support pre/post reconcile scripts

Signed-off-by: Travis Glenn Hansen <travisghansen@yahoo.com>

CHANGELOG.md

@@ -1,10 +1,20 @@
+# v0.4.1
+
+Released 2023-07-21
+
+- add additional packages to container image
+- support executing arbitrary pre/post scripts during reconcile (should be
+  idempotent)
+- bump docker base image to `hydrogen-bookworm-slim`
+
 # v0.4.0
 
 Released 2023-07-20
 
 - remove management of `TABLE_NAME` in `/etc/iproute2/rt_tables`
 - better management of watches to unsubscribe when appropriate
 - more robust reconcile logic to prevent race conditions
+- support `RULE_FWMARK`
 
 # v0.3.2
 

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:gallium-bullseye-slim AS build
+FROM node:hydrogen-bookworm-slim AS build
 
 ENV DEBIAN_FRONTEND=noninteractive
 
@@ -19,7 +19,7 @@ COPY . .
 ######################
 # actual image
 ######################
-FROM node:gallium-bullseye-slim
+FROM node:hydrogen-bookworm-slim
 
 LABEL org.opencontainers.image.source https://github.com/travisghansen/metallb-node-route-agent
 
@@ -31,7 +31,17 @@ ARG BUILDPLATFORM
 
 RUN echo "I am running on final $BUILDPLATFORM, building for $TARGETPLATFORM"
 
-RUN apt-get update && apt-get install -y iproute2 && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && \
+    cd ~ && \
+    apt-get install -y iproute2 xz-utils conntrack ipset iptables wget curl jq && \
+    wget -c https://xyne.dev/projects/idemptables/src/idemptables-2012.tar.xz -O - | tar -Jxv && \
+    install -o root -g root -m 0755 idemptables-2012/idemptables /usr/sbin/idemptables && \
+    rm -rf idemptables-2012/ && \
+    sed -i 's:#!/bin/sh:#!/bin/bash:g' /usr/sbin/idemptables && \
+    curl -LO https://dl.k8s.io/release/v1.27.3/bin/linux/amd64/kubectl && \
+    install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl && \
+    rm -rf kubectl && \
+    rm -rf /var/lib/apt/lists/*
 
 COPY --from=build /app /app
 

README.md

@@ -41,8 +41,12 @@ your nodes have the sysctl `net.ipv4.fib_multipath_use_neigh` set to `1`.
 - `RULE_FWMARK` - the fwmark to give to the managed rules (show be provided in
   hex format exactly as the `ip` output shows)
   - default: unset
-- `DESTINATION` - the `dst` network of the rule
+- `DESTINATION` - the `dst` network of the route
   - default: `default`
+- `PRE_RECONCILE_SCRIPT_PATH` - path to script (must be marked executable) to
+  run _before_ the reonciliation happens
+- `POST_RECONCILE_SCRIPT_PATH` - path to script (must be marked executable) to
+  run _after_ the reonciliation happens
 - `METALLB_NAMESPACE` - namespace where `metallb` is running
   - default: `""`
   - will fallback to the value in
@@ -53,6 +57,8 @@ your nodes have the sysctl `net.ipv4.fib_multipath_use_neigh` set to `1`.
 - `METALLB_STATIC_FILE` - a static file on the filesystem to monitor (mostly
   for development purposes). If set the k8s watch is disabled entirely.
 - `METALLB_USE_CRDS` - prefer `CRDs` over configmap
+- `LOG_LEVEL` - `error|warn|info|verbose|debug|silly`
+  - default: `info`
 - `CLEANANDEXIT` - if equals `1` then all rules/tables will be deleted and the
   process will exit
 - `ONESHOT` - if equals `1` then then reconciliation will complete once and the

agent.js

@@ -1,4 +1,5 @@
 const _ = require('lodash');
+const cp = require('child_process');
 const AsyncMutex = require('async-mutex');
 const fs = require('fs');
 const { IpAddress, IpRange } = require('cidr-calc');
@@ -58,6 +59,9 @@ const METALLB_USE_CRDS = process.env.METALLB_USE_CRDS;
 
 const NODE_NAME = process.env.NODE_NAME;
 
+const PRE_RECONCILE_SCRIPT_PATH = process.env.PRE_RECONCILE_SCRIPT_PATH;
+const POST_RECONCILE_SCRIPT_PATH = process.env.POST_RECONCILE_SCRIPT_PATH;
+
 // globals
 let metallb_loaded = false;
 
