Add in sysctl container

- based on @riyazdf earlier unmerged Go version 891c006d34/alpine/containers/cloud-config/main.go

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

base/binfmt/Makefile

@@ -2,7 +2,7 @@ QEMU_IMAGE=mobylinux/qemu-user-static:da39a3ee5e6b4b0d3255bfef95601890afd80709@s
 QEMU_FILES=qemu-arm qemu-aarch64 qemu-ppc64le
 QEMU_BINARIES=$(addprefix usr/bin/,$(QEMU_FILES))
 
-GO_COMPILE=mobylinux/go-compile:d2d25ac665b5148ad356d0eab3ff3762a68c633d@sha256:aab55d0c317460850e66a07dd94139cc11ea9e1c0bee88716a6a8c768740885f
+GO_COMPILE=mobylinux/go-compile:236629d9fc0779db9e7573ceb8b0e92f08f553be@sha256:16020c2d90cecb1f1d2d731187e947535c23f38b62319dd386ae642b4b32e1fb
 
 BINFMT_BINARY=usr/bin/binfmt
 

base/sysctl/.gitignore

@@ -0,0 +1,4 @@
+dev
+proc
+sys
+usr

base/sysctl/Dockerfile

@@ -0,0 +1,3 @@
+FROM scratch
+COPY . ./
+CMD ["/usr/bin/sysctl"]

base/sysctl/Makefile

@@ -0,0 +1,44 @@
+GO_COMPILE=mobylinux/go-compile:236629d9fc0779db9e7573ceb8b0e92f08f553be@sha256:16020c2d90cecb1f1d2d731187e947535c23f38b62319dd386ae642b4b32e1fb
+
+SHA_IMAGE=alpine:3.5@sha256:dfbd4a3a8ebca874ebd2474f044a0b33600d4523d03b0df76e5c5986cb02d7e8
+
+SYSCTL_BINARY=usr/bin/sysctl
+
+IMAGE=sysctl
+
+.PHONY: tag push clean container
+default: push
+
+$(SYSCTL_BINARY): main.go
+	mkdir -p $(dir $@)
+	tar cf - $^ | docker run --rm --net=none --log-driver=none -i $(GO_COMPILE) -o $@ | tar xf -
+
+DIRS=dev proc sys
+$(DIRS):
+	mkdir -p $@
+
+DEPS=$(DIRS) $(SYSCTL_BINARY) etc/sysctl.d/00-moby.conf
+
+container: Dockerfile $(DEPS)
+	tar cf - $^ | docker build --no-cache -t $(IMAGE):build -
+
+hash: Dockerfile $(DEPS)
+	find $^ -type f | xargs cat | docker run --rm -i $(SHA_IMAGE) sha1sum - | sed 's/ .*//' > hash
+
+push: hash container
+	docker pull mobylinux/$(IMAGE):$(shell cat hash) || \
+		(docker tag $(IMAGE):build mobylinux/$(IMAGE):$(shell cat hash) && \
+		 docker push mobylinux/$(IMAGE):$(shell cat hash))
+	docker rmi $(IMAGE):build
+	rm -f hash
+
+tag: hash container
+	docker pull mobylinux/$(IMAGE):$(shell cat hash) || \
+		docker tag $(IMAGE):build mobylinux/$(IMAGE):$(shell cat hash)
+	docker rmi $(IMAGE):build
+	rm -f hash
+
+clean:
+	rm -rf hash $(DIRS) usr
+
+.DELETE_ON_ERROR:

base/sysctl/etc/sysctl.d/00-moby.conf

@@ -0,0 +1,22 @@
+# general limits
+vm.max_map_count = 262144
+vm.overcommit_memory = 1
+net.core.somaxconn = 1024
+net.ipv4.neigh.default.gc_thresh1 = 30000
+net.ipv4.neigh.default.gc_thresh2 = 32000
+net.ipv4.neigh.default.gc_thresh3 = 32768
+fs.aio-max-nr = 1048576
+fs.inotify.max_user_watches = 524288
+fs.file-max = 524288
+# for rngd
+kernel.random.write_wakeup_threshold = 3072
+# security restrictions
+kernel.kptr_restrict = 2
+net.ipv4.conf.all.send_redirects = 0
+net.ipv4.conf.default.accept_redirects = 0
+net.ipv4.conf.default.accept_source_route = 0
+net.ipv6.conf.all.accept_redirects = 0
+net.ipv6.conf.default.accept_redirects = 0
+kernel.perf_event_paranoid = 3
+fs.protected_hardlinks = 1
+fs.protected_symlinks = 1

