Merge branch 'master' into 2449-keep-index-status-handlers

[arvados.git] / services / keep / keep.go

diff --git a/services/keep/keep.go b/services/keep/keep.go
index 4ee9fb3832698cd594826a5b95a391e4563bf13c..8683abf100557c35bf96fe08279737d8ddb65058 100644 (file)
--- a/services/keep/keep.go
+++ b/services/keep/keep.go
@@ -4,7 +4,9 @@ import (
        "bufio"
        "bytes"
        "crypto/md5"
+       "encoding/json"
        "errors"
+       "flag"
        "fmt"
        "github.com/gorilla/mux"
        "io/ioutil"
@@ -18,8 +20,8 @@ import (
        "time"
 )
 
-// Default TCP port on which to listen for requests.
-const DEFAULT_PORT = 25107
+// Default TCP address on which to listen for requests.
+const DEFAULT_ADDR = ":25107"
 
 // A Keep "block" is 64MB.
 const BLOCKSIZE = 64 * 1024 * 1024
@@ -51,8 +53,42 @@ func (e *KeepError) Error() string {
 }
 
 func main() {
+       // Parse command-line flags:
+       //
+       // -listen=ipaddr:port
+       //    Interface on which to listen for requests. Use :port without
+       //    an ipaddr to listen on all network interfaces.
+       //    Examples:
+       //      -listen=127.0.0.1:4949
+       //      -listen=10.0.1.24:8000
+       //      -listen=:25107 (to listen to port 25107 on all interfaces)
+       //
+       // -volumes
+       //    A comma-separated list of directories to use as Keep volumes.
+       //    Example:
+       //      -volumes=/var/keep01,/var/keep02,/var/keep03/subdir
+       //
+       //    If -volumes is empty or is not present, Keep will select volumes
+       //    by looking at currently mounted filesystems for /keep top-level
+       //    directories.
+
+       var listen, keepvols string
+       flag.StringVar(&listen, "listen", DEFAULT_ADDR,
+               "interface on which to listen for requests, in the format ipaddr:port. e.g. -listen=10.0.1.24:8000. Use -listen=:port to listen on all network interfaces.")
+       flag.StringVar(&keepvols, "volumes", "",
+               "Comma-separated list of directories to use for Keep volumes, e.g. -volumes=/var/keep1,/var/keep2. If empty or not supplied, Keep will scan mounted filesystems for volumes with a /keep top-level directory.")
+       flag.Parse()
+
        // Look for local keep volumes.
-       KeepVolumes = FindKeepVolumes()
+       if keepvols == "" {
+               // TODO(twp): decide whether this is desirable default behavior.
+               // In production we may want to require the admin to specify
+               // Keep volumes explicitly.
+               KeepVolumes = FindKeepVolumes()
+       } else {
+               KeepVolumes = strings.Split(keepvols, ",")
+       }
+
        if len(KeepVolumes) == 0 {
                log.Fatal("could not find any keep volumes")
        }
@@ -77,8 +113,7 @@ func main() {
        http.Handle("/", rest)
 
        // Start listening for requests.
-       port := fmt.Sprintf(":%d", DEFAULT_PORT)
-       http.ListenAndServe(port, nil)
+       http.ListenAndServe(listen, nil)
 }
 
 // FindKeepVolumes
@@ -209,6 +244,14 @@ func StatusHandler(w http.ResponseWriter, req *http.Request) {
        for _, vol := range KeepVolumes {
                st.Volumes[vol] = GetVolumeStatus(vol)
        }
+
+       if jstat, err := json.Marshal(st); err == nil {
+               w.Write(jstat)
+       } else {
+               log.Printf("json.Marshal: %s\n", err)
+               log.Printf("NodeStatus = %v\n", st)
+               http.Error(w, err.Error(), 500)
+       }
 }
 
 // GetVolumeStatus