110 lines
2.6 KiB
Go
110 lines
2.6 KiB
Go
// Package don is a little helper if you need to check for the readiness of something.
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// This could be a command to run (like ssh) or a `db.Ping()` for check of the readiness
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// of a database container.
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//
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// Use as commandline tool
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//
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// Download the tool from the (download page) https://github.com/xsteadfastx/don/releases or
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// install via brew:
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//
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// brew tap xsteadfastx/tap https://github.com/xsteadfastx/homebrew-tap
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// brew install don
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// don -t 15m -r 15s -c "ssh -o StrictHostKeyChecking=no -o ConnectTimeout=10 root@container"
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//
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// This example checks every 15 seconds if the ssh container is ready. It would timeout with an
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// error after 15 minutes.
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//
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// Use as a library
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//
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// If you want to use don as a library, it just takes a `func() bool` in `don.Ready()`
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// have a function that runs the readiness check and returns `true` or `false` if its
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// ready or not. The second argument is the overall timeout and
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// the third argument is the check interval. Import it like this:
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//
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// import go.xsfx.dev/don
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//
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// Doing the readiness check like this:
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//
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// if err := don.Ready(
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// func() bool {
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// db, err := sql.Open("oracle", dbConn)
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// if err != nil {
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// log.Warn().Err(err).Str("dbConn", dbConn).Msg("could not open connection")
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//
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// return false
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// }
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//
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// if err := db.Ping(); err != nil {
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// log.Warn().Err(err).Str("dbConn", dbConn).Msg("could not ping")
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//
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// return false
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// }
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//
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// return true
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// },
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// 10*time.Minute,
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// 30*time.Second,
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// ); err != nil {
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// log.Error().Err(err).Msg("received error")
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// teardown(pool, resource, tmpState.Name())
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// os.Exit(1)
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// }
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//
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package don
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import (
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"errors"
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"os"
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"os/exec"
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"time"
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"github.com/rs/zerolog/log"
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)
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var errTimeout = errors.New("timeout")
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// Cmd returns a `func() bool` for working with `don.Ready()`. It executes a command and
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// returns a true if everything looks fine or a false if there was some kind of error.
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func Cmd(c string) func() bool {
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return func() bool {
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cmd := exec.Command("sh", "-c", c)
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cmd.Stdout = os.Stdout
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cmd.Stderr = os.Stderr
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if err := cmd.Run(); err != nil {
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log.Warn().Err(err).Msg("cmd has error")
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return false
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}
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return true
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}
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}
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// Ready takes a function that executes something and returns a bool to indicate if
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// something is ready or not. It returns an error if it timeouts.
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func Ready(f func() bool, timeout time.Duration, retry time.Duration) error {
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chReady := make(chan struct{})
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go func() {
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for {
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if f() {
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chReady <- struct{}{}
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return
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}
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<-time.After(retry)
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log.Info().Msg("retrying")
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}
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}()
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select {
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case <-chReady:
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return nil
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case <-time.After(timeout):
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return errTimeout
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}
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}
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