add project size to arthur JSON output

merlin/cmd/arthur/arthur.go

@@ -11,6 +11,8 @@ import (
 	"log"
 	"net"
 	"os"
+	"os/exec"
+	"regexp"
 	"strings"
 	"text/tabwriter"
 	"time"
@@ -33,6 +35,14 @@ FLAGS:
 //go:embed layout.html
 var layoutHtmlTemplate string
 
+type EnrichedRepoStatusInfo struct {
+	serverArthurPkg.RepoStatusInfo
+	Size string `json:"size,omitempty"`
+}
+type EnrichedStatusInfo struct {
+	Repos []*EnrichedRepoStatusInfo `json:"repos"`
+}
+
 func main() {
 	log.SetPrefix("[ERROR]: ")
 	log.SetFlags(0)
@@ -80,19 +90,22 @@ func main() {
 		fmt.Println(string(response))
 		return
 	}
-	statusInfo := serverArthurPkg.StatusInfo{}
+	statusInfo := EnrichedStatusInfo{}
 	err = json.Unmarshal(response, &statusInfo)
 	if err != nil {
 		log.Fatal(err)
 	}
 
 	if shouldOutputJson {
+		filesystemSizes := getFilesystemSizes()
+		for _, repoInfo := range statusInfo.Repos {
+			repoInfo.Size = filesystemSizes[repoInfo.Name]
+		}
 		jsonOutput, jsonErr := json.MarshalIndent(&statusInfo, "", "  ")
-		if jsonErr == nil {
-			fmt.Println(string(jsonOutput))
-		} else {
+		if jsonErr != nil {
 			log.Fatal(jsonErr)
 		}
+		fmt.Println(string(jsonOutput))
 	} else if shouldOutputHtml {
 		funcs := template.FuncMap{
 			"unixTimeToStr": unixTimeToStr,
@@ -145,3 +158,32 @@ func unixTimeToStr(unixTime int64) string {
 	// for other ways to format the time see: https://pkg.go.dev/time#pkg-constants
 	return time.Unix(unixTime, 0).In(location).Format(time.RFC1123)
 }
+
+// getFilesystemSizes parses the output of the `zfs list` command and returns
+// a map which looks like {"debian":"1.62T","gnu":"148G",...}.
+func getFilesystemSizes() map[string]string {
+	pattern := regexp.MustCompile(`^cscmirror\d/([^ ]+) (.*)$`)
+	result := make(map[string]string)
+	// Use the absolute path to the zfs command because /sbin isn't in the
+	// mirror user's PATH variable when running from cron
+	cmd := exec.Command("sh", "-c", `/sbin/zfs list -t filesystem -H | awk '/^cscmirror[[:digit:]]\// {print $1 " " $2}'`)
+	output, err := cmd.Output()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "zfs list failed: %+v\n", err)
+		return result
+	}
+	lines := bytes.Split(output, []byte("\n"))
+	for _, line := range lines {
+		if len(line) == 0 {
+			continue
+		}
+		matches := pattern.FindSubmatch(line)
+		if matches == nil {
+			continue
+		}
+		projectName := string(matches[1])
+		diskUsage := string(matches[2])
+		result[projectName] = diskUsage
+	}
+	return result
+}

merlin/cmd/arthur/layout.html

@@ -84,7 +84,7 @@
             {{if .IsRunning}} Is currently syncing {{else}} Is not syncing {{end}}
           </div>
           <div class="repo-data-item">
-            Last sync time: {{unixTimeToStr .LastAttemptStartTime}}
+            {{if .IsRunning}}Sync started at{{else}}Last sync time{{end}}: {{unixTimeToStr .LastAttemptStartTime}}
           </div>
           <div class="repo-data-item">
             Last sync result: {{.LastAttemptExit}}