[GitHub] [trafficcontrol] mhoppa commented on a change in pull request #4379: Rewrite isos to Golang

[GitBox <gi...@apache.org>]

mhoppa commented on a change in pull request #4379: Rewrite isos to Golang
URL: https://github.com/apache/trafficcontrol/pull/4379#discussion_r382802365
 
 

 ##########
 File path: traffic_ops/traffic_ops_golang/iso/iso.go
 ##########
 @@ -0,0 +1,368 @@
+// Package iso provides support for generating ISO images.
+package iso
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/apache/trafficcontrol/lib/go-log"
+	"github.com/apache/trafficcontrol/lib/go-rfc"
+	"github.com/apache/trafficcontrol/lib/go-tc"
+	"github.com/apache/trafficcontrol/lib/go-util"
+	"github.com/apache/trafficcontrol/traffic_ops/traffic_ops_golang/api"
+	"github.com/apache/trafficcontrol/traffic_ops/traffic_ops_golang/auth"
+	"github.com/jmoiron/sqlx"
+)
+
+// Various directories and filenames related to ISO generation.
+const (
+	cfgDefaultDir   = "/var/www/files"  // Default directory containing config file
+	cfgFilename     = "osversions.json" // The JSON config file containing mapping of OS names to directories
+	cfgFilenamePerl = "osversions.cfg"  // Config file name in the Perl version
+
+	// This is the directory name inside each OS directory where
+	// configuration files for kickstart scripts are placed.
+	ksCfgDir = "ks_scripts"
+
+	// Configuration files that are generated inside the ks_scripts directory.
+	ksCfgNetwork     = "network.cfg"
+	ksCfgMgmtNetwork = "mgmt_network.cfg"
+	ksCfgPassword    = "password.cfg"
+	ksCfgDisk        = "disk.cfg"
+	ksStateOut       = "state.out"
+
+	ksAltCommand = "generate" // Optional executable that is invoked instead of mkisofs
+)
+
+// Various database columns and values.
+const (
+	ksFilesParamName       = "kickstart.files.location"
+	ksFilesParamConfigFile = "mkisofs"
+)
+
+// Various HTTP-related values.
+const (
+	httpHeaderContentDisposition = "Content-Disposition"
+	httpHeaderContentType        = "Content-Type"
+	httpHeaderContentDownload    = "application/download"
+)
+
+// ISOs handler is responsible for generating and returning an ISO image,
+// as a streaming download.
+//
+// Response types:
+//
+// Error:
+//   HTTP 400
+//   {
+//     "alerts": [
+//       {"level":"error","text":"hostName is required"},
+//       {"level":"error","text":"disk is required"},
+//       ...,
+//     ]
+//   }
+//
+// Success:
+//   HTTP 200
+//   Content-Disposition: attachment; filename="db.infra.ciab.test-centos72.iso"
+//   Content-Type: application/download
+//
+func ISOs(w http.ResponseWriter, req *http.Request) {
+	inf, userErr, sysErr, errCode := api.NewInfo(req, nil, nil)
+	if userErr != nil || sysErr != nil {
+		api.HandleErr(w, req, inf.Tx.Tx, errCode, userErr, sysErr)
+		return
+	}
+	defer inf.Close()
+
+	// Decode request body into isoRequest instance.
+	var ir isoRequest
+	if err := json.NewDecoder(req.Body).Decode(&ir); err != nil {
+		userErr := errors.New("unable to decode JSON request")
+		api.HandleErr(w, req, inf.Tx.Tx, http.StatusBadRequest, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	}
+
+	isos(w, req, inf.Tx, inf.User, ir)
+}
+
+// cmdOverwriteCtxKey is used in an http.Request's context
+// to set a cmd override value.
+var cmdOverwriteCtxKey struct{}
+
+// isos performs the majority of work for the /isos endpoint handler. It is separated out from
+// the exported handler for testability.
+func isos(w http.ResponseWriter, req *http.Request, tx *sqlx.Tx, user *auth.CurrentUser, ir isoRequest) {
+	// Ensure isoRequest is valid.
+	if errMsgs := ir.validate(); len(errMsgs) > 0 {
+		writeRespErrorAlerts(w, req, errMsgs)
+		return
+	}
+
+	// Ensure that the given OSVersionDir is defined in the osversions.json config
+	// file as a valid directory. This directory is later referenced for ISO creation
+	// and therefore must an allowed value.
+	if ok, err := ir.validateOSDir(tx); err != nil {
+		statusCode := http.StatusInternalServerError
+		userErr := errors.New("unable to read osversions configuration")
+		api.HandleErr(w, req, tx.Tx, statusCode, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	} else if !ok {
+		statusCode := http.StatusBadRequest
+		err := fmt.Errorf("invalid OS version directory: %q", ir.OSVersionDir)
+		api.HandleErr(w, req, tx.Tx, statusCode, err, err)
+		return
+	}
+
+	// Determine the kickstart root directory, which is either a default
+	// value or may be overridden by a database/Parameter entry.
+	ksDir, err := kickstarterDir(tx, ir.OSVersionDir)
+	if err != nil {
+		statusCode := http.StatusInternalServerError
+		userErr := errors.New("unable to determine kickstarter directory")
+		api.HandleErr(w, req, tx.Tx, statusCode, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	}
+
+	// cfgDir holds the kickstart config files within the root
+	// kickstart directory.
+	cfgDir := filepath.Join(ksDir, ksCfgDir)
+	log.Infof("cfg_dir: %s", cfgDir)
+
+	genISOCmd, err := newStreamISOCmd(ksDir)
+	if err != nil {
+		statusCode := http.StatusInternalServerError
+		userErr := errors.New("unable to initialize genISO command")
+		api.HandleErr(w, req, tx.Tx, statusCode, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	}
+	defer genISOCmd.cleanup()
+
+	// Allow for the request context to carry a modifier function that can change the
+	// genISOCmd's command. This is purely used for testing.
+	if cmdMod, ok := req.Context().Value(cmdOverwriteCtxKey).(func(in *exec.Cmd) *exec.Cmd); ok {
+		genISOCmd.cmd = cmdMod(genISOCmd.cmd)
+	}
+
+	log.Infof("Using %s ISO generation command: %s", genISOCmd.cmdType, genISOCmd.String())
+
+	if err = writeKSCfgs(cfgDir, ir, genISOCmd.String()); err != nil {
+		statusCode := http.StatusInternalServerError
+		userErr := errors.New("unable to create kickstarter files")
+		api.HandleErr(w, req, tx.Tx, statusCode, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	}
+
+	isoFilename := fmt.Sprintf("%s-%s.iso", ir.fqdn(), ir.OSVersionDir)
+	// strings.ReplaceAll was added in Go 1.12
+	isoFilename = strings.Replace(isoFilename, "/", "_", -1)
+
+	w.Header().Set(httpHeaderContentDisposition, fmt.Sprintf("attachment; filename=%q", isoFilename))
+	w.Header().Set(httpHeaderContentType, httpHeaderContentDownload)
+
+	if err = genISOCmd.stream(w); err != nil {
+		statusCode := http.StatusInternalServerError
+		userErr := errors.New("unable to generate ISO")
+		api.HandleErr(w, req, tx.Tx, statusCode, userErr, fmt.Errorf("%v: %v", userErr, err))
+		return
+	}
+
+	// Create changelog entry
+	err = api.CreateChangeLogBuildMsg(
+		api.ApiChange,
+		api.Created,
+		user,
+		tx.Tx,
+		"ISO",
+		ir.fqdn(),
+		map[string]interface{}{"OS": ir.OSVersionDir},
+	)
+	if err != nil {
+		// At this point, it's not possible to modify the HTTP response.
+		log.Errorf("error creating changelog entry for ISO creation: %v", err)
+	}
+}
+
+// writeRespErrorAlerts writes to w an Alerts JSON response with
