Get RancherOS logging to throw debug logs to a remote syslog server when the kernel netconsole is configured

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

config/cmdline/cmdline.go

@@ -0,0 +1,171 @@
+package cmdline
+
+import (
+	"io/ioutil"
+	"strings"
+
+	yaml "github.com/cloudfoundry-incubator/candiedyaml"
+	"github.com/rancher/os/util"
+)
+
+func Read(parseAll bool) (m map[interface{}]interface{}, err error) {
+	cmdLine, err := ioutil.ReadFile("/proc/cmdline")
+	if err != nil {
+		return nil, err
+	}
+
+	if len(cmdLine) == 0 {
+		return nil, nil
+	}
+
+	cmdLineObj := Parse(strings.TrimSpace(util.UnescapeKernelParams(string(cmdLine))), parseAll)
+
+	return cmdLineObj, nil
+}
+
+func GetCmdline(key string) interface{} {
+	parseAll := true
+	if strings.HasPrefix(key, "cc.") || strings.HasPrefix(key, "rancher.") {
+		// the normal case
+		parseAll = false
+	}
+	cmdline, _ := Read(parseAll)
+	v, _ := GetOrSetVal(key, cmdline, nil)
+	return v
+}
+
+func GetOrSetVal(args string, data map[interface{}]interface{}, value interface{}) (interface{}, map[interface{}]interface{}) {
+	parts := strings.Split(args, ".")
+
+	tData := data
+	if value != nil {
+		tData = util.MapCopy(data)
+	}
+	t := tData
+	for i, part := range parts {
+		val, ok := t[part]
+		last := i+1 == len(parts)
+
+		// Reached end, set the value
+		if last && value != nil {
+			if s, ok := value.(string); ok {
+				value = unmarshalOrReturnString(s)
+			}
+
+			t[part] = value
+			return value, tData
+		}
+
+		// Missing intermediate key, create key
+		if !last && value != nil && !ok {
+			newData := map[interface{}]interface{}{}
+			t[part] = newData
+			t = newData
+			continue
+		}
+
+		if !ok {
+			break
+		}
+
+		if last {
+			return val, tData
+		}
+
+		newData, ok := val.(map[interface{}]interface{})
+		if !ok {
+			break
+		}
+
+		t = newData
+	}
+
+	return "", tData
+}
+
+// Replace newlines, colons, and question marks with random strings
+// This is done to avoid YAML treating these as special characters
+var (
+	newlineMagicString      = "9XsJcx6dR5EERYCC"
+	colonMagicString        = "V0Rc21pIVknMm2rr"
+	questionMarkMagicString = "FoPL6JLMAaJqKMJT"
+)
+
+func reverseReplacement(result interface{}) interface{} {
+	switch val := result.(type) {
+	case map[interface{}]interface{}:
+		for k, v := range val {
+			val[k] = reverseReplacement(v)
+		}
+		return val
+	case []interface{}:
+		for i, item := range val {
+			val[i] = reverseReplacement(item)
+		}
+		return val
+	case string:
+		val = strings.Replace(val, newlineMagicString, "\n", -1)
+		val = strings.Replace(val, colonMagicString, ":", -1)
+		val = strings.Replace(val, questionMarkMagicString, "?", -1)
+		return val
+	}
+
+	return result
+}
+
+func unmarshalOrReturnString(value string) (result interface{}) {
+	value = strings.Replace(value, "\n", newlineMagicString, -1)
+	value = strings.Replace(value, ":", colonMagicString, -1)
+	value = strings.Replace(value, "?", questionMarkMagicString, -1)
+	if err := yaml.Unmarshal([]byte(value), &result); err != nil {
+		result = value
+	}
+	result = reverseReplacement(result)
+	return
+}
+
+func Parse(cmdLine string, parseAll bool) map[interface{}]interface{} {
+	result := make(map[interface{}]interface{})
+
+outer:
+	for _, part := range strings.Split(cmdLine, " ") {
+		if strings.HasPrefix(part, "cc.") {
+			part = part[3:]
+		} else if !strings.HasPrefix(part, "rancher.") {
+			if !parseAll {
+				continue
+			}
+		}
+
+		var value string
+		kv := strings.SplitN(part, "=", 2)
+
+		if len(kv) == 1 {
+			value = "true"
+		} else {
+			value = kv[1]
+		}
+
+		current := result
+		keys := strings.Split(kv[0], ".")
+		for i, key := range keys {
+			if i == len(keys)-1 {
+				current[key] = unmarshalOrReturnString(value)
+			} else {
+				if obj, ok := current[key]; ok {
+					if newCurrent, ok := obj.(map[interface{}]interface{}); ok {
+						current = newCurrent
+					} else {
+						continue outer
+					}
+				} else {
+					newCurrent := make(map[interface{}]interface{})
+					current[key] = newCurrent
+					current = newCurrent
+				}
+			}
+		}
+	}
+
+	return result
+}