Fix S3 metrics test to actually test the correct code path

.github/workflows/test.yml

@@ -22,3 +22,16 @@ jobs:
           install-awslocal: 'true'
       - name: Run tests
         run: go test -v ./...
+        env:
+          # localstack requires these environment variables
+          AWS_DEFAULT_REGION: ap-northeast-1
+          # Credentials are important for localstack
+          # Without them, the tests will fail like:
+          #   operation error S3: CreateBucket, get identity: get credentials: failed to refresh cached credentials, no EC2 IMDS role found, operation error ec2imds: GetMetadata, failed to get API token, operation error ec2imds: getToken, http response error StatusCode: 400, request to EC2 IMDS failed
+          AWS_ACCESS_KEY_ID: test
+          AWS_SECRET_ACCESS_KEY: test
+          # These environment variables are required by main and main_test
+          # Without them, the tests will fail like:
+          #   operation error S3: CreateBucket, exceeded maximum number of attempts, 3, https response error StatusCode: 500, RequestID: 346f5995-bbe8-41e2-be03-3a6ab0ad5edd, HostID: s9lzHYrFp76ZVxRcpX9+5cjAnEH2ROuNkd2BHfIa6UkFVdtjf5mKR3/eTPFvsiP/XV/VLi31234=, api error InternalError: exception while calling s3 with unknown operation: Unable to find operation for request to service s3: PUT /
+          S3_BUCKET: mybucket
+          S3_KEY: mykey

go.mod

@@ -34,11 +34,12 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_model v0.5.0 // indirect
-	github.com/prometheus/common v0.48.0 // indirect
-	github.com/prometheus/procfs v0.12.0 // indirect
-	golang.org/x/sys v0.17.0 // indirect
-	google.golang.org/protobuf v1.33.0 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	golang.org/x/sys v0.21.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -58,25 +58,37 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.19.1 h1:wZWJDwK+NameRJuPGDhlnFgx8e8HN3XHQeLaYJFJBOE=
 github.com/prometheus/client_golang v1.19.1/go.mod h1:mP78NwGzrVks5S2H6ab8+ZZGJLZUq1hoULYBAYBw1Ho=
 github.com/prometheus/client_model v0.5.0 h1:VQw1hfvPvk3Uv6Qf29VrPF32JB6rtbgI6cYPYQjL0Qw=
 github.com/prometheus/client_model v0.5.0/go.mod h1:dTiFglRmd66nLR9Pv9f0mZi7B7fk5Pm3gvsjB5tr+kI=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
 github.com/prometheus/common v0.48.0 h1:QO8U2CdOzSn1BBsmXJXduaaW+dY/5QLjfB8svtSzKKE=
 github.com/prometheus/common v0.48.0/go.mod h1:0/KsvlIEfPQCQ5I2iNSAWKPZziNCvRs5EC6ILDTlAPc=
+github.com/prometheus/common v0.55.0 h1:KEi6DK7lXW/m7Ig5i47x0vRzuBsHuvJdi5ee6Y3G1dc=
+github.com/prometheus/common v0.55.0/go.mod h1:2SECS4xJG1kd8XF9IcM1gMX6510RAEL65zxzNImwdc8=
 github.com/prometheus/procfs v0.12.0 h1:jluTpSng7V9hY0O2R9DzzJHYb2xULk9VTR1V1R/k6Bo=
 github.com/prometheus/procfs v0.12.0/go.mod h1:pcuDEFsWDnvcgNzo4EEweacyhjeA9Zk3cnaOZAZEfOo=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
 golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
 google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

main_test.go

@@ -10,8 +10,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/config"
 	"github.com/aws/aws-sdk-go-v2/service/s3"
+	s3types "github.com/aws/aws-sdk-go-v2/service/s3/types"
 	"github.com/cw-sakamoto/sample/localstack"
+	"github.com/prometheus/common/expfmt"
 	"github.com/stretchr/testify/require"
 )
 
