Merge pull request #44 from aojea/flags_better_than_env

don't use obscure env variables and use flags
kubernetes-sigs · Jun 26, 2024 · 1b5734b · 1b5734b
2 parents ac15c29 + 639cb81
commit 1b5734b
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Showing 5 changed files with 12 additions and 6 deletions.
diff --git a/cmd/main.go b/cmd/main.go
@@ -22,6 +22,7 @@ import (
 	v1 "k8s.io/client-go/informers/core/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
+	nodeutil "k8s.io/component-helpers/node/util"
 	"k8s.io/klog/v2"
 
 	"golang.org/x/sys/unix"
@@ -33,6 +34,7 @@ var (
 	baselineAdminNetworkPolicy bool // 	BaselineAdminNetworkPolicy is alpha so keep it feature gated behind a flag
 	queueID                    int
 	metricsBindAddress         string
+	hostnameOverride           string
 )
 
 func init() {
@@ -41,6 +43,7 @@ func init() {
 	flag.BoolVar(&baselineAdminNetworkPolicy, "baseline-admin-network-policy", false, "If set, enable Baseline Admin Network Policy API")
 	flag.IntVar(&queueID, "nfqueue-id", 100, "Number of the nfqueue used")
 	flag.StringVar(&metricsBindAddress, "metrics-bind-address", ":9080", "The IP address and port for the metrics server to serve on")
+	flag.StringVar(&hostnameOverride, "hostname-override", "", "If non-empty, will be used as the name of the Node that kube-network-policies is running on. If unset, the node name is assumed to be the same as the node's hostname.")
 
 	flag.Usage = func() {
 		fmt.Fprint(os.Stderr, "Usage: kube-network-policies [options]\n\n")
@@ -64,9 +67,9 @@ func main() {
 		klog.Fatalf("error parsing metrics bind address %s : %v", metricsBindAddress, err)
 	}
 
-	nodeName := os.Getenv("MY_NODE_NAME")
-	if nodeName == "" {
-		klog.Fatalf("node name not set, please set the environment variable using the Downward API")
+	nodeName, err := nodeutil.GetHostname(hostnameOverride)
+	if err != nil {
+		klog.Fatalf("can not obtain the node name, use the hostname-override flag if you want to set it to a specific value: %v", err)
 	}
 
 	cfg := networkpolicy.Config{

diff --git a/go.mod b/go.mod
@@ -11,6 +11,7 @@ require (
 	k8s.io/apimachinery v0.30.2
 	k8s.io/client-go v0.30.2
 	k8s.io/component-base v0.30.2
+	k8s.io/component-helpers v0.30.2
 	k8s.io/klog/v2 v2.130.1
 	k8s.io/utils v0.0.0-20240310230437-4693a0247e57
 	sigs.k8s.io/knftables v0.0.16

diff --git a/go.sum b/go.sum
@@ -185,6 +185,8 @@ k8s.io/client-go v0.30.2 h1:sBIVJdojUNPDU/jObC+18tXWcTJVcwyqS9diGdWHk50=
 k8s.io/client-go v0.30.2/go.mod h1:JglKSWULm9xlJLx4KCkfLLQ7XwtlbflV6uFFSHTMgVs=
 k8s.io/component-base v0.30.2 h1:pqGBczYoW1sno8q9ObExUqrYSKhtE5rW3y6gX88GZII=
 k8s.io/component-base v0.30.2/go.mod h1:yQLkQDrkK8J6NtP+MGJOws+/PPeEXNpwFixsUI7h/OE=
+k8s.io/component-helpers v0.30.2 h1:kDMYLiWEYeWU7H6jBI+Ua1i2hqNh0DzqDHNIppFC3po=
+k8s.io/component-helpers v0.30.2/go.mod h1:tI0anfS6AbRqooaICkGg7UVAQLedOauVSQW9srDBnJw=
 k8s.io/klog/v2 v2.130.1 h1:n9Xl7H1Xvksem4KFG4PYbdQCQxqc/tTUyrgXaOhHSzk=
 k8s.io/klog/v2 v2.130.1/go.mod h1:3Jpz1GvMt720eyJH1ckRHK1EDfpxISzJ7I9OYgaDtPE=
 k8s.io/kube-openapi v0.0.0-20240411171206-dc4e619f62f3 h1:SbdLaI6mM6ffDSJCadEaD4IkuPzepLDGlkd2xV0t1uA=

diff --git a/install-anp.yaml b/install-anp.yaml
@@ -80,7 +80,7 @@ spec:
       - name: kube-network-policies
         image: registry.k8s.io/networking/kube-network-policies:v0.3.0
         command: ["/bin/netpol"]
-        args: ["-v=2", "-admin-network-policy=true", "-baseline-admin-network-policy=true"]
+        args: ["-v=2", "-admin-network-policy=true", "-baseline-admin-network-policy=true","--hostname-override=$(MY_NODE_NAME)"]
         volumeMounts:
         - name: lib-modules
           mountPath: /lib/modules

diff --git a/install.yaml b/install.yaml
@@ -72,8 +72,8 @@ spec:
         image: registry.k8s.io/networking/kube-network-policies:v0.3.0
         args:
         - /bin/netpol
-        - -v
-        - "2"
+        - --hostname-override=$(MY_NODE_NAME)
+        - --v=2
         volumeMounts:
         - name: lib-modules
           mountPath: /lib/modules