feat(worker): add AWS IAM flags to worker command for RDS IAM auth

cmd/aws.go

@@ -0,0 +1,146 @@
+package cmd
+
+import (
+	"context"
+	"database/sql/driver"
+	"fmt"
+	"net/url"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	awsconfig "github.com/aws/aws-sdk-go-v2/config"
+	"github.com/aws/aws-sdk-go-v2/credentials/stscreds"
+	"github.com/aws/aws-sdk-go-v2/feature/rds/auth"
+	"github.com/aws/aws-sdk-go-v2/service/sts"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/stdlib"
+	"github.com/spf13/pflag"
+	"github.com/xo/dburl"
+
+	"github.com/formancehq/go-libs/v5/pkg/cloud/aws/iam"
+	"github.com/formancehq/go-libs/v5/pkg/storage/bun/connect"
+)
+
+// roleIAMConnector implements driver.Connector for AWS RDS IAM authentication
+// under an assumed IAM role. A fresh RDS auth token is obtained on every
+// Connect call. The underlying STS credentials are managed by an
+// aws.CredentialsCache so that AssumeRole is only called when the cached
+// session is about to expire, not on every database connection.
+type roleIAMConnector struct {
+	dsn    string
+	region string
+	creds  aws.CredentialsProvider
+}
+
+// Connect obtains a short-lived RDS authentication token signed with the
+// assumed-role credentials and uses it as the PostgreSQL password.
+func (c *roleIAMConnector) Connect(ctx context.Context) (driver.Conn, error) {
+	u, err := dburl.Parse(c.dsn)
+	if err != nil {
+		return nil, fmt.Errorf("aws: parsing postgres uri: %w", err)
+	}
+
+	authToken, err := auth.BuildAuthToken(
+		ctx,
+		u.Host,
+		c.region,
+		u.URL.User.Username(),
+		c.creds,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("aws: building rds iam auth token for assumed role: %w", err)
+	}
+
+	// Inject the auth token as the password in the DSN.
+	authedURL := u.URL
+	authedURL.User = url.UserPassword(u.URL.User.Username(), authToken)
+	authedDSN := authedURL.String()
+
+	pgxCfg, err := pgx.ParseConfig(authedDSN)
+	if err != nil {
+		return nil, fmt.Errorf("aws: parsing dsn with iam auth token: %w", err)
+	}
+
+	return stdlib.GetConnector(*pgxCfg).Connect(ctx)
+}
+
+// Driver returns the underlying driver. database/sql calls this only when
+// sql.DB.Driver() is invoked by callers, which is uncommon.
+func (c *roleIAMConnector) Driver() driver.Driver { return &roleIAMDriver{} }
+
+// roleIAMDriver satisfies driver.Driver so that roleIAMConnector.Driver() has a
+// concrete, non-nil return value.
+type roleIAMDriver struct{}
+
+func (d *roleIAMDriver) Open(name string) (driver.Conn, error) {
+	return nil, fmt.Errorf("aws: roleIAMDriver.Open is not supported; use OpenConnector")
+}
+
+// connectionOptionsFromFlags is a drop-in replacement for
+// connect.ConnectionOptionsFromFlags that additionally handles the
+// --aws-role-arn flag.
+//
+// When --postgres-aws-enable-iam is true and --aws-role-arn is non-empty, the
+// base AWS credentials loaded from the other IAM flags are wrapped with an STS
+// AssumeRole provider. The RDS authentication token that is generated on every
+// connection will therefore be signed by the assumed role's credentials rather
+// than the caller's identity.
+//
+// In all other cases (IAM disabled, or no role ARN supplied) the function
+// delegates directly to connect.ConnectionOptionsFromFlags, preserving
+// identical behaviour.
+func connectionOptionsFromFlags(flags *pflag.FlagSet, ctx context.Context) (*connect.ConnectionOptions, error) {
+	awsEnable, _ := flags.GetBool(connect.PostgresAWSEnableIAMFlag)
+	if !awsEnable {
+		return connect.ConnectionOptionsFromFlags(flags, ctx)
+	}
+
+	roleArn, _ := flags.GetString(iam.AWSRoleArnFlag)
+	if roleArn == "" {
+		// No role assumption requested; existing code path handles this.
+		return connect.ConnectionOptionsFromFlags(flags, ctx)
+	}
+
+	// Load the base AWS configuration from the remaining IAM flags
+	// (region, static credentials, profile, etc.).
+	cfg, err := awsconfig.LoadDefaultConfig(ctx, iam.LoadOptionFromFlags(flags))
+	if err != nil {
+		return nil, fmt.Errorf("aws: loading base aws config: %w", err)
+	}
+
+	// Wrap the base credentials with an STS AssumeRole provider, then cache
+	// the resulting temporary credentials with aws.NewCredentialsCache.
+	// Without the cache, stscreds.AssumeRoleProvider would call STS on every
+	// new physical DB connection, adding latency and risk of STS throttling
+	// under connection churn. The cache reuses credentials until they are
+	// about to expire and only then calls STS to refresh them.
+	stsClient := sts.NewFromConfig(cfg)
+	cachedCreds := aws.NewCredentialsCache(stscreds.NewAssumeRoleProvider(stsClient, roleArn))
+
+	postgresURI, _ := flags.GetString(connect.PostgresURIFlag)
+	if postgresURI == "" {
+		return nil, fmt.Errorf("aws: missing --%s", connect.PostgresURIFlag)
+	}
+
+	connector := &roleIAMConnector{
+		dsn:    postgresURI,
+		region: cfg.Region,
+		creds:  cachedCreds,
+	}
+
+	maxIdleConns, _ := flags.GetInt(connect.PostgresMaxIdleConnsFlag)
+	connMaxIdleTime, _ := flags.GetDuration(connect.PostgresConnMaxIdleTimeFlag)
+	connMaxLifetime, _ := flags.GetDuration(connect.PostgresConnMaxLifetimeFlag)
+	maxOpenConns, _ := flags.GetInt(connect.PostgresMaxOpenConnsFlag)
+
+	return &connect.ConnectionOptions{
+		DatabaseSourceName: postgresURI,
+		MaxIdleConns:       maxIdleConns,
+		ConnMaxIdleTime:    connMaxIdleTime,
+		ConnMaxLifetime:    connMaxLifetime,
+		MaxOpenConns:       maxOpenConns,
+		Connector: func(dsn string) (driver.Connector, error) {
+			return connector, nil
+		},
+	}, nil
+}
+