@@ -128,6 +132,22 @@ async function reconcile() {
         return;
       }
 
+      if (PRE_RECONCILE_SCRIPT_PATH) {
+        logger.verbose(
+          `executing PRE_RECONCILE_SCRIPT_PATH: ${PRE_RECONCILE_SCRIPT_PATH}`
+        );
+        let res = cp.spawnSync(PRE_RECONCILE_SCRIPT_PATH, [], {
+          timeout: 10 * 1000
+        });
+
+        let message = `executed ${PRE_RECONCILE_SCRIPT_PATH}: code=${res.status}, signal=${res.signal}, stdout=${res.stdout}, stderr=${res.stderr}`;
+        if (res.status != 0) {
+          logger.warn(message);
+        } else {
+          logger.debug(message);
+        }
+      }
+
       let args = [];
 
       //logger.info('skipping reconcile, development debug');
@@ -351,6 +371,22 @@ async function reconcile() {
         }
       }
 
+      if (POST_RECONCILE_SCRIPT_PATH) {
+        logger.verbose(
+          `executing POST_RECONCILE_SCRIPT_PATH: ${POST_RECONCILE_SCRIPT_PATH}`
+        );
+        let res = cp.spawnSync(POST_RECONCILE_SCRIPT_PATH, [], {
+          timeout: 10 * 1000
+        });
+
+        let message = `executed ${POST_RECONCILE_SCRIPT_PATH}: code=${res.status}, signal=${res.signal}, stdout=${res.stdout}, stderr=${res.stderr}`;
+        if (res.status != 0) {
+          logger.warn(message);
+        } else {
+          logger.debug(message);
+        }
+      }
+
       logger.verbose('reconcile finished');
       if (process.env.ONESHOT == '1') {
         logger.info('exiting due to ONESHOT');

charts/metallb-node-route-agent/Chart.yaml

@@ -15,10 +15,10 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.4.0
+version: 0.4.1
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
 # It is recommended to use it with quotes.
-appVersion: "0.4.0"
+appVersion: "0.4.1"

charts/metallb-node-route-agent/templates/configmap.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ include "metallb-node-route-agent.fullname" . }}
+  labels:
+    {{- include "metallb-node-route-agent.labels" . | nindent 4 }}
+data:
+  config.yaml: |
+   foo: bar
+{{- with .Values.configMapData }}
+{{- toYaml . | nindent 2 }}
+{{- end }}

charts/metallb-node-route-agent/templates/daemonset.yaml

@@ -39,6 +39,9 @@ spec:
           volumeMounts:
           - name: iproute2
             mountPath: /etc/iproute2
+          - name: configmap
+            mountPath: /tmp/config
+            readOnly: true
           env:
           - name: NODE_NAME
             valueFrom:
@@ -66,3 +69,8 @@ spec:
         hostPath:
           path: /etc/iproute2
           type: Directory
+      - name: configmap
+        configMap:
+          name: {{ include "metallb-node-route-agent.fullname" . }}
+          # 770 in unix decimal
+          defaultMode: 504

charts/metallb-node-route-agent/templates/rbac.yaml

@@ -17,6 +17,8 @@ apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: {{ include "metallb-node-route-agent.serviceAccountName" . }}
   namespace: {{ .Release.Namespace | quote }}
+  labels:
+    {{- include "metallb-node-route-agent.labels" . | nindent 4 }}
 rules:
 - apiGroups:
   - ""
@@ -41,6 +43,8 @@ apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: {{ include "metallb-node-route-agent.serviceAccountName" . }}
   namespace: {{ .Release.Namespace | quote }}
+  labels:
+    {{- include "metallb-node-route-agent.labels" . | nindent 4 }}
 subjects:
   - kind: ServiceAccount
     name: {{ include "metallb-node-route-agent.serviceAccountName" . }}
@@ -54,6 +58,8 @@ kind: ClusterRole
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: {{ include "metallb-node-route-agent.serviceAccountName" . }}
+  labels:
+    {{- include "metallb-node-route-agent.labels" . | nindent 4 }}
 rules:
 - apiGroups:
   - ""
@@ -68,6 +74,8 @@ kind: ClusterRoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: {{ include "metallb-node-route-agent.serviceAccountName" . }}
+  labels:
+    {{- include "metallb-node-route-agent.labels" . | nindent 4 }}
 roleRef:
   apiGroup: rbac.authorization.k8s.io
   kind: ClusterRole

charts/metallb-node-route-agent/values.yaml

@@ -15,6 +15,15 @@ imagePullSecrets: []
 nameOverride: ""
 fullnameOverride: ""
 
+# all files get mounted to /tmp/config 770 perms
+configMapData: {}
+#  pre.sh: |
+#    #/bin/bash
+#    echo hello world
+#  post.sh: |
+#    #/bin/bash
+#    echo hello world
+
 rbac:
   enabled: true
 

lib/ip.js

@@ -223,7 +223,13 @@ class IpCommand {
       });
 
       child.on('close', function (code) {
-        const result = { code, stdout, stderr, timeout: false };
+        const result = {
+          code,
+          stdout,
+          stderr,
+          timeout: false,
+          command: `${command} ${args.join(' ')}`
+        };
 
         ip.options.logger.debug('ip command result:', result);
         // timeout scenario