remote: fix implementation of build with --userns=auto for API

`podman-remote` and Libpod API does not supports build with
`--userns=auto` since `IDMappingOptions` were not implemented for API
and bindings, following PR implements passing `IDMappingOptions` via
bindings to API.

Closes: https://github.com/containers/podman/issues/15476

Signed-off-by: Aditya R <arajan@redhat.com>

2 files changed, 32 insertions, 0 deletions

diff --git a/test/e2e/build/Containerfile.userns-auto b/test/e2e/build/Containerfile.userns-auto
new file mode 100644
index 000000000..921610982
--- /dev/null
+++ b/test/e2e/build/Containerfile.userns-auto
@@ -0,0 +1,2 @@
+FROM alpine
+RUN cat /proc/self/uid_map
diff --git a/test/e2e/run_userns_test.go b/test/e2e/run_userns_test.go
index f247b2dac..62e512d3a 100644
--- a/test/e2e/run_userns_test.go
+++ b/test/e2e/run_userns_test.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	. "github.com/containers/podman/v4/test/utils"
+	"github.com/containers/storage"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	. "github.com/onsi/gomega/gexec"
@@ -42,6 +43,33 @@ var _ = Describe("Podman UserNS support", func() {
 
 	})
 
+	// Note: Lot of tests for build with --userns=auto are already there in buildah
+	// but they are skipped in podman CI because bud tests are executed in rootfull
+	// environment ( where mappings for the `containers` user is not present in /etc/subuid )
+	// causing them to skip hence this is a redundant test for sanity to make sure
+	// we don't break this feature for podman-remote.
+	It("podman build with --userns=auto", func() {
+		u, err := user.Current()
+		Expect(err).To(BeNil())
+		name := u.Name
+		if name == "root" {
+			name = "containers"
+		}
+		content, err := ioutil.ReadFile("/etc/subuid")
+		if err != nil {
+			Skip("cannot read /etc/subuid")
+		}
+		if !strings.Contains(string(content), name) {
+			Skip("cannot find mappings for the current user")
+		}
+		session := podmanTest.Podman([]string{"build", "-f", "build/Containerfile.userns-auto", "-t", "test", "--userns=auto"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		// `1024` is the default size or length of the range of user IDs
+		// that is mapped between the two user namespaces by --userns=auto.
+		Expect(session.OutputToString()).To(ContainSubstring(fmt.Sprintf("%d", storage.AutoUserNsMinSize)))
+	})
+
 	It("podman uidmapping and gidmapping", func() {
 		session := podmanTest.Podman([]string{"run", "--uidmap=0:100:5000", "--gidmap=0:200:5000", "alpine", "echo", "hello"})
 		session.WaitWithDefaultTimeout()
@@ -157,6 +185,8 @@ var _ = Describe("Podman UserNS support", func() {
 			session.WaitWithDefaultTimeout()
 			Expect(session).Should(Exit(0))
 			l := session.OutputToString()
+			// `1024` is the default size or length of the range of user IDs
+			// that is mapped between the two user namespaces by --userns=auto.
 			Expect(l).To(ContainSubstring("1024"))
 			m[l] = l
 		}