Create sdk/ and api/ submodules (#6583)

sdk/helper/pluginutil/env.go

@@ -0,0 +1,69 @@
+package pluginutil
+
+import (
+	"os"
+
+	version "github.com/hashicorp/go-version"
+	"github.com/hashicorp/vault/sdk/helper/mlock"
+)
+
+var (
+	// PluginMlockEnabled is the ENV name used to pass the configuration for
+	// enabling mlock
+	PluginMlockEnabled = "VAULT_PLUGIN_MLOCK_ENABLED"
+
+	// PluginVaultVersionEnv is the ENV name used to pass the version of the
+	// vault server to the plugin
+	PluginVaultVersionEnv = "VAULT_VERSION"
+
+	// PluginMetadataModeEnv is an ENV name used to disable TLS communication
+	// to bootstrap mounting plugins.
+	PluginMetadataModeEnv = "VAULT_PLUGIN_METADATA_MODE"
+
+	// PluginUnwrapTokenEnv is the ENV name used to pass unwrap tokens to the
+	// plugin.
+	PluginUnwrapTokenEnv = "VAULT_UNWRAP_TOKEN"
+
+	// PluginCACertPEMEnv is an ENV name used for holding a CA PEM-encoded
+	// string. Used for testing.
+	PluginCACertPEMEnv = "VAULT_TESTING_PLUGIN_CA_PEM"
+)
+
+// OptionallyEnableMlock determines if mlock should be called, and if so enables
+// mlock.
+func OptionallyEnableMlock() error {
+	if os.Getenv(PluginMlockEnabled) == "true" {
+		return mlock.LockMemory()
+	}
+
+	return nil
+}
+
+// GRPCSupport defaults to returning true, unless VAULT_VERSION is missing or
+// it fails to meet the version constraint.
+func GRPCSupport() bool {
+	verString := os.Getenv(PluginVaultVersionEnv)
+	// If the env var is empty, we fall back to netrpc for backward compatibility.
+	if verString == "" {
+		return false
+	}
+	if verString != "unknown" {
+		ver, err := version.NewVersion(verString)
+		if err != nil {
+			return true
+		}
+		// Due to some regressions on 0.9.2 & 0.9.3 we now require version 0.9.4
+		// to allow the plugin framework to default to gRPC.
+		constraint, err := version.NewConstraint(">= 0.9.4")
+		if err != nil {
+			return true
+		}
+		return constraint.Check(ver)
+	}
+	return true
+}
+
+// InMetadataMode returns true if the plugin calling this function is running in metadata mode.
+func InMetadataMode() bool {
+	return os.Getenv(PluginMetadataModeEnv) == "true"
+}