github.com/kaisenlinux/docker.io@v0.0.0-20230510090727-ea55db55fac7/engine/daemon/config/config.go (about)

     1  package config // import "github.com/docker/docker/daemon/config"
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/json"
     6  	"fmt"
     7  	"io"
     8  	"net"
     9  	"os"
    10  	"reflect"
    11  	"strings"
    12  	"sync"
    13  
    14  	daemondiscovery "github.com/docker/docker/daemon/discovery"
    15  	"github.com/docker/docker/opts"
    16  	"github.com/docker/docker/pkg/authorization"
    17  	"github.com/docker/docker/pkg/discovery"
    18  	"github.com/docker/docker/registry"
    19  	"github.com/imdario/mergo"
    20  	"github.com/pkg/errors"
    21  	"github.com/sirupsen/logrus"
    22  	"github.com/spf13/pflag"
    23  )
    24  
    25  const (
    26  	// DefaultMaxConcurrentDownloads is the default value for
    27  	// maximum number of downloads that
    28  	// may take place at a time for each pull.
    29  	DefaultMaxConcurrentDownloads = 3
    30  	// DefaultMaxConcurrentUploads is the default value for
    31  	// maximum number of uploads that
    32  	// may take place at a time for each push.
    33  	DefaultMaxConcurrentUploads = 5
    34  	// DefaultDownloadAttempts is the default value for
    35  	// maximum number of attempts that
    36  	// may take place at a time for each pull when the connection is lost.
    37  	DefaultDownloadAttempts = 5
    38  	// DefaultShmSize is the default value for container's shm size
    39  	DefaultShmSize = int64(67108864)
    40  	// DefaultNetworkMtu is the default value for network MTU
    41  	DefaultNetworkMtu = 1500
    42  	// DisableNetworkBridge is the default value of the option to disable network bridge
    43  	DisableNetworkBridge = "none"
    44  	// DefaultInitBinary is the name of the default init binary
    45  	DefaultInitBinary = "docker-init"
    46  
    47  	// StockRuntimeName is the reserved name/alias used to represent the
    48  	// OCI runtime being shipped with the docker daemon package.
    49  	StockRuntimeName = "runc"
    50  	// LinuxV1RuntimeName is the runtime used to specify the containerd v1 shim with the runc binary
    51  	// Note this is different than io.containerd.runc.v1 which would be the v1 shim using the v2 shim API.
    52  	// This is specifically for the v1 shim using the v1 shim API.
    53  	LinuxV1RuntimeName = "io.containerd.runtime.v1.linux"
    54  	// LinuxV2RuntimeName is the runtime used to specify the containerd v2 runc shim
    55  	LinuxV2RuntimeName = "io.containerd.runc.v2"
    56  )
    57  
    58  var builtinRuntimes = map[string]bool{
    59  	StockRuntimeName:   true,
    60  	LinuxV1RuntimeName: true,
    61  	LinuxV2RuntimeName: true,
    62  }
    63  
    64  // flatOptions contains configuration keys
    65  // that MUST NOT be parsed as deep structures.
    66  // Use this to differentiate these options
    67  // with others like the ones in CommonTLSOptions.
    68  var flatOptions = map[string]bool{
    69  	"cluster-store-opts": true,
    70  	"log-opts":           true,
    71  	"runtimes":           true,
    72  	"default-ulimits":    true,
    73  	"features":           true,
    74  	"builder":            true,
    75  }
    76  
    77  // skipValidateOptions contains configuration keys
    78  // that will be skipped from findConfigurationConflicts
    79  // for unknown flag validation.
    80  var skipValidateOptions = map[string]bool{
    81  	"features": true,
    82  	"builder":  true,
    83  	// Corresponding flag has been removed because it was already unusable
    84  	"deprecated-key-path": true,
    85  }
    86  
    87  // skipDuplicates contains configuration keys that
    88  // will be skipped when checking duplicated
    89  // configuration field defined in both daemon
    90  // config file and from dockerd cli flags.
    91  // This allows some configurations to be merged
    92  // during the parsing.
    93  var skipDuplicates = map[string]bool{
    94  	"runtimes": true,
    95  }
    96  
    97  // LogConfig represents the default log configuration.
