metrics_middleware.go

Copyright 2020 Red Hat, 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
httputils

Documentation in literate-programming-style is available at: https://redhatinsights.github.io/insights-operator-utils/packages/http/metrics_middleware.html


import
(
"fmt"
"net/http"
"time"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
"github.com/rs/zerolog/log"
"github.com/RedHatInsights/insights-operator-utils/metrics"
)
type
loggingResponseWriter
struct
{
http
.
ResponseWriter
endpoint
string
}
func
(
writer
loggingResponseWriter
)
WriteHeader
(
statusCode
int
)
{
writer
.
ResponseWriter
.
WriteHeader
(
statusCode
)
metrics
.
APIResponseStatusCodes
.
With
(
prometheus
.
Labels
{
"status_code"
:
fmt
.
Sprint
(
statusCode
)
,
"endpoint"
:
writer
.
endpoint
}
,
)
.
Inc
(
)
}
func
logRequestHandler
(
writer
http
.
ResponseWriter
,
request
*
http
.
Request
,
nextHandler
http
.
Handler
)
{
log
.
Info
(
)
.
Msgf
(
"Request received - URI: %s, Method: %s"
,
request
.
RequestURI
,
request
.
Method
)
route
:=
mux
.
CurrentRoute
(
request
)
endpoint
,
err
:=
route
.
GetPathTemplate
(
)
if
err
!=
nil
{
log
.
Error
(
)
.
Err
(
err
)
endpoint
=
""
}
metrics
.
APIRequests
.
With
(
prometheus
.
Labels
{
"endpoint"
:
endpoint
}
)
.
Inc
(
)
startTime
:=
time
.
Now
(
)
nextHandler
.
ServeHTTP
(
&
loggingResponseWriter
{
ResponseWriter
:
writer
,
endpoint
:
endpoint
,
}
,
request
)
duration
:=
time
.
Since
(
startTime
)
metrics
.
APIResponsesTime
.
With
(
prometheus
.
Labels
{
"endpoint"
:
endpoint
}
,
)
.
Observe
(
duration
.
Seconds
(
)
)
}

LogRequest - middleware for logging requests

func
LogRequest
(
nextHandler
http
.
Handler
)
http
.
Handler
{
return
http
.
HandlerFunc
(
func
(
writer
http
.
ResponseWriter
,
request
*
http
.
Request
)
{
logRequestHandler
(
writer
,
request
,
nextHandler
)
}
)
}