ContainerImage.Pinniped/internal/config/supervisor/config.go

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// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package supervisor contains functionality to load/store Config's from/to
// some source.
package supervisor
import (
"context"
"fmt"
"io/ioutil"
"net"
"strings"
"k8s.io/utils/pointer"
"sigs.k8s.io/yaml"
"go.pinniped.dev/internal/constable"
"go.pinniped.dev/internal/groupsuffix"
"go.pinniped.dev/internal/plog"
)
const (
NetworkDisabled = "disabled"
NetworkUnix = "unix"
NetworkTCP = "tcp"
// Use 10250 because it happens to be the same port on which the Kubelet listens, so some cluster types
// are more permissive with servers that run on this port. For example, GKE private clusters do not
// allow traffic from the control plane to most ports, but do allow traffic to port 10250. This allows
// the Concierge to work without additional configuration on these types of clusters.
aggregatedAPIServerPortDefault = 10250
)
// FromPath loads an Config from a provided local file path, inserts any
// defaults (from the Config documentation), and verifies that the config is
// valid (Config documentation).
func FromPath(ctx context.Context, path string) (*Config, error) {
data, err := ioutil.ReadFile(path)
if err != nil {
return nil, fmt.Errorf("read file: %w", err)
}
var config Config
if err := yaml.Unmarshal(data, &config); err != nil {
return nil, fmt.Errorf("decode yaml: %w", err)
}
if config.Labels == nil {
config.Labels = make(map[string]string)
}
maybeSetAPIGroupSuffixDefault(&config.APIGroupSuffix)
if err := validateAPIGroupSuffix(*config.APIGroupSuffix); err != nil {
return nil, fmt.Errorf("validate apiGroupSuffix: %w", err)
}
maybeSetAggregatedAPIServerPortDefaults(&config.AggregatedAPIServerPort)
if err := validateServerPort(config.AggregatedAPIServerPort); err != nil {
return nil, fmt.Errorf("validate aggregatedAPIServerPort: %w", err)
}
if err := validateNames(&config.NamesConfig); err != nil {
return nil, fmt.Errorf("validate names: %w", err)
}
plog.MaybeSetDeprecatedLogLevel(config.LogLevel, &config.Log)
if err := plog.ValidateAndSetLogLevelAndFormatGlobally(ctx, config.Log); err != nil {
return nil, fmt.Errorf("validate log level: %w", err)
}
// support setting this to null or {} or empty in the YAML
if config.Endpoints == nil {
config.Endpoints = &Endpoints{}
}
maybeSetEndpointDefault(&config.Endpoints.HTTPS, Endpoint{
Network: NetworkTCP,
Address: ":8443",
})
maybeSetEndpointDefault(&config.Endpoints.HTTP, Endpoint{
Network: NetworkDisabled,
})
if err := validateEndpoint(*config.Endpoints.HTTPS); err != nil {
return nil, fmt.Errorf("validate https endpoint: %w", err)
}
if err := validateEndpoint(*config.Endpoints.HTTP); err != nil {
return nil, fmt.Errorf("validate http endpoint: %w", err)
}
if err := validateAdditionalHTTPEndpointRequirements(*config.Endpoints.HTTP, config.AllowExternalHTTP); err != nil {
return nil, fmt.Errorf("validate http endpoint: %w", err)
}
if err := validateAtLeastOneEnabledEndpoint(*config.Endpoints.HTTPS, *config.Endpoints.HTTP); err != nil {
return nil, fmt.Errorf("validate endpoints: %w", err)
}
return &config, nil
}
func maybeSetEndpointDefault(endpoint **Endpoint, defaultEndpoint Endpoint) {
if *endpoint != nil {
return
}
*endpoint = &defaultEndpoint
}
func maybeSetAPIGroupSuffixDefault(apiGroupSuffix **string) {
if *apiGroupSuffix == nil {
*apiGroupSuffix = pointer.StringPtr(groupsuffix.PinnipedDefaultSuffix)
}
}
func validateAPIGroupSuffix(apiGroupSuffix string) error {
return groupsuffix.Validate(apiGroupSuffix)
}
func maybeSetAggregatedAPIServerPortDefaults(port **int64) {
if *port == nil {
*port = pointer.Int64Ptr(aggregatedAPIServerPortDefault)