    98  // It includes json tags to deserialize configuration from a file
    99  // using the same names that the flags in the command line use.
   100  type LogConfig struct {
   101  	Type   string            `json:"log-driver,omitempty"`
   102  	Config map[string]string `json:"log-opts,omitempty"`
   103  }
   104  
   105  // commonBridgeConfig stores all the platform-common bridge driver specific
   106  // configuration.
   107  type commonBridgeConfig struct {
   108  	Iface     string `json:"bridge,omitempty"`
   109  	FixedCIDR string `json:"fixed-cidr,omitempty"`
   110  }
   111  
   112  // NetworkConfig stores the daemon-wide networking configurations
   113  type NetworkConfig struct {
   114  	// Default address pools for docker networks
   115  	DefaultAddressPools opts.PoolsOpt `json:"default-address-pools,omitempty"`
   116  	// NetworkControlPlaneMTU allows to specify the control plane MTU, this will allow to optimize the network use in some components
   117  	NetworkControlPlaneMTU int `json:"network-control-plane-mtu,omitempty"`
   118  }
   119  
   120  // CommonTLSOptions defines TLS configuration for the daemon server.
   121  // It includes json tags to deserialize configuration from a file
   122  // using the same names that the flags in the command line use.
   123  type CommonTLSOptions struct {
   124  	CAFile   string `json:"tlscacert,omitempty"`
   125  	CertFile string `json:"tlscert,omitempty"`
   126  	KeyFile  string `json:"tlskey,omitempty"`
   127  }
   128  
   129  // DNSConfig defines the DNS configurations.
   130  type DNSConfig struct {
   131  	DNS           []string `json:"dns,omitempty"`
   132  	DNSOptions    []string `json:"dns-opts,omitempty"`
   133  	DNSSearch     []string `json:"dns-search,omitempty"`
   134  	HostGatewayIP net.IP   `json:"host-gateway-ip,omitempty"`
   135  }
   136  
   137  // CommonConfig defines the configuration of a docker daemon which is
   138  // common across platforms.
   139  // It includes json tags to deserialize configuration from a file
   140  // using the same names that the flags in the command line use.
   141  type CommonConfig struct {
   142  	AuthzMiddleware       *authorization.Middleware `json:"-"`
   143  	AuthorizationPlugins  []string                  `json:"authorization-plugins,omitempty"` // AuthorizationPlugins holds list of authorization plugins
   144  	AutoRestart           bool                      `json:"-"`
   145  	Context               map[string][]string       `json:"-"`
   146  	DisableBridge         bool                      `json:"-"`
   147  	ExecOptions           []string                  `json:"exec-opts,omitempty"`
   148  	GraphDriver           string                    `json:"storage-driver,omitempty"`
   149  	GraphOptions          []string                  `json:"storage-opts,omitempty"`
   150  	Labels                []string                  `json:"labels,omitempty"`
   151  	Mtu                   int                       `json:"mtu,omitempty"`
   152  	NetworkDiagnosticPort int                       `json:"network-diagnostic-port,omitempty"`
   153  	Pidfile               string                    `json:"pidfile,omitempty"`
   154  	RawLogs               bool                      `json:"raw-logs,omitempty"`
   155  	RootDeprecated        string                    `json:"graph,omitempty"`
   156  	Root                  string                    `json:"data-root,omitempty"`
   157  	ExecRoot              string                    `json:"exec-root,omitempty"`
   158  	SocketGroup           string                    `json:"group,omitempty"`
   159  	CorsHeaders           string                    `json:"api-cors-header,omitempty"`
   160  
   161  	// TrustKeyPath is used to generate the daemon ID and for signing schema 1 manifests
   162  	// when pushing to a registry which does not support schema 2. This field is marked as
   163  	// deprecated because schema 1 manifests are deprecated in favor of schema 2 and the
   164  	// daemon ID will use a dedicated identifier not shared with exported signatures.
