Configuration updates (EKS 1.24+)

amazon-eks-al2.pkr.hcl

@@ -142,6 +142,10 @@ build {
  provisioner "shell" {
  execute_command = "echo 'packer' | {{ .Vars }} sudo -S -E bash -eux '{{ .Path }}'"
 
+ env = {
+ MOTD_CONTENT = var.motd_content
+ }
+
  scripts = [
  "scripts/cis-benchmark.sh",
  "scripts/cis-docker.sh",

scripts/cis-benchmark.sh

@@ -200,43 +200,16 @@ sed -i 's/SELINUX=disabled/SELINUX=enforcing/g' /etc/selinux/config
 
 echo "1.7.1.1 - ensure message of the day is configured properly"
 rm -f /etc/cron.d/update-motd
-cat > /etc/update-motd.d/30-banner <<"OUTEREOF"
+cat > /etc/update-motd.d/30-banner <<EOF
 #!/bin/sh
-cat <<"EOF"
-You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.
-
-By using this IS (which includes any device attached to this IS), you consent to the following conditions:
--The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
--At any time, the USG may inspect and seize data stored on this IS.
--Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
--This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.
--Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
+cat "$MOTD_CONTENT"
 EOF
-OUTEREOF
 
 echo "1.7.1.2 - ensure local login warning banner is configured properly"
-cat > /etc/issue <<EOF
-You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.
-
-By using this IS (which includes any device attached to this IS), you consent to the following conditions:
--The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
--At any time, the USG may inspect and seize data stored on this IS.
--Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
--This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.
--Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
-EOF
+cat > /etc/issue <<< "$MOTD_CONTENT"
 
 echo "1.7.1.3 - ensure remote login warning banner is configured properly"
-cat > /etc/issue.net <<EOF
-You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.
-
-By using this IS (which includes any device attached to this IS), you consent to the following conditions:
--The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
--At any time, the USG may inspect and seize data stored on this IS.
--Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
--This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.
--Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
-EOF
+cat > /etc/issue.net <<< "$MOTD_CONTENT"
 
 echo "1.7.1.4 - ensure permissions on /etc/motd are configured"
 chown root:root /etc/motd
@@ -327,8 +300,10 @@ echo "2.2.4 - ensure LDAP client is not installed"
 yum_remove openldap-clients
 
 echo "3.1.1 - ensure IP forwarding is disabled"
-sysctl_entry "net.ipv4.ip_forward = 0"
-sysctl_entry "net.ipv6.conf.all.forwarding = 0"
+# Required for working container networking
+# sysctl_entry "net.ipv4.ip_forward = 0"
+# sysctl_entry "net.ipv4.conf.all.forwarding = 0"
+# sysctl_entry "net.ipv6.conf.all.forwarding = 0"
 
 echo "3.1.2 - ensure packet redirect sending is disabled"
 sysctl_entry "net.ipv4.conf.all.send_redirects = 0"
@@ -593,7 +568,7 @@ AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
 AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
 AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE
 AcceptEnv XMODIFIERS
-Subsystem sftp /usr/libexec/openssh/sftp-server
+Subsystem sftp /usr/libexec/openssh/sftp-server
 AuthorizedKeysCommand /opt/aws/bin/eic_run_authorized_keys %u %f
 AuthorizedKeysCommandUser ec2-instance-connect
 

scripts/cis-docker.sh

@@ -49,11 +49,10 @@ echo "2.1 - 2.17 - ensure the docker configuration is secure"
 cat > /etc/docker/daemon.json <<EOF
 {
  "bridge": "none",
- "log-level": "info",
  "log-driver": "json-file",
  "log-opts": {
  "max-size": "10m",
- "max-file": "5"
+ "max-file": "10"
  },
  "icc": false,
  "iptables": true,
@@ -71,10 +70,21 @@ cat > /etc/docker/daemon.json <<EOF
  }
  },
  "live-restore": true,
- "userland-proxy": false,
  "max-concurrent-downloads": 10,
- "experimental": false,
- "insecure-registries": [],
+ "default-ulimits": {
+ "memlock": {
+ "Name": "memlock",
+ "Soft": -1,
+ "Hard": -1
+ },
+ "nproc": {
+ "Name": "nproc",
+ "Hard": 32768,
+ "Soft": 16384
+ }
+ },
+ "icc": false,
+ "userland-proxy": false,
  "no-new-privileges": true
 }
 EOF

scripts/cis-eks.sh

@@ -58,10 +58,31 @@ cat > /etc/kubernetes/kubelet/kubelet-config.json <<EOF
  "protectKernelDefaults": true,
  "serializeImagePulls": false,
  "serverTLSBootstrap": true,
- "streamingConnectionIdleTimeout": "4h0m0s",
- "makeIPTablesUtilChains": true,
- "eventRecordQPS": 5,
- "RotateCertificate": true,
- "tlsCipherSuites": ["TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256", "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256", "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305", "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384", "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305", "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384", "TLS_RSA_WITH_AES_256_GCM_SHA384", "TLS_RSA_WITH_AES_128_GCM_SHA256"]
+ "rotateCertificates": false,
+ "tlsCipherSuites": [
+ "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+ "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+ "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
+ "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
+ "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
+ "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+ "TLS_RSA_WITH_AES_256_GCM_SHA384",
+ "TLS_RSA_WITH_AES_128_GCM_SHA256"
+ ],
+ "clusterDNS": [
+ "172.20.0.10"
+ ]
 }
 EOF
+
+# /usr/bin/kubelet --version
+# Kubernetes v1.20.15-eks-ba74326
+# -> 1.20
+KUBERNETES_VERSION=$(/usr/bin/kubelet --version | sed -E -e 's!^Kubernetes v([0-9]\.[0-9]+).[0-9]+-.*$!\1!')
+
+# Inject CSIServiceAccountToken feature gate to kubelet config if kubernetes version starts with 1.20.
+# This is only injected for 1.20 since CSIServiceAccountToken will be moved to beta starting 1.21.
+if [[ $KUBERNETES_VERSION == "1.20" ]]; then
+ KUBELET_CONFIG_WITH_CSI_SERVICE_ACCOUNT_TOKEN_ENABLED=$(cat "/etc/kubernetes/kubelet/kubelet-config.json" | jq '.featureGates += {CSIServiceAccountToken: true}')
+ echo $KUBELET_CONFIG_WITH_CSI_SERVICE_ACCOUNT_TOKEN_ENABLED > "/etc/kubernetes/kubelet/kubelet-config.json"
+fi

variables.pkr.hcl

@@ -172,3 +172,18 @@ variable "snapshot_users" {
  type = list(string)
  default = []
 }
+
+variable "motd_content" {
+ description = "Message Of The Day (MOTD) banner content."
+ type = string
+ default = <<EOF
+You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.
+
+By using this IS (which includes any device attached to this IS), you consent to the following conditions:
+-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
+-At any time, the USG may inspect and seize data stored on this IS.
+-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
+-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.
+-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.
+EOF
+}