From 0daa37fa0256b1bde99c2892118e22e3705431bd Mon Sep 17 00:00:00 2001 From: Aliaksandr Valialkin Date: Mon, 27 Apr 2020 11:44:28 +0300 Subject: [PATCH] lib/promscrape/discovery/gce: allow empty project and zone for gce_sd_config --- app/vmagent/README.md | 6 ++- docs/vmagent.md | 6 ++- lib/promscrape/discovery/gce/api.go | 74 +++++++++++++++++++++++++---- lib/promscrape/discovery/gce/gce.go | 36 ++++++++++++-- 4 files changed, 109 insertions(+), 13 deletions(-) diff --git a/app/vmagent/README.md b/app/vmagent/README.md index 67dcc8c01..520bd428c 100644 --- a/app/vmagent/README.md +++ b/app/vmagent/README.md @@ -135,7 +135,11 @@ The following scrape types in [scrape_config](https://prometheus.io/docs/prometh See [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) for details. * `gce_sd_configs` - for scraping targets in Google Compute Engine (GCE). See [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config) for details. - `vmagent` supports empty `zone` arg inside `gce_sd_config` - in this case it autodetects all the zones for the given project. + `vmagent` provides the following additional functionality `gce_sd_config`: + * if `project` arg is missing, then `vmagent` uses the project for the instance where it runs; + * if `zone` arg is missing, then `vmagent` uses the zone for the instance where it runs; + * if `zone` arg equals to `"*"`, then `vmagent` discovers all the zones for the given project; + * `zone` may contain arbitrary number of zones, i.e. `zone: [us-east1-a, us-east1-b]`. The following service discovery mechanisms will be added to `vmagent` soon: diff --git a/docs/vmagent.md b/docs/vmagent.md index 67dcc8c01..520bd428c 100644 --- a/docs/vmagent.md +++ b/docs/vmagent.md @@ -135,7 +135,11 @@ The following scrape types in [scrape_config](https://prometheus.io/docs/prometh See [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) for details. * `gce_sd_configs` - for scraping targets in Google Compute Engine (GCE). See [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config) for details. - `vmagent` supports empty `zone` arg inside `gce_sd_config` - in this case it autodetects all the zones for the given project. + `vmagent` provides the following additional functionality `gce_sd_config`: + * if `project` arg is missing, then `vmagent` uses the project for the instance where it runs; + * if `zone` arg is missing, then `vmagent` uses the zone for the instance where it runs; + * if `zone` arg equals to `"*"`, then `vmagent` discovers all the zones for the given project; + * `zone` may contain arbitrary number of zones, i.e. `zone: [us-east1-a, us-east1-b]`. The following service discovery mechanisms will be added to `vmagent` soon: diff --git a/lib/promscrape/discovery/gce/api.go b/lib/promscrape/discovery/gce/api.go index 7fd03cf8f..79aaa9a9b 100644 --- a/lib/promscrape/discovery/gce/api.go +++ b/lib/promscrape/discovery/gce/api.go @@ -10,6 +10,7 @@ import ( "sync" "time" + "github.com/VictoriaMetrics/VictoriaMetrics/lib/logger" "golang.org/x/oauth2/google" ) @@ -77,16 +78,32 @@ func newAPIConfig(sdc *SDConfig) (*apiConfig, error) { if err != nil { return nil, fmt.Errorf("cannot create oauth2 client for gce: %s", err) } - var zones []string - if len(sdc.Zone) == 0 { - // Autodetect zones for sdc.Project. - zs, err := getZonesForProject(client, sdc.Project, sdc.Filter) + project := sdc.Project + if len(project) == 0 { + proj, err := getCurrentProject() if err != nil { - return nil, fmt.Errorf("cannot obtain zones for project %q: %s", sdc.Project, err) + return nil, fmt.Errorf("cannot determine the current project; make sure `vmagent` runs inside GCE; error: %s", err) + } + project = proj + logger.Infof("autodetected the current GCE project: %q", project) + } + zones := sdc.Zone.zones + if len(zones) == 0 { + // Autodetect the current zone. + zone, err := getCurrentZone() + if err != nil { + return nil, fmt.Errorf("cannot determine the current zone; make sure `vmagent` runs inside GCE; error: %s", err) + } + zones = append(zones, zone) + logger.Infof("autodetected the current GCE zone: %q", zone) + } else