play kube: support optional/mandatory env var from config map

In K8S the pod creation fails if an env var reference a non existing
config map key. It can be marked as optional, but per default it is
mandatory. Podman on the other hand always treat such references as
optional.

Rework envVarsFrom() and envVarValue() to additionaly return an error
and add support for the optional attribute in configMapRef and
configMapKeyRef.

Signed-off-by: Alban Bedel <albeu@free.fr>

1 files changed, 107 insertions, 2 deletions

diff --git a/pkg/specgen/generate/kube/play_test.go b/pkg/specgen/generate/kube/play_test.go
index 35975a70b..c38b3e40b 100644
--- a/pkg/specgen/generate/kube/play_test.go
+++ b/pkg/specgen/generate/kube/play_test.go
@@ -13,6 +13,7 @@ func TestEnvVarsFrom(t *testing.T) {
 		name     string
 		envFrom  v1.EnvFromSource
 		options  CtrSpecGenOptions
+		succeed  bool
 		expected map[string]string
 	}{
 		{
@@ -27,6 +28,7 @@ func TestEnvVarsFrom(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: configMapList,
 			},
+			true,
 			map[string]string{
 				"myvar": "foo",
 			},
@@ -43,6 +45,23 @@ func TestEnvVarsFrom(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: configMapList,
 			},
+			false,
+			nil,
+		},
+		{
+			"OptionalConfigMapDoesNotExist",
+			v1.EnvFromSource{
+				ConfigMapRef: &v1.ConfigMapEnvSource{
+					LocalObjectReference: v1.LocalObjectReference{
+						Name: "doesnotexist",
+					},
+					Optional: &optional,
+				},
+			},
+			CtrSpecGenOptions{
+				ConfigMaps: configMapList,
+			},
+			true,
 			map[string]string{},
 		},
 		{
@@ -57,6 +76,23 @@ func TestEnvVarsFrom(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: []v1.ConfigMap{},
 			},
+			false,
+			nil,
+		},
+		{
+			"OptionalEmptyConfigMapList",
+			v1.EnvFromSource{
+				ConfigMapRef: &v1.ConfigMapEnvSource{
+					LocalObjectReference: v1.LocalObjectReference{
+						Name: "foo",
+					},
+					Optional: &optional,
+				},
+			},
+			CtrSpecGenOptions{
+				ConfigMaps: []v1.ConfigMap{},
+			},
+			true,
 			map[string]string{},
 		},
 	}
@@ -64,7 +100,8 @@ func TestEnvVarsFrom(t *testing.T) {
 	for _, test := range tests {
 		test := test
 		t.Run(test.name, func(t *testing.T) {
-			result := envVarsFrom(test.envFrom, &test.options)
+			result, err := envVarsFrom(test.envFrom, &test.options)
+			assert.Equal(t, err == nil, test.succeed)
 			assert.Equal(t, test.expected, result)
 		})
 	}
@@ -75,6 +112,7 @@ func TestEnvVarValue(t *testing.T) {
 		name     string
 		envVar   v1.EnvVar
 		options  CtrSpecGenOptions
+		succeed  bool
 		expected string
 	}{
 		{
@@ -93,6 +131,7 @@ func TestEnvVarValue(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: configMapList,
 			},
+			true,
 			"foo",
 		},
 		{
@@ -111,6 +150,27 @@ func TestEnvVarValue(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: configMapList,
 			},
+			false,
+			"",
+		},
+		{
+			"OptionalContainerKeyDoesNotExistInConfigMap",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "foo",
+						},
+						Key:      "doesnotexist",
+						Optional: &optional,
+					},
+				},
+			},
+			CtrSpecGenOptions{
+				ConfigMaps: configMapList,
+			},
+			true,
 			"",
 		},
 		{
@@ -129,6 +189,27 @@ func TestEnvVarValue(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: configMapList,
 			},
+			false,
+			"",
+		},
+		{
+			"OptionalConfigMapDoesNotExist",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "doesnotexist",
+						},
+						Key:      "myvar",
+						Optional: &optional,
+					},
+				},
+			},
+			CtrSpecGenOptions{
+				ConfigMaps: configMapList,
+			},
+			true,
 			"",
 		},
 		{
@@ -147,6 +228,27 @@ func TestEnvVarValue(t *testing.T) {
 			CtrSpecGenOptions{
 				ConfigMaps: []v1.ConfigMap{},
 			},
+			false,
+			"",
+		},
+		{
+			"OptionalEmptyConfigMapList",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "foo",
+						},
+						Key:      "myvar",
+						Optional: &optional,
+					},
+				},
+			},
+			CtrSpecGenOptions{
+				ConfigMaps: []v1.ConfigMap{},
+			},
+			true,
 			"",
 		},
 	}
@@ -154,7 +256,8 @@ func TestEnvVarValue(t *testing.T) {
 	for _, test := range tests {
 		test := test
 		t.Run(test.name, func(t *testing.T) {
-			result := envVarValue(test.envVar, &test.options)
+			result, err := envVarValue(test.envVar, &test.options)
+			assert.Equal(t, err == nil, test.succeed)
 			assert.Equal(t, test.expected, result)
 		})
 	}
@@ -184,3 +287,5 @@ var configMapList = []v1.ConfigMap{
 		},
 	},
 }
+
+var optional = true