https://github.com/saulortega/gcl
Logger for Google Cloud Logging
https://github.com/saulortega/gcl
gcloud gcp logger logging
Last synced: 2 months ago
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Logger for Google Cloud Logging
- Host: GitHub
- URL: https://github.com/saulortega/gcl
- Owner: saulortega
- License: bsd-3-clause
- Created: 2021-10-02T03:34:11.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2021-10-20T02:10:04.000Z (over 3 years ago)
- Last Synced: 2025-01-28T00:26:59.893Z (4 months ago)
- Topics: gcloud, gcp, logger, logging
- Language: Go
- Homepage:
- Size: 10.7 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.en.md
- License: LICENSE
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README
# gcl
This library allows to generate logs compatible with the Google Cloud Logging API that can be used in code implemented in Cloud Functions, Cloud Run, or Kubernetes.
## Methods
```go
// error cause.
gcl.Cause(err)
// Custom fields with arbitrary values.
// Will appear in the entry of Cloud Logging in «jsonPayload».
gcl.Field("user", 573298)
gcl.Field("role", "supervisor")
// Custom fields for labels.
// Will appear in the entry of Cloud Logging in «labels».
gcl.Label("app", "my-app")
// Description of the error with severity.
// This must be a message suitable for be replied to the final user
// when it is used in HTTP requests.
gcl.Debug("oops")
gcl.Info("oops")
gcl.Notice("oops")
gcl.Warning("oops")
gcl.Error("oops")
gcl.Critical("oops")
gcl.Alert("oops")
gcl.Emergency("oops")
// Set HTTP status code and data from HTTP request.
gcl.HTTPStatus(http.StatusNotFound)
gcl.HTTPRequest(r)
// All the above methods can be chained:
gcl.Cause(err).Field("user", 573298).Warning("user not found").HTTPStatus(http.StatusNotFound)
// The above methods initialize the entry of log, but does not write the log.
// To write the log to stdout, use Log():
gcl.Cause(err).Field("user", 573298).Warning("user not found").HTTPStatus(http.StatusNotFound).Log()
// To return an error and handle it later, use Err():
gcl.Cause(err).Field("user", 573298).Warning("user not found").HTTPStatus(http.StatusNotFound).Err()
```
## Error handling in HTTP requests:
```go
package main
import (
"encoding/json"
"fmt"
"log"
"net/http"
"github.com/saulortega/gcl"
)
func main() {
http.HandleFunc("/users", users)
log.Fatal(http.ListenAndServe(":80", nil))
}
func users(w http.ResponseWriter, r *http.Request) {
data, err := getUser(r.FormValue("user"))
if err != nil {
res, cod := handleError(r, err)
http.Error(w, res, cod)
return
}
fmt.Fprint(w, data)
}
func getUser(u string) ([]byte, error) {
if u == "" {
return nil, gcl.Notice("empty user").HTTPStatus(http.StatusBadRequest).Err()
}
var user = struct {
name string
}{}
err := db.QueryRow("SELECT name FROM users WHERE id = $1", u).Scan(&user)
if err == sql.ErrNoRows {
return nil, gcl.Cause(err).Notice("user not found").HTTPStatus(http.StatusNotFound).Err()
} else if err != nil {
return nil, gcl.Cause(err).Field("user", u).Error("something went wrong").HTTPStatus(http.StatusInternalServerError).Err()
}
b, err := json.Marshal(user)
if err != nil {
return nil, gcl.Cause(err).Field("user", u).Error("something went wrong").HTTPStatus(http.StatusInternalServerError).Err()
}
return b, nil
}
func handleError(r *http.Request, e error) (string, int) {
// An *gcl.Err is expected. If not, this parameters will be used:
msg := "something went wrong"
cod := http.StatusInternalServerError
res := fmt.Sprintf(`{"error":"%s"}`, msg)
err, ok := e.(*gcl.Err)
if ok {
// Returns the code previously setted, or 500 if not was setted.
cod = err.HTTPStatus()
// Returns the setted message in one of the eight functions with severity (Debug, Info, Error, etc.), or msg if not was setted.
msg = err.Message(msg)
res = fmt.Sprintf(`{"error":"%s"}`, msg)
// Set HTTP Request data:
err.HTTPRequest(r)
// Write log to stdout:
err.Log()
}
return res, cod
}
```