app")
+	}
+
+	if cfg.VersionAndExit {
+		logrus.WithField("version", version).Info("backoff")
+		os.Exit(0)
+	}
+
+	if len(rconfig.Args()[1:]) < 1 {
+		logrus.Fatal("Usage: backoff [options] -- <command / args>")
+	}
+
+	var stdin io.ReadSeeker
+	if cfg.Stdin {
+		sbuf := new(bytes.Buffer)
+		if _, err = io.Copy(sbuf, os.Stdin); err != nil {
+			logrus.WithError(err).Fatal("reading stdin to buffer")
+		}
+		stdin = bytes.NewReader(sbuf.Bytes())
+	}
+
+	var (
+		bo = backoff.NewBackoff().
+			WithMaxIterations(cfg.MaxIterations).
+			WithMaxIterationTime(cfg.MaxIterationTime).
+			WithMaxTotalTime(cfg.MaxTotalTime).
+			WithMinIterationTime(cfg.MinIterationTime).
+			WithMultiplier(cfg.Multiplier)
+		try int
+	)
+
+	if err = bo.Retry(func() error {
+		try++
+
+		logrus.WithField("try", try).Debug("starting execution")
+
+		if cfg.Stdin {
+			if _, err = stdin.Seek(0, io.SeekStart); err != nil {
+				logrus.WithError(err).Fatal("resetting seek position in stdin buffer")
+			}
+		}
+
+		cmd := exec.Command(rconfig.Args()[1], rconfig.Args()[2:]...)
+		cmd.Env = os.Environ() // Env-Passthrough
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+
+		if cfg.Stdin {
+			cmd.Stdin = stdin
+		}
+
+		return errors.Wrap(cmd.Run(), "executing command")
+	}); err != nil {
+		logrus.WithError(err).Fatal("retrying command")
+	}
+}