cmd/serve.go

@@ -105,7 +105,7 @@ func NewServeCommand() *cobra.Command {
 				return err
 			}
 
-			connectionOptions, err := connect.ConnectionOptionsFromFlags(cmd.Flags(), cmd.Context())
+			connectionOptions, err := connectionOptionsFromFlags(cmd.Flags(), cmd.Context())
 			if err != nil {
 				return err
 			}

cmd/worker.go

@@ -10,6 +10,7 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 
+	"github.com/formancehq/go-libs/v5/pkg/cloud/aws/iam"
 	"github.com/formancehq/go-libs/v5/pkg/fx/storagefx"
 	"github.com/formancehq/go-libs/v5/pkg/observe/metrics"
 	"github.com/formancehq/go-libs/v5/pkg/observe/traces"
@@ -93,7 +94,7 @@ func NewWorkerCommand() *cobra.Command {
 		Use:          "worker",
 		SilenceUsage: true,
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			connectionOptions, err := connect.ConnectionOptionsFromFlags(cmd.Flags(), cmd.Context())
+			connectionOptions, err := connectionOptionsFromFlags(cmd.Flags(), cmd.Context())
 			if err != nil {
 				return err
 			}
@@ -132,6 +133,7 @@ func NewWorkerCommand() *cobra.Command {
 	connect.AddFlags(cmd.Flags())
 	metrics.AddFlags(cmd.Flags())
 	traces.AddFlags(cmd.Flags())
+	iam.AddFlags(cmd.Flags())
 
