Fixes #874: fixed panic in snapd when sections of the configuration f…

…ile are all commented out (at a top-level)

control/config.go

@@ -63,6 +63,9 @@ type pluginConfigItem struct {
 }
 
 // holds the configuration passed in through the SNAP config file
+//   Note: if this struct is modified, then the switch statement in the
+//         UnmarshalJSON method in this same file needs to be modified to
+//         match the field mapping that is defined here
 type Config struct {
 	MaxRunningPlugins int               `json:"max_running_plugins,omitempty"yaml:"max_running_plugins,omitempty"`
 	PluginTrust       int               `json:"plugin_trust_level,omitempty"yaml:"plugin_trust_level,omitempty"`
@@ -84,6 +87,49 @@ func GetDefaultConfig() *Config {
 	}
 }
 
+// UnmarshalJSON unmarshals valid json into a Config.  An example Config can be found
+// at github.com/intelsdi-x/snap/blob/master/examples/configs/snap-config-sample.json
+func (c *Config) UnmarshalJSON(data []byte) error {
+	// construct a map of strings to json.RawMessages (to defer the parsing of individual
+	// fields from the unmarshalled interface until later) and unmarshal the input
+	// byte array into that map
+	t := make(map[string]json.RawMessage)
+	if err := json.Unmarshal(data, &t); err != nil {
+		return err
+	}
+	// loop through the individual map elements, parse each in turn, and set
+	// the appropriate field in this configuration
+	for k, v := range t {
+		switch k {
+		case "max_running_plugins":
+			if err := json.Unmarshal(v, &(c.MaxRunningPlugins)); err != nil {
+				return err
+			}
+		case "plugin_trust_level":
+			if err := json.Unmarshal(v, &(c.PluginTrust)); err != nil {
+				return err
+			}
+		case "auto_discover_path":
+			if err := json.Unmarshal(v, &(c.AutoDiscoverPath)); err != nil {
+				return err
+			}
+		case "keyring_paths":
+			if err := json.Unmarshal(v, &(c.KeyringPaths)); err != nil {
+				return err
+			}
+		case "cache_expiration":
+			if err := json.Unmarshal(v, &(c.CacheExpiration)); err != nil {
+				return err
+			}
+		case "plugins":
+			if err := json.Unmarshal(v, c.Plugins); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 // NewPluginsConfig returns a map of *pluginConfigItems where the key is the plugin name.
 func NewPluginsConfig() map[string]*pluginConfigItem {
 	return map[string]*pluginConfigItem{}

mgmt/rest/server.go

@@ -67,6 +67,9 @@ var (
 )
 
 // holds the configuration passed in through the SNAP config file
+//   Note: if this struct is modified, then the switch statement in the
+//         UnmarshalJSON method in this same file needs to be modified to
+//         match the field mapping that is defined here
 type Config struct {
 	Enable           bool   `json:"enable,omitempty"yaml:"enable,omitempty"`
 	Port             int    `json:"port,omitempty"yaml:"port,omitempty"`
@@ -181,6 +184,53 @@ func GetDefaultConfig() *Config {
 	}
 }
 
+// UnmarshalJSON unmarshals valid json into a Config.  An example Config can be found
+// at github.com/intelsdi-x/snap/blob/master/examples/configs/snap-config-sample.json
+func (c *Config) UnmarshalJSON(data []byte) error {
+	// construct a map of strings to json.RawMessages (to defer the parsing of individual
+	// fields from the unmarshalled interface until later) and unmarshal the input
+	// byte array into that map
+	t := make(map[string]json.RawMessage)
+	if err := json.Unmarshal(data, &t); err != nil {
+		return err
+	}
+	// loop through the individual map elements, parse each in turn, and set
+	// the appropriate field in this configuration
+	for k, v := range t {
+		switch k {
+		case "enable":
+			if err := json.Unmarshal(v, &(c.Enable)); err != nil {
+				return err
+			}
+		case "port":
+			if err := json.Unmarshal(v, &(c.Port)); err != nil {
+				return err
+			}
+		case "https":
+			if err := json.Unmarshal(v, &(c.HTTPS)); err != nil {
+				return err
+			}
+		case "rest_certificate":
+			if err := json.Unmarshal(v, &(c.RestCertificate)); err != nil {
+				return err
+			}
+		case "rest_key":
+			if err := json.Unmarshal(v, &(c.RestKey)); err != nil {
+				return err
+			}
+		case "rest_auth":
+			if err := json.Unmarshal(v, &(c.RestAuth)); err != nil {
+				return err
+			}
+		case "rest_auth_password":
+			if err := json.Unmarshal(v, &(c.RestAuthPassword)); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 // SetAPIAuth sets API authentication to enabled or disabled
 func (s *Server) SetAPIAuth(auth bool) {
 	s.auth = auth

mgmt/tribe/config.go

@@ -20,6 +20,7 @@ limitations under the License.
 package tribe
 
 import (
+	"encoding/json"
 	"net"
 	"os"
 	"time"
@@ -41,6 +42,9 @@ const (
 )
 
 // holds the configuration passed in through the SNAP config file
+//   Note: if this struct is modified, then the switch statement in the
+//         UnmarshalJSON method in this same file needs to be modified to
+//         match the field mapping that is defined here
 type Config struct {
 	Name                      string             `json:"name,omitempty"yaml:"name,omitempty"`
 	Enable                    bool               `json:"enable,omitempty"yaml:"enable,omitempty"`
@@ -73,6 +77,45 @@ func GetDefaultConfig() *Config {
 	}
 }
 
