Fix support for mongodb/leofs urls without scheme (#2900)

This was broken by changes in go 1.8 to url.Parse.  This change allows
the string but prompts the user to move to the correct url string.

plugins/inputs/leofs/leofs.go

@@ -3,6 +3,7 @@ package leofs
 import (
 	"bufio"
 	"fmt"
+	"log"
 	"net/url"
 	"os/exec"
 	"strconv"
@@ -18,7 +19,7 @@ import (
 const oid = ".1.3.6.1.4.1.35450"
 
 // For Manager Master
-const defaultEndpoint = "127.0.0.1:4020"
+const defaultEndpoint = "udp://127.0.0.1:4020"
 
 type ServerType int
 
@@ -135,9 +136,9 @@ var serverTypeMapping = map[string]ServerType{
 }
 
 var sampleConfig = `
-  ## An array of URI to gather stats about LeoFS.
-  ## Specify an ip or hostname with port. ie 127.0.0.1:4020
-  servers = ["127.0.0.1:4021"]
+  ## An array of URLs of the form:
+  ##   "udp://" host [ ":" port]
+  servers = ["udp://127.0.0.1:4020"]
 `
 
 func (l *LeoFS) SampleConfig() string {
@@ -154,17 +155,28 @@ func (l *LeoFS) Gather(acc telegraf.Accumulator) error {
 		return nil
 	}
 	var wg sync.WaitGroup
-	for _, endpoint := range l.Servers {
-		_, err := url.Parse(endpoint)
+	for i, endpoint := range l.Servers {
+		if !strings.HasPrefix(endpoint, "udp://") {
+			// Preserve backwards compatibility for hostnames without a
+			// scheme, broken in go 1.8. Remove in Telegraf 2.0
+			endpoint = "udp://" + endpoint
+			log.Printf("W! [inputs.mongodb] Using %q as connection URL; please update your configuration to use an URL", endpoint)
+			l.Servers[i] = endpoint
+		}
+		u, err := url.Parse(endpoint)
 		if err != nil {
-			acc.AddError(fmt.Errorf("Unable to parse the address:%s, err:%s", endpoint, err))
+			acc.AddError(fmt.Errorf("Unable to parse address %q: %s", endpoint, err))
 			continue
 		}
-		port, err := retrieveTokenAfterColon(endpoint)
-		if err != nil {
-			acc.AddError(err)
+		if u.Host == "" {
+			acc.AddError(fmt.Errorf("Unable to parse address %q", endpoint))
 			continue
 		}
+
+		port := u.Port()
+		if port == "" {
+			port = "4020"
+		}
 		st, ok := serverTypeMapping[port]
 		if !ok {
 			st = ServerTypeStorage

plugins/inputs/mongodb/README.md

@@ -4,12 +4,12 @@
 
 ```toml
 [[inputs.mongodb]]
-  ## An array of URI to gather stats about. Specify an ip or hostname
-  ## with optional port add password. ie,
+  ## An array of URLs of the form:
+  ##   "mongodb://" [user ":" pass "@"] host [ ":" port]
+  ## For example:
   ##   mongodb://user:auth_key@10.10.3.30:27017,
   ##   mongodb://10.10.3.33:18832,
-  ##   10.0.0.1:10000, etc.
-  servers = ["127.0.0.1:27017"]
+  servers = ["mongodb://127.0.0.1:27017"]
   gather_perdb_stats = false
 
   ## Optional SSL Config
@@ -19,15 +19,8 @@
   ## Use SSL but skip chain & host verification
   # insecure_skip_verify = false
 ```
-
-For authenticated mongodb instances use `mongodb://` connection URI
-
-```toml
-[[inputs.mongodb]]
-  servers = ["mongodb://username:password@10.XX.XX.XX:27101/mydatabase?authSource=admin"]
-```
-This connection uri may be different based on your environement and mongodb
-setup. If the user doesn't have the required privilege to execute serverStatus 
+This connection uri may be different based on your environment and mongodb
+setup. If the user doesn't have the required privilege to execute serverStatus
 command the you will get this error on telegraf
 
 ```

plugins/inputs/mongodb/mongodb.go

@@ -4,8 +4,10 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
+	"log"
 	"net"
 	"net/url"
+	"strings"
 	"sync"
 	"time"
 
@@ -37,12 +39,12 @@ type Ssl struct {
 }
 
 var sampleConfig = `
-  ## An array of URI to gather stats about. Specify an ip or hostname
-  ## with optional port add password. ie,
+  ## An array of URLs of the form:
+  ##   "mongodb://" [user ":" pass "@"] host [ ":" port]
+  ## For example:
   ##   mongodb://user:auth_key@10.10.3.30:27017,
   ##   mongodb://10.10.3.33:18832,
-  ##   10.0.0.1:10000, etc.
-  servers = ["127.0.0.1:27017"]
+  servers = ["mongodb://127.0.0.1:27017"]
   gather_perdb_stats = false
 
   ## Optional SSL Config
@@ -61,7 +63,7 @@ func (*MongoDB) Description() string {
 	return "Read metrics from one or many MongoDB servers"
 }
 
-var localhost = &url.URL{Host: "127.0.0.1:27017"}
+var localhost = &url.URL{Host: "mongodb://127.0.0.1:27017"}
 
 // Reads stats from all configured servers accumulates stats.
 // Returns one of the errors encountered while gather stats (if any).
@@ -72,19 +74,25 @@ func (m *MongoDB) Gather(acc telegraf.Accumulator) error {
 	}
 
 	var wg sync.WaitGroup
-	for _, serv := range m.Servers {
+	for i, serv := range m.Servers {
+		if !strings.HasPrefix(serv, "mongodb://") {
+			// Preserve backwards compatibility for hostnames without a
+			// scheme, broken in go 1.8. Remove in Telegraf 2.0
+			serv = "mongodb://" + serv
+			log.Printf("W! [inputs.mongodb] Using %q as connection URL; please update your configuration to use an URL", serv)
+			m.Servers[i] = serv
+		}
+
 		u, err := url.Parse(serv)
 		if err != nil {
-			acc.AddError(fmt.Errorf("Unable to parse to address '%s': %s", serv, err))
+			acc.AddError(fmt.Errorf("Unable to parse address %q: %s", serv, err))
 			continue
-		} else if u.Scheme == "" {
-			u.Scheme = "mongodb"
-			// fallback to simple string based address (i.e. "10.0.0.1:10000")
-			u.Host = serv
-			if u.Path == u.Host {
-				u.Path = ""
-			}
 		}
+		if u.Host == "" {
+			acc.AddError(fmt.Errorf("Unable to parse address %q", serv))
+			continue
+		}
+
 		wg.Add(1)
 		go func(srv *Server) {
 			defer wg.Done()