Merge branch 'sqlquery'

README.md

@@ -72,10 +72,10 @@ Pausing might be the easiest way to make circologd only run "when needed".
 
 When circologd resumes, no previous message is lost.
 
-
-To pause circologd with signals , send a `USR1` signal to the main pid. To "resume", send a `USR1` again.
-
-To pause with HTTP, send a `POST /pause/toggle` to your circologd control socket.
+To pause/unpause:
+ * `circologctl pause`
+ * `pkill -USR1 circologd`
+ * `POST /pause/toggle` to your circologd control socket
 
 ### Clear
 
@@ -83,3 +83,27 @@ When you clear the circologd's buffer, it will discard every message it has, but
 messages.
 
 You can do that with `POST /logs/clear`
+
+### Filter
+
+circologd can drop irrelevant messages using filters. A filter is a sql-like expression (for the exact syntax
+you can see [the doc for the underlying library](https://github.com/araddon/qlbridge/blob/master/FilterQL.md),
+qlbridge), but just imitating sql where clauses can be enough!
+
+`circologctl filter message NOT LIKE '%usb%'` will discard everything related to usb.
+
+The filter will be applied to incoming messages, so messages mentioning usb will not be saved in memory at all.
+
+You can put zero or one filters at a time. That is, you can not stack more filters... but FilterQL syntax
+supports `AND` operators, so this is not an issue.
+
+To remove filtering (thus accepting every message) run `circologctl filter`
+
+NOTE: `circolog-tail` supports filters with exactly the same syntax, but they are two different kinds of
+filtering: one is server-side, the other is client-side. When you filter server-side with `circologctl
+filter`, circologd will refuse messages not matching the filter. If you only filter with `circolog-tail`, the
+message you are filtering out will still consume space in memory (and will be available to other clients).
+
+Filtering brings big dependencies, which will add some 5-6 megabytes to circolog binaries. If you want to
+avoid it, install with `go install -tags nofilter git.lattuga.net/boyska/circolog/...` and your binaries will
+be a bit smaller.

cmd/circolog-tail/main.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"time"
 
+	"git.lattuga.net/boyska/circolog/filtering"
 	"git.lattuga.net/boyska/circolog/formatter"
 	"github.com/gorilla/websocket"
 	"gopkg.in/mcuadros/go-syslog.v2/format"
@@ -21,6 +22,8 @@ func main() {
 	addr := flag.String("addr", "localhost:9080", "http service address")
 	querySocket := flag.String("socket", "", "Path to a unix domain socket for the HTTP server")
 	backlogLimit := flag.Int("n", -1, "Limit the backlog length, defaults to no limit (-1)")
+	var filter filtering.ExprValue
+	flag.Var(&filter, "where", "sql-like query to filter logs")
 	flag.Parse()
 
 	interrupt := make(chan os.Signal, 1)
@@ -69,7 +72,10 @@ func main() {
 			}
 			var parsed format.LogParts
 			if err := bson.Unmarshal(serialized, &parsed); err != nil {
-				log.Println("invalid YAML", err)
+				log.Println("invalid BSON", err)
+				continue
+			}
+			if !filter.Validate(parsed) {
 				continue
 			}
 			if err := formatter.WriteFormatted(os.Stdout, formatter.FormatSyslog, parsed); err != nil {

cmd/circologctl/main.go

@@ -9,6 +9,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"strings"
 	"time"
 )
 
@@ -30,6 +31,7 @@ func init() {
 		//"set":     setCmd,
 		//"get":     getCmd,
 		"pause":   pauseCmd,
+		"filter":  filterCmd,
 		"reload":  reloadCmd,
 		"restart": restartCmd,
 		"help":    helpCmd,
@@ -40,6 +42,24 @@ func init() {
 
 //func getCmd(ctlSock string, args []string) error {}
 
+func filterCmd(args []string) error {
+	filter := strings.Join(args[1:], " ")
+	postBody := make(map[string][]string)
+	postBody["where"] = []string{filter}
+	if globalOpts.debug {
+		fmt.Println("[DEBUG] postBody:", postBody)
+	}
+	resp, err := ctl.PostForm("http://unix/filter", postBody)
+	if resp.StatusCode != 200 || globalOpts.verbose {
+		defer resp.Body.Close()
+		bodyBytes, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(bodyBytes))
+	}
+	return err
+}
 func pauseCmd(args []string) error {
 	var dontChangeAgain time.Duration
 	flagset := flag.NewFlagSet(args[0], flag.ExitOnError)

cmd/circologd/http_ctl.go

@@ -16,6 +16,7 @@ import (
 func setupHTTPCtl(hub circolog.Hub, verbose, debug bool) *mux.Router {
 	m := mux.NewRouter()
 	m.HandleFunc("/pause/toggle", togglePause(hub, verbose, debug)).Methods("POST")
+	m.HandleFunc("/filter", setFilter(hub, verbose, debug)).Methods("POST")
 	m.HandleFunc("/status", getStatus(hub, verbose, debug)).Methods("GET")
 	m.HandleFunc("/logs/clear", clearQueue(hub, verbose)).Methods("POST")
 	m.HandleFunc("/help", printHelp(verbose)).Methods("GET")
@@ -71,6 +72,26 @@ func togglePause(hub circolog.Hub, verbose, debug bool) http.HandlerFunc {
 	}
 }
 