base/sysctl/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var (
+	configDir string
+	sysctlDir string
+)
+
+func init() {
+	flag.StringVar(&configDir, "configDir", "/etc/sysctl.d", "directory with config files")
+	flag.StringVar(&sysctlDir, "sysctlDir", "/proc/sys", "mount point for sysctls")
+}
+
+func sysctl(line []byte) error {
+	// parse line into a string of expected form X.Y.Z=VALUE
+	sysctlLineKV := strings.Split(string(line[:]), "=")
+	if len(sysctlLineKV) != 2 {
+		if len(sysctlLineKV) >= 1 && len(sysctlLineKV[0]) >= 1 && strings.Trim(sysctlLineKV[0], " ")[:1] == "#" {
+			return nil
+		}
+		return fmt.Errorf("Cannot parse %s", string(line))
+	}
+	// trim any extra whitespace
+	sysctlSetting, sysctlValue := strings.Trim(sysctlLineKV[0], " "), strings.Trim(sysctlLineKV[1], " ")
+	sysctlFile := filepath.Join(sysctlDir, filepath.Join(strings.Split(sysctlSetting, ".")...))
+	file, err := os.OpenFile(sysctlFile, os.O_WRONLY, 0)
+	if err != nil {
+		return fmt.Errorf("Cannot open %s: %s", sysctlFile, err)
+	}
+	defer file.Close()
+	_, err = file.Write([]byte(sysctlValue))
+	if err != nil {
+		return fmt.Errorf("Cannot write to %s: %s", sysctlFile, err)
+	}
+	return nil
+}
+
+func main() {
+	flag.Parse()
+
+	files, err := ioutil.ReadDir(configDir)
+	if err != nil {
+		log.Fatalf("Cannot read directory %s: %s", configDir, err)
+	}
+
+	for _, file := range files {
+		contents, err := ioutil.ReadFile(filepath.Join(configDir, file.Name()))
+		if err != nil {
+			log.Fatalf("Cannot read file %s: %s", file.Name(), err)
+		}
+		lines := bytes.Split(contents, []byte("\n"))
+		for _, line := range lines {
+			if len(line) == 0 {
+				continue
+			}
+			err = sysctl(line)
+			if err != nil {
+				log.Fatal(err)
+			}
+		}
+	}
+}

config.go

@@ -37,6 +37,7 @@ type MobyImage struct {
 	Command      []string
 	NetworkMode  string `yaml:"network_mode"`
 	Pid          string
+	Ipc          string
 }
 
 const riddler = "mobylinux/riddler:7d4545d8b8ac2700971a83f12a3446a76db28c14@sha256:11b7310df6482fc38aa52b419c2ef1065d7b9207c633d47554e13aa99f6c0b72"
@@ -77,6 +78,10 @@ func ConfigToRun(order int, path string, image *MobyImage) []string {
 		// TODO only "host" supported
 		args = append(args, "--pid="+image.Pid)
 	}
+	if image.Ipc != "" {
+		// TODO only "host" supported
+		args = append(args, "--ipc="+image.Pid)
+	}
 	for _, bind := range image.Binds {
 		args = append(args, "-v", bind)
 	}

moby.yaml

@@ -1,6 +1,13 @@
 kernel: "mobylinux/kernel:598481c08deafa37dccb33c88ad69fdecda57909"
 init: "mobylinux/init:2f1b5c1be1157cb17e5b1e6dee171dccdebb5277"
 system:
+  - name: sysctl
+    image: "mobylinux/sysctl:9bef9130afb8023ed1b2cecb4d961ba34a0f6628"
+    network_mode: host
+    pid: host
+    ipc: host
+    capabilities:
+     - CAP_SYS_ADMIN
   - name: binfmt
     image: "mobylinux/binfmt:a94e0587b702edaa95cc6f303464959d0eb2311c@sha256:432732b90cbe0498f5ca148d75b90bb1eabd8fbfe8c872df8b23906c225091b1"
     binds: