Refactor exporter so that it can be used as a library.

collector/postgres_exporter_test.go

@@ -0,0 +1,179 @@
+// +build !integration
+
+package collector
+
+import (
+	. "gopkg.in/check.v1"
+	"testing"
+
+	"github.com/blang/semver"
+	"os"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) { TestingT(t) }
+
+type FunctionalSuite struct {
+}
+
+var _ = Suite(&FunctionalSuite{})
+
+func (s *FunctionalSuite) SetUpSuite(c *C) {
+
+}
+
+func (s *FunctionalSuite) TestSemanticVersionColumnDiscard(c *C) {
+	testMetricMap := map[string]map[string]ColumnMapping{
+		"test_namespace": {
+			"metric_which_stays":    {COUNTER, "This metric should not be eliminated", nil, nil},
+			"metric_which_discards": {COUNTER, "This metric should be forced to DISCARD", nil, nil},
+		},
+	}
+
+	{
+		// No metrics should be eliminated
+		resultMap := makeDescMap(semver.MustParse("0.0.1"), testMetricMap)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_stays"].discard,
+			Equals,
+			false,
+		)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_discards"].discard,
+			Equals,
+			false,
+		)
+	}
+
+	{
+		// Update the map so the discard metric should be eliminated
+		discardableMetric := testMetricMap["test_namespace"]["metric_which_discards"]
+		discardableMetric.supportedVersions = semver.MustParseRange(">0.0.1")
+		testMetricMap["test_namespace"]["metric_which_discards"] = discardableMetric
+
+		// Discard metric should be discarded
+		resultMap := makeDescMap(semver.MustParse("0.0.1"), testMetricMap)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_stays"].discard,
+			Equals,
+			false,
+		)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_discards"].discard,
+			Equals,
+			true,
+		)
+	}
+
+	{
+		// Update the map so the discard metric should be kept but has a version
+		discardableMetric := testMetricMap["test_namespace"]["metric_which_discards"]
+		discardableMetric.supportedVersions = semver.MustParseRange(">0.0.1")
+		testMetricMap["test_namespace"]["metric_which_discards"] = discardableMetric
+
+		// Discard metric should be discarded
+		resultMap := makeDescMap(semver.MustParse("0.0.2"), testMetricMap)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_stays"].discard,
+			Equals,
+			false,
+		)
+		c.Check(
+			resultMap["test_namespace"].columnMappings["metric_which_discards"].discard,
+			Equals,
+			false,
+		)
+	}
+}
+
+// test read username and password from file
+func (s *FunctionalSuite) TestEnvironmentSettingWithSecretsFiles(c *C) {
+
+	err := os.Setenv("DATA_SOURCE_USER_FILE", "../tests/username_file")
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_USER_FILE")
+
+	err = os.Setenv("DATA_SOURCE_PASS_FILE", "../tests/userpass_file")
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_PASS_FILE")
+
+	err = os.Setenv("DATA_SOURCE_URI", "localhost:5432/?sslmode=disable")
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_URI")
+
+	var expected = "postgresql://custom_username:custom_password@localhost:5432/?sslmode=disable"
+
+	dsn := GetDataSource()
+	if dsn != expected {
+		c.Errorf("Expected Username to be read from file. Found=%v, expected=%v", dsn, expected)
+	}
+}
+
+// test read DATA_SOURCE_NAME from environment
+func (s *FunctionalSuite) TestEnvironmentSettingWithDns(c *C) {
+
+	envDsn := "postgresql://user:password@localhost:5432/?sslmode=enabled"
+	err := os.Setenv("DATA_SOURCE_NAME", envDsn)
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_NAME")
+
+	dsn := GetDataSource()
+	if dsn != envDsn {
+		c.Errorf("Expected Username to be read from file. Found=%v, expected=%v", dsn, envDsn)
+	}
+}
+
+// test DATA_SOURCE_NAME is used even if username and password environment variables are set
+func (s *FunctionalSuite) TestEnvironmentSettingWithDnsAndSecrets(c *C) {
+
+	envDsn := "postgresql://userDsn:passwordDsn@localhost:55432/?sslmode=disabled"
+	err := os.Setenv("DATA_SOURCE_NAME", envDsn)
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_NAME")
+
+	err = os.Setenv("DATA_SOURCE_USER_FILE", "../tests/username_file")
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_USER_FILE")
+
+	err = os.Setenv("DATA_SOURCE_PASS", "envUserPass")
+	c.Assert(err, IsNil)
+	defer UnsetEnvironment(c, "DATA_SOURCE_PASS")
+
+	dsn := GetDataSource()
+	if dsn != envDsn {
+		c.Errorf("Expected Username to be read from file. Found=%v, expected=%v", dsn, envDsn)
+	}
+}
+
+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)
+}