1 files changed, 51 insertions, 0 deletions
diff --git a/internal/dependency.go b/internal/dependency.go
new file mode 100644
index 0000000..020b4f5
--- /dev/null
+++ b/internal/dependency.go
@@ -0,0 +1,51 @@
+package internal
+
+import (
+	"context"
+	"fmt"
+)
+
+type dependency struct {
+	okMap  map[string]chan struct{}
+	nokMap map[string]chan struct{}
+}
+
+func newDependency(config config) dependency {
+	d := dependency{
+		okMap:  make(map[string]chan struct{}, len(config.Checks)),
+		nokMap: make(map[string]chan struct{}, len(config.Checks)),
+	}
+
+	for name := range config.Checks {
+		d.okMap[name] = make(chan struct{})
+		d.nokMap[name] = make(chan struct{})
+	}
+
+	return d
+}
+
+func (d dependency) ok(name string) {
+	close(d.okMap[name])
+}
+
+func (d dependency) notOk(name string) {
+	close(d.nokMap[name])
+}
+
+// Wait for all dependant checks to be executed!
+func (d dependency) wait(ctx context.Context, dependencies []string) error {
+	for _, dep := range dependencies {
+		if _, ok := d.okMap[dep]; !ok {
+			// We sent an error mail already via config.sanityCheck for this case.
+			continue
+		}
+		select {
+		case <-d.okMap[dep]:
+		case <-d.nokMap[dep]:
+			return fmt.Errorf("dependency '%s' is not OK!", dep)
+		case <-ctx.Done():
+			return fmt.Errorf("waited for too long for dependency '%s': %s", dep, ctx.Err().Error())
+		}
+	}
+	return nil
+}