bindings: reuse context for API requests

One of the main uses of context.Context is to provide cancellation for
go-routines, including API requests. While all user-facing bindings
already used a context parameter, it was only used to pass the client
information around.

This commit changes the internal DoRequest wrapper to take an additional
context argument, and pass that to the http request. Previously, the context
was derived from context.Background(), which made it impossible to cancel
once started.

All the convenience wrappers already supported the context parameter, so the
only user facing change is that cancelling those context now works as one
would expect.

Signed-off-by: Moritz "WanzenBug" Wanzenböck <moritz@wanzenbug.xyz>

1 files changed, 68 insertions, 0 deletions

diff --git a/pkg/bindings/test/connection_test.go b/pkg/bindings/test/connection_test.go
new file mode 100644
index 000000000..561cf32b5
--- /dev/null
+++ b/pkg/bindings/test/connection_test.go
@@ -0,0 +1,68 @@
+package test_bindings
+
+import (
+	"context"
+	"time"
+
+	"github.com/containers/podman/v3/pkg/bindings/containers"
+	"github.com/containers/podman/v3/pkg/bindings/system"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("Podman connection", func() {
+	var (
+		bt *bindingTest
+		s  *gexec.Session
+	)
+
+	BeforeEach(func() {
+		bt = newBindingTest()
+		bt.RestoreImagesFromCache()
+		s = bt.startAPIService()
+		time.Sleep(1 * time.Second)
+		err := bt.NewConnection()
+		Expect(err).To(BeNil())
+	})
+
+	AfterEach(func() {
+		s.Kill()
+		bt.cleanup()
+	})
+
+	It("request on cancelled context results in error", func() {
+		ctx, cancel := context.WithCancel(bt.conn)
+		cancel()
+		_, err := system.Version(ctx, nil)
+		Expect(err).To(MatchError(ctx.Err()))
+	})
+
+	It("cancel request in flight reports cancelled context", func() {
+		var name = "top"
+		_, err := bt.RunTopContainer(&name, nil)
+		Expect(err).To(BeNil())
+
+		errChan := make(chan error)
+		ctx, cancel := context.WithCancel(bt.conn)
+
+		go func() {
+			defer close(errChan)
+			_, err := containers.Wait(ctx, name, nil)
+			errChan <- err
+		}()
+
+		// Wait for the goroutine to fire the request
+		time.Sleep(1 * time.Second)
+
+		cancel()
+
+		select {
+		case err, ok := <-errChan:
+			Expect(ok).To(BeTrue())
+			Expect(err).To(MatchError(ctx.Err()))
+		case <-time.NewTimer(1 * time.Second).C:
+			Fail("cancelled request did not return in less than 1 second")
+		}
+	})
+})