+// UnmarshalJSON unmarshals valid json into a Config.  An example Config can be found
+// at github.com/intelsdi-x/snap/blob/master/examples/configs/snap-config-sample.json
+func (c *Config) UnmarshalJSON(data []byte) error {
+	// construct a map of strings to json.RawMessages (to defer the parsing of individual
+	// fields from the unmarshalled interface until later) and unmarshal the input
+	// byte array into that map
+	t := make(map[string]json.RawMessage)
+	if err := json.Unmarshal(data, &t); err != nil {
+		return err
+	}
+	// loop through the individual map elements, parse each in turn, and set
+	// the appropriate field in this configuration
+	for k, v := range t {
+		switch k {
+		case "name":
+			if err := json.Unmarshal(v, &(c.Name)); err != nil {
+				return err
+			}
+		case "enable":
+			if err := json.Unmarshal(v, &(c.Enable)); err != nil {
+				return err
+			}
+		case "bind_addr":
+			if err := json.Unmarshal(v, &(c.BindAddr)); err != nil {
+				return err
+			}
+		case "bind_port":
+			if err := json.Unmarshal(v, &(c.BindPort)); err != nil {
+				return err
+			}
+		case "seed":
+			if err := json.Unmarshal(v, &(c.Seed)); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 func getHostname() string {
 	hostname, err := os.Hostname()
 	if err != nil {

scheduler/config.go

@@ -19,13 +19,18 @@ limitations under the License.
 
 package scheduler
 
+import "encoding/json"
+
 // default configuration values
 const (
 	defaultWorkManagerQueueSize uint = 25
 	defaultWorkManagerPoolSize  uint = 4
 )
 
 // holds the configuration passed in through the SNAP config file
+//   Note: if this struct is modified, then the switch statement in the
+//         UnmarshalJSON method in this same file needs to be modified to
+//         match the field mapping that is defined here
 type Config struct {
 	WorkManagerQueueSize uint `json:"work_manager_queue_size,omitempty"yaml:"work_manager_queue_size,omitempty"`
 	WorkManagerPoolSize  uint `json:"work_manager_pool_size,omitempty"yaml:"work_manager_pool_size,omitempty"`
@@ -38,3 +43,30 @@ func GetDefaultConfig() *Config {
 		WorkManagerPoolSize:  defaultWorkManagerPoolSize,
 	}
 }
+
+// UnmarshalJSON unmarshals valid json into a Config.  An example Config can be found
+// at github.com/intelsdi-x/snap/blob/master/examples/configs/snap-config-sample.json
+func (c *Config) UnmarshalJSON(data []byte) error {
+	// construct a map of strings to json.RawMessages (to defer the parsing of individual
+	// fields from the unmarshalled interface until later) and unmarshal the input
+	// byte array into that map
+	t := make(map[string]json.RawMessage)
+	if err := json.Unmarshal(data, &t); err != nil {
+		return err
+	}
+	// loop through the individual map elements, parse each in turn, and set
+	// the appropriate field in this configuration
+	for k, v := range t {
+		switch k {
+		case "work_manager_queue_size":
+			if err := json.Unmarshal(v, &(c.WorkManagerQueueSize)); err != nil {
+				return err
+			}
+		case "work_manager_pool_size":
+			if err := json.Unmarshal(v, &(c.WorkManagerPoolSize)); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

snapd.go

@@ -20,6 +20,7 @@ limitations under the License.
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -147,6 +148,9 @@ const (
 )
 
 // holds the configuration passed in through the SNAP config file
+//   Note: if this struct is modified, then the switch statement in the
+//         UnmarshalJSON method in this same file needs to be modified to
+//         match the field mapping that is defined here
 type Config struct {
 	LogLevel   int               `json:"log_level,omitempty"yaml:"log_level,omitempty"`
 	GoMaxProcs int               `json:"gomaxprocs,omitempty"yaml:"gomaxprocs,omitempty"`
@@ -702,6 +706,53 @@ func setMaxProcs(maxProcs int) {
 	}
 }
 
+// UnmarshalJSON unmarshals valid json into a Config.  An example Config can be found
+// at github.com/intelsdi-x/snap/blob/master/examples/configs/snap-config-sample.json
+func (c *Config) UnmarshalJSON(data []byte) error {
+	// construct a map of strings to json.RawMessages (to defer the parsing of individual
+	// fields from the unmarshalled interface until later), then unmarshal the input
+	// byte array into that map
+	t := make(map[string]json.RawMessage)
+	if err := json.Unmarshal(data, &t); err != nil {
+		return err
+	}
+	// loop through the individual map elements, parse each in turn, and set
+	// the appropriate field in this configuration
+	for k, v := range t {
+		switch k {
+		case "log_level":
+			if err := json.Unmarshal(v, &(c.LogLevel)); err != nil {
+				return err
+			}
+		case "gomaxprocs":
+			if err := json.Unmarshal(v, &(c.GoMaxProcs)); err != nil {
+				return err
+			}
+		case "log_path":
+			if err := json.Unmarshal(v, &(c.LogPath)); err != nil {
+				return err
+			}
+		case "control":
+			if err := json.Unmarshal(v, c.Control); err != nil {
+				return err
+			}
+		case "restapi":
+			if err := json.Unmarshal(v, c.RestAPI); err != nil {
+				return err
+			}
+		case "scheduler":
+			if err := json.Unmarshal(v, c.Scheduler); err != nil {
+				return err
+			}
+		case "tribe":
+			if err := json.Unmarshal(v, c.Tribe); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 func startModule(m coreModule) error {
 	err := m.Start()
 	if err == nil {