fixed version parsing for Windows and EnterpriseDB (prometheus-community#151)

* fixed version parsing for Windows and EnterpriseDB * fixed formatting

Author: marcinbudny

postgres_exporter.go

@@ -80,7 +80,7 @@ func (cu *ColumnUsage) UnmarshalYAML(unmarshal func(interface{}) error) error {
 }
 
 // Regex used to get the "short-version" from the postgres version field.
-var versionRegex = regexp.MustCompile(`^\w+ ((\d+)(\.\d+)?(\.\d+)?)\s`)
+var versionRegex = regexp.MustCompile(`^\w+ ((\d+)(\.\d+)?(\.\d+)?)`)
 var lowestSupportedVersion = semver.MustParse("9.1.0")
 
 // Parses the version of postgres into the short version string we can use to

postgres_exporter_test.go

@@ -145,6 +145,34 @@ func (s *FunctionalSuite) TestEnvironmentSettingWithDnsAndSecrets(c *C) {
 }
 }
 
+func (s *FunctionalSuite) TestPostgresVersionParsing(c *C) {
+type TestCase struct {
+input string
+expected string
+}
+
+cases := []TestCase{
+{
+input: "PostgreSQL 10.1 on x86_64-pc-linux-gnu, compiled by gcc (Debian 6.3.0-18) 6.3.0 20170516, 64-bit",
+expected: "10.1.0",
+},
+{
+input: "PostgreSQL 9.5.4, compiled by Visual C++ build 1800, 64-bit",
+expected: "9.5.4",
+},
+{
+input: "EnterpriseDB 9.6.5.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16), 64-bit",
+expected: "9.6.5",
+},
+}
+
+for _, cs := range cases {
+ver, err := parseVersion(cs.input)
+c.Assert(err, IsNil)
+c.Assert(ver.String(), Equals, cs.expected)
+}
+}
+
 func UnsetEnvironment(c *C, d string) {
 err := os.Unsetenv(d)
 c.Assert(err, IsNil)