@@ -25,10 +29,17 @@ func TestSigint(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
+	awsConfig, err := config.LoadDefaultConfig(ctx)
+	require.NoError(t, err)
+
+	s3EndpointResolver := localstack.S3EndpointResolver()
+
+	setupS3BucketAndObject(t, ctx, awsConfig, s3EndpointResolver)
+
 	go func() {
 		runErr <- Run(ContextWithSignal(ctx, sigs), func(c *checker) {
 			// Use localstack for S3
-			c.s3Opts = append(c.s3Opts, s3.WithEndpointResolverV2(localstack.S3EndpointResolver()))
+			c.s3Opts = append(c.s3Opts, s3.WithEndpointResolverV2(s3EndpointResolver))
 		})
 
 		cancel()
@@ -55,7 +66,38 @@ func TestSigint(t *testing.T) {
 		// m is the metrics in the Prometheus exposition format,
 		// expectedly containing the aws_request_duration_seconds metric.
 		// We can check the presence of any metric here, in any detail.
-		require.Contains(t, m, "promhttp_metric_handler_requests_total")
+
+		p := expfmt.TextParser{}
+		mf, err := p.TextToMetricFamilies(strings.NewReader(m))
+		require.NoError(t, err)
+
+		mt, ok := mf["aws_request_duration_seconds"]
+		require.True(t, ok)
+
+		type labels struct {
+			service, method, status string
+		}
+
+		mm := make(map[labels]struct{})
+
+		for _, m := range mt.Metric {
+			t.Logf("Metric: %v", m)
+			var labels labels
+			for _, l := range m.Label {
+				switch *l.Name {
+				case "service":
+					labels.service = *l.Value
+				case "method":
+					labels.method = *l.Value
+				case "status":
+					labels.status = *l.Value
+				}
+			}
+			mm[labels] = struct{}{}
+		}
+
+		require.Len(t, mm, 1)
+		require.Contains(t, mm, labels{"S3", "GetObject", "Success"})
 	case <-time.After(2 * time.Second):
 		// We assume that the server is expected to start and expose metrics within 2 seconds.
 		// Otherwise, we consider it as a failure, and you may need to fix the server implementation,
@@ -75,6 +117,51 @@ func TestSigint(t *testing.T) {
 	}
 }
 
+// Put s3 object for testing
+func setupS3BucketAndObject(t *testing.T, ctx context.Context, awsConfig aws.Config, s3EndpointResolver s3.EndpointResolverV2) {
+	s3Client := s3.NewFromConfig(awsConfig, s3.WithEndpointResolverV2(s3EndpointResolver))
+
+	// We assume that S3_BUCKET and S3_KEY are set in the environment variables
+	// before running the tests.
+	s3Bucket := os.Getenv("S3_BUCKET")
+	s3Key := os.Getenv("S3_KEY")
+
+	_, err := s3Client.CreateBucket(ctx, &s3.CreateBucketInput{
+		Bucket: &s3Bucket,
+		// LocationConstraint is required when AWS_DEFAULT_REGION is not us-east-1
+		// Otherwise, you will get the following error:
+		//   IllegalLocationConstraintException: The unspecified location constraint is incompatible for the region specific endpoint this request was sent to.
+		CreateBucketConfiguration: &s3types.CreateBucketConfiguration{
+			LocationConstraint: s3types.BucketLocationConstraint(os.Getenv("AWS_DEFAULT_REGION")),
+		},
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		_, err = s3Client.DeleteBucket(context.Background(), &s3.DeleteBucketInput{
+			Bucket: &s3Bucket,
+		})
+		if err != nil {
+			t.Logf("Error: %v", err)
+		}
+	})
+
+	_, err = s3Client.PutObject(ctx, &s3.PutObjectInput{
+		Bucket: &s3Bucket,
+		Key:    &s3Key,
+		Body:   strings.NewReader("hello"),
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		_, err := s3Client.DeleteObject(context.Background(), &s3.DeleteObjectInput{
+			Bucket: &s3Bucket,
+			Key:    &s3Key,
+		})
+		if err != nil {
+			t.Logf("Error: %v", err)
+		}
+	})
+}
+
 func httpGetStr(t *testing.T, url string) string {
 	resp, err := http.Get(url)
 	if err != nil {