   165  	TrustKeyPath string `json:"deprecated-key-path,omitempty"`
   166  
   167  	// LiveRestoreEnabled determines whether we should keep containers
   168  	// alive upon daemon shutdown/start
   169  	LiveRestoreEnabled bool `json:"live-restore,omitempty"`
   170  
   171  	// ClusterStore is the storage backend used for the cluster information. It is used by both
   172  	// multihost networking (to store networks and endpoints information) and by the node discovery
   173  	// mechanism.
   174  	// Deprecated: host-discovery and overlay networks with external k/v stores are deprecated
   175  	ClusterStore string `json:"cluster-store,omitempty"`
   176  
   177  	// ClusterOpts is used to pass options to the discovery package for tuning libkv settings, such
   178  	// as TLS configuration settings.
   179  	// Deprecated: host-discovery and overlay networks with external k/v stores are deprecated
   180  	ClusterOpts map[string]string `json:"cluster-store-opts,omitempty"`
   181  
   182  	// ClusterAdvertise is the network endpoint that the Engine advertises for the purpose of node
   183  	// discovery. This should be a 'host:port' combination on which that daemon instance is
   184  	// reachable by other hosts.
   185  	// Deprecated: host-discovery and overlay networks with external k/v stores are deprecated
   186  	ClusterAdvertise string `json:"cluster-advertise,omitempty"`
   187  
   188  	// MaxConcurrentDownloads is the maximum number of downloads that
   189  	// may take place at a time for each pull.
   190  	MaxConcurrentDownloads *int `json:"max-concurrent-downloads,omitempty"`
   191  
   192  	// MaxConcurrentUploads is the maximum number of uploads that
   193  	// may take place at a time for each push.
   194  	MaxConcurrentUploads *int `json:"max-concurrent-uploads,omitempty"`
   195  
   196  	// MaxDownloadAttempts is the maximum number of attempts that
   197  	// may take place at a time for each push.
   198  	MaxDownloadAttempts *int `json:"max-download-attempts,omitempty"`
   199  
   200  	// ShutdownTimeout is the timeout value (in seconds) the daemon will wait for the container
   201  	// to stop when daemon is being shutdown
   202  	ShutdownTimeout int `json:"shutdown-timeout,omitempty"`
   203  
   204  	Debug     bool     `json:"debug,omitempty"`
   205  	Hosts     []string `json:"hosts,omitempty"`
   206  	LogLevel  string   `json:"log-level,omitempty"`
   207  	TLS       *bool    `json:"tls,omitempty"`
   208  	TLSVerify *bool    `json:"tlsverify,omitempty"`
   209  
   210  	// Embedded structs that allow config
   211  	// deserialization without the full struct.
   212  	CommonTLSOptions
   213  
   214  	// SwarmDefaultAdvertiseAddr is the default host/IP or network interface
   215  	// to use if a wildcard address is specified in the ListenAddr value
   216  	// given to the /swarm/init endpoint and no advertise address is
   217  	// specified.
   218  	SwarmDefaultAdvertiseAddr string `json:"swarm-default-advertise-addr"`
   219  
   220  	// SwarmRaftHeartbeatTick is the number of ticks in time for swarm mode raft quorum heartbeat
   221  	// Typical value is 1
   222  	SwarmRaftHeartbeatTick uint32 `json:"swarm-raft-heartbeat-tick"`
   223  
   224  	// SwarmRaftElectionTick is the number of ticks to elapse before followers in the quorum can propose
   225  	// a new round of leader election.  Default, recommended value is at least 10X that of Heartbeat tick.
   226  	// Higher values can make the quorum less sensitive to transient faults in the environment, but this also
   227  	// means it takes longer for the managers to detect a down leader.
   228  	SwarmRaftElectionTick uint32 `json:"swarm-raft-election-tick"`
   229  
   230  	MetricsAddress string `json:"metrics-addr"`
   231  
   232  	DNSConfig
   233  	LogConfig
   234  	BridgeConfig // bridgeConfig holds bridge network specific configuration.
   235  	NetworkConfig
   236  	registry.ServiceOptions
   237  
   238  	sync.Mutex
   239  	// FIXME(vdemeester) This part is not that clear and is mainly dependent on cli flags
   240  	// It should probably be handled outside this package.
