Go rewrite

.github/workflows/build.yaml

@@ -0,0 +1,40 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - golang
+
+jobs:
+  docker:
+    runs-on: ubuntu-20.04
+
+    env:
+      PLATFORMS: linux/amd64,linux/386,linux/arm64,linux/arm/v7
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Install script dependencies
+        run: pip3 install -r scripts/requirements.txt
+
+      - id: vars
+        name: Generate build vars
+        run: |
+          SHA="${{ github.sha }}"
+          echo "::set-output name=tag::"${SHA:0:8}-$(date +%s)Z""
+
+      - name: Build
+        run: make PLUGIN_TAG=${{ steps.vars.outputs.tag }} multiarch
+
+      - name: Push
+        env:
+          REGISTRY_USERNAME: ${{ github.actor }}
+          REGISTRY_PASSWORD: ${{ secrets.GITHUB_TOKEN }}
+        run: make PLUGIN_TAG=${{ steps.vars.outputs.tag }} push-multiarch

.gitignore

@@ -1,4 +1,6 @@
+/bin/*
+!/bin/.gitkeep
 /plugin/
-__pycache__/
+/multiarch/
 
 .vscode/

Dockerfile

@@ -1,12 +1,19 @@
-FROM python:3-alpine
+FROM golang:1.16-alpine3.13 AS builder
 
-COPY requirements.txt /opt/
-RUN apk --no-cache add gcc musl-dev && \
-    pip install -r /opt/requirements.txt && \
-    apk --no-cache del gcc musl-dev
+WORKDIR /usr/local/src/docker-net-dhcp
+COPY go.* ./
+RUN go mod download
 
-RUN mkdir -p /opt/plugin /run/docker/plugins /var/run/docker/netns
-COPY net-dhcp/ /opt/plugin/net_dhcp
+COPY cmd/ ./cmd/
+COPY pkg/ ./pkg/
+RUN mkdir bin/ && go build -o bin/ ./cmd/...
 
-WORKDIR /opt/plugin
-ENTRYPOINT ["python", "-m", "net_dhcp"]
+
+FROM alpine:3.13
+
+RUN mkdir -p /run/docker/plugins
+
+COPY --from=builder /usr/local/src/docker-net-dhcp/bin/net-dhcp /usr/sbin/
+COPY --from=builder /usr/local/src/docker-net-dhcp/bin/udhcpc-handler /usr/lib/net-dhcp/udhcpc-handler
+
+ENTRYPOINT ["/usr/sbin/net-dhcp"]

Makefile

@@ -1,40 +1,55 @@
-PLUGIN_NAME = devplayer0/net-dhcp
-PLUGIN_TAG ?= latest
+PLUGIN_NAME = ghcr.io/devplayer0/docker-net-dhcp
+PLUGIN_TAG ?= golang
+PLATFORMS ?= linux/amd64,linux/arm64
 
-all: clean build rootfs create enable
+SOURCES = $(shell find pkg/ cmd/ -name '*.go')
+BINARY = bin/net-dhcp
+
+.PHONY: all debug build create enable disable pdebug push clean
+
+all: create enable
+
+bin/%: $(SOURCES)
+	go build -o $@ ./cmd/$(shell basename $@)
+
+debug: $(BINARY)
+	sudo $< -log debug
+
+build: $(SOURCES)
+	docker build -t $(PLUGIN_NAME):rootfs .
+
+plugin/rootfs: build
+	mkdir -p plugin/rootfs
+	docker create --name tmp $(PLUGIN_NAME):rootfs
+	docker export tmp | tar xC plugin/rootfs
+	docker rm -vf tmp
+
+plugin: plugin/rootfs config.json
+	cp config.json $@/
+
+create: plugin
+	docker plugin rm -f $(PLUGIN_NAME):$(PLUGIN_TAG) || true
+	docker plugin create $(PLUGIN_NAME):$(PLUGIN_TAG) $<
+	docker plugin set $(PLUGIN_NAME):$(PLUGIN_TAG) LOG_LEVEL=trace
+
+enable: plugin
+	docker plugin enable $(PLUGIN_NAME):$(PLUGIN_TAG)
+disable:
+	docker plugin disable $(PLUGIN_NAME):$(PLUGIN_TAG)
+
+pdebug: create enable
+	sudo sh -c 'tail -f /var/lib/docker/plugins/*/rootfs/var/log/net-dhcp.log'
+
+push: create
+	docker plugin push $(PLUGIN_NAME):$(PLUGIN_TAG)
+
+multiarch: $(SOURCES)
+	docker buildx build --platform=$(PLATFORMS) -o type=local,dest=$@ .
+
+push-multiarch: multiarch config.json
+	scripts/push_multiarch_plugin.py -p $(PLATFORMS) config.json multiarch $(PLUGIN_NAME):$(PLUGIN_TAG)
 
