Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/ecs/client.go

@@ -0,0 +1,173 @@
+package ecs
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/docker/docker/api/types/container"
+)
+
+var (
+	// https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint-v2.html
+	ecsMetadataPathV2  = "/v2/metadata"
+	ecsMetaStatsPathV2 = "/v2/stats"
+
+	// https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint-v3.html
+	// https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint-v4.html
+	ecsMetadataPath  = "/task"
+	ecsMetaStatsPath = "/task/stats"
+)
+
+// client is the ECS client contract
+type client interface {
+	task() (*ecsTask, error)
+	containerStats() (map[string]*container.StatsResponse, error)
+}
+
+type httpClient interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
+// newClient constructs an ECS client with the passed configuration params
+func newClient(timeout time.Duration, endpoint string, version int) (*ecsClient, error) {
+	if version < 2 || version > 4 {
+		const msg = "expected metadata version 2, 3 or 4, got %d"
+		return nil, fmt.Errorf(msg, version)
+	}
+
+	baseURL, err := url.Parse(endpoint)
+	if err != nil {
+		return nil, err
+	}
+
+	c := &http.Client{
+		Timeout: timeout,
+	}
+
+	return &ecsClient{
+		client:   c,
+		baseURL:  baseURL,
+		taskURL:  resolveTaskURL(baseURL, version),
+		statsURL: resolveStatsURL(baseURL, version),
+		version:  version,
+	}, nil
+}
+
+func resolveTaskURL(base *url.URL, version int) string {
+	var path string
+	switch version {
+	case 2:
+		path = ecsMetadataPathV2
+	case 3:
+		path = ecsMetadataPath
+	case 4:
+		path = ecsMetadataPath
+	default:
+		const msg = "resolveTaskURL: unexpected version %d"
+		panic(fmt.Errorf(msg, version))
+	}
+	return resolveURL(base, path)
+}
+
+func resolveStatsURL(base *url.URL, version int) string {
+	var path string
+	switch version {
+	case 2:
+		path = ecsMetaStatsPathV2
+	case 3:
+		path = ecsMetaStatsPath
+	case 4:
+		path = ecsMetaStatsPath
+	default:
+		// Should never happen.
+		const msg = "resolveStatsURL: unexpected version %d"
+		panic(fmt.Errorf(msg, version))
+	}
+	return resolveURL(base, path)
+}
+
+// resolveURL returns a URL string by concatenating the string representation of base
+// and path. This is consistent with AWS metadata documentation:
+// https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint-v3.html#task-metadata-endpoint-v3-paths
+func resolveURL(base *url.URL, path string) string {
+	return base.String() + path
+}
+
+// ecsClient contains ECS connection config
+type ecsClient struct {
+	client   httpClient
+	version  int
+	baseURL  *url.URL
+	taskURL  string
+	statsURL string
+}
+
+// task calls the ECS metadata endpoint and returns a populated task
+func (c *ecsClient) task() (*ecsTask, error) {
+	req, err := http.NewRequest("GET", c.taskURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		//nolint:errcheck // LimitReader returns io.EOF and we're not interested in read errors.
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 200))
+		return nil, fmt.Errorf("%s returned HTTP status %s: %q", c.taskURL, resp.Status, body)
+	}
+
+	task, err := unmarshalTask(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	return task, nil
+}
+
+// containerStats calls the ECS stats endpoint and returns a populated container stats map
+func (c *ecsClient) containerStats() (map[string]*container.StatsResponse, error) {
+	req, err := http.NewRequest("GET", c.statsURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		//nolint:errcheck // LimitReader returns io.EOF and we're not interested in read errors.
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 200))
+		return nil, fmt.Errorf("%s returned HTTP status %s: %q", c.statsURL, resp.Status, body)
+	}
+
+	return unmarshalStats(resp.Body)
+}
+
+// pollSync executes task and containerStats in parallel.
+// If both succeed, both structs are returned.
+// If either errors, a single error is returned.
+func pollSync(c client) (*ecsTask, map[string]*container.StatsResponse, error) {
+	var task *ecsTask
+	var stats map[string]*container.StatsResponse
+	var err error
+
+	if stats, err = c.containerStats(); err != nil {
+		return nil, nil, err
+	}
+
+	if task, err = c.task(); err != nil {
+		return nil, nil, err
+	}
+
+	return task, stats, nil
+}