   241  	ValuesSet map[string]interface{} `json:"-"`
   242  
   243  	Experimental bool `json:"experimental"` // Experimental indicates whether experimental features should be exposed or not
   244  
   245  	// Exposed node Generic Resources
   246  	// e.g: ["orange=red", "orange=green", "orange=blue", "apple=3"]
   247  	NodeGenericResources []string `json:"node-generic-resources,omitempty"`
   248  
   249  	// ContainerAddr is the address used to connect to containerd if we're
   250  	// not starting it ourselves
   251  	ContainerdAddr string `json:"containerd,omitempty"`
   252  
   253  	// CriContainerd determines whether a supervised containerd instance
   254  	// should be configured with the CRI plugin enabled. This allows using
   255  	// Docker's containerd instance directly with a Kubernetes kubelet.
   256  	CriContainerd bool `json:"cri-containerd,omitempty"`
   257  
   258  	// Features contains a list of feature key value pairs indicating what features are enabled or disabled.
   259  	// If a certain feature doesn't appear in this list then it's unset (i.e. neither true nor false).
   260  	Features map[string]bool `json:"features,omitempty"`
   261  
   262  	Builder BuilderConfig `json:"builder,omitempty"`
   263  
   264  	ContainerdNamespace       string `json:"containerd-namespace,omitempty"`
   265  	ContainerdPluginNamespace string `json:"containerd-plugin-namespace,omitempty"`
   266  }
   267  
   268  // IsValueSet returns true if a configuration value
   269  // was explicitly set in the configuration file.
   270  func (conf *Config) IsValueSet(name string) bool {
   271  	if conf.ValuesSet == nil {
   272  		return false
   273  	}
   274  	_, ok := conf.ValuesSet[name]
   275  	return ok
   276  }
   277  
   278  // New returns a new fully initialized Config struct
   279  func New() *Config {
   280  	config := Config{}
   281  	config.LogConfig.Config = make(map[string]string)
   282  	config.ClusterOpts = make(map[string]string)
   283  	return &config
   284  }
   285  
   286  // ParseClusterAdvertiseSettings parses the specified advertise settings
   287  func ParseClusterAdvertiseSettings(clusterStore, clusterAdvertise string) (string, error) {
   288  	if clusterAdvertise == "" {
   289  		return "", daemondiscovery.ErrDiscoveryDisabled
   290  	}
   291  	if clusterStore == "" {
   292  		return "", errors.New("invalid cluster configuration. --cluster-advertise must be accompanied by --cluster-store configuration")
   293  	}
   294  
   295  	advertise, err := discovery.ParseAdvertise(clusterAdvertise)
   296  	if err != nil {
   297  		return "", errors.Wrap(err, "discovery advertise parsing failed")
   298  	}
   299  	return advertise, nil
   300  }
   301  
   302  // GetConflictFreeLabels validates Labels for conflict
   303  // In swarm the duplicates for labels are removed
   304  // so we only take same values here, no conflict values
   305  // If the key-value is the same we will only take the last label
   306  func GetConflictFreeLabels(labels []string) ([]string, error) {
   307  	labelMap := map[string]string{}
   308  	for _, label := range labels {
   309  		stringSlice := strings.SplitN(label, "=", 2)
   310  		if len(stringSlice) > 1 {
   311  			// If there is a conflict we will return an error
   312  			if v, ok := labelMap[stringSlice[0]]; ok && v != stringSlice[1] {
   313  				return nil, fmt.Errorf("conflict labels for %s=%s and %s=%s", stringSlice[0], stringSlice[1], stringSlice[0], v)
   314  			}
   315  			labelMap[stringSlice[0]] = stringSlice[1]
   316  		}
   317  	}
   318  
   319  	newLabels := []string{}
   320  	for k, v := range labelMap {
   321  		newLabels = append(newLabels, fmt.Sprintf("%s=%s", k, v))
   322  	}
   323  	return newLabels, nil
   324  }
   325  
   326  // Reload reads the configuration in the host and reloads the daemon and server.
