podman rmi: refactor logic

While this commit was initially meant to fix #5847, it has turned into a
bigger refactoring which I did not manage to break into smaller pieces:

 * Fix #5847 by refactoring the image-removal logic.

 * Make the api handler for image-removal use the ABI code. This way,
   both (i.e., ABI and Tunnel) end up using the same code.  Achieving
   this code share required to move some code around to prevent circular
   dependencies.

 * Everything in pkg/api (excluding pkg/api/types) must now only be
   accessed from code using `ABISupport`.

 * Avoid imports from entities on handlers to prevent circular
   dependencies.

 * Move `podman system service` logic into `cmd` to prevent circular
   dependencies - it depends on pkg/api.

 * Also remove the build header from infra/abi files.  It will otherwise
   confuse swagger and other tools; errors we cannot fix as go doesn't
   expose a build-tag env variable.

Fixes: #5847
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

3 files changed, 73 insertions, 1 deletions

diff --git a/cmd/podman/system/service.go b/cmd/podman/system/service.go
index e09107b53..f4b91dd78 100644
--- a/cmd/podman/system/service.go
+++ b/cmd/podman/system/service.go
@@ -90,7 +90,8 @@ func service(cmd *cobra.Command, args []string) error {
 
 	logrus.Warn("This function is EXPERIMENTAL")
 	fmt.Fprintf(os.Stderr, "This function is EXPERIMENTAL.\n")
-	return registry.ContainerEngine().RestService(registry.GetContext(), opts)
+
+	return restService(opts, cmd.Flags(), registry.PodmanConfig())
 }
 
 func resolveApiURI(_url []string) (string, error) {
diff --git a/cmd/podman/system/service_abi.go b/cmd/podman/system/service_abi.go
new file mode 100644
index 000000000..3da6ccfc7
--- /dev/null
+++ b/cmd/podman/system/service_abi.go
@@ -0,0 +1,57 @@
+// +build ABISupport
+
+package system
+
+import (
+	"context"
+	"net"
+	"strings"
+
+	api "github.com/containers/libpod/pkg/api/server"
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/containers/libpod/pkg/domain/infra"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/pflag"
+)
+
+func restService(opts entities.ServiceOptions, flags *pflag.FlagSet, cfg *entities.PodmanConfig) error {
+	var (
+		listener *net.Listener
+		err      error
+	)
+
+	if opts.URI != "" {
+		fields := strings.Split(opts.URI, ":")
+		if len(fields) == 1 {
+			return errors.Errorf("%s is an invalid socket destination", opts.URI)
+		}
+		address := strings.Join(fields[1:], ":")
+		l, err := net.Listen(fields[0], address)
+		if err != nil {
+			return errors.Wrapf(err, "unable to create socket %s", opts.URI)
+		}
+		listener = &l
+	}
+
+	rt, err := infra.GetRuntime(context.Background(), flags, cfg)
+	if err != nil {
+		return err
+	}
+
+	server, err := api.NewServerWithSettings(rt, opts.Timeout, listener)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err := server.Shutdown(); err != nil {
+			logrus.Warnf("Error when stopping API service: %s", err)
+		}
+	}()
+
+	err = server.Serve()
+	if listener != nil {
+		_ = (*listener).Close()
+	}
+	return err
+}
diff --git a/cmd/podman/system/service_unsupported.go b/cmd/podman/system/service_unsupported.go
new file mode 100644
index 000000000..95f8189f6
--- /dev/null
+++ b/cmd/podman/system/service_unsupported.go
@@ -0,0 +1,14 @@
+// +build !ABISupport
+
+package system
+
+import (
+	"errors"
+
+	"github.com/containers/libpod/pkg/domain/entities"
+	"github.com/spf13/pflag"
+)
+
+func restService(opts entities.ServiceOptions, flags *pflag.FlagSet, cfg *entities.PodmanConfig) error {
+	return errors.New("not supported")
+}