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Rework port binding logic without privileges
This is a breaking change! To start Nginx Ingress Controller with this commit applied, you must use an updated image. Historically, the Ingress Controller entrypoint launched with restricted capabilities. Then Nginx process escalated privileges (NET_BIND_SERVICE) to bind ports 80 and 443 as non-root user. Allowing privilege escalation is generally frowned upon in various policies. The Nginx binary in old images was adding NET_BIND_SERVICE to its Permitted capability set and also setting the Effective bit, to enforce the Permitted capability during launch. (That's the escalation there.) With this change, privilege escalation is no longer allowed and the NET_BIND_SERVICE capability is removed. To allow the binary to start, the capabilities are no longer being adjusted on the binary file. This works because Kubernetes v1.22+ allows Pods to independently lower unprivileged port range to start with zero without affecting other ports (namespaced/"safe" sysctls). OBS! An old image may be used if the binary's Effective bit is removed: FROM nginx/nginx-ingress:3.0.2 USER root RUN setcap 'cap_net_bind_service=-e' /usr/sbin/nginx 'cap_net_bind_service=-e' /usr/sbin/nginx-debug \ && setcap -v 'cap_net_bind_service=-e' /usr/sbin/nginx 'cap_net_bind_service=-e' /usr/sbin/nginx-debug # 101 is nginx USER 101
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-26
lines changed

12 files changed

+37
-26
lines changed

‎.github/workflows/ci.yml‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -296,7 +296,7 @@ jobs:
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{\"image\": \"debian-plus-nap\", \"marker\": \"appprotect\"}], \
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\"k8s\": [\"${{ needs.checks.outputs.k8s_latest }}\"]}" >> $GITHUB_OUTPUT
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else
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echo "matrix={\"k8s\": [\"1.21.14\", \"1.22.15\", \"1.23.13\", \"1.24.7\", \"1.25.3\", \"${{ needs.checks.outputs.k8s_latest }}\"], \
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echo "matrix={\"k8s\": [\"1.22.15\", \"1.23.13\", \"1.24.7\", \"1.25.3\", \"${{ needs.checks.outputs.k8s_latest }}\"], \
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\"images\": [{\"image\": \"debian\"}, {\"image\": \"debian-plus\"}]}" >> $GITHUB_OUTPUT
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fi
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‎build/Dockerfile‎

Lines changed: 1 addition & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -186,7 +186,7 @@ RUN --mount=type=secret,id=nginx-repo.crt,dst=/etc/ssl/nginx/nginx-repo.crt,mode
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# RUN update-ca-trust extract
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189-
############################################# Create common files, permissions and setcap #############################################
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############################################# Create common files and permissions #############################################
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FROM ${BUILD_OS} as common
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ARG BUILD_OS
@@ -209,8 +209,6 @@ RUN [ -n "${NAP_MODULES##*dos*}" ] && exit 0; mkdir -p /root/app_protect_dos /et
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&& chmod 777 /shared/cores /var/log/adm /var/run/adm /etc/app_protect_dos
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RUN --mount=type=bind,target=/tmp mkdir -p /var/lib/nginx /etc/nginx/secrets /etc/nginx/stream-conf.d \
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&& setcap 'cap_net_bind_service=+ep' /usr/sbin/nginx 'cap_net_bind_service=+ep' /usr/sbin/nginx-debug \
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&& setcap -v 'cap_net_bind_service=+ep' /usr/sbin/nginx 'cap_net_bind_service=+ep' /usr/sbin/nginx-debug \
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&& [ -z "${BUILD_OS##*plus*}" ] && PLUS=-plus; cp -a /tmp/internal/configs/version1/nginx$PLUS.ingress.tmpl /tmp/internal/configs/version1/nginx$PLUS.tmpl \
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/tmp/internal/configs/version2/nginx$PLUS.virtualserver.tmpl /tmp/internal/configs/version2/nginx$PLUS.transportserver.tmpl / \
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&& chown -R 101:0 /etc/nginx /var/cache/nginx /var/lib/nginx /*.tmpl \

‎cmd/nginx-ingress/main.go‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -233,7 +233,7 @@ func kubernetesVersionInfo(kubeClient kubernetes.Interface) {
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}
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glog.Infof("Kubernetes version: %v", k8sVersion)
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236-
minK8sVersion, err := util_version.ParseGeneric("1.21.0")
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minK8sVersion, err := util_version.ParseGeneric("1.22.0")
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if err != nil {
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glog.Fatalf("unexpected error parsing minimum supported version: %v", err)
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}

‎deployments/daemon-set/nginx-ingress.yaml‎

Lines changed: 5 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -19,6 +19,10 @@ spec:
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spec:
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serviceAccountName: nginx-ingress
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automountServiceAccountToken: true
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securityContext:
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sysctls:
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- name: "net.ipv4.ip_unprivileged_port_start"
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value: "0"
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containers:
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- image: nginx/nginx-ingress:3.0.2
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imagePullPolicy: IfNotPresent
@@ -47,13 +51,11 @@ spec:
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# cpu: "1"
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# memory: "1Gi"
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securityContext:
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allowPrivilegeEscalation: true
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allowPrivilegeEscalation: false
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runAsUser: 101 #nginx
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capabilities:
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drop:
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- ALL
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add:
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- NET_BIND_SERVICE
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env:
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- name: POD_NAMESPACE
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valueFrom:

‎deployments/daemon-set/nginx-plus-ingress.yaml‎

Lines changed: 5 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -19,6 +19,10 @@ spec:
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spec:
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serviceAccountName: nginx-ingress
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automountServiceAccountToken: true
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securityContext:
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sysctls:
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- name: "net.ipv4.ip_unprivileged_port_start"
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value: "0"
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containers:
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- image: nginx-plus-ingress:3.0.2
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imagePullPolicy: IfNotPresent
@@ -47,13 +51,11 @@ spec:
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# cpu: "1"
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# memory: "1Gi"
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securityContext:
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allowPrivilegeEscalation: true
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allowPrivilegeEscalation: false
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runAsUser: 101 #nginx
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capabilities:
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drop:
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- ALL
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add:
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- NET_BIND_SERVICE
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env:
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- name: POD_NAMESPACE
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valueFrom:

‎deployments/deployment/nginx-ingress.yaml‎

Lines changed: 5 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -20,6 +20,10 @@ spec:
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spec:
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serviceAccountName: nginx-ingress
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automountServiceAccountToken: true
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securityContext:
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sysctls:
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- name: "net.ipv4.ip_unprivileged_port_start"
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value: "0"
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containers:
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- image: nginx/nginx-ingress:3.0.2
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imagePullPolicy: IfNotPresent
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# cpu: "1"
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# memory: "1Gi"
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securityContext:
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allowPrivilegeEscalation: true
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allowPrivilegeEscalation: false
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runAsUser: 101 #nginx
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runAsNonRoot: true
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capabilities:
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drop:
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- ALL
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add:
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- NET_BIND_SERVICE
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env:
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- name: POD_NAMESPACE
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valueFrom:

‎deployments/deployment/nginx-plus-ingress.yaml‎

Lines changed: 5 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -20,6 +20,10 @@ spec:
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spec:
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serviceAccountName: nginx-ingress
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automountServiceAccountToken: true
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securityContext:
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sysctls:
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- name: "net.ipv4.ip_unprivileged_port_start"
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value: "0"
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containers:
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- image: nginx-plus-ingress:3.0.2
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imagePullPolicy: IfNotPresent
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# cpu: "1"
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# memory: "1Gi"
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securityContext:
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allowPrivilegeEscalation: true
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allowPrivilegeEscalation: false
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runAsUser: 101 #nginx
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runAsNonRoot: true
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capabilities:
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drop:
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- ALL
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add:
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- NET_BIND_SERVICE
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env:
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- name: POD_NAMESPACE
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valueFrom:

‎deployments/helm-chart-dos-arbitrator/Chart.yaml‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,7 @@ name: nginx-appprotect-dos-arbitrator
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version: 0.1.0
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appVersion: 1.1.0
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apiVersion: v1
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kubeVersion: ">= 1.21.0-0"
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kubeVersion: ">= 1.22.0-0"
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description: NGINX App Protect Dos arbitrator
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icon: https://raw.githubusercontent.com/nginxinc/kubernetes-ingress/v3.0.2/deployments/helm-chart-dos-arbitrator/chart-icon.png
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home: https://github.com/nginxinc/kubernetes-ingress

‎deployments/helm-chart/Chart.yaml‎

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Original file line numberDiff line numberDiff line change
@@ -2,7 +2,7 @@ apiVersion: v2
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name: nginx-ingress
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version: 0.16.2
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appVersion: 3.0.2
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kubeVersion: ">= 1.21.0-0"
5+
kubeVersion: ">= 1.22.0-0"
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type: application
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description: NGINX Ingress Controller
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icon: https://raw.githubusercontent.com/nginxinc/kubernetes-ingress/v3.0.2/deployments/helm-chart/chart-icon.png

‎deployments/helm-chart/templates/controller-daemonset.yaml‎

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Original file line numberDiff line numberDiff line change
@@ -43,6 +43,10 @@ spec:
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spec:
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serviceAccountName: {{ include "nginx-ingress.serviceAccountName" . }}
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automountServiceAccountToken: true
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securityContext:
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sysctls:
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- name: "net.ipv4.ip_unprivileged_port_start"
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value: "0"
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terminationGracePeriodSeconds: {{ .Values.controller.terminationGracePeriodSeconds }}
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{{- if .Values.controller.nodeSelector }}
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nodeSelector:
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initialDelaySeconds: {{ .Values.controller.readyStatus.initialDelaySeconds }}
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{{- end }}
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securityContext:
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allowPrivilegeEscalation: true
117+
allowPrivilegeEscalation: false
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runAsUser: 101 #nginx
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runAsNonRoot: true
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capabilities:
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drop:
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- ALL
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add:
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- NET_BIND_SERVICE
121123
{{- if or .Values.controller.volumeMounts .Values.nginxServiceMesh.enable }}
122124
volumeMounts:
123125
{{- end }}

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