   327  func Reload(configFile string, flags *pflag.FlagSet, reload func(*Config)) error {
   328  	logrus.Infof("Got signal to reload configuration, reloading from: %s", configFile)
   329  	newConfig, err := getConflictFreeConfiguration(configFile, flags)
   330  	if err != nil {
   331  		if flags.Changed("config-file") || !os.IsNotExist(err) {
   332  			return errors.Wrapf(err, "unable to configure the Docker daemon with file %s", configFile)
   333  		}
   334  		newConfig = New()
   335  	}
   336  
   337  	if err := Validate(newConfig); err != nil {
   338  		return errors.Wrap(err, "file configuration validation failed")
   339  	}
   340  
   341  	// Check if duplicate label-keys with different values are found
   342  	newLabels, err := GetConflictFreeLabels(newConfig.Labels)
   343  	if err != nil {
   344  		return err
   345  	}
   346  	newConfig.Labels = newLabels
   347  
   348  	reload(newConfig)
   349  	return nil
   350  }
   351  
   352  // boolValue is an interface that boolean value flags implement
   353  // to tell the command line how to make -name equivalent to -name=true.
   354  type boolValue interface {
   355  	IsBoolFlag() bool
   356  }
   357  
   358  // MergeDaemonConfigurations reads a configuration file,
   359  // loads the file configuration in an isolated structure,
   360  // and merges the configuration provided from flags on top
   361  // if there are no conflicts.
   362  func MergeDaemonConfigurations(flagsConfig *Config, flags *pflag.FlagSet, configFile string) (*Config, error) {
   363  	fileConfig, err := getConflictFreeConfiguration(configFile, flags)
   364  	if err != nil {
   365  		return nil, err
   366  	}
   367  
   368  	if err := Validate(fileConfig); err != nil {
   369  		return nil, errors.Wrap(err, "configuration validation from file failed")
   370  	}
   371  
   372  	// merge flags configuration on top of the file configuration
   373  	if err := mergo.Merge(fileConfig, flagsConfig); err != nil {
   374  		return nil, err
   375  	}
   376  
   377  	// We need to validate again once both fileConfig and flagsConfig
   378  	// have been merged
   379  	if err := Validate(fileConfig); err != nil {
   380  		return nil, errors.Wrap(err, "merged configuration validation from file and command line flags failed")
   381  	}
   382  
   383  	return fileConfig, nil
   384  }
   385  
   386  // getConflictFreeConfiguration loads the configuration from a JSON file.
   387  // It compares that configuration with the one provided by the flags,
   388  // and returns an error if there are conflicts.
   389  func getConflictFreeConfiguration(configFile string, flags *pflag.FlagSet) (*Config, error) {
   390  	b, err := os.ReadFile(configFile)
   391  	if err != nil {
   392  		return nil, err
   393  	}
   394  
   395  	var config Config
   396  	var reader io.Reader
   397  	if flags != nil {
   398  		var jsonConfig map[string]interface{}
   399  		reader = bytes.NewReader(b)
   400  		if err := json.NewDecoder(reader).Decode(&jsonConfig); err != nil {
   401  			return nil, err
   402  		}
   403  
   404  		configSet := configValuesSet(jsonConfig)
   405  
   406  		if err := findConfigurationConflicts(configSet, flags); err != nil {
   407  			return nil, err
   408  		}
   409  
   410  		// Override flag values to make sure the values set in the config file with nullable values, like `false`,
   411  		// are not overridden by default truthy values from the flags that were not explicitly set.
   412  		// See https://github.com/docker/docker/issues/20289 for an example.
   413  		//
   414  		// TODO: Rewrite configuration logic to avoid same issue with other nullable values, like numbers.
   415  		namedOptions := make(map[string]interface{})
   416  		for key, value := range configSet {
   417  			f := flags.Lookup(key)
   418  			if f == nil { // ignore named flags that don't match
   419  				namedOptions[key] = value
   420  				continue
   421  			}
   422  
   423  			if _, ok := f.Value.(boolValue); ok {
   424  				f.Value.Set(fmt.Sprintf("%v", value))
   425  			}
   426  		}
   427  		if len(namedOptions) > 0 {
   428  			// set also default for mergeVal flags that are boolValue at the same time.
