Add envprovider package for accessing environment variables

Signed-off-by: Burak Varlı <[email protected]>

pkg/driver/node/envprovider/provider.go

@@ -0,0 +1,90 @@
+// Package envprovider provides utilities for accessing environment variables to pass Mountpoint.
+package envprovider
+
+import (
+	"fmt"
+	"os"
+	"slices"
+)
+
+const (
+	EnvRegion                = "AWS_REGION"
+	EnvDefaultRegion         = "AWS_DEFAULT_REGION"
+	EnvSTSRegionalEndpoints  = "AWS_STS_REGIONAL_ENDPOINTS"
+	EnvMaxAttempts           = "AWS_MAX_ATTEMPTS"
+	EnvProfile               = "AWS_PROFILE"
+	EnvConfigFile            = "AWS_CONFIG_FILE"
+	EnvSharedCredentialsFile = "AWS_SHARED_CREDENTIALS_FILE"
+	EnvRoleARN               = "AWS_ROLE_ARN"
+	EnvWebIdentityTokenFile  = "AWS_WEB_IDENTITY_TOKEN_FILE"
+	EnvEC2MetadataDisabled   = "AWS_EC2_METADATA_DISABLED"
+	EnvAccessKeyID           = "AWS_ACCESS_KEY_ID"
+	EnvSecretAccessKey       = "AWS_SECRET_ACCESS_KEY"
+	EnvSessionToken          = "AWS_SESSION_TOKEN"
+
+	EnvMountpointCacheKey = "UNSTABLE_MOUNTPOINT_CACHE_KEY"
+)
+
+// Key represents an environment variable name.
+type Key = string
+
+// Value represents an environment variable value.
+type Value = string
+
+// Environment represents a list of environment variables as key-value pairs.
+type Environment map[Key]Value
+
+// envAllowlist is the list of environment variables to pass-by by default.
+// If any of these set, it will be returned as-is in [Default].
+var envAllowlist = []Key{
+	EnvRegion,
+	EnvDefaultRegion,
+	EnvSTSRegionalEndpoints,
+}
+
+// Region returns detected region from environment variables `AWS_REGION` or `AWS_DEFAULT_REGION`.
+// It returns an empty string if both is unset.
+func Region() Value {
+	region := os.Getenv(EnvRegion)
+	if region != "" {
+		return region
+	}
+	return os.Getenv(EnvDefaultRegion)
+}
+
+// Default returns list of environment variables to pass Mountpoint.
+func Default() Environment {
+	environment := make(Environment)
+	for _, key := range envAllowlist {
+		val := os.Getenv(key)
+		if val != "" {
+			environment[key] = val
+		}
+	}
+	return environment
+}
+
+// List returns a sorted slice of environment variables in "KEY=VALUE" format.
+func (env Environment) List() []string {
+	list := []string{}
+	for key, val := range env {
+		list = append(list, format(key, val))
+	}
+	slices.Sort(list)
+	return list
+}
+
+// Delete deletes the environment variable with the specified key.
+func (env Environment) Delete(key Key) {
+	delete(env, key)
+}
+
+// Set adds or updates the environment variable with the specified key and value.
+func (env Environment) Set(key Key, value Value) {
+	env[key] = value
+}
+
+// format formats given key and value to be used as an environment variable.
+func format(key Key, value Value) string {
+	return fmt.Sprintf("%s=%s", key, value)
+}

