Add WithEnv and WithMount oci options

Signed-off-by: Paul Knopf <pauldotknopf@gmail.com>

oci/spec_opts_test.go

@@ -0,0 +1,73 @@
+package oci
+
+import (
+	"testing"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func TestWithEnv(t *testing.T) {
+	t.Parallel()
+
+	s := specs.Spec{}
+	s.Process = &specs.Process{
+		Env: []string{"DEFAULT=test"},
+	}
+
+	WithEnv([]string{"env=1"})(nil, nil, nil, &s)
+
+	if len(s.Process.Env) != 2 {
+		t.Fatal("didn't append")
+	}
+
+	WithEnv([]string{"env2=1"})(nil, nil, nil, &s)
+
+	if len(s.Process.Env) != 3 {
+		t.Fatal("didn't append")
+	}
+
+	WithEnv([]string{"env2=2"})(nil, nil, nil, &s)
+
+	if s.Process.Env[2] != "env2=2" {
+		t.Fatal("could't update")
+	}
+
+	WithEnv([]string{"env2"})(nil, nil, nil, &s)
+
+	if len(s.Process.Env) != 2 {
+		t.Fatal("coudn't unset")
+	}
+}
+
+func TestWithMounts(t *testing.T) {
+
+	t.Parallel()
+
+	s := specs.Spec{
+		Mounts: []specs.Mount{
+			{
+				Source:      "default-source",
+				Destination: "default-dest",
+			},
+		},
+	}
+
+	WithMounts([]specs.Mount{
+		{
+			Source:      "new-source",
+			Destination: "new-dest",
+		},
+	})(nil, nil, nil, &s)
+
+	if len(s.Mounts) != 2 {
+		t.Fatal("didn't append")
+	}
+
+	if s.Mounts[1].Source != "new-source" {
+		t.Fatal("invaid mount")
+	}
+
+	if s.Mounts[1].Destination != "new-dest" {
+		t.Fatal("invaid mount")
+	}
+}