don/README.md
Marvin Preuss f9038b02f6
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# don
[![GoDoc](https://img.shields.io/badge/pkg.go.dev-doc-blue)](http://pkg.go.dev/go.xsfx.dev/don)
[![Go Report Card](https://goreportcard.com/badge/go.xsfx.dev/don)](https://goreportcard.com/report/go.xsfx.dev/don)
Package don is a little helper if you need to check for the readiness of something.
This could be a command to run (like ssh) or a `db.Ping()` for check of the readiness
of a database container.
![readme](./README.gif)
## Use as commandline tool
Download the tool from the [download page](https://github.com/xsteadfastx/don/releases) or
install via brew:
```go
brew tap xsteadfastx/tap [https://github.com/xsteadfastx/homebrew-tap](https://github.com/xsteadfastx/homebrew-tap)
brew install don
don -t 15m -r 15s -c "ssh -o StrictHostKeyChecking=no -o ConnectTimeout=10 root@container"
```
This example checks every 15 seconds if the ssh container is ready. It would timeout with an
error after 15 minutes.
## Use as a library
If you want to use don as a library, it just takes a `func() bool` in `don.Ready()`
have a function that runs the readiness check and returns `true` or `false` if its
ready or not. The second argument is the overall timeout and
the third argument is the check interval. Import it like this:
```go
import go.xsfx.dev/don
```
Doing the readiness check like this:
```go
if err := don.Ready(
func() bool {
db, err := sql.Open("oracle", dbConn)
if err != nil {
log.Warn().Err(err).Str("dbConn", dbConn).Msg("could not open connection")
return false
}
if err := db.Ping(); err != nil {
log.Warn().Err(err).Str("dbConn", dbConn).Msg("could not ping")
return false
}
return true
},
10*time.Minute, // When to timeout completly.
30*time.Second, // Whats the time between retries.
false, // If you want a progressbar.
); err != nil {
log.Error().Err(err).Msg("received error")
teardown(pool, resource, tmpState.Name())
os.Exit(1)
}
```
## Functions
### func [Cmd](/don.go#L72)
`func Cmd(c string) func() bool`
Cmd returns a `func() bool` for working with `don.Ready()`. It executes a command and
returns a true if everything looks fine or a false if there was some kind of error.
### func [Ready](/don.go#L90)
`func Ready(f func() bool, timeout time.Duration, retry time.Duration, bar bool) error`
Ready takes a function that executes something and returns a bool to indicate if
something is ready or not. It returns an error if it timeouts.