Merge pull request #1 from caas-team/feat/check-routine

Feat/check routine

cmd/run/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	"github.com/caas-team/sparrow/pkg/sparrow"
+)
+
+func main() {
+
+	config := sparrow.NewConfig()
+	sparrow := sparrow.New(config)
+
+	log.Println("running sparrow")
+	if err := sparrow.Run(context.Background()); err != nil {
+		panic(err)
+	}
+
+}

pkg/checks/checks.go

@@ -0,0 +1,42 @@
+package checks
+
+import (
+	"context"
+	"time"
+)
+
+// Available Checks will be registered in this map
+// The key is the name of the Check
+// The name needs to map the configuration item key
+var RegisteredChecks = map[string]func(string) Check{
+	"rtt": GetRoundtripCheck,
+}
+
+type Check interface {
+	// Run is called once per check interval
+	// this should error if there is a problem running the check
+	// Returns an error and a result. Returning a non nil error will cause a shutdown of the system
+	Run(ctx context.Context) (Result, error)
+	// Startup is called once when the check is registered
+	// In the Run() method, the check should send results to the cResult channel
+	// this will cause sparrow to update its data store with the results
+	Startup(ctx context.Context, cResult chan<- Result) error
+	// Shutdown is called once when the check is unregistered or sparrow shuts down
+	Shutdown(ctx context.Context) error
+	// SetConfig is called once when the check is registered
+	// This is also called while the check is running, if the remote config is updated
+	// This should return an error if the config is invalid
+	SetConfig(ctx context.Context, config any) error
+	// Name returns the name of the check
+	Name() string
+}
+
+type Result struct {
+	// data contains performance metrics about the check run
+	Data any
+	// Timestamp is the UTC time the check was run
+	Timestamp time.Time
+	// Err should be nil if the check ran successfully indicating the check is "healthy"
+	// if the check failed, this should be an error message that will be logged and returned to an API user
+	Err error
+}

pkg/checks/errors.go

@@ -0,0 +1,6 @@
+package checks
+
+import "errors"
+
+
+var ErrInvalidConfig = errors.New("invalid config")

pkg/checks/roundtrip.go

@@ -0,0 +1,62 @@
+package checks
+
+import (
+	"context"
+	"net/http"
+)
+
+// ensure that RoundTrip implements the Check interface
+var _ Check = &RoundTrip{}
+
+type roundTripConfig struct{}
+
+// RoundTrip is a check that measures the round trip time of a request
+type RoundTrip struct {
+	name   string
+	c      chan<- Result
+	config roundTripConfig
+}
+
+// Constructor for the RoundtripCheck
+func GetRoundtripCheck(name string) Check {
+	return &RoundTrip{
+		name: name,
+	}
+}
+
+func (rt *RoundTrip) Run(ctx context.Context) (Result, error) {
+	return Result{}, nil
+}
+
+func (rt *RoundTrip) Startup(ctx context.Context, cResult chan<- Result) error {
+	// TODO register http handler for this check
+	http.HandleFunc("/rtt", func(w http.ResponseWriter, r *http.Request) {
+		// TODO handle
+	})
+
+	rt.c = cResult
+	return nil
+}
+
+// Shutdown is called once when the check is unregistered or sparrow shuts down
+
+func (rt *RoundTrip) Shutdown(ctx context.Context) error {
+	http.Handle("/rtt", http.NotFoundHandler())
+
+	return nil
+}
+
+// Name returns the name of the check
+func (rt *RoundTrip) Name() string {
+	return rt.name
+}
+
+func (rt *RoundTrip) SetConfig(ctx context.Context, config any) error {
+	checkConfig, ok := config.(roundTripConfig)
+	if !ok {
+		return ErrInvalidConfig
+	}
+	rt.config = checkConfig
+	return nil
+}
+

pkg/sparrow/config.go

@@ -0,0 +1,12 @@
+package sparrow
+
+type Config struct {
+	Checks map[string]any
+}
+
+func NewConfig() *Config {
+	// TODO read this from config file
+	return &Config{
+		Checks: map[string]any{},
+	}
+}

pkg/sparrow/run.go

@@ -0,0 +1,54 @@
+package sparrow
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/caas-team/sparrow/pkg/checks"
+)
+
+type Sparrow struct {
+	checks []checks.Check
+	config *Config
+	c      chan checks.Result
+}
+
+// New creates a new sparrow from a given configfile
+func New(config *Config) *Sparrow {
+	// TODO read this from config file
+	return &Sparrow{
+		config: config,
+		c:      make(chan checks.Result),
+	}
+}
+
+// Run starts the sparrow
+func (s *Sparrow) Run(ctx context.Context) error {
+	// TODO Setup before checks run
+	// setup database
+	// setup http server
+
+	for checkName, checkConfig := range s.config.Checks {
+		check := checks.RegisteredChecks[checkName](checkName)
+		s.checks = append(s.checks, check)
+
+		err := check.SetConfig(ctx, checkConfig)
+		if err != nil {
+			return fmt.Errorf("failed to set config for check %s: %w", check.Name(), err)
+		}
+		err = check.Startup(ctx, s.c)
+		if err != nil {
+			return fmt.Errorf("failed to startup check %s: %w", check.Name(), err)
+		}
+		go check.Run(ctx)
+	}
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case result := <-s.c:
+			// TODO write result to database
+			fmt.Println(result)
+		}
+	}
+}