Cache remote repos and service definitions

util/network/network.go

@@ -0,0 +1,122 @@
+package network
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	yaml "github.com/cloudfoundry-incubator/candiedyaml"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/rancher/os/config"
+)
+
+var (
+	ErrNoNetwork = errors.New("Networking not available to load resource")
+	ErrNotFound  = errors.New("Failed to find resource")
+)
+
+func GetServices(urls []string) ([]string, error) {
+	result := []string{}
+
+	for _, url := range urls {
+		indexUrl := fmt.Sprintf("%s/index.yml", url)
+		content, err := LoadResource(indexUrl, true)
+		if err != nil {
+			log.Errorf("Failed to load %s: %v", indexUrl, err)
+			continue
+		}
+
+		services := make(map[string][]string)
+		err = yaml.Unmarshal(content, &services)
+		if err != nil {
+			log.Errorf("Failed to unmarshal %s: %v", indexUrl, err)
+			continue
+		}
+
+		if list, ok := services["services"]; ok {
+			result = append(result, list...)
+		}
+	}
+
+	return result, nil
+}
+
+func retryHttp(f func() (*http.Response, error), times int) (resp *http.Response, err error) {
+	for i := 0; i < times; i++ {
+		if resp, err = f(); err == nil {
+			return
+		}
+		log.Warnf("Error making HTTP request: %s. Retrying", err)
+	}
+	return
+}
+
+func loadFromNetwork(location string, network bool) ([]byte, error) {
+	bytes := cacheLookup(location)
+	if bytes != nil {
+		return bytes, nil
+	}
+
+	resp, err := retryHttp(func() (*http.Response, error) {
+		return http.Get(location)
+	}, 8)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("non-200 http response: %d", resp.StatusCode)
+	}
+	defer resp.Body.Close()
+
+	bytes, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	cacheAdd(location, bytes)
+
+	return bytes, nil
+}
+
+func LoadResource(location string, network bool) ([]byte, error) {
+	if strings.HasPrefix(location, "http:/") || strings.HasPrefix(location, "https:/") {
+		if !network {
+			return nil, ErrNoNetwork
+		}
+		return loadFromNetwork(location, network)
+	} else if strings.HasPrefix(location, "/") {
+		return ioutil.ReadFile(location)
+	}
+
+	return nil, ErrNotFound
+}
+
+func serviceUrl(url, name string) string {
+	return fmt.Sprintf("%s/%s/%s.yml", url, name[0:1], name)
+}
+
+func LoadServiceResource(name string, useNetwork bool, cfg *config.CloudConfig) ([]byte, error) {
+	bytes, err := LoadResource(name, useNetwork)
+	if err == nil {
+		log.Debugf("Loaded %s from %s", name, name)
+		return bytes, nil
+	}
+	if err == ErrNoNetwork || !useNetwork {
+		return nil, ErrNoNetwork
+	}
+
+	urls := cfg.Rancher.Repositories.ToArray()
+	for _, url := range urls {
+		serviceUrl := serviceUrl(url, name)
+		bytes, err := LoadResource(serviceUrl, useNetwork)
+		if err == nil {
+			log.Debugf("Loaded %s from %s", name, serviceUrl)
+			return bytes, nil
+		}
+	}
+
+	return nil, ErrNotFound
+}