Merge pull request #1606 from rneugeba/meta2

Improve/Fix metadata package and use it

examples/gcp.yml

@@ -26,14 +26,14 @@ onboot:
      - CAP_NET_RAW
     net: host
     command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
-  - name: metadata-gcp
-    image: "mobylinux/metadata-gcp:7fc3dd5ef92e0408fb3f76048bbaae88bbb55ad9"
+  - name: metadata
+    image: "mobylinux/metadata:5c64c2305040009891b713df22bd4bae7894c3ec"
     binds:
-     - /tmp:/etc/ssh
+     - /dev:/dev
+     - /var:/var
      - /tmp/etc/resolv.conf:/etc/resolv.conf
     readonly: true
     net: host
-    uts: host
     capabilities:
      - CAP_SYS_ADMIN
 services:
@@ -50,7 +50,7 @@ services:
     net: host
     pid: host
     binds:
-     - /tmp/authorized_keys:/root/.ssh/authorized_keys
+     - /var/config/ssh/authorized_keys:/root/.ssh/authorized_keys
      - /tmp/etc/resolv.conf:/etc/resolv.conf
   - name: nginx
     image: "nginx:alpine"

pkg/metadata-gcp/.gitignore

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

pkg/metadata-gcp/Dockerfile

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

pkg/metadata-gcp/Makefile

@@ -1,44 +0,0 @@
-GO_COMPILE=mobylinux/go-compile:3afebc59c5cde31024493c3f91e6102d584a30b9@sha256:e0786141ea7df8ba5735b63f2a24b4ade9eae5a02b0e04c4fca33b425ec69b0a
-
-SHA_IMAGE=alpine:3.5@sha256:dfbd4a3a8ebca874ebd2474f044a0b33600d4523d03b0df76e5c5986cb02d7e8
-
-METADATA_BINARY=usr/bin/metadata-gcp
-
-IMAGE=metadata-gcp
-
-.PHONY: tag push clean container
-default: push
-
-$(METADATA_BINARY): gcp.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) $(METADATA_BINARY)
-
-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:

pkg/metadata-gcp/gcp.go

@@ -1,75 +0,0 @@
-package main
-
-import (
-	"io/ioutil"
-	"log"
-	"net/http"
-	"strings"
-	"syscall"
-	"time"
-)
-
-const (
-	project  = "http://metadata.google.internal/computeMetadata/v1/project/"
-	instance = "http://metadata.google.internal/computeMetadata/v1/instance/"
-)
-
-// If optional not set, will panic. Optional will allow 404
-// We assume most failure cases are that this code is included in a non Google Cloud
-// environment, which should generally be ok, so just fail fast.
-func metadata(url string, optional bool) []byte {
-	var client = &http.Client{
-		Timeout: time.Second * 2,
-	}
-
-	req, err := http.NewRequest("", url, nil)
-	if err != nil {
-		log.Fatalf("http NewRequest failed: %v", err)
-	}
-	req.Header.Set("Metadata-Flavor", "Google")
-
-	resp, err := client.Do(req)
-	if err != nil {
-		// Probably not running on Google Cloud but this package included
-		log.Fatalf("Could not contact Google Cloud Metadata service: %v", err)
-	}
-	if optional && resp.StatusCode == 404 {
-		return []byte{}
-	}
-	if resp.StatusCode != 200 {
-		// Probably not running on Google Cloud but this package included
-		log.Fatalf("Google Cloud Metadata Server http error: %s", resp.Status)
-	}
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		log.Fatalf("Failed to read http response: %v", err)
-	}
-	return body
-}
-
-func main() {
-	hostname := metadata(instance+"hostname", false)
-	err := syscall.Sethostname(hostname)
-	if err != nil {
-		log.Printf("Failed to set hostname: %v", err)
-	}
-	sshKeys := metadata(project+"attributes/sshKeys", true)
-	// TODO also retrieve the instance keys and respect block project keys see https://cloud.google.com/compute/docs/instances/ssh-keys
-
-	// the keys have usernames attached, but as a simplification we are going to add them all to one root file
-	// TODO split them into individual user files and make the ssh container construct those users
-
-	rootKeys := ""
-	for _, line := range strings.Split(string(sshKeys), "\n") {
-		parts := strings.SplitN(line, ":", 2)
-		// ignoring username for now
-		if len(parts) == 2 {
-			rootKeys = rootKeys + parts[1] + "\n"
-		}
-	}
-
-	err = ioutil.WriteFile("/etc/ssh/authorized_keys", []byte(rootKeys), 0600)
-	if err != nil {
-		log.Printf("Failed to write ssh keys: %v", err)
-	}
-}

pkg/metadata/main.go

@@ -29,6 +29,9 @@ const (
 
 // Provider is a generic interface for metadata/userdata providers.
 type Provider interface {
+	// String should return a unique name for the Provider
+	String() string
+
 	// Probe returns true if the provider was detected.
 	Probe() bool
 
@@ -53,11 +56,13 @@ func main() {
 		log.Fatalf("Could not create %s: %s", ConfigPath, err)
 	}
 