   429  			flags.VisitAll(func(f *pflag.Flag) {
   430  				if opt, named := f.Value.(opts.NamedOption); named {
   431  					v, set := namedOptions[opt.Name()]
   432  					_, boolean := f.Value.(boolValue)
   433  					if set && boolean {
   434  						f.Value.Set(fmt.Sprintf("%v", v))
   435  					}
   436  				}
   437  			})
   438  		}
   439  
   440  		config.ValuesSet = configSet
   441  	}
   442  
   443  	reader = bytes.NewReader(b)
   444  	if err := json.NewDecoder(reader).Decode(&config); err != nil {
   445  		return nil, err
   446  	}
   447  
   448  	if config.RootDeprecated != "" {
   449  		logrus.Warn(`The "graph" config file option is deprecated. Please use "data-root" instead.`)
   450  
   451  		if config.Root != "" {
   452  			return nil, errors.New(`cannot specify both "graph" and "data-root" config file options`)
   453  		}
   454  
   455  		config.Root = config.RootDeprecated
   456  	}
   457  
   458  	return &config, nil
   459  }
   460  
   461  // configValuesSet returns the configuration values explicitly set in the file.
   462  func configValuesSet(config map[string]interface{}) map[string]interface{} {
   463  	flatten := make(map[string]interface{})
   464  	for k, v := range config {
   465  		if m, isMap := v.(map[string]interface{}); isMap && !flatOptions[k] {
   466  			for km, vm := range m {
   467  				flatten[km] = vm
   468  			}
   469  			continue
   470  		}
   471  
   472  		flatten[k] = v
   473  	}
   474  	return flatten
   475  }
   476  
   477  // findConfigurationConflicts iterates over the provided flags searching for
   478  // duplicated configurations and unknown keys. It returns an error with all the conflicts if
   479  // it finds any.
   480  func findConfigurationConflicts(config map[string]interface{}, flags *pflag.FlagSet) error {
   481  	// 1. Search keys from the file that we don't recognize as flags.
   482  	unknownKeys := make(map[string]interface{})
   483  	for key, value := range config {
   484  		if flag := flags.Lookup(key); flag == nil && !skipValidateOptions[key] {
   485  			unknownKeys[key] = value
   486  		}
   487  	}
   488  
   489  	// 2. Discard values that implement NamedOption.
   490  	// Their configuration name differs from their flag name, like `labels` and `label`.
   491  	if len(unknownKeys) > 0 {
   492  		unknownNamedConflicts := func(f *pflag.Flag) {
   493  			if namedOption, ok := f.Value.(opts.NamedOption); ok {
   494  				delete(unknownKeys, namedOption.Name())
   495  			}
   496  		}
   497  		flags.VisitAll(unknownNamedConflicts)
   498  	}
   499  
   500  	if len(unknownKeys) > 0 {
   501  		var unknown []string
   502  		for key := range unknownKeys {
   503  			unknown = append(unknown, key)
   504  		}
   505  		return fmt.Errorf("the following directives don't match any configuration option: %s", strings.Join(unknown, ", "))
   506  	}
   507  
   508  	var conflicts []string
   509  	printConflict := func(name string, flagValue, fileValue interface{}) string {
   510  		return fmt.Sprintf("%s: (from flag: %v, from file: %v)", name, flagValue, fileValue)
   511  	}
   512  
   513  	// 3. Search keys that are present as a flag and as a file option.
   514  	duplicatedConflicts := func(f *pflag.Flag) {
   515  		// search option name in the json configuration payload if the value is a named option
   516  		if namedOption, ok := f.Value.(opts.NamedOption); ok {
   517  			if optsValue, ok := config[namedOption.Name()]; ok && !skipDuplicates[namedOption.Name()] {
   518  				conflicts = append(conflicts, printConflict(namedOption.Name(), f.Value.String(), optsValue))
   519  			}
   520  		} else {
   521  			// search flag name in the json configuration payload
   522  			for _, name := range []string{f.Name, f.Shorthand} {
   523  				if value, ok := config[name]; ok && !skipDuplicates[name] {
   524  					conflicts = append(conflicts, printConflict(name, f.Value.String(), value))
   525  					break
   526  				}
   527  			}
   528  		}
   529  	}
   530  
   531  	flags.Visit(duplicatedConflicts)
   532  
   533  	if len(conflicts) > 0 {
   534  		return fmt.Errorf("the following directives are specified both as a flag and in the configuration file: %s", strings.Join(conflicts, ", "))
   535  	}
   536  	return nil
   537  }
   538  
   539  // Validate validates some specific configs.
   540  // such as config.DNS, config.Labels, config.DNSSearch,
   541  // as well as config.MaxConcurrentDownloads, config.MaxConcurrentUploads and config.MaxDownloadAttempts.
   542  func Validate(config *Config) error {
   543  	// validate DNS
   544  	for _, dns := range config.DNS {
   545  		if _, err := opts.ValidateIPAddress(dns); err != nil {
   546  			return err
   547  		}
   548  	}
   549  
   550  	// validate DNSSearch
   551  	for _, dnsSearch := range config.DNSSearch {
   552  		if _, err := opts.ValidateDNSSearch(dnsSearch); err != nil {
   553  			return err
   554  		}
   555  	}
   556  
   557  	// validate Labels
   558  	for _, label := range config.Labels {
   559  		if _, err := opts.ValidateLabel(label); err != nil {
   560  			return err
   561  		}
   562  	}
   563  	// validate MaxConcurrentDownloads
   564  	if config.MaxConcurrentDownloads != nil && *config.MaxConcurrentDownloads < 0 {
   565  		return fmt.Errorf("invalid max concurrent downloads: %d", *config.MaxConcurrentDownloads)
   566  	}
   567  	// validate MaxConcurrentUploads
   568  	if config.MaxConcurrentUploads != nil && *config.MaxConcurrentUploads < 0 {
   569  		return fmt.Errorf("invalid max concurrent uploads: %d", *config.MaxConcurrentUploads)
   570  	}
   571  	if err := ValidateMaxDownloadAttempts(config); err != nil {
   572  		return err
   573  	}
   574  
   575  	// validate that "default" runtime is not reset
   576  	if runtimes := config.GetAllRuntimes(); len(runtimes) > 0 {
   577  		if _, ok := runtimes[StockRuntimeName]; ok {
   578  			return fmt.Errorf("runtime name '%s' is reserved", StockRuntimeName)
   579  		}
   580  	}
   581  
   582  	if _, err := ParseGenericResources(config.NodeGenericResources); err != nil {
   583  		return err
   584  	}
   585  
   586  	if defaultRuntime := config.GetDefaultRuntimeName(); defaultRuntime != "" {
   587  		if !builtinRuntimes[defaultRuntime] {
   588  			runtimes := config.GetAllRuntimes()
   589  			if _, ok := runtimes[defaultRuntime]; !ok {
   590  				return fmt.Errorf("specified default runtime '%s' does not exist", defaultRuntime)
   591  			}
   592  		}
   593  	}
   594  
   595  	// validate platform-specific settings
   596  	return config.ValidatePlatformConfig()
   597  }
   598  
   599  // ValidateMaxDownloadAttempts validates if the max-download-attempts is within the valid range
   600  func ValidateMaxDownloadAttempts(config *Config) error {
   601  	if config.MaxDownloadAttempts != nil && *config.MaxDownloadAttempts <= 0 {
   602  		return fmt.Errorf("invalid max download attempts: %d", *config.MaxDownloadAttempts)
   603  	}
   604  	return nil
   605  }
   606  
   607  // ModifiedDiscoverySettings returns whether the discovery configuration has been modified or not.
   608  func ModifiedDiscoverySettings(config *Config, backendType, advertise string, clusterOpts map[string]string) bool {
   609  	if config.ClusterStore != backendType || config.ClusterAdvertise != advertise {
   610  		return true
   611  	}
   612  
   613  	if (config.ClusterOpts == nil && clusterOpts == nil) ||
   614  		(config.ClusterOpts == nil && len(clusterOpts) == 0) ||
   615  		(len(config.ClusterOpts) == 0 && clusterOpts == nil) {
   616  		return false
   617  	}
   618  
   619  	return !reflect.DeepEqual(config.ClusterOpts, clusterOpts)
   620  }