 	return cmd
 }

cmd/worker_test.go

@@ -0,0 +1,112 @@
+package cmd
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/formancehq/go-libs/v5/pkg/cloud/aws/iam"
+	"github.com/formancehq/go-libs/v5/pkg/storage/bun/connect"
+)
+
+// TestWorkerCommandHasAWSIAMFlags verifies that the worker command registers
+// all required AWS IAM flags, so that users running the standalone worker binary
+// (e.g. on AWS ECS Fargate) can configure RDS IAM auth for the primary store
+// via CLI flags, not just via environment variables.
+func TestWorkerCommandHasAWSIAMFlags(t *testing.T) {
+	t.Parallel()
+
+	cmd := NewWorkerCommand()
+	flags := cmd.Flags()
+
+	// These flags come from connect.AddFlags and enable IAM on the primary store
+	t.Run("postgres-aws-enable-iam flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(connect.PostgresAWSEnableIAMFlag)
+		require.NotNil(t, f, "--postgres-aws-enable-iam flag must be registered on the worker command")
+		assert.Equal(t, "false", f.DefValue)
+	})
+
+	// These flags come from iam.AddFlags (added to fix issue #1556).
+	t.Run("aws-region flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSRegionFlag)
+		require.NotNil(t, f, "--aws-region flag must be registered on the worker command")
+	})
+
+	t.Run("aws-access-key-id flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSAccessKeyIDFlag)
+		require.NotNil(t, f, "--aws-access-key-id flag must be registered on the worker command")
+	})
+
+	t.Run("aws-secret-access-key flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSSecretAccessKeyFlag)
+		require.NotNil(t, f, "--aws-secret-access-key flag must be registered on the worker command")
+	})
+
+	t.Run("aws-session-token flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSSessionTokenFlag)
+		require.NotNil(t, f, "--aws-session-token flag must be registered on the worker command")
+	})
+
+	t.Run("aws-profile flag is registered", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSProfileFlag)
+		require.NotNil(t, f, "--aws-profile flag must be registered on the worker command")
+	})
+
+	// --aws-role-arn is now fully supported: connectionOptionsFromFlags wraps
+	// the base AWS credentials with an STS AssumeRole provider when this flag
+	// is set, so the flag must be registered AND visible to operators.
+	t.Run("aws-role-arn flag is registered and visible", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSRoleArnFlag)
+		require.NotNil(t, f, "--aws-role-arn flag must be registered on the worker command")
+		assert.False(t, f.Hidden, "--aws-role-arn must be visible now that role assumption is implemented")
+	})
+}
+
+// TestServeCommandHasAWSIAMFlags verifies the serve command also exposes
+// the same AWS IAM flags for parity (regression guard).
+func TestServeCommandHasAWSIAMFlags(t *testing.T) {
+	t.Parallel()
+
+	cmd := NewServeCommand()
+	flags := cmd.Flags()
+
+	// Verify the IAM-enable flag defaults to false on serve as well
+	f := flags.Lookup(connect.PostgresAWSEnableIAMFlag)
+	require.NotNil(t, f, "--postgres-aws-enable-iam flag must be registered on the serve command")
+	assert.Equal(t, "false", f.DefValue)
+
+	iamFlags := []string{
+		connect.PostgresAWSEnableIAMFlag,
+		iam.AWSRegionFlag,
+		iam.AWSAccessKeyIDFlag,
+		iam.AWSSecretAccessKeyFlag,
+		iam.AWSSessionTokenFlag,
+		iam.AWSProfileFlag,
+		iam.AWSRoleArnFlag,
+	}
+
+	for _, flagName := range iamFlags {
+		t.Run(flagName+" is registered on serve", func(t *testing.T) {
+			t.Parallel()
+			f := flags.Lookup(flagName)
+			require.NotNil(t, f, "--%s flag must be registered on the serve command", flagName)
+		})
+	}
+
+	// --aws-role-arn must be visible: connectionOptionsFromFlags implements role
+	// assumption via STS, so hiding it would mislead operators.
+	t.Run("aws-role-arn is visible on serve", func(t *testing.T) {
+		t.Parallel()
+		f := flags.Lookup(iam.AWSRoleArnFlag)
+		require.NotNil(t, f)
+		assert.False(t, f.Hidden, "--aws-role-arn must be visible now that role assumption is implemented")
+	})
+}

go.mod

@@ -141,19 +141,19 @@ require (
 	github.com/ajg/form v1.7.1 // indirect
 	github.com/antlr4-go/antlr/v4 v4.13.1 // indirect
 	github.com/aws/aws-msk-iam-sasl-signer-go v1.0.4 // indirect
-	github.com/aws/aws-sdk-go-v2 v1.41.5 // indirect
-	github.com/aws/aws-sdk-go-v2/config v1.32.12 // indirect
-	github.com/aws/aws-sdk-go-v2/credentials v1.19.12 // indirect
+	github.com/aws/aws-sdk-go-v2 v1.41.5
+	github.com/aws/aws-sdk-go-v2/config v1.32.12
+	github.com/aws/aws-sdk-go-v2/credentials v1.19.12
 	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.20 // indirect
-	github.com/aws/aws-sdk-go-v2/feature/rds/auth v1.6.20 // indirect
+	github.com/aws/aws-sdk-go-v2/feature/rds/auth v1.6.20
 	github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.21 // indirect
 	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.21 // indirect
 	github.com/aws/aws-sdk-go-v2/internal/ini v1.8.6 // indirect
 	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.7 // indirect
 	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.21 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sso v1.30.13 // indirect
 	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.17 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sts v1.41.9 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sts v1.41.9
 	github.com/aws/smithy-go v1.24.2 // indirect
 	github.com/bahlo/generic-list-go v0.2.0 // indirect
 	github.com/buger/jsonparser v1.1.2 // indirect