 clean:
-	@echo "### rm ./plugin"
-	@rm -rf ./plugin
-
-build:
-	@echo "### docker build: rootfs image with net-dhcp"
-	@docker build -t ${PLUGIN_NAME}:rootfs .
-
-rootfs:
-	@echo "### create rootfs directory in ./plugin/rootfs"
-	@mkdir -p ./plugin/rootfs
-	@docker create --name tmp ${PLUGIN_NAME}:rootfs
-	@docker export tmp | tar -x -C ./plugin/rootfs
-	@echo "### copy config.json to ./plugin/"
-	@cp config.json ./plugin/
-	@docker rm -vf tmp
-
-create:
-	@echo "### remove existing plugin ${PLUGIN_NAME}:${PLUGIN_TAG} if exists"
-	@docker plugin rm -f ${PLUGIN_NAME}:${PLUGIN_TAG} || true
-	@echo "### create new plugin ${PLUGIN_NAME}:${PLUGIN_TAG} from ./plugin"
-	@docker plugin create ${PLUGIN_NAME}:${PLUGIN_TAG} ./plugin
-
-debug:
-	@docker run --rm -ti --cap-add CAP_SYS_ADMIN --network host --volume /run/docker/plugins:/run/docker/plugins \
-		--volume /run/docker.sock:/run/docker.sock --volume /var/run/docker/netns:/var/run/docker/netns \
-		${PLUGIN_NAME}:rootfs
-
-enable:
-	@echo "### enable plugin ${PLUGIN_NAME}:${PLUGIN_TAG}"		
-	@docker plugin enable ${PLUGIN_NAME}:${PLUGIN_TAG}
-
-push:
-	@echo "### push plugin ${PLUGIN_NAME}:${PLUGIN_TAG}"
-	@docker plugin push ${PLUGIN_NAME}:${PLUGIN_TAG}
+	-rm -rf multiarch/
+	-rm -rf plugin/
+	-rm bin/*

cmd/net-dhcp/main.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"flag"
+	"os"
+	"os/signal"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+
+	"github.com/devplayer0/docker-net-dhcp/pkg/plugin"
+)
+
+var (
+	logLevel = flag.String("log", "", "log level")
+	logFile  = flag.String("logfile", "", "log file")
+	bindSock = flag.String("sock", "/run/docker/plugins/net-dhcp.sock", "bind unix socket")
+)
+
+func main() {
+	flag.Parse()
+
+	if *logLevel == "" {
+		if *logLevel = os.Getenv("LOG_LEVEL"); *logLevel == "" {
+			*logLevel = "info"
+		}
+	}
+
+	level, err := log.ParseLevel(*logLevel)
+	if err != nil {
+		log.WithError(err).Fatal("Failed to parse log level")
+	}
+	log.SetLevel(level)
+
+	if *logFile != "" {
+		f, err := os.OpenFile(*logFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+		if err != nil {
+			log.WithError(err).Fatal("Failed to open log file for writing")
+		}
+		defer f.Close()
+
+		log.StandardLogger().Out = f
+	}
+
+	p, err := plugin.NewPlugin()
+	if err != nil {
+		log.WithError(err).Fatal("Failed to create plugin")
+	}
+
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, unix.SIGINT, unix.SIGTERM)
+
+	go func() {
+		log.Info("Starting server...")
+		if err := p.Listen(*bindSock); err != nil {
+			log.WithError(err).Fatal("Failed to start plugin")
+		}
+	}()
+
+	<-sigs
+	log.Info("Shutting down...")
+	if err := p.Close(); err != nil {
+		log.WithError(err).Fatal("Failed to stop plugin")
+	}
+}

