Enable k8s configmaps as flags for play kube

Signed-off-by: Eduardo Vega <edvegavalerio@gmail.com>

3 files changed, 341 insertions, 4 deletions

diff --git a/pkg/domain/entities/play.go b/pkg/domain/entities/play.go
index 2ba369b83..356e6869d 100644
--- a/pkg/domain/entities/play.go
+++ b/pkg/domain/entities/play.go
@@ -24,6 +24,8 @@ type PlayKubeOptions struct {
 	// SeccompProfileRoot - path to a directory containing seccomp
 	// profiles.
 	SeccompProfileRoot string
+	// ConfigMaps - slice of pathnames to kubernetes configmap YAMLs.
+	ConfigMaps []string
 }
 
 // PlayKubePod represents a single pod and associated containers created by play kube
diff --git a/pkg/domain/infra/abi/play.go b/pkg/domain/infra/abi/play.go
index 40edc1ae3..2de98d8f5 100644
--- a/pkg/domain/infra/abi/play.go
+++ b/pkg/domain/infra/abi/play.go
@@ -311,6 +311,22 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 		ctrRestartPolicy = libpod.RestartPolicyAlways
 	}
 
+	configMaps := []v1.ConfigMap{}
+	for _, p := range options.ConfigMaps {
+		f, err := os.Open(p)
+		if err != nil {
+			return nil, err
+		}
+		defer f.Close()
+
+		cm, err := readConfigMapFromFile(f)
+		if err != nil {
+			return nil, errors.Wrapf(err, "%q", p)
+		}
+
+		configMaps = append(configMaps, cm)
+	}
+
 	containers := make([]*libpod.Container, 0, len(podYAML.Spec.Containers))
 	for _, container := range podYAML.Spec.Containers {
 		pullPolicy := util.PullImageMissing
@@ -334,7 +350,7 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 		if err != nil {
 			return nil, err
 		}
-		conf, err := kubeContainerToCreateConfig(ctx, container, newImage, namespaces, volumes, pod.ID(), podName, podInfraID, seccompPaths)
+		conf, err := kubeContainerToCreateConfig(ctx, container, newImage, namespaces, volumes, pod.ID(), podName, podInfraID, configMaps, seccompPaths)
 		if err != nil {
 			return nil, err
 		}
@@ -447,7 +463,7 @@ func setupSecurityContext(securityConfig *createconfig.SecurityConfig, userConfi
 }
 
 // kubeContainerToCreateConfig takes a v1.Container and returns a createconfig describing a container
-func kubeContainerToCreateConfig(ctx context.Context, containerYAML v1.Container, newImage *image.Image, namespaces map[string]string, volumes map[string]string, podID, podName, infraID string, seccompPaths *kubeSeccompPaths) (*createconfig.CreateConfig, error) {
+func kubeContainerToCreateConfig(ctx context.Context, containerYAML v1.Container, newImage *image.Image, namespaces map[string]string, volumes map[string]string, podID, podName, infraID string, configMaps []v1.ConfigMap, seccompPaths *kubeSeccompPaths) (*createconfig.CreateConfig, error) {
 	var (
 		containerConfig createconfig.CreateConfig
 		pidConfig       createconfig.PidConfig
@@ -572,8 +588,17 @@ func kubeContainerToCreateConfig(ctx context.Context, containerYAML v1.Container
 		}
 		envs = imageEnv
 	}
-	for _, e := range containerYAML.Env {
-		envs[e.Name] = e.Value
+	for _, env := range containerYAML.Env {
+		value := envVarValue(env, configMaps)
+
+		envs[env.Name] = value
+	}
+	for _, envFrom := range containerYAML.EnvFrom {
+		cmEnvs := envVarsFromConfigMap(envFrom, configMaps)
+
+		for k, v := range cmEnvs {
+			envs[k] = v
+		}
 	}
 	containerConfig.Env = envs
 
@@ -594,6 +619,62 @@ func kubeContainerToCreateConfig(ctx context.Context, containerYAML v1.Container
 	return &containerConfig, nil
 }
 