pkg/driver/node/envprovider/provider_test.go

@@ -0,0 +1,211 @@
+package envprovider_test
+
+import (
+	"testing"
+
+	"github.com/awslabs/aws-s3-csi-driver/pkg/driver/node/envprovider"
+	"github.com/awslabs/aws-s3-csi-driver/pkg/util/testutil/assert"
+)
+
+func TestGettingRegion(t *testing.T) {
+	testCases := []struct {
+		name             string
+		envRegion        string
+		envDefaultRegion string
+		want             string
+	}{
+		{
+			name:             "both region envs are set",
+			envRegion:        "us-west-1",
+			envDefaultRegion: "us-east-1",
+			want:             "us-west-1",
+		},
+		{
+			name:             "only default region env is set",
+			envRegion:        "",
+			envDefaultRegion: "us-east-1",
+			want:             "us-east-1",
+		},
+		{
+			name:             "no region env is set",
+			envRegion:        "",
+			envDefaultRegion: "",
+			want:             "",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Setenv("AWS_REGION", testCase.envRegion)
+			t.Setenv("AWS_DEFAULT_REGION", testCase.envDefaultRegion)
+			assert.Equals(t, testCase.want, envprovider.Region())
+		})
+	}
+}
+
+func TestProvidingDefaultEnvironmentVariables(t *testing.T) {
+	testCases := []struct {
+		name string
+		env  map[string]string
+		want []string
+	}{
+		{
+			name: "no env vars set",
+			env:  map[string]string{},
+			want: []string{},
+		},
+		{
+			name: "some allowed env vars set",
+			env: map[string]string{
+				"AWS_REGION":                 "us-west-1",
+				"AWS_DEFAULT_REGION":         "us-east-1",
+				"AWS_STS_REGIONAL_ENDPOINTS": "regional",
+				"AWS_MAX_ATTEMPTS":           "10",
+			},
+			want: []string{
+				"AWS_DEFAULT_REGION=us-east-1",
+				"AWS_REGION=us-west-1",
+				"AWS_STS_REGIONAL_ENDPOINTS=regional",
+			},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			for k, v := range testCase.env {
+				t.Setenv(k, v)
+			}
+			assert.Equals(t, testCase.want, envprovider.Default().List())
+		})
+	}
+}
+
+func TestRemovingAKeyFromListOfEnvironmentVariables(t *testing.T) {
+	testCases := []struct {
+		name string
+		env  envprovider.Environment
+		key  string
+		want envprovider.Environment
+	}{
+		{
+			name: "empty environment",
+			env:  envprovider.Environment{},
+			key:  "AWS_REGION",
+			want: envprovider.Environment{},
+		},
+		{
+			name: "remove existing key",
+			env:  envprovider.Environment{"AWS_REGION": "us-west-1", "AWS_DEFAULT_REGION": "us-east-1"},
+			key:  "AWS_REGION",
+			want: envprovider.Environment{"AWS_DEFAULT_REGION": "us-east-1"},
+		},
+		{
+			name: "remove non-existing key",
+			env:  envprovider.Environment{"AWS_REGION": "us-west-1", "AWS_DEFAULT_REGION": "us-east-1"},
+			key:  "AWS_MAX_ATTEMPTS",
+			want: envprovider.Environment{"AWS_REGION": "us-west-1", "AWS_DEFAULT_REGION": "us-east-1"},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			testCase.env.Delete(testCase.key)
+			assert.Equals(t, testCase.want, testCase.env)
+		})
+	}
+}
+
+func TestSettingKeyValueInEnvironmentVariables(t *testing.T) {
+	testCases := []struct {
+		name  string
+		env   envprovider.Environment
+		key   string
+		value string
+		want  envprovider.Environment
+	}{
+		{
+			name:  "add to empty environment",
+			env:   envprovider.Environment{},
+			key:   "AWS_REGION",
+			value: "us-west-1",
+			want:  envprovider.Environment{"AWS_REGION": "us-west-1"},
+		},
+		{
+			name:  "update existing key",
+			env:   envprovider.Environment{"AWS_REGION": "us-west-1"},
+			key:   "AWS_REGION",
+			value: "us-east-1",
+			want:  envprovider.Environment{"AWS_REGION": "us-east-1"},
+		},
+		{
+			name:  "add new key to non-empty environment",
+			env:   envprovider.Environment{"AWS_REGION": "us-west-1"},
+			key:   "AWS_DEFAULT_REGION",
+			value: "us-east-1",
+			want:  envprovider.Environment{"AWS_REGION": "us-west-1", "AWS_DEFAULT_REGION": "us-east-1"},
+		},
+		{
+			name:  "set empty value",
+			env:   envprovider.Environment{"AWS_REGION": "us-west-1"},
+			key:   "AWS_DEFAULT_REGION",
+			value: "",
+			want:  envprovider.Environment{"AWS_REGION": "us-west-1", "AWS_DEFAULT_REGION": ""},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			testCase.env.Set(testCase.key, testCase.value)
+			assert.Equals(t, testCase.want, testCase.env)
+		})
+	}
+}
+
+func TestEnvironmentList(t *testing.T) {
+	testCases := []struct {
+		name string
+		env  envprovider.Environment
+		want []string
+	}{
+		{
+			name: "empty environment",
+			env:  envprovider.Environment{},
+			want: []string{},
+		},
+		{
+			name: "single environment variable",
+			env:  envprovider.Environment{"AWS_REGION": "us-west-1"},
+			want: []string{"AWS_REGION=us-west-1"},
+		},
+		{
+			name: "multiple environment variables are sorted",
+			env: envprovider.Environment{
+				"AWS_REGION":                 "us-west-1",
+				"AWS_DEFAULT_REGION":         "us-east-1",
+				"AWS_STS_REGIONAL_ENDPOINTS": "regional",
+			},
+			want: []string{
+				"AWS_DEFAULT_REGION=us-east-1",
+				"AWS_REGION=us-west-1",
+				"AWS_STS_REGIONAL_ENDPOINTS=regional",
+			},
+		},
+		{
+			name: "environment variables with empty values",
+			env: envprovider.Environment{
+				"AWS_REGION":         "",
+				"AWS_DEFAULT_REGION": "us-east-1",
+			},
+			want: []string{
+				"AWS_DEFAULT_REGION=us-east-1",
+				"AWS_REGION=",
+			},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			assert.Equals(t, testCase.want, testCase.env.List())
+		})
+	}
+}

