Specify Linux constraints by default

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

gateway/handlers/createhandler.go

@@ -0,0 +1,146 @@
+package handlers
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/alexellis/faas/gateway/metrics"
+	"github.com/alexellis/faas/gateway/requests"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/swarm"
+	"github.com/docker/docker/client"
+	"github.com/docker/docker/registry"
+)
+
+// MakeNewFunctionHandler creates a new function (service) inside the swarm network.
+func MakeNewFunctionHandler(metricsOptions metrics.MetricOptions, c *client.Client, maxRestarts uint64) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+		body, _ := ioutil.ReadAll(r.Body)
+
+		request := requests.CreateFunctionRequest{}
+		err := json.Unmarshal(body, &request)
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		fmt.Println(request)
+
+		// TODO: review why this was here... debugging?
+		// w.WriteHeader(http.StatusNotImplemented)
+
+		options := types.ServiceCreateOptions{}
+		if len(request.RegistryAuth) > 0 {
+			auth, err := BuildEncodedAuthConfig(request.RegistryAuth, request.Image)
+			if err != nil {
+				log.Println("Error while building registry auth configuration", err)
+				w.WriteHeader(http.StatusBadRequest)
+				w.Write([]byte("Invalid registry auth"))
+				return
+			}
+			options.EncodedRegistryAuth = auth
+		}
+		spec := makeSpec(&request, maxRestarts)
+
+		response, err := c.ServiceCreate(context.Background(), spec, options)
+		if err != nil {
+			log.Println(err)
+		}
+		log.Println(response.ID, response.Warnings)
+	}
+}
+
+func makeSpec(request *requests.CreateFunctionRequest, maxRestarts uint64) swarm.ServiceSpec {
+	linuxOnlyConstraints := []string{"node.platform.os == linux"}
+
+	nets := []swarm.NetworkAttachmentConfig{
+		{Target: request.Network},
+	}
+	restartDelay := time.Second * 5
+
+	spec := swarm.ServiceSpec{
+		TaskTemplate: swarm.TaskSpec{
+			RestartPolicy: &swarm.RestartPolicy{
+				MaxAttempts: &maxRestarts,
+				Condition:   swarm.RestartPolicyConditionAny,
+				Delay:       &restartDelay,
+			},
+			ContainerSpec: swarm.ContainerSpec{
+				Image:  request.Image,
+				Labels: map[string]string{"function": "true"},
+			},
+			Networks: nets,
+			Placement: &swarm.Placement{
+				Constraints: linuxOnlyConstraints,
+			},
+		},
+		Annotations: swarm.Annotations{
+			Name: request.Service,
+		},
+	}
+
+	// TODO: request.EnvProcess should only be set if it's not nil, otherwise we override anything in the Docker image already
+	var env []string
+	if len(request.EnvProcess) > 0 {
+		env = append(env, fmt.Sprintf("fprocess=%s", request.EnvProcess))
+	}
+	for k, v := range request.EnvVars {
+		env = append(env, fmt.Sprintf("%s=%s", k, v))
+	}
+
+	if len(env) > 0 {
+		spec.TaskTemplate.ContainerSpec.Env = env
+	}
+
+	return spec
+}
+
+func BuildEncodedAuthConfig(basicAuthB64 string, dockerImage string) (string, error) {
+	// extract registry server address
+	distributionRef, err := reference.ParseNormalizedNamed(dockerImage)
+	if err != nil {
+		return "", err
+	}
+	repoInfo, err := registry.ParseRepositoryInfo(distributionRef)
+	if err != nil {
+		return "", err
+	}
+	// extract registry user & password
+	user, password, err := userPasswordFromBasicAuth(basicAuthB64)
+	if err != nil {
+		return "", err
+	}
+	// build encoded registry auth config
+	buf, err := json.Marshal(types.AuthConfig{
+		Username:      user,
+		Password:      password,
+		ServerAddress: repoInfo.Index.Name,
+	})
+	if err != nil {
+		return "", err
+	}
+	return base64.URLEncoding.EncodeToString(buf), nil
+}
+
+func userPasswordFromBasicAuth(basicAuthB64 string) (string, string, error) {
+	c, err := base64.StdEncoding.DecodeString(basicAuthB64)
+	if err != nil {
+		return "", "", err
+	}
+	cs := string(c)
+	s := strings.IndexByte(cs, ':')
+	if s < 0 {
+		return "", "", errors.New("Invalid basic auth")
+	}
+	return cs[:s], cs[s+1:], nil
+}