+func setFilter(hub circolog.Hub, verbose, debug bool) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		r.ParseForm()
+		where := r.FormValue("where")
+		response := make(chan circolog.CommandResponse)
+		hub.Commands <- circolog.HubFullCommand{
+			Command:    circolog.CommandNewFilter,
+			Response:   response,
+			Parameters: map[string]interface{}{"where": where},
+		}
+		resp := <-response
+		if !resp.Value.(map[string]interface{})["success"].(bool) {
+			w.WriteHeader(400)
+		}
+		w.Header().Set("content-type", "application/json")
+		enc := json.NewEncoder(w)
+		enc.Encode(resp.Value)
+	}
+}
+
 func clearQueue(hub circolog.Hub, verbose bool) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if verbose {

filtering/filter.go

@@ -0,0 +1,56 @@
+// +build !nofilter
+
+package filtering
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/araddon/qlbridge/datasource"
+	"github.com/araddon/qlbridge/expr"
+	"github.com/araddon/qlbridge/value"
+	"github.com/araddon/qlbridge/vm"
+)
+
+type ExprValue struct {
+	node       expr.Node
+	expression string
+}
+
+func (e *ExprValue) String() string {
+	if e.node != nil {
+		return e.node.String()
+	} else {
+		return "<Empty Expression>"
+	}
+}
+func (e *ExprValue) Set(value string) error {
+	if value == "" {
+		e.node = nil
+		e.expression = value
+		return nil
+	}
+	ast, err := expr.ParseExpression(value)
+	if err != nil {
+		return err
+	}
+	e.node = ast
+	e.expression = value
+	return nil
+}
+
+func (e *ExprValue) Validate(line map[string]interface{}) bool {
+	if e.node == nil {
+		return true
+	}
+	context := datasource.NewContextSimpleNative(line)
+	val, ok := vm.Eval(context, e.node)
+	if !ok || val == nil { // errors when evaluating
+		return false
+	}
+	if bv, isBool := val.(value.BoolValue); isBool {
+		return bv.Val()
+	}
+	fmt.Fprintln(os.Stderr, "WARNING: The 'where' expression doesn't return a boolean")
+	return false
+}

filtering/filter_fake.go

@@ -0,0 +1,17 @@
+// +build nofilter
+
+package filtering
+
+type ExprValue struct {
+}
+
+func (e *ExprValue) String() string {
+	return "<filtering disabled>"
+}
+
+func (e *ExprValue) Set(value string) error {
+	return nil
+}
+func (e *ExprValue) Validate(line map[string]interface{}) bool {
+	return true
+}

hub.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"time"
 
+	"git.lattuga.net/boyska/circolog/filtering"
 	"gopkg.in/mcuadros/go-syslog.v2/format"
 )
 
@@ -34,6 +35,7 @@ const (
 	CommandClear       = iota
 	CommandPauseToggle = iota
 	CommandStatus      = iota
+	CommandNewFilter   = iota
 )
 
 // An HubFullCommand is a Command, complete with arguments
@@ -102,6 +104,7 @@ func (h *Hub) register(cl Client) {
 // Run is hub main loop; keeps everything going
 func (h *Hub) Run() {
 	active := true
+	var filter filtering.ExprValue
 	for {
 		select {
 		case cl := <-h.Register:
@@ -113,7 +116,7 @@ func (h *Hub) Run() {
 				delete(h.clients, cl)
 			}
 		case msg := <-h.LogMessages:
-			if active == true {
+			if active == true && filter.Validate(msg) {
 				h.circbuf.Value = msg
 				h.circbuf = h.circbuf.Next()
 				for client := range h.clients {
@@ -141,7 +144,21 @@ func (h *Hub) Run() {
 				cmd.Response <- CommandResponse{Value: map[string]interface{}{
 					"size":   h.circbuf.Len(),
 					"paused": !active,
+					"filter": filter.String(),
 				}}
+			case CommandNewFilter:
+				if err := filter.Set(cmd.Parameters["where"].(string)); err != nil {
+					cmd.Response <- CommandResponse{Value: map[string]interface{}{
+						"success": false,
+						"error":   err.Error(),
+					}}
+				} else {
+					cmd.Response <- CommandResponse{Value: map[string]interface{}{
+						"success": true,
+						"error":   "",
+					}}
+				}
+
 			}
 		}
 	}