+// readConfigMapFromFile returns a kubernetes configMap obtained from --configmap flag
+func readConfigMapFromFile(r io.Reader) (v1.ConfigMap, error) {
+	var cm v1.ConfigMap
+
+	content, err := ioutil.ReadAll(r)
+	if err != nil {
+		return cm, errors.Wrapf(err, "unable to read ConfigMap YAML content")
+	}
+
+	if err := yaml.Unmarshal(content, &cm); err != nil {
+		return cm, errors.Wrapf(err, "unable to read YAML as Kube ConfigMap")
+	}
+
+	if cm.Kind != "ConfigMap" {
+		return cm, errors.Errorf("invalid YAML kind: %q. [ConfigMap] is the only supported by --configmap", cm.Kind)
+	}
+
+	return cm, nil
+}
+
+// envVarsFromConfigMap returns all key-value pairs as env vars from a configMap that matches the envFrom setting of a container
+func envVarsFromConfigMap(envFrom v1.EnvFromSource, configMaps []v1.ConfigMap) map[string]string {
+	envs := map[string]string{}
+
+	if envFrom.ConfigMapRef != nil {
+		cmName := envFrom.ConfigMapRef.Name
+
+		for _, c := range configMaps {
+			if cmName == c.Name {
+				envs = c.Data
+				break
+			}
+		}
+	}
+
+	return envs
+}
+
+// envVarValue returns the environment variable value configured within the container's env setting.
+// It gets the value from a configMap if specified, otherwise returns env.Value
+func envVarValue(env v1.EnvVar, configMaps []v1.ConfigMap) string {
+	for _, c := range configMaps {
+		if env.ValueFrom != nil {
+			if env.ValueFrom.ConfigMapKeyRef != nil {
+				if env.ValueFrom.ConfigMapKeyRef.Name == c.Name {
+					if value, ok := c.Data[env.ValueFrom.ConfigMapKeyRef.Key]; ok {
+						return value
+					}
+				}
+			}
+		}
+	}
+
+	return env.Value
+}
+
 // kubeSeccompPaths holds information about a pod YAML's seccomp configuration
 // it holds both container and pod seccomp paths
 type kubeSeccompPaths struct {
diff --git a/pkg/domain/infra/abi/play_test.go b/pkg/domain/infra/abi/play_test.go
new file mode 100644
index 000000000..5595476c3
--- /dev/null
+++ b/pkg/domain/infra/abi/play_test.go
@@ -0,0 +1,254 @@
+package abi
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+var configMapList = []v1.ConfigMap{
+	{
+		TypeMeta: metav1.TypeMeta{
+			Kind: "ConfigMap",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "bar",
+		},
+		Data: map[string]string{
+			"myvar": "bar",
+		},
+	},
+	{
+		TypeMeta: metav1.TypeMeta{
+			Kind: "ConfigMap",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "foo",
+		},
+		Data: map[string]string{
+			"myvar": "foo",
+		},
+	},
+}
+
+func TestReadConfigMapFromFile(t *testing.T) {
+	tests := []struct {
+		name             string
+		configMapContent string
+		expectError      bool
+		expectedErrorMsg string
+		expected         v1.ConfigMap
+	}{
+		{
+			"ValidConfigMap",
+			`
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo
+data:
+  myvar: foo
+`,
+			false,
+			"",
+			v1.ConfigMap{
+				TypeMeta: metav1.TypeMeta{
+					Kind:       "ConfigMap",
+					APIVersion: "v1",
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "foo",
+				},
+				Data: map[string]string{
+					"myvar": "foo",
+				},
+			},
+		},
+		{
+			"InvalidYAML",
+			`
+Invalid YAML
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo
+data:
+  myvar: foo
+`,
+			true,
+			"unable to read YAML as Kube ConfigMap",
+			v1.ConfigMap{},
+		},
+		{
+			"InvalidKind",
+			`
+apiVersion: v1
+kind: InvalidKind
+metadata:
+  name: foo
+data:
+  myvar: foo
+`,
+			true,
+			"invalid YAML kind",
+			v1.ConfigMap{},
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			buf := bytes.NewBufferString(test.configMapContent)
+			cm, err := readConfigMapFromFile(buf)
+
+			if test.expectError {
+				assert.Error(t, err)
+				assert.Contains(t, err.Error(), test.expectedErrorMsg)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, test.expected, cm)
+			}
+		})
+	}
+}
+
+func TestEnvVarsFromConfigMap(t *testing.T) {
+	tests := []struct {
+		name          string
+		envFrom       v1.EnvFromSource
+		configMapList []v1.ConfigMap
+		expected      map[string]string
+	}{
+		{
+			"ConfigMapExists",
+			v1.EnvFromSource{
+				ConfigMapRef: &v1.ConfigMapEnvSource{
+					LocalObjectReference: v1.LocalObjectReference{
+						Name: "foo",
+					},
+				},
+			},
+			configMapList,
+			map[string]string{
+				"myvar": "foo",
+			},
+		},
+		{
+			"ConfigMapDoesNotExist",
+			v1.EnvFromSource{
+				ConfigMapRef: &v1.ConfigMapEnvSource{
+					LocalObjectReference: v1.LocalObjectReference{
+						Name: "doesnotexist",
+					},
+				},
+			},
+			configMapList,
+			map[string]string{},
+		},
+		{
+			"EmptyConfigMapList",
+			v1.EnvFromSource{
+				ConfigMapRef: &v1.ConfigMapEnvSource{
+					LocalObjectReference: v1.LocalObjectReference{
+						Name: "foo",
+					},
+				},
+			},
+			[]v1.ConfigMap{},
+			map[string]string{},
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			result := envVarsFromConfigMap(test.envFrom, test.configMapList)
+			assert.Equal(t, test.expected, result)
+		})
+	}
+}
+
+func TestEnvVarValue(t *testing.T) {
+	tests := []struct {
+		name          string
+		envVar        v1.EnvVar
+		configMapList []v1.ConfigMap
+		expected      string
+	}{
+		{
+			"ConfigMapExists",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "foo",
+						},
+						Key: "myvar",
+					},
+				},
+			},
+			configMapList,
+			"foo",
+		},
+		{
+			"ContainerKeyDoesNotExistInConfigMap",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "foo",
+						},
+						Key: "doesnotexist",
+					},
+				},
+			},
+			configMapList,
+			"",
+		},
+		{
+			"ConfigMapDoesNotExist",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "doesnotexist",
+						},
+						Key: "myvar",
+					},
+				},
+			},
+			configMapList,
+			"",
+		},
+		{
+			"EmptyConfigMapList",
+			v1.EnvVar{
+				Name: "FOO",
+				ValueFrom: &v1.EnvVarSource{
+					ConfigMapKeyRef: &v1.ConfigMapKeySelector{
+						LocalObjectReference: v1.LocalObjectReference{
+							Name: "foo",
+						},
+						Key: "myvar",
+					},
+				},
+			},
+			[]v1.ConfigMap{},
+			"",
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			result := envVarValue(test.envVar, test.configMapList)
+			assert.Equal(t, test.expected, result)
+		})
+	}
+}