+	var p Provider
 	var userdata []byte
 	var err error
 	found := false
-	for _, p := range netProviders {
+	for _, p = range netProviders {
 		if p.Probe() {
+			log.Printf("%s: Probe succeeded", p)
 			userdata, err = p.Extract()
 			found = true
 			break
@@ -76,8 +81,9 @@ func main() {
 		defer syscall.Unmount(MountPoint, 0)
 		// Don't worry about removing MountPoint. We are in a container
 
-		for _, p := range cdromProviders {
+		for _, p = range cdromProviders {
 			if p.Probe() {
+				log.Printf("%s: Probe succeeded", p)
 				userdata, err = p.Extract()
 				found = true
 				break
@@ -95,6 +101,11 @@ ErrorOut:
 		log.Printf("Error during metadata probe: %s", err)
 	}
 
+	err = ioutil.WriteFile(path.Join(ConfigPath, "provider"), []byte(p.String()), 0644)
+	if err != nil {
+		log.Printf("Error writing metadata provider: %s", err)
+	}
+
 	if userdata != nil {
 		if err := processUserData(userdata); err != nil {
 			log.Printf("Could not extract user data: %s", err)
@@ -139,16 +150,28 @@ func processUserData(data []byte) error {
 		// This is not an error
 		return nil
 	}
-	cm := fd.(map[string]interface{})
+	cm, ok := fd.(map[string]interface{})
+	if !ok {
+		log.Printf("Could convert JSON to desired format: %s", fd)
+		return nil
+	}
 	for d, val := range cm {
 		dir := path.Join(ConfigPath, d)
 		if err := os.Mkdir(dir, 0755); err != nil {
 			log.Printf("Failed to create %s: %s", dir, err)
 			continue
 		}
-		files := val.(map[string]interface{})
+		files, ok := val.(map[string]interface{})
+		if !ok {
+			log.Printf("Could convert JSON for files: %s", val)
+			continue
+		}
 		for f, i := range files {
 			fi := i.(map[string]interface{})
+			if !ok {
+				log.Printf("Could convert JSON for items: %s", i)
+				continue
+			}
 			if _, ok := fi["perm"]; !ok {
 				log.Printf("No permission provided %s:%s", f, fi)
 				continue

pkg/metadata/provider_cdrom.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"io/ioutil"
-	"log"
 	"os"
 	"path"
 )
@@ -22,12 +21,13 @@ func NewCDROM() *ProviderCDROM {
 	return &ProviderCDROM{}
 }
 
+func (p *ProviderCDROM) String() string {
+	return "CDROM"
+}
+
 // Probe checks if the CD has the right file
 func (p *ProviderCDROM) Probe() bool {
 	_, err := os.Stat(path.Join(MountPoint, configFile))
-	if err != nil {
-		log.Printf("CDROM: Probe -> %s", err)
-	}
 	return (!os.IsNotExist(err))
 }
 

pkg/metadata/provider_gcp.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
+	"os"
 	"path"
 	"strings"
 	"time"
@@ -24,11 +25,14 @@ func NewGCP() *ProviderGCP {
 	return &ProviderGCP{}
 }
 
+func (p *ProviderGCP) String() string {
+	return "GCP"
+}
+
 // Probe checks if we are running on GCP
 func (p *ProviderGCP) Probe() bool {
 	// Getting the hostname should always work...
 	_, err := gcpGet(instance + "hostname")
-	log.Printf("GCP: Probe -> %s", err)
 	return (err == nil)
 }
 
@@ -54,6 +58,10 @@ func (p *ProviderGCP) Extract() ([]byte, error) {
 	//      container construct those users
 	sshKeys, err := gcpGet(project + "attributes/sshKeys")
 	if err == nil {
+		if err := os.Mkdir(path.Join(ConfigPath, SSH), 0755); err != nil {
+			log.Printf("Failed to create %s: %s", SSH, err)
+			goto ErrorSSH
+		}
 		rootKeys := ""
 		for _, line := range strings.Split(string(sshKeys), "\n") {
 			parts := strings.SplitN(line, ":", 2)
@@ -68,6 +76,7 @@ func (p *ProviderGCP) Extract() ([]byte, error) {
 		}
 	}
 
+ErrorSSH:
 	// Generic userdata
 	userData, err := gcpGet(instance + "attributes/userdata")
 	if err != nil {

projects/demo/etcd/etcd.yml

@@ -43,14 +43,15 @@ onboot:
     net: host
     command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
   - name: metadata
-    image: mobylinux/metadata:960e6c371c9a07cf512dfcfa9734a5e0db427e96
-    net: host
+    image: "mobylinux/metadata:5c64c2305040009891b713df22bd4bae7894c3ec"
     binds:
-      - /dev:/dev
-      - /var:/var
-      - /etc/resolv.conf:/etc/resolv.conf
+     - /dev:/dev
+     - /var:/var
+     - /tmp/etc/resolv.conf:/etc/resolv.conf
+    readonly: true
+    net: host
     capabilities:
-      - all
+     - CAP_SYS_ADMIN
 services:
   - name: rngd
     image: "mobylinux/rngd:3dad6dd43270fa632ac031e99d1947f20b22eec9"