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/federation"
  22         "git.curoverse.com/arvados.git/lib/controller/railsproxy"
  23         "git.curoverse.com/arvados.git/lib/controller/router"
  24         "git.curoverse.com/arvados.git/sdk/go/arvados"
  25         "git.curoverse.com/arvados.git/sdk/go/health"
  26         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  27         _ "github.com/lib/pq"
  28 )
  29
  30 type Handler struct {
  31         Cluster *arvados.Cluster
  32
  33         setupOnce      sync.Once
  34         handlerStack   http.Handler
  35         proxy          *proxy
  36         secureClient   *http.Client
  37         insecureClient *http.Client
  38         pgdb           *sql.DB
  39         pgdbMtx        sync.Mutex
  40 }
  41
  42 func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
  43         h.setupOnce.Do(h.setup)
  44         if req.Method != "GET" && req.Method != "HEAD" {
  45                 // http.ServeMux returns 301 with a cleaned path if
  46                 // the incoming request has a double slash. Some
  47                 // clients (including the Go standard library) change
  48                 // the request method to GET when following a 301
  49                 // redirect if the original method was not HEAD
  50                 // (RFC7231 6.4.2 specifically allows this in the case
  51                 // of POST). Thus "POST //foo" gets misdirected to
  52                 // "GET /foo". To avoid this, eliminate double slashes
  53                 // before passing the request to ServeMux.
  54                 for strings.Contains(req.URL.Path, "//") {
  55                         req.URL.Path = strings.Replace(req.URL.Path, "//", "/", -1)
  56                 }
  57         }
  58         if h.Cluster.API.RequestTimeout > 0 {
  59                 ctx, cancel := context.WithDeadline(req.Context(), time.Now().Add(time.Duration(h.Cluster.API.RequestTimeout)))
  60                 req = req.WithContext(ctx)
  61                 defer cancel()
  62         }
  63
  64         h.handlerStack.ServeHTTP(w, req)
  65 }
  66
  67 func (h *Handler) CheckHealth() error {
  68         h.setupOnce.Do(h.setup)
  69         _, _, err := railsproxy.FindRailsAPI(h.Cluster)
  70         return err
  71 }
  72
  73 func neverRedirect(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }
  74
  75 func (h *Handler) setup() {
  76         mux := http.NewServeMux()
  77         mux.Handle("/_health/", &health.Handler{
  78                 Token:  h.Cluster.ManagementToken,
  79                 Prefix: "/_health/",
  80                 Routes: health.Routes{"ping": func() error { _, err := h.db(&http.Request{}); return err }},
  81         })
  82
  83         mux.Handle("/arvados/v1/config", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  84                 var buf bytes.Buffer
  85                 err := config.ExportJSON(&buf, h.Cluster)
  86                 if err != nil {
  87                         httpserver.Error(w, err.Error(), http.StatusInternalServerError)
  88                         return
  89                 }
  90                 w.Header().Set("Content-Type", "application/json")
  91                 io.Copy(w, &buf)
  92         }))
  93
  94         if h.Cluster.EnableBetaController14287 {
  95                 rtr := router.New(federation.New(h.Cluster))
  96                 mux.Handle("/arvados/v1/collections", rtr)
  97                 mux.Handle("/arvados/v1/collections/", rtr)
  98         }
  99
 100         hs := http.NotFoundHandler()
 101         hs = prepend(hs, h.proxyRailsAPI)
 102         hs = h.setupProxyRemoteCluster(hs)
 103         mux.Handle("/", hs)
 104         h.handlerStack = mux
 105
 106         sc := *arvados.DefaultSecureClient
 107         sc.CheckRedirect = neverRedirect
 108         h.secureClient = &sc
 109
 110         ic := *arvados.InsecureHTTPClient
 111         ic.CheckRedirect = neverRedirect
 112         h.insecureClient = &ic
 113
 114         h.proxy = &proxy{
 115                 Name: "arvados-controller",
 116         }
 117 }
 118
 119 var errDBConnection = errors.New("database connection error")
 120
 121 func (h *Handler) db(req *http.Request) (*sql.DB, error) {
 122         h.pgdbMtx.Lock()
 123         defer h.pgdbMtx.Unlock()
 124         if h.pgdb != nil {
 125                 return h.pgdb, nil
 126         }
 127
 128         db, err := sql.Open("postgres", h.Cluster.PostgreSQL.Connection.String())
 129         if err != nil {
 130                 httpserver.Logger(req).WithError(err).Error("postgresql connect failed")
 131                 return nil, errDBConnection
 132         }
 133         if p := h.Cluster.PostgreSQL.ConnectionPool; p > 0 {
 134                 db.SetMaxOpenConns(p)
 135         }
 136         if err := db.Ping(); err != nil {
 137                 httpserver.Logger(req).WithError(err).Error("postgresql connect succeeded but ping failed")
 138                 return nil, errDBConnection
 139         }
 140         h.pgdb = db
 141         return db, nil
 142 }
 143
 144 type middlewareFunc func(http.ResponseWriter, *http.Request, http.Handler)
 145
 146 func prepend(next http.Handler, middleware middlewareFunc) http.Handler {
 147         return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 148                 middleware(w, req, next)
 149         })
 150 }
 151
 152 func (h *Handler) localClusterRequest(req *http.Request) (*http.Response, error) {
 153         urlOut, insecure, err := railsproxy.FindRailsAPI(h.Cluster)
 154         if err != nil {
 155                 return nil, err
 156         }
 157         urlOut = &url.URL{
 158                 Scheme:   urlOut.Scheme,
 159                 Host:     urlOut.Host,
 160                 Path:     req.URL.Path,
 161                 RawPath:  req.URL.RawPath,
 162                 RawQuery: req.URL.RawQuery,
 163         }
 164         client := h.secureClient
 165         if insecure {
 166                 client = h.insecureClient
 167         }
 168         return h.proxy.Do(req, urlOut, client)
 169 }
 170
 171 func (h *Handler) proxyRailsAPI(w http.ResponseWriter, req *http.Request, next http.Handler) {
 172         resp, err := h.localClusterRequest(req)
 173         n, err := h.proxy.ForwardResponse(w, resp, err)
 174         if err != nil {
 175                 httpserver.Logger(req).WithError(err).WithField("bytesCopied", n).Error("error copying response body")
 176         }
 177 }
 178
 179 // Use a localhost entry from Services.RailsAPI.InternalURLs if one is
 180 // present, otherwise choose an arbitrary entry.
 181 func findRailsAPI(cluster *arvados.Cluster) (*url.URL, bool, error) {
 182         var best *url.URL
 183         for target := range cluster.Services.RailsAPI.InternalURLs {
 184                 target := url.URL(target)
 185                 best = &target
 186                 if strings.HasPrefix(target.Host, "localhost:") || strings.HasPrefix(target.Host, "127.0.0.1:") || strings.HasPrefix(target.Host, "[::1]:") {
 187                         break
 188                 }
 189         }
 190         if best == nil {
 191                 return nil, false, fmt.Errorf("Services.RailsAPI.InternalURLs is empty")
 192         }
 193         return best, cluster.TLS.Insecure, nil
 194 }