varlink images

implement varlink image functions for working with libpod with the exception of a
couple due to incompletions on the libpod side of things (build).

also, created a first pass at a libpodpy package which will stand as a client to
working with libpod's varlink methods using python.

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

Closes: #669
Approved by: baude

1 files changed, 66 insertions, 0 deletions

diff --git a/pkg/util/utils.go b/pkg/util/utils.go
index edcf63f80..1bbfe30d3 100644
--- a/pkg/util/utils.go
+++ b/pkg/util/utils.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/containers/image/types"
+	"github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"golang.org/x/crypto/ssh/terminal"
 )
@@ -54,3 +55,68 @@ func StringInSlice(s string, sl []string) bool {
 	}
 	return false
 }
+
+// GetImageConfig converts the --change flag values in the format "CMD=/bin/bash USER=example"
+// to a type v1.ImageConfig
+func GetImageConfig(changes []string) (v1.ImageConfig, error) {
+	// USER=value | EXPOSE=value | ENV=value | ENTRYPOINT=value |
+	// CMD=value | VOLUME=value | WORKDIR=value | LABEL=key=value | STOPSIGNAL=value
+
+	var (
+		user       string
+		env        []string
+		entrypoint []string
+		cmd        []string
+		workingDir string
+		stopSignal string
+	)
+
+	exposedPorts := make(map[string]struct{})
+	volumes := make(map[string]struct{})
+	labels := make(map[string]string)
+
+	for _, ch := range changes {
+		pair := strings.Split(ch, "=")
+		if len(pair) == 1 {
+			return v1.ImageConfig{}, errors.Errorf("no value given for instruction %q", ch)
+		}
+		switch pair[0] {
+		case "USER":
+			user = pair[1]
+		case "EXPOSE":
+			var st struct{}
+			exposedPorts[pair[1]] = st
+		case "ENV":
+			env = append(env, pair[1])
+		case "ENTRYPOINT":
+			entrypoint = append(entrypoint, pair[1])
+		case "CMD":
+			cmd = append(cmd, pair[1])
+		case "VOLUME":
+			var st struct{}
+			volumes[pair[1]] = st
+		case "WORKDIR":
+			workingDir = pair[1]
+		case "LABEL":
+			if len(pair) == 3 {
+				labels[pair[1]] = pair[2]
+			} else {
+				labels[pair[1]] = ""
+			}
+		case "STOPSIGNAL":
+			stopSignal = pair[1]
+		}
+	}
+
+	return v1.ImageConfig{
+		User:         user,
+		ExposedPorts: exposedPorts,
+		Env:          env,
+		Entrypoint:   entrypoint,
+		Cmd:          cmd,
+		Volumes:      volumes,
+		WorkingDir:   workingDir,
+		Labels:       labels,
+		StopSignal:   stopSignal,
+	}, nil
+}