}
}
func validateNames(names *NamesConfigSpec) error {
missingNames := []string{}
if names.DefaultTLSCertificateSecret == "" {
missingNames = append(missingNames, "defaultTLSCertificateSecret")
}
if len(missingNames) > 0 {
return constable.Error("missing required names: " + strings.Join(missingNames, ", "))
}
return nil
}
func validateEndpoint(endpoint Endpoint) error {
switch n := endpoint.Network; n {
case NetworkTCP, NetworkUnix:
if len(endpoint.Address) == 0 {
return fmt.Errorf("address must be set with %q network", n)
}
return nil
case NetworkDisabled:
if len(endpoint.Address) != 0 {
return fmt.Errorf("address set to %q when disabled, should be empty", endpoint.Address)
}
return nil
default:
return fmt.Errorf("unknown network %q", n)
}
}
func validateAdditionalHTTPEndpointRequirements(endpoint Endpoint, allowExternalHTTP stringOrBoolAsBool) error {
if endpoint.Network == NetworkTCP && !addrIsOnlyOnLoopback(endpoint.Address) {
if allowExternalHTTP {
// Log that the validation should have been triggered.
plog.Warning("Listening on non-loopback interfaces for the HTTP port is deprecated and will be removed " +
"in a future release. Your current configuration would not be allowed in that future release. " +
"Please see comments in deploy/supervisor/values.yaml and review your settings.")
// Skip enforcement of the validation.
return nil
}
return fmt.Errorf(
"http listener address %q for %q network may only bind to loopback interfaces",
endpoint.Address,
endpoint.Network)
}
return nil
}
func validateAtLeastOneEnabledEndpoint(endpoints ...Endpoint) error {
for _, endpoint := range endpoints {
if endpoint.Network != NetworkDisabled {
return nil
}
}
return constable.Error("all endpoints are disabled")
}
// For tcp networks, the address can be in several formats: host:port, host:, and :port.
// See address description in https://pkg.go.dev/net#Listen and https://pkg.go.dev/net#Dial.
// The host may be a literal IP address, or a host name that can be resolved to IP addresses,
// or a literal unspecified IP address (as in "0.0.0.0:80" or "[::]:80"), or empty.
// If the host is a literal IPv6 address it must be enclosed in square brackets, as in "[2001:db8::1]:80" or
// "[fe80::1%zone]:80". The zone specifies the scope of the literal IPv6 address as defined in RFC 4007.
// The port may be a literal port number or a service name, the value 0, or empty.
// Returns true if a net.Listen listener at this address would only listen on loopback interfaces.
// Returns false if the listener would listen on any non-loopback interfaces, or when called with illegal input.
func addrIsOnlyOnLoopback(addr string) bool {
// First try parsing as a `host:port`. net.SplitHostPort allows empty host and empty port.
host, _, err := net.SplitHostPort(addr)
if err != nil {
// Illegal input.
return false
}
if host == "" {
// Input was :port. This would bind to all interfaces, so it is not only on loopback.
return false
}
if host == "localhost" || host == "ip6-localhost" || host == "ip6-loopback" {
// These hostnames are documented as the loopback hostnames seen inside the pod's containers in
// https://kubernetes.io/docs/tasks/network/customize-hosts-file-for-pods/#default-hosts-file-content
return true
}
// The host could be a hostname, an IPv4 address, or an IPv6 address.
ip := net.ParseIP(host)
if ip == nil {
// The address was not an IP. It must have been some hostname other than "localhost".
return false
}
return ip.IsLoopback()
}
func validateServerPort(port *int64) error {
// It cannot be below 1024 because the container is not running as root.
if *port < 1024 || *port > 65535 {
return constable.Error("must be within range 1024 to 65535")
}
return nil
}