Fix issue in watchdog - not reading false config overrides.

watchdog/README.md

@@ -25,13 +25,35 @@ ENV fprocess="/bin/cat"
 CMD ["fwatchdog"]
 ```
 
+**Implementing the a healthcheck**
+
+Docker swarm will keep your function out of the DNS-RR / IPVS pool if the task (container) is not healthy.
+
+Here is an example of the `echo` function implementing a healthcheck with a 5-second checking interval.
+
+```
+FROM functions/alpine
+
+ENV fprocess="cat /etc/hostname"
+
+HEALTHCHECK --interval=5s CMD [ -e /tmp/.lock ] || exit 1
+```
+
+The watchdog process creates a .lock file in `/tmp/` on starting its internal Golang HTTP server. `[ -e file_name ]` is shell to check if a file exists.
+
+Swarm tutorial on Healthchecks:
+
+ * [Test-drive Docker Healthcheck in 10 minutes](http://blog.alexellis.io/test-drive-healthcheck/)
+
+
 **Environmental overrides:**
 
 A number of environmental overrides can be added for additional flexibility and options:
 
 | Option                 | Usage             |
 |------------------------|--------------|
-| `fprocess`     | The process to invoke for each function call. This must be a UNIX binary and accept input via STDIN and output via STDOUT.  |
+| `fprocess`             | The process to invoke for each function call. This must be a UNIX binary and accept input via STDIN and output via STDOUT.  |
 | `marshal_requests`     | Instead of re-directing the raw HTTP body into your fprocess, it will first be marshalled into JSON. Use this if you need to work with HTTP headers |
-| `write_timeout`     | HTTP timeout for writing a response body from your function  |
-| `read_timeout`     | HTTP timeout for reading the payload from the client caller  |
+| `write_timeout`        | HTTP timeout for writing a response body from your function  |
+| `read_timeout`         | HTTP timeout for reading the payload from the client caller  |
+| `suppress_lock`        | The watchdog will attempt to write a lockfile to /tmp/ for swarm healthchecks - set this to true to disable behaviour. |

watchdog/build.sh

@@ -3,7 +3,7 @@
 # Below makes use of "builder pattern" so that binary is extracted separate
 # from the golang runtime/SDK
 
-docker build --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy \
+docker build --no-cache --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy \
     -t functions/watchdog:build .
 docker create --name buildoutput functions/watchdog:build echo
 docker cp buildoutput:/go/src/github.com/alexellis/faas/watchdog/watchdog ./fwatchdog

watchdog/config_test.go

@@ -29,19 +29,46 @@ func TestRead_WriteDebug_DefaultIsTrueConfig(t *testing.T) {
 	config := readConfig.Read(defaults)
 
 	if config.writeDebug != true {
-		t.Logf("writeDebug should have been true")
+		t.Logf("writeDebug should have been true (unspecified)")
 		t.Fail()
 	}
 }
-func TestRead_WriteDebug_FalseConfig(t *testing.T) {
+
+func TestRead_WriteDebug_FalseOverrideConfig(t *testing.T) {
 	defaults := NewEnvBucket()
 	readConfig := ReadConfig{}
-	defaults.Setenv("writeDebug", "true")
+	defaults.Setenv("write_debug", "false")
+
+	config := readConfig.Read(defaults)
+
+	if config.writeDebug != false {
+		t.Logf("writeDebug should have been false (specified)")
+		t.Fail()
+	}
+}
+
+func TestRead_WriteDebug_TrueConfig(t *testing.T) {
+	defaults := NewEnvBucket()
+	readConfig := ReadConfig{}
+	defaults.Setenv("write_debug", "true")
 
 	config := readConfig.Read(defaults)
 
 	if config.writeDebug != true {
-		t.Logf("writeDebug should have been true")
+		t.Logf("writeDebug should have been true (specified)")
+		t.Fail()
+	}
+}
+
+func TestRead_SuppressLockConfig(t *testing.T) {
+	defaults := NewEnvBucket()
+	readConfig := ReadConfig{}
+	defaults.Setenv("suppress_lock", "true")
+
+	config := readConfig.Read(defaults)
+
+	if config.suppressLock != true {
+		t.Logf("suppress_lock envVariable incorrect, got: %s.\n", config.faasProcess)
 		t.Fail()
 	}
 }

watchdog/main.go

@@ -136,9 +136,11 @@ func main() {
 	http.HandleFunc("/", makeRequestHandler(&config))
 
 	if config.suppressLock == false {
-		writeErr := ioutil.WriteFile("/tmp/.lock", []byte{}, 0660)
+		path := "/tmp/.lock"
+		log.Printf("Writing lock-file to: %s\n", path)
+		writeErr := ioutil.WriteFile(path, []byte{}, 0660)
 		if writeErr != nil {
-			log.Panicf("Cannot write /tmp/.lock for healthcheck: %s \n", writeErr.Error())
+			log.Panicf("Cannot write %s. Error: %s\n", path, writeErr.Error())
 		}
 	}
 

watchdog/readconfig.go

@@ -18,7 +18,7 @@ func parseBoolValue(val string) bool {
 	if val == "true" {
 		return true
 	}
-	return true
+	return false
 }
 
 func parseIntValue(val string) int {
@@ -55,11 +55,15 @@ func (ReadConfig) Read(hasEnv HasEnv) WatchdogConfig {
 	cfg.readTimeout = time.Duration(readTimeout) * time.Second
 	cfg.writeTimeout = time.Duration(writeTimeout) * time.Second
 
-	cfg.writeDebug = parseBoolValue(hasEnv.Getenv("write_debug"))
+	if len(hasEnv.Getenv("write_debug")) > 0 {
+		cfg.writeDebug = parseBoolValue(hasEnv.Getenv("write_debug"))
+	}
 
 	cfg.marshalRequest = parseBoolValue(hasEnv.Getenv("marshal_request"))
 	cfg.debugHeaders = parseBoolValue(hasEnv.Getenv("debug_headers"))
+
 	cfg.suppressLock = parseBoolValue(hasEnv.Getenv("suppress_lock"))
+
 	return cfg
 }