podman: split env variables in env and overrides

There are three different priorities for applying env variables:

1) environment/config file environment variables
2) image's config
3) user overrides (--env)

The third kind are known to the client, while the default config and image's
config is handled by the backend.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

2 files changed, 18 insertions, 12 deletions

diff --git a/pkg/specgen/generate/container.go b/pkg/specgen/generate/container.go
index 92a2b4d35..e4bd2991a 100644
--- a/pkg/specgen/generate/container.go
+++ b/pkg/specgen/generate/container.go
@@ -9,6 +9,7 @@ import (
 	envLib "github.com/containers/libpod/pkg/env"
 	"github.com/containers/libpod/pkg/signal"
 	"github.com/containers/libpod/pkg/specgen"
+	"github.com/pkg/errors"
 	"golang.org/x/sys/unix"
 )
 
@@ -48,24 +49,28 @@ func CompleteSpec(ctx context.Context, r *libpod.Runtime, s *specgen.SpecGenerat
 		s.StopSignal = &sig
 	}
 
+	rtc, err := r.GetConfig()
+	if err != nil {
+		return err
+	}
+	// Get Default Environment
+	defaultEnvs, err := envLib.ParseSlice(rtc.Containers.Env)
+	if err != nil {
+		return errors.Wrap(err, "Env fields in containers.conf failed to parse")
+	}
+
 	// Image envs from the image if they don't exist
-	// already
-	env, err := newImage.Env(ctx)
+	// already, overriding the default environments
+	imageEnvs, err := newImage.Env(ctx)
 	if err != nil {
 		return err
 	}
 
-	if len(env) > 0 {
-		envs, err := envLib.ParseSlice(env)
-		if err != nil {
-			return err
-		}
-		for k, v := range envs {
-			if _, exists := s.Env[k]; !exists {
-				s.Env[v] = k
-			}
-		}
+	envs, err := envLib.ParseSlice(imageEnvs)
+	if err != nil {
+		return errors.Wrap(err, "Env fields from image failed to parse")
 	}
+	s.Env = envLib.Join(envLib.Join(defaultEnvs, envs), s.Env)
 
 	labels, err := newImage.Labels(ctx)
 	if err != nil {
diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index 4ad6dd6fb..bb01a5d14 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -47,6 +47,7 @@ type ContainerBasicConfig struct {
 	// Optional.
 	Env map[string]string `json:"env,omitempty"`
 	// Terminal is whether the container will create a PTY.
+	// Optional.
 	Terminal bool `json:"terminal,omitempty"`
 	// Stdin is whether the container will keep its STDIN open.
 	Stdin bool `json:"stdin,omitempty"`