if len(zones) == 1 && zones[0] == "*" { + // Autodetect zones for project. + zs, err := getZonesForProject(client, project, sdc.Filter) + if err != nil { + return nil, fmt.Errorf("cannot obtain zones for project %q: %s", project, err) } zones = zs - } else { - zones = []string{sdc.Zone} + logger.Infof("autodetected all the zones for the GCE project %q: %q", project, zones) } tagSeparator := "," if sdc.TagSeparator != nil { @@ -99,7 +116,7 @@ func newAPIConfig(sdc *SDConfig) (*apiConfig, error) { return &apiConfig{ client: client, zones: zones, - project: sdc.Project, + project: project, filter: sdc.Filter, tagSeparator: tagSeparator, port: port, @@ -113,6 +130,10 @@ func getAPIResponse(client *http.Client, apiURL, filter, pageToken string) ([]by if err != nil { return nil, fmt.Errorf("cannot query %q: %s", apiURL, err) } + return readResponseBody(resp, apiURL) +} + +func readResponseBody(resp *http.Response, apiURL string) ([]byte, error) { data, err := ioutil.ReadAll(resp.Body) _ = resp.Body.Close() if err != nil { @@ -135,3 +156,40 @@ func appendNonEmptyQueryArg(apiURL, arg string) string { } return apiURL + fmt.Sprintf("%spageToken=%s", prefix, url.QueryEscape(arg)) } + +func getCurrentZone() (string, error) { + // See https://cloud.google.com/compute/docs/storing-retrieving-metadata#default + data, err := getGCEMetadata("instance/zone") + if err != nil { + return "", err + } + parts := strings.Split(string(data), "/") + if len(parts) != 4 { + return "", fmt.Errorf("unexpected data returned from GCE; it must contain something like `projects/projectnum/zones/zone`; data: %q", data) + } + return parts[3], nil +} + +func getCurrentProject() (string, error) { + // See https://cloud.google.com/compute/docs/storing-retrieving-metadata#default + data, err := getGCEMetadata("project/project-id") + if err != nil { + return "", err + } + return string(data), nil +} + +func getGCEMetadata(path string) ([]byte, error) { + // See https://cloud.google.com/compute/docs/storing-retrieving-metadata#default + metadataURL := "http://metadata.google.internal/computeMetadata/v1/" + path + req, err := http.NewRequest("GET", metadataURL, nil) + if err != nil { + return nil, fmt.Errorf("cannot create http request for %q: %s", metadataURL, err) + } + req.Header.Set("Metadata-Flavor", "Google") + resp, err := http.DefaultClient.Do(req) + if err != nil { + return nil, fmt.Errorf("cannot obtain response to %q: %s", metadataURL, err) + } + return readResponseBody(resp, metadataURL) +} diff --git a/lib/promscrape/discovery/gce/gce.go b/lib/promscrape/discovery/gce/gce.go index ea68627f6..3f1f9809e 100644 --- a/lib/promscrape/discovery/gce/gce.go +++ b/lib/promscrape/discovery/gce/gce.go @@ -8,15 +8,45 @@ import ( // // See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config type SDConfig struct { - Project string `yaml:"project"` - Zone string `yaml:"zone"` - Filter string `yaml:"filter"` + Project string `yaml:"project"` + Zone ZoneYAML `yaml:"zone"` + Filter string `yaml:"filter"` // RefreshInterval time.Duration `yaml:"refresh_interval"` // refresh_interval is obtained from `-promscrape.gceSDCheckInterval` command-line option. Port *int `yaml:"port"` TagSeparator *string `yaml:"tag_separator"` } +// ZoneYAML holds info about zones. +type ZoneYAML struct { + zones []string +} + +// UnmarshalYAML implements yaml.Unmarshaler +func (z *ZoneYAML) UnmarshalYAML(unmarshal func(interface{}) error) error { + var v interface{} + if err := unmarshal(&v); err != nil { + return err + } + var zones []string + switch v.(type) { + case string: + zones = []string{v.(string)} + case []interface{}: + for _, vv := range v.([]interface{}) { + zone, ok := vv.(string) + if !ok { + return fmt.Errorf("unexpected zone type detected: %T; contents: %#v", vv, vv) + } + zones = append(zones, zone) + } + default: + return fmt.Errorf("unexpected type unmarshaled for ZoneYAML: %T; contents: %#v", v, v) + } + z.zones = zones + return nil +} + // GetLabels returns gce labels according to sdc. func GetLabels(sdc *SDConfig) ([]map[string]string, error) { cfg, err := getAPIConfig(sdc)