make remote-client error messaging more robust

the remote-client is currently weak for carrying error messages
over the varlink interface and displaying something useful to users
and developers for the purposes of debug.  this is a starting point
to improve that user experience.

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 49 insertions, 16 deletions

diff --git a/cmd/podman/errors.go b/cmd/podman/errors.go
new file mode 100644
index 000000000..192f97049
--- /dev/null
+++ b/cmd/podman/errors.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+
+	"github.com/containers/libpod/cmd/podman/varlink"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+func outputError(err error) {
+	if MainGlobalOpts.LogLevel == "debug" {
+		logrus.Errorf(err.Error())
+	} else {
+		if ee, ok := err.(*exec.ExitError); ok {
+			if status, ok := ee.Sys().(syscall.WaitStatus); ok {
+				exitCode = status.ExitStatus()
+			}
+		}
+		var ne error
+		switch e := err.(type) {
+		// For some reason golang wont let me list them with commas so listing them all.
+		case *iopodman.ImageNotFound:
+			ne = errors.New(e.Reason)
+		case *iopodman.ContainerNotFound:
+			ne = errors.New(e.Reason)
+		case *iopodman.PodNotFound:
+			ne = errors.New(e.Reason)
+		case *iopodman.VolumeNotFound:
+			ne = errors.New(e.Reason)
+		case *iopodman.ErrorOccurred:
+			ne = errors.New(e.Reason)
+		default:
+			ne = err
+		}
+		fmt.Fprintln(os.Stderr, "Error:", ne.Error())
+	}
+}
diff --git a/cmd/podman/main.go b/cmd/podman/main.go
index 990e55a8c..cf6e44fcd 100644
--- a/cmd/podman/main.go
+++ b/cmd/podman/main.go
@@ -2,11 +2,9 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"io"
 	"log/syslog"
 	"os"
-	"os/exec"
 	"runtime/pprof"
 	"strings"
 	"syscall"
@@ -18,7 +16,7 @@ import (
 	"github.com/containers/libpod/pkg/tracing"
 	"github.com/containers/libpod/version"
 	"github.com/containers/storage/pkg/reexec"
-	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	lsyslog "github.com/sirupsen/logrus/hooks/syslog"
@@ -223,16 +221,7 @@ func main() {
 		return
 	}
 	if err := rootCmd.Execute(); err != nil {
-		if MainGlobalOpts.LogLevel == "debug" {
-			logrus.Errorf(err.Error())
-		} else {
-			if ee, ok := err.(*exec.ExitError); ok {
-				if status, ok := ee.Sys().(syscall.WaitStatus); ok {
-					exitCode = status.ExitStatus()
-				}
-			}
-			fmt.Fprintln(os.Stderr, "Error:", err.Error())
-		}
+		outputError(err)
 	} else {
 		// The exitCode modified from 125, indicates an application
 		// running inside of a container failed, as opposed to the
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index 09d178760..8ecc2feff 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -1108,16 +1108,19 @@ method GetPodsByContext(all: bool, latest: bool, args: []string) -> (pods: []str
 method LoadImage(name: string, inputFile: string, quiet: bool, deleteFile: bool) -> (reply: MoreResponse)
 
 # ImageNotFound means the image could not be found by the provided name or ID in local storage.
-error ImageNotFound (id: string)
+error ImageNotFound (id: string, reason: string)
 
 # ContainerNotFound means the container could not be found by the provided name or ID in local storage.
-error ContainerNotFound (id: string)
+error ContainerNotFound (id: string, reason: string)
 
 # NoContainerRunning means none of the containers requested are running in a command that requires a running container.
 error NoContainerRunning ()
 
 # PodNotFound means the pod could not be found by the provided name or ID in local storage.
-error PodNotFound (name: string)
+error PodNotFound (name: string, reason: string)
+
+# VolumeNotFound means the volume could not be found by the name or ID in local storage.
+error VolumeNotFound (id: string, reason: string)
 
 # PodContainerError means a container associated with a pod failed to preform an operation. It contains
 # a container ID of the container that failed.