+// an error level. Note: api.WriteRespAlertObj could not be used here
+// because it accepts a single "alert", whereas this response
+// may contain multiple alerts.
+func writeRespErrorAlerts(w http.ResponseWriter, req *http.Request, errMsgs []string) {
+	alerts := tc.CreateAlerts(tc.ErrorLevel, errMsgs...)
+
+	body, err := json.Marshal(alerts)
+	if err != nil {
+		statusCode := http.StatusInternalServerError
+		api.HandleErr(w, req, nil, statusCode, errors.New(http.StatusText(statusCode)), fmt.Errorf("error marshalling JSON: %v", err))
+		return
+	}
+
+	w.Header().Set(rfc.ContentType, rfc.ApplicationJSON)
+	w.WriteHeader(http.StatusBadRequest)
+	w.Write(body)
+}
+
+// isoRequest represents the JSON object clients use to
+// request an ISO be generated.
+type isoRequest struct {
+	OSVersionDir  string          `json:"osversionDir"`
+	HostName      string          `json:"hostName"`
+	DomainName    string          `json:"domainName"`
+	RootPass      string          `json:"rootPass"`
+	DHCP          boolStr         `json:"dhcp"`
+	IPAddr        net.IP          `json:"ipAddress"`
+	IPNetmask     net.IP          `json:"ipNetmask"`
+	IPGateway     net.IP          `json:"ipGateway"`
+	IP6Address    net.IP          `json:"ip6Address"`
+	IP6Gateway    net.IP          `json:"ip6Gateway"`
+	InterfaceName string          `json:"interfaceName"`
+	InterfaceMTU  util.JSONIntStr `json:"interfaceMtu"`
+	Disk          string          `json:"disk"`
+	MgmtIPAddress net.IP          `json:"mgmtIpAddress"`
+	MgmtIPNetmask net.IP          `json:"mgmtIpNetmask"`
+	MgmtIPGateway net.IP          `json:"mgmtIpGateway"`
+	MgmtInterface string          `json:"mgmtInterface"`
+	Stream        boolStr         `json:"stream"`
+}
+
+func (i *isoRequest) fqdn() string {
+	fqdn := i.HostName
+	if i.DomainName != "" {
+		fqdn += "." + i.DomainName
+	}
+	return fqdn
+}
+
+// validate returns an empty slice if the isoRequest is valid. Otherwise,
+// it returns a slice of error messages.
+func (i *isoRequest) validate() []string {
+	var errs []string
+	addErr := func(msg string) { errs = append(errs, msg) }
+
+	if i.OSVersionDir == "" {
+		addErr("osversionDir is required")
+	}
+	if i.HostName == "" {
+		addErr("hostName is required")
+	}
+	if i.DomainName == "" {
+		addErr("domainName is required")
+	}
+	if i.RootPass == "" {
+		addErr("rootPass is required")
+	}
+	if !i.DHCP.isSet {
+		addErr("dhcp is required")
+	}
+	if i.InterfaceMTU == 0 {
+		addErr("interfaceMtu is required")
+	}
+	if i.Disk == "" {
+		addErr("disk is required")
+	}
+	if len(i.MgmtIPAddress) > 0 {
+		if i.MgmtInterface == "" {
+			addErr("mgmtInterface is required when mgmtIpAddress is provided")
+		}
+		if len(i.MgmtIPGateway) == 0 {
+			addErr("mgmtIpGateway is required when mgmtIpAddress is provided")
+		}
+	}
+	if v, ok := i.DHCP.val(); ok && !v {
+		if len(i.IPAddr) == 0 {
+			addErr("ipAddress is required if DHCP is no")
+		}
+		if len(i.IPNetmask) == 0 {
+			addErr("ipNetmask is required if DHCP is no")
+		}
+		if len(i.IPGateway) == 0 {
+			addErr("ipGateway is required if DHCP is no")
+		}
+	}
+
+	// Use of stream is deprecated it will always stream
+	// regardless if this is set or not.
+	if v, ok := i.Stream.val(); ok && !v {
+		addErr("stream request parameter is deprecated")
+	}
 
 Review comment:
   my thought was to catch ppl trying to use it in a legacy manner but our other endpoints do that so yeah removing

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