woodpecker/cmd/agent/health.go
velsinki dda4998261
Change healtcheck port into address format, redo #1197 (#1423)
As discussed in the comments in PR #1197. Also add documenation
accordingly.

One thing I'm not sure about is the simple check in health.go if the
address is usable in the GET request or not. From reading
https://pkg.go.dev/net#Dial it seems that the only non-standard address
format that would work in the `net` package but not in a GET url would
likely only be `:port`, as the others listed here are actually also
valid urls:

`For TCP, UDP and IP networks, if the host is empty or a literal
unspecified IP address, as in ":80", "0.0.0.0:80" or "[::]:80" for TCP
and UDP, "", "0.0.0.0" or "::" for IP, the local system is assumed.`

One additional thing I noticed is that while `WOODPECKER_SERVER_ADDR`
and `WOODPECKER_SERVER_ADDR` use the default value format of `:PORT`,
`WOODPECKER_SERVER` actually uses `localhost:9000`. I guess it makes a
bit of sense, considering the server might not be local to the agent,
but it looks a bit inconsistent this way. I don't think it would hurt to
make the `WOODPECKER_HEALTHCHECK_ADDR` in this format too, but then it's
different from the server flags again... :-)
2022-11-19 13:06:51 +02:00

96 lines
2.5 KiB
Go

// Copyright 2018 Drone.IO Inc.
//
// 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 main
import (
"encoding/json"
"fmt"
"net/http"
"strings"
"github.com/rs/zerolog/log"
"github.com/urfave/cli/v2"
"github.com/woodpecker-ci/woodpecker/agent"
"github.com/woodpecker-ci/woodpecker/version"
)
// the file implements some basic healthcheck logic based on the
// following specification:
// https://github.com/mozilla-services/Dockerflow
func init() {
http.HandleFunc("/varz", handleStats)
http.HandleFunc("/healthz", handleHeartbeat)
http.HandleFunc("/version", handleVersion)
}
func handleHeartbeat(w http.ResponseWriter, r *http.Request) {
if counter.Healthy() {
w.WriteHeader(200)
} else {
w.WriteHeader(500)
}
}
func handleVersion(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
w.Header().Add("Content-Type", "text/json")
_ = json.NewEncoder(w).Encode(versionResp{
Source: "https://github.com/woodpecker-ci/woodpecker",
Version: version.String(),
})
}
func handleStats(w http.ResponseWriter, r *http.Request) {
if counter.Healthy() {
w.WriteHeader(200)
} else {
w.WriteHeader(500)
}
w.Header().Add("Content-Type", "text/json")
if _, err := counter.WriteTo(w); err != nil {
log.Error().Err(err).Msg("handleStats")
}
}
type versionResp struct {
Version string `json:"version"`
Source string `json:"source"`
}
// default statistics counter
var counter = &agent.State{
Metadata: map[string]agent.Info{},
}
// handles pinging the endpoint and returns an error if the
// agent is in an unhealthy state.
func pinger(c *cli.Context) error {
healthcheckAddress := c.String("healthcheck-addr")
if strings.HasPrefix(healthcheckAddress, ":") {
// this seems sufficient according to https://pkg.go.dev/net#Dial
healthcheckAddress = "localhost" + healthcheckAddress
}
resp, err := http.Get("http://" + healthcheckAddress + "/healthz")
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
return fmt.Errorf("agent returned non-200 status code")
}
return nil
}