vendor: revendor

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

vendor/github.com/metalmatze/signal/healthcheck/checks.go

@@ -0,0 +1,129 @@
+// Copyright 2020 by the contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package healthcheck
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"net"
+	"net/http"
+	"runtime"
+	"time"
+)
+
+// TCPDialCheck returns a Check that checks TCP connectivity to the provided
+// endpoint.
+func TCPDialCheck(addr string, timeout time.Duration) Check {
+	return func() error {
+		conn, err := net.DialTimeout("tcp", addr, timeout)
+		if err != nil {
+			return err
+		}
+		return conn.Close()
+	}
+}
+
+// HTTPGetCheck returns a Check that performs an HTTP GET request against the
+// specified URL. The check fails if the response times out or returns a non-200
+// status code.
+func HTTPGetCheck(url string, timeout time.Duration) Check {
+	return func() error {
+		return HTTPCheck(url, http.MethodGet, http.StatusOK, timeout)()
+	}
+}
+
+// HTTPCheck returns a Check that performs a HTTP request against the specified URL.
+// The Check fails if the response times out or returns an unexpected status code.
+func HTTPCheck(url string, method string, status int, timeout time.Duration) Check {
+	client := &http.Client{
+		Timeout: timeout,
+		CheckRedirect: func(*http.Request, []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+
+	return HTTPCheckClient(client, url, method, status, timeout)
+}
+
+// HTTPCheckClient returns a Check that performs a HTTP request against the specified URL.
+// The Check fails if the response times out or returns an unexpected status code.
+// On top of that it uses a custom client specified by the caller.
+func HTTPCheckClient(client *http.Client, url string, method string, status int, timeout time.Duration) Check {
+	return func() error {
+		ctx, cancel := context.WithTimeout(context.Background(), timeout)
+		defer cancel()
+
+		req, err := http.NewRequest(method, url, nil)
+		if err != nil {
+			return err
+		}
+		req = req.WithContext(ctx)
+
+		resp, err := client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode != status {
+			return fmt.Errorf("returned status %d, expected %d", resp.StatusCode, status)
+		}
+		return nil
+	}
+}
+
+// DatabasePingCheck returns a Check that validates connectivity to a
+// database/sql.DB using Ping().
+func DatabasePingCheck(database *sql.DB, timeout time.Duration) Check {
+	return func() error {
+		ctx, cancel := context.WithTimeout(context.Background(), timeout)
+		defer cancel()
+		if database == nil {
+			return fmt.Errorf("database is nil")
+		}
+		return database.PingContext(ctx)
+	}
+}
+
+// DNSResolveCheck returns a Check that makes sure the provided host can resolve
+// to at least one IP address within the specified timeout.
+func DNSResolveCheck(host string, timeout time.Duration) Check {
+	resolver := net.Resolver{}
+	return func() error {
+		ctx, cancel := context.WithTimeout(context.Background(), timeout)
+		defer cancel()
+		addrs, err := resolver.LookupHost(ctx, host)
+		if err != nil {
+			return err
+		}
+		if len(addrs) < 1 {
+			return fmt.Errorf("could not resolve host")
+		}
+		return nil
+	}
+}
+
+// GoroutineCountCheck returns a Check that fails if too many goroutines are
+// running (which could indicate a resource leak).
+func GoroutineCountCheck(threshold int) Check {
+	return func() error {
+		count := runtime.NumGoroutine()
+		if count > threshold {
+			return fmt.Errorf("too many goroutines (%d > %d)", count, threshold)
+		}
+		return nil
+	}
+}