From 76d80295faffc60963ed45aa99d4b025593df1cc Mon Sep 17 00:00:00 2001
From: Christian Kellner <christian@kellner.me>
Date: Sat, 9 Jul 2022 23:30:14 +0200
Subject: [PATCH] container: add new resolver helper

Add a new class `container.Resolver` which can be used to resolve
multiple container images to their respective ids in parallel.
It should make it easy for all existing tools and api endpoints
to adpot container resultion.
---
 internal/container/resolver.go | 73 ++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 internal/container/resolver.go

diff --git a/internal/container/resolver.go b/internal/container/resolver.go
new file mode 100644
index 000000000..6e5a41506
--- /dev/null
+++ b/internal/container/resolver.go
@@ -0,0 +1,73 @@
+package container
+
+import (
+	"context"
+	"fmt"
+	"strings"
+)
+
+type resolveResult struct {
+	spec Spec
+	err  error
+}
+
+type Resolver struct {
+	jobs  int
+	queue chan resolveResult
+
+	ctx context.Context
+
+	Arch string
+}
+
+func NewResolver(arch string) Resolver {
+	return Resolver{
+		ctx:   context.Background(),
+		queue: make(chan resolveResult, 2),
+		Arch:  arch,
+	}
+}
+
+func (r *Resolver) Add(source, name string, TLSVerify *bool) {
+	client, err := NewClient(source)
+	r.jobs += 1
+
+	if err != nil {
+		r.queue <- resolveResult{err: err}
+		return
+	}
+
+	client.SetTLSVerify(TLSVerify)
+	client.SetArchitectureChoice(r.Arch)
+
+	go func() {
+		spec, err := client.Resolve(r.ctx, name)
+		if err != nil {
+			err = fmt.Errorf("'%s': %w", source, err)
+		}
+		r.queue <- resolveResult{spec: spec, err: err}
+	}()
+}
+
+func (r *Resolver) Finish() ([]Spec, error) {
+
+	specs := make([]Spec, 0, r.jobs)
+	errs := make([]string, 0, r.jobs)
+	for r.jobs > 0 {
+		result := <-r.queue
+		r.jobs -= 1
+
+		if result.err == nil {
+			specs = append(specs, result.spec)
+		} else {
+			errs = append(errs, result.err.Error())
+		}
+	}
+
+	if len(errs) > 0 {
+		detail := strings.Join(errs, "; ")
+		return specs, fmt.Errorf("failed to resolve container: %s", detail)
+	}
+
+	return specs, nil
+}