cmd/udhcpc-handler/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"encoding/json"
+	"net"
+	"os"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/devplayer0/docker-net-dhcp/pkg/udhcpc"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		log.Fatalf("Usage: %v <event type>", os.Args[0])
+		return
+	}
+
+	event := udhcpc.Event{
+		Type: os.Args[1],
+	}
+
+	switch event.Type {
+	case "bound", "renew":
+		if v6, ok := os.LookupEnv("ipv6"); ok {
+			// Clean up the IP (udhcpc6 emits a _lot_ of zeros)
+			_, netV6, err := net.ParseCIDR(v6 + "/128")
+			if err != nil {
+				log.WithError(err).Warn("Failed to parse IPv6 address")
+			}
+
+			event.Data.IP = netV6.String()
+		} else {
+			event.Data.IP = os.Getenv("ip") + "/" + os.Getenv("mask")
+			event.Data.Gateway = os.Getenv("router")
+			event.Data.Domain = os.Getenv("domain")
+		}
+	case "deconfig", "leasefail", "nak":
+	default:
+		log.Warnf("Ignoring unknown event type `%v`", event.Type)
+		return
+	}
+
+	if err := json.NewEncoder(os.Stdout).Encode(event); err != nil {
+		log.Fatalf("Failed to encode udhcpc event: %w", err)
+		return
+	}
+}

config.json

@@ -6,8 +6,18 @@
             "docker.networkdriver/1.0"
         ]
     },
-    "entrypoint": [ "python", "-m", "net_dhcp" ],
-    "workdir": "/opt/plugin",
+    "entrypoint": ["/usr/sbin/net-dhcp", "-logfile", "/var/log/net-dhcp.log"],
+    "env": [
+        {
+            "description": "Log level",
+            "name": "LOG_LEVEL",
+            "value": "info",
+            "settable": [
+                "value"
+            ]
+        }
+    ],
+    "workdir": "/",
     "network": {
         "type": "host"
     },
@@ -19,15 +29,20 @@
             "options": [
                 "bind"
             ]
+        },
+        {
+            "source": "/var/run/docker",
+            "destination": "/run/docker",
+            "type": "bind",
+            "options": [
+                "bind"
+            ]
         }
     ],
-    "pidhost": true,
     "linux": {
         "capabilities": [
             "CAP_NET_ADMIN",
-            "CAP_SYS_ADMIN",
-            "CAP_SYS_PTRACE",
-            "CAP_SYS_RESOURCE"
+            "CAP_SYS_ADMIN"
         ]
     }
 }

go.mod

@@ -0,0 +1,23 @@
+module github.com/devplayer0/docker-net-dhcp
+
+go 1.16
+
+require (
+	github.com/Microsoft/go-winio v0.5.0 // indirect
+	github.com/containerd/containerd v1.5.2 // indirect
+	github.com/docker/docker v20.10.7+incompatible
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/gorilla/handlers v1.5.1
+	github.com/gorilla/mux v1.8.0 // indirect
+	github.com/mitchellh/mapstructure v1.4.1
+	github.com/moby/term v0.0.0-20201216013528-df9cb8a40635 // indirect
+	github.com/morikuni/aec v1.0.0 // indirect
+	github.com/sirupsen/logrus v1.8.1
+	github.com/stretchr/testify v1.7.0 // indirect
+	github.com/vishvananda/netlink v1.1.1-0.20201029203352-d40f9887b852
+	github.com/vishvananda/netns v0.0.0-20210104183010-2eb08e3e575f
+	golang.org/x/net v0.0.0-20210525063256-abc453219eb5 // indirect
+	golang.org/x/sys v0.0.0-20210603125802-9665404d3644
+	golang.org/x/time v0.0.0-20210220033141-f8bda1e9f3ba // indirect
+	google.golang.org/grpc v1.38.0 // indirect
+)