grafana/pkg/services/ngalert/remote/client/alertmanager.go

125 lines
3.5 KiB
Go

package client
import (
"context"
"fmt"
"net/http"
"net/url"
"time"
httptransport "github.com/go-openapi/runtime/client"
"github.com/grafana/grafana/pkg/infra/log"
"github.com/grafana/grafana/pkg/services/ngalert/client"
"github.com/grafana/grafana/pkg/services/ngalert/metrics"
amclient "github.com/prometheus/alertmanager/api/v2/client"
)
const alertmanagerAPIMountPath = "/alertmanager"
const alertmanagerReadyPath = "/-/ready"
type AlertmanagerConfig struct {
TenantID string
Password string
URL *url.URL
Logger log.Logger
}
type Alertmanager struct {
*amclient.AlertmanagerAPI
httpClient client.Requester
url *url.URL
logger log.Logger
}
func NewAlertmanager(cfg *AlertmanagerConfig, metrics *metrics.RemoteAlertmanager) (*Alertmanager, error) {
// First, add the authentication middleware.
c := &http.Client{Transport: &MimirAuthRoundTripper{
TenantID: cfg.TenantID,
Password: cfg.Password,
Next: http.DefaultTransport,
}}
tc := client.NewTimedClient(c, metrics.RequestLatency)
apiEndpoint := *cfg.URL
// Next, make sure you set the right path.
u := apiEndpoint.JoinPath(alertmanagerAPIMountPath, amclient.DefaultBasePath)
// Create an Alertmanager client using the timed client as the transport.
r := httptransport.New(u.Host, u.Path, []string{u.Scheme})
r.Transport = tc
return &Alertmanager{
logger: cfg.Logger,
url: cfg.URL,
AlertmanagerAPI: amclient.New(r, nil),
httpClient: tc,
}, nil
}
// GetAuthedClient returns a client.Requester that includes a configured MimirAuthRoundTripper.
// Requests using this client are fully authenticated.
func (am *Alertmanager) GetAuthedClient() client.Requester {
return am.httpClient
}
// IsReadyWithBackoff executes a readiness check against the `/-/ready` Alertmanager endpoint.
// If it takes more than 10s to get a response back - we abort the check.
func (am *Alertmanager) IsReadyWithBackoff(ctx context.Context) (bool, error) {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
readyURL := am.url.JoinPath(am.url.Path, alertmanagerAPIMountPath, alertmanagerReadyPath)
attempt := func() (int, error) {
req, err := http.NewRequestWithContext(ctx, http.MethodGet, readyURL.String(), nil)
if err != nil {
return 0, fmt.Errorf("error creating the readiness request: %w", err)
}
res, err := am.httpClient.Do(req)
if err != nil {
return 0, fmt.Errorf("error performing the readiness check: %w", err)
}
defer func() {
if err := res.Body.Close(); err != nil {
am.logger.Warn("Error closing response body", "err", err)
}
}()
return res.StatusCode, nil
}
var attempts int
ticker := time.NewTicker(100 * time.Millisecond)
deadlineCh := time.After(10 * time.Second)
defer ticker.Stop()
for {
select {
case <-ticker.C:
attempts++
status, err := attempt()
if err != nil {
am.logger.Debug("Ready check attempt failed", "attempt", attempts, "err", err)
continue
}
if status != http.StatusOK {
if status >= 400 && status < 500 {
am.logger.Debug("Ready check failed with non-retriable status code", "attempt", attempts, "status", status)
return false, fmt.Errorf("ready check failed with non-retriable status code %d", status)
}
am.logger.Debug("Ready check failed, status code is not 200", "attempt", attempts, "status", status, "err", err)
continue
}
return true, nil
case <-deadlineCh:
cancel()
return false, fmt.Errorf("ready check timed out after %d attempts", attempts)
}
}
}