package libpod import ( "encoding/json" "net/http" "time" "github.com/containers/podman/v3/libpod" "github.com/containers/podman/v3/pkg/api/handlers/utils" "github.com/containers/podman/v3/pkg/cgroups" "github.com/containers/podman/v3/pkg/domain/entities" "github.com/containers/podman/v3/pkg/domain/infra/abi" "github.com/containers/podman/v3/pkg/rootless" "github.com/gorilla/schema" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) const DefaultStatsPeriod = 5 * time.Second func StatsContainer(w http.ResponseWriter, r *http.Request) { runtime := r.Context().Value("runtime").(*libpod.Runtime) decoder := r.Context().Value("decoder").(*schema.Decoder) // Check if service is running rootless (cheap check) if rootless.IsRootless() { // if so, then verify cgroup v2 available (more expensive check) if isV2, _ := cgroups.IsCgroup2UnifiedMode(); !isV2 { msg := "Container stats resource only available for cgroup v2" utils.Error(w, msg, http.StatusConflict, errors.New(msg)) return } } query := struct { Containers []string `schema:"containers"` Stream bool `schema:"stream"` }{ Stream: true, } if err := decoder.Decode(&query, r.URL.Query()); err != nil { utils.Error(w, "Something went wrong.", http.StatusBadRequest, errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String())) return } // Reduce code duplication and use the local/abi implementation of // container stats. containerEngine := abi.ContainerEngine{Libpod: runtime} statsOptions := entities.ContainerStatsOptions{ Stream: query.Stream, } // Stats will stop if the connection is closed. statsChan, err := containerEngine.ContainerStats(r.Context(), query.Containers, statsOptions) if err != nil { utils.InternalServerError(w, err) return } // Write header and content type. w.WriteHeader(http.StatusOK) w.Header().Add("Content-Type", "application/json") if flusher, ok := w.(http.Flusher); ok { flusher.Flush() } // Setup JSON encoder for streaming. coder := json.NewEncoder(w) coder.SetEscapeHTML(true) for stats := range statsChan { if err := coder.Encode(stats); err != nil { // Note: even when streaming, the stats goroutine will // be notified (and stop) as the connection will be // closed. logrus.Errorf("Unable to encode stats: %v", err) return } if flusher, ok := w.(http.Flusher); ok { flusher.Flush() } } }