Merge pull request #47 from NYTimes/max_versions

Adding "max_versions" feature to clean up older GAE versions post-deploy

main.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"text/template"
 
@@ -52,6 +53,14 @@ type GAE struct {
 	// and autoscaling configurations.
 	AppFile string `json:"app_file"`
 
+	// MaxVersions is an optional value that can be used along with the "deploy" or
+	// "update" actions. If set to a non-zero value, the plugin will look up the versions
+	// of the deployed service and delete any older versions beyond the "max" value
+	// provided. If any of the "older" versions that should be deleted are actually
+	// serving traffic, they will not be deleted. This may result in the actual version
+	// count being higher than the max listed here.
+	MaxVersions int `json:"max_versions"`
+
 	// CronFile is the name of the cron.yaml file to use for this deployment. This field
 	// is only required if your cron.yaml file is not named 'cron.yaml'
 	CronFile string `json:"cron_file"`
@@ -154,13 +163,23 @@ func wrapMain() error {
 	}
 
 	// if gcloud app cmd, run it
-	if found := gcloudCmds[vargs.Action]; found {
-		return runGcloud(runner, workspace, vargs)
+	if gcloudCmds[vargs.Action] {
+		err = runGcloud(runner, workspace, vargs)
+	} else {
+		// otherwise, do appcfg.py command
+		err = runAppCfg(runner, workspace, vargs)
+	}
+
+	if err != nil {
+		return err
 	}
 
-	// otherwise, do appcfg.py command
-	return runAppCfg(runner, workspace, vargs)
+	// check if MaxVersions is supplied + deploy action
+	if vargs.MaxVersions > 0 && (vargs.Action == "deploy" || vargs.Action == "update") {
+		return removeOldVersions(runner, workspace, vargs)
+	}
 
+	return nil
 }
 
 func configFromStdin(vargs *GAE, workspace *string) error {
@@ -202,6 +221,7 @@ func configFromEnv(vargs *GAE, workspace *string) error {
 	vargs.Dir = os.Getenv("PLUGIN_DIR")
 	vargs.AppCfgCmd = os.Getenv("PLUGIN_APPCFG_CMD")
 	vargs.GCloudCmd = os.Getenv("PLUGIN_GCLOUD_CMD")
+	vargs.MaxVersions, _ = strconv.Atoi(os.Getenv("PLUGIN_MAX_VERSIONS"))
 
 	// Maps
 	dummyVargs := dummyGAE{}
@@ -357,7 +377,6 @@ func runGcloud(runner *Environ, workspace string, vargs GAE) error {
 	if err != nil {
 		return fmt.Errorf("error: %s\n", err)
 	}
-
 	return nil
 }
 

remove.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v2"
+)
+
+func removeOldVersions(runner *Environ, workspace string, vargs GAE) error {
+	// read in the app.yaml file to grab the module/service mame we just deployed
+	appLoc := filepath.Join(workspace, vargs.Dir, "app.yaml")
+	appFile, err := os.Open(appLoc)
+	if err != nil {
+		return fmt.Errorf("error: %s\n", err)
+	}
+	defer appFile.Close()
+	var appStruct struct {
+		Service string `yaml:"service"`
+		Module  string `yaml:"module"`
+	}
+	err = yaml.NewDecoder(appFile).Decode(&appStruct)
+	if err != nil {
+		return fmt.Errorf("error: %s\n", err)
+	}
+
+	service := appStruct.Service
+	if service == "" {
+		service = appStruct.Module
+	}
+
+	// look up existing versions for given service ordered by create time desc
+	var versionJSON bytes.Buffer
+	sout := runner.stdout
+	runner.stdout = &versionJSON
+	err = runner.Run(vargs.GCloudCmd, "app", "versions", "list",
+		"--service", service, "--project", vargs.Project,
+		"--format", "json", "--sort-by", "~version.createTime", "--quiet")
+	if err != nil {
+		return fmt.Errorf("error: %s\n", err)
+	}
+
+	var results []struct {
+		ID           string  `json:"id"`
+		TrafficSplit float64 `json:"traffic_split"`
+	}
+	err = json.NewDecoder(&versionJSON).Decode(&results)
+	if err != nil {
+		return err
+	}
+
+	var toDelete []string
+	for i, res := range results {
+		// keep newer versions, the newly deployed version or anything that has traffic
+		if i < vargs.MaxVersions || res.ID == vargs.Version || res.TrafficSplit > 0 {
+			continue
+		}
+		toDelete = append(toDelete, res.ID)
+	}
+
+	if len(toDelete) == 0 {
+		return nil
+	}
+
+	log.Printf("deleting %d versions: %s", len(toDelete), toDelete)
+
+	runner.stdout = sout
+	args := []string{"app", "versions", "delete",
+		"--service", service, "--project", vargs.Project, "--quiet"}
+	args = append(args, toDelete...)
+	err = runner.Run(vargs.GCloudCmd, args...)
+	if err != nil {
+		return fmt.Errorf("error: %s\n", err)
+	}
+
+	return nil
+}