pkg/driver/node/mounter/credential_provider.go

@@ -21,6 +21,7 @@ import (
 	"k8s.io/klog/v2"
 	k8sstrings "k8s.io/utils/strings"
 
+	"github.com/awslabs/aws-s3-csi-driver/pkg/driver/node/envprovider"
 	"github.com/awslabs/aws-s3-csi-driver/pkg/driver/node/volumecontext"
 	"github.com/awslabs/aws-s3-csi-driver/pkg/mountpoint"
 )
@@ -109,14 +110,14 @@ func (c *CredentialProvider) provideFromDriver() (*MountCredentials, error) {
 
 	return &MountCredentials{
 		AuthenticationSource: AuthenticationSourceDriver,
-		AccessKeyID:          os.Getenv(keyIdEnv),
-		SecretAccessKey:      os.Getenv(accessKeyEnv),
-		SessionToken:         os.Getenv(sessionTokenEnv),
-		Region:               os.Getenv(regionEnv),
-		DefaultRegion:        os.Getenv(defaultRegionEnv),
+		AccessKeyID:          os.Getenv(envprovider.EnvAccessKeyID),
+		SecretAccessKey:      os.Getenv(envprovider.EnvSecretAccessKey),
+		SessionToken:         os.Getenv(envprovider.EnvSessionToken),
+		Region:               os.Getenv(envprovider.EnvRegion),
+		DefaultRegion:        os.Getenv(envprovider.EnvDefaultRegion),
 		WebTokenPath:         hostTokenPath,
-		StsEndpoints:         os.Getenv(stsEndpointsEnv),
-		AwsRoleArn:           os.Getenv(roleArnEnv),
+		StsEndpoints:         os.Getenv(envprovider.EnvSTSRegionalEndpoints),
+		AwsRoleArn:           os.Getenv(envprovider.EnvRoleARN),
 	}, nil
 }
 
@@ -150,7 +151,7 @@ func (c *CredentialProvider) provideFromPod(ctx context.Context, volumeID string
 		return nil, status.Errorf(codes.InvalidArgument, "Failed to detect STS AWS Region, please explicitly set the AWS Region, see "+stsConfigDocsPage)
 	}
 
-	defaultRegion := os.Getenv(defaultRegionEnv)
+	defaultRegion := os.Getenv(envprovider.EnvDefaultRegion)
 	if defaultRegion == "" {
 		defaultRegion = region
 	}
@@ -177,7 +178,7 @@ func (c *CredentialProvider) provideFromPod(ctx context.Context, volumeID string
 
 		Region:        region,
 		DefaultRegion: defaultRegion,
-		StsEndpoints:  os.Getenv(stsEndpointsEnv),
+		StsEndpoints:  os.Getenv(envprovider.EnvSTSRegionalEndpoints),
 		WebTokenPath:  hostTokenPath,
 		AwsRoleArn:    awsRoleARN,
 
@@ -258,13 +259,13 @@ func (c *CredentialProvider) stsRegion(volumeCtx map[string]string, args mountpo
 		return region, nil
 	}
 
-	region = os.Getenv(regionEnv)
+	region = os.Getenv(envprovider.EnvRegion)
 	if region != "" {
 		klog.V(5).Infof("NodePublishVolume: Pod-level: Detected STS region %s from `AWS_REGION` env variable", region)
 		return region, nil
 	}
 
-	region = os.Getenv(defaultRegionEnv)
+	region = os.Getenv(envprovider.EnvDefaultRegion)
 	if region != "" {
 		klog.V(5).Infof("NodePublishVolume: Pod-level: Detected STS region %s from `AWS_DEFAULT_REGION` env variable", region)
 		return region, nil