Build a shim binary that converts node-config.yaml to kubelet args

Will remove the need to have the kubelet start from openshift master

cmd/openshift-node-config/openshift-node-config.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/MakeNowJust/heredoc"
+	"github.com/spf13/cobra"
+
+	"k8s.io/apiserver/pkg/util/logs"
+
+	configapilatest "github.com/openshift/origin/pkg/cmd/server/apis/config/latest"
+	"github.com/openshift/origin/pkg/cmd/server/origin/node"
+)
+
+func main() {
+	logs.InitLogs()
+	defer logs.FlushLogs()
+
+	rand.Seed(time.Now().UTC().UnixNano())
+
+	var configFile string
+
+	cmd := &cobra.Command{
+		Use: "openshift-node-config",
+		Long: heredoc.Doc(`
+			Generate Kubelet configuration from node-config.yaml
+
+			This command converts an existing OpenShift node configuration into the appropriate
+			Kubelet command-line flags.
+		`),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			nodeConfig, err := configapilatest.ReadAndResolveNodeConfig(configFile)
+			if err != nil {
+				return err
+			}
+			return node.WriteKubeletFlags(*nodeConfig)
+		},
+	}
+	cmd.Flags().StringVar(&configFile, "config", "", "The config file to convert to Kubelet arguments.")
+
+	if err := cmd.RunE(cmd, os.Args); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v", err)
+		os.Exit(1)
+	}
+}

hack/lib/constants.sh

@@ -34,6 +34,7 @@ readonly OS_SDN_COMPILE_TARGETS_LINUX=(
 )
 readonly OS_IMAGE_COMPILE_TARGETS_LINUX=(
   "${OS_SDN_COMPILE_TARGETS_LINUX[@]}"
+  cmd/openshift-node-config
 )
 readonly OS_SCRATCH_IMAGE_COMPILE_TARGETS_LINUX=(
   images/pod

pkg/cmd/server/origin/node/node.go

@@ -0,0 +1,43 @@
+package node
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	configapi "github.com/openshift/origin/pkg/cmd/server/apis/config"
+	nodeoptions "github.com/openshift/origin/pkg/cmd/server/kubernetes/node/options"
+)
+
+// safeArgRegexp matches only characters that are known safe. DO NOT add to this list
+// without fully considering whether that new character can be used to break shell escaping
+// rules.
+var safeArgRegexp = regexp.MustCompile(`^[\da-zA-Z\-=_\.,/\:]+$`)
+
+// shellEscapeArg quotes an argument if it contains characters that my cause a shell
+// interpreter to split the single argument into multiple.
+func shellEscapeArg(s string) string {
+	if safeArgRegexp.MatchString(s) {
+		return s
+	}
+	return strconv.Quote(s)
+}
+
+// WriteKubeletFlags writes the correct set of flags to start a Kubelet from the provided node config to
+// stdout, instead of launching anything.
+func WriteKubeletFlags(nodeConfig configapi.NodeConfig) error {
+	kubeletArgs, err := nodeoptions.ComputeKubeletFlags(nodeConfig.KubeletArguments, nodeConfig)
+	if err != nil {
+		return fmt.Errorf("cannot create kubelet args: %v", err)
+	}
+	if err := nodeoptions.CheckFlags(kubeletArgs); err != nil {
+		return err
+	}
+	var outputArgs []string
+	for _, s := range kubeletArgs {
+		outputArgs = append(outputArgs, shellEscapeArg(s))
+	}
+	fmt.Println(strings.Join(outputArgs, " "))
+	return nil
+}

pkg/cmd/server/start/start_node.go

@@ -7,8 +7,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"regexp"
-	"strconv"
 	"strings"
 	"syscall"
 
@@ -35,6 +33,7 @@ import (
 	networkoptions "github.com/openshift/origin/pkg/cmd/server/kubernetes/network/options"
 	"github.com/openshift/origin/pkg/cmd/server/kubernetes/node"
 	nodeoptions "github.com/openshift/origin/pkg/cmd/server/kubernetes/node/options"
+	originnode "github.com/openshift/origin/pkg/cmd/server/origin/node"
 	cmdutil "github.com/openshift/origin/pkg/cmd/util"
 	utilflags "github.com/openshift/origin/pkg/cmd/util/flags"
 	"github.com/openshift/origin/pkg/version"
@@ -281,7 +280,7 @@ func (o NodeOptions) RunNode() error {
 	}
 
 	if o.NodeArgs.WriteFlagsOnly {
-		return WriteKubeletFlags(*nodeConfig)
+		return originnode.WriteKubeletFlags(*nodeConfig)
 	}
 
 	return StartNode(*nodeConfig, o.NodeArgs.Components)
@@ -427,38 +426,6 @@ func execKubelet(kubeletArgs []string) error {
 	return syscall.Exec(kubeletPath, args, os.Environ())
 }
 
-// safeArgRegexp matches only characters that are known safe. DO NOT add to this list
-// without fully considering whether that new character can be used to break shell escaping
-// rules.
-var safeArgRegexp = regexp.MustCompile(`^[\da-zA-Z\-=_\.,/\:]+$`)
-
-// shellEscapeArg quotes an argument if it contains characters that my cause a shell
-// interpreter to split the single argument into multiple.
-func shellEscapeArg(s string) string {
-	if safeArgRegexp.MatchString(s) {
-		return s
-	}
-	return strconv.Quote(s)
-}
-
-// WriteKubeletFlags writes the correct set of flags to start a Kubelet from the provided node config to
-// stdout, instead of launching anything.
-func WriteKubeletFlags(nodeConfig configapi.NodeConfig) error {
-	kubeletArgs, err := nodeoptions.ComputeKubeletFlags(nodeConfig.KubeletArguments, nodeConfig)
-	if err != nil {
-		return fmt.Errorf("cannot create kubelet args: %v", err)
-	}
-	if err := nodeoptions.CheckFlags(kubeletArgs); err != nil {
-		return err
-	}
-	var outputArgs []string
-	for _, s := range kubeletArgs {
-		outputArgs = append(outputArgs, shellEscapeArg(s))
-	}
-	fmt.Println(strings.Join(outputArgs, " "))
-	return nil
-}
-
 // StartNode launches the node processes.
 func StartNode(nodeConfig configapi.NodeConfig, components *utilflags.ComponentFlag) error {
 	kubeletArgs, err := nodeoptions.ComputeKubeletFlags(nodeConfig.KubeletArguments, nodeConfig)