lib/controller/handler.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package controller
   6
   7 import (
   8         "bytes"
   9         "context"
  10         "database/sql"
  11         "errors"
  12         "fmt"
  13         "io"
  14         "net/http"
  15         "net/url"
  16         "strings"
  17         "sync"
  18         "time"
  19
  20         "git.curoverse.com/arvados.git/lib/config"
  21         "git.curoverse.com/arvados.git/lib/controller/railsproxy"
  22         "git.curoverse.com/arvados.git/lib/controller/router"
  23         "git.curoverse.com/arvados.git/sdk/go/arvados"
  24         "git.curoverse.com/arvados.git/sdk/go/health"
  25         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  26         _ "github.com/lib/pq"
  27 )
  28
  29 type Handler struct {
  30         Cluster *arvados.Cluster
  31
  32         setupOnce      sync.Once
  33         handlerStack   http.Handler
  34         proxy          *proxy
  35         secureClient   *http.Client
  36         insecureClient *http.Client
  37         pgdb           *sql.DB
  38         pgdbMtx        sync.Mutex
  39 }
  40
  41 func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
  42         h.setupOnce.Do(h.setup)
  43         if req.Method != "GET" && req.Method != "HEAD" {
  44                 // http.ServeMux returns 301 with a cleaned path if
  45                 // the incoming request has a double slash. Some
  46                 // clients (including the Go standard library) change
  47                 // the request method to GET when following a 301
  48                 // redirect if the original method was not HEAD
  49                 // (RFC7231 6.4.2 specifically allows this in the case
  50                 // of POST). Thus "POST //foo" gets misdirected to
  51                 // "GET /foo". To avoid this, eliminate double slashes
  52                 // before passing the request to ServeMux.
  53                 for strings.Contains(req.URL.Path, "//") {
  54                         req.URL.Path = strings.Replace(req.URL.Path, "//", "/", -1)
  55                 }
  56         }
  57         if h.Cluster.API.RequestTimeout > 0 {
  58                 ctx, cancel := context.WithDeadline(req.Context(), time.Now().Add(time.Duration(h.Cluster.API.RequestTimeout)))
  59                 req = req.WithContext(ctx)
  60                 defer cancel()
  61         }
  62
  63         h.handlerStack.ServeHTTP(w, req)
  64 }
  65
  66 func (h *Handler) CheckHealth() error {
  67         h.setupOnce.Do(h.setup)
  68         _, _, err := railsproxy.FindRailsAPI(h.Cluster)
  69         return err
  70 }
  71
  72 func neverRedirect(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }
  73
  74 func (h *Handler) setup() {
  75         mux := http.NewServeMux()
  76         mux.Handle("/_health/", &health.Handler{
  77                 Token:  h.Cluster.ManagementToken,
  78                 Prefix: "/_health/",
  79                 Routes: health.Routes{"ping": func() error { _, err := h.db(&http.Request{}); return err }},
  80         })
  81
  82         mux.Handle("/arvados/v1/config", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  83                 var buf bytes.Buffer
  84                 err := config.ExportJSON(&buf, h.Cluster)
  85                 if err != nil {
  86                         httpserver.Error(w, err.Error(), http.StatusInternalServerError)
  87                         return
  88                 }
  89                 w.Header().Set("Content-Type", "application/json")
  90                 io.Copy(w, &buf)
  91         }))
  92
  93         if h.Cluster.EnableBetaController14287 {
  94                 rtr := router.New(h.Cluster)
  95                 mux.Handle("/arvados/v1/collections", rtr)
  96                 mux.Handle("/arvados/v1/collections/", rtr)
  97         }
  98
  99         hs := http.NotFoundHandler()
 100         hs = prepend(hs, h.proxyRailsAPI)
 101         hs = h.setupProxyRemoteCluster(hs)
 102         mux.Handle("/", hs)
 103         h.handlerStack = mux
 104
 105         sc := *arvados.DefaultSecureClient
 106         sc.CheckRedirect = neverRedirect
 107         h.secureClient = &sc
 108
 109         ic := *arvados.InsecureHTTPClient
 110         ic.CheckRedirect = neverRedirect
 111         h.insecureClient = &ic
 112
 113         h.proxy = &proxy{
 114                 Name: "arvados-controller",
 115         }
 116 }
 117
 118 var errDBConnection = errors.New("database connection error")
 119
 120 func (h *Handler) db(req *http.Request) (*sql.DB, error) {
 121         h.pgdbMtx.Lock()
 122         defer h.pgdbMtx.Unlock()
 123         if h.pgdb != nil {
 124                 return h.pgdb, nil
 125         }
 126
 127         db, err := sql.Open("postgres", h.Cluster.PostgreSQL.Connection.String())
 128         if err != nil {
 129                 httpserver.Logger(req).WithError(err).Error("postgresql connect failed")
 130                 return nil, errDBConnection
 131         }
 132         if p := h.Cluster.PostgreSQL.ConnectionPool; p > 0 {
 133                 db.SetMaxOpenConns(p)
 134         }
 135         if err := db.Ping(); err != nil {
 136                 httpserver.Logger(req).WithError(err).Error("postgresql connect succeeded but ping failed")
 137                 return nil, errDBConnection
 138         }
 139         h.pgdb = db
 140         return db, nil
 141 }
 142
 143 type middlewareFunc func(http.ResponseWriter, *http.Request, http.Handler)
 144
 145 func prepend(next http.Handler, middleware middlewareFunc) http.Handler {
 146         return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 147                 middleware(w, req, next)
 148         })
 149 }
 150
 151 func (h *Handler) localClusterRequest(req *http.Request) (*http.Response, error) {
 152         urlOut, insecure, err := railsproxy.FindRailsAPI(h.Cluster)
 153         if err != nil {
 154                 return nil, err
 155         }
 156         urlOut = &url.URL{
 157                 Scheme:   urlOut.Scheme,
 158                 Host:     urlOut.Host,
 159                 Path:     req.URL.Path,
 160                 RawPath:  req.URL.RawPath,
 161                 RawQuery: req.URL.RawQuery,
 162         }
 163         client := h.secureClient
 164         if insecure {
 165                 client = h.insecureClient
 166         }
 167         return h.proxy.Do(req, urlOut, client)
 168 }
 169
 170 func (h *Handler) proxyRailsAPI(w http.ResponseWriter, req *http.Request, next http.Handler) {
 171         resp, err := h.localClusterRequest(req)
 172         n, err := h.proxy.ForwardResponse(w, resp, err)
 173         if err != nil {
 174                 httpserver.Logger(req).WithError(err).WithField("bytesCopied", n).Error("error copying response body")
 175         }
 176 }
 177
 178 // Use a localhost entry from Services.RailsAPI.InternalURLs if one is
 179 // present, otherwise choose an arbitrary entry.
 180 func findRailsAPI(cluster *arvados.Cluster) (*url.URL, bool, error) {
 181         var best *url.URL
 182         for target := range cluster.Services.RailsAPI.InternalURLs {
 183                 target := url.URL(target)
 184                 best = &target
 185                 if strings.HasPrefix(target.Host, "localhost:") || strings.HasPrefix(target.Host, "127.0.0.1:") || strings.HasPrefix(target.Host, "[::1]:") {
 186                         break
 187                 }
 188         }
 189         if best == nil {
 190                 return nil, false, fmt.Errorf("Services.RailsAPI.InternalURLs is empty")
 191         }
 192         return best, cluster.TLS.Insecure, nil
 193 }