Automate execution of go mod download for pulumi new Go templates

[EvanBoyle]

fixes #4236

Evans-MBP:newtest evanboyle$ pulumi new
Please choose a template: Show additional templates
Please choose a template: go                         A minimal Go Pulumi program
This command will walk you through creating a new Pulumi project.

Enter a value or leave blank to accept the (default), and press <ENTER>.
Press ^C at any time to quit.

project name: abc
project description: (A minimal Go Pulumi program) def
Created project 'abc'

Please enter your desired stack name.
To create a stack in an organization, use the format <org-name>/<stack-name> (e.g. `acmecorp/dev`).
stack name: (dev) 
Created stack 'dev'

Installing dependencies...

go: finding cloud.google.com/go v0.26.0
go: finding github.com/BurntSushi/toml v0.3.1
go: finding github.com/Microsoft/go-winio v0.4.14
go: finding github.com/OneOfOne/xxhash v1.2.2
go: finding github.com/alcortesm/tgz v0.0.0-20161220082320-9c5fe88206d7
go: finding github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc
go: finding github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf
go: finding github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239
go: finding github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6
go: finding github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5
go: finding github.com/beorn7/perks v1.0.0
go: finding github.com/blang/semver v3.5.1+incompatible
go: finding github.com/census-instrumentation/opencensus-proto v0.2.1
go: finding github.com/cespare/xxhash v1.1.0
go: finding github.com/cheggaaa/pb v1.0.18
go: finding github.com/client9/misspell v0.3.4
go: finding github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f
go: finding github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd
go: finding github.com/coreos/bbolt v1.3.2
go: finding github.com/coreos/etcd v3.3.10+incompatible
go: finding github.com/coreos/go-semver v0.2.0
go: finding github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e
go: finding github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f
go: finding github.com/cpuguy83/go-md2man/v2 v2.0.0
go: finding github.com/creack/pty v1.1.7
go: finding github.com/davecgh/go-spew v1.1.1
go: finding github.com/dgrijalva/jwt-go v3.2.0+incompatible
go: finding github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954
go: finding github.com/djherbis/times v1.2.0
go: finding github.com/emirpasic/gods v1.12.0
go: finding github.com/envoyproxy/go-control-plane v0.9.4
go: finding github.com/envoyproxy/protoc-gen-validate v0.1.0
go: finding github.com/fatih/color v1.9.0
go: finding github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568
go: finding github.com/fsnotify/fsnotify v1.4.7
go: finding github.com/ghodss/yaml v1.0.0
go: finding github.com/gliderlabs/ssh v0.2.2
go: finding github.com/go-kit/kit v0.8.0
go: finding github.com/go-logfmt/logfmt v0.4.0
go: finding github.com/go-stack/stack v1.8.0
go: finding github.com/gofrs/flock v0.7.1
go: finding github.com/gogo/protobuf v1.2.1
go: finding github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
go: finding github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef
go: finding github.com/golang/mock v1.1.1
go: finding github.com/golang/protobuf v1.3.5
go: finding github.com/google/btree v1.0.0
go: finding github.com/google/go-cmp v0.3.0
go: finding github.com/gorilla/websocket v1.4.0
go: finding github.com/grpc-ecosystem/go-grpc-middleware v1.0.0
go: finding github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
go: finding github.com/grpc-ecosystem/grpc-gateway v1.9.0
go: finding github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645
go: finding github.com/hashicorp/errwrap v1.0.0
go: finding github.com/hashicorp/go-multierror v1.0.0
go: finding github.com/hashicorp/hcl v1.0.0
go: finding github.com/inconshreveable/mousetrap v1.0.0
go: finding github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99
go: finding github.com/jessevdk/go-flags v1.4.0
go: finding github.com/jonboulle/clockwork v0.1.0
go: finding github.com/julienschmidt/httprouter v1.2.0
go: finding github.com/kevinburke/ssh_config v0.0.0-20190725054713-01f96b0aa0cd
go: finding github.com/kisielk/errcheck v1.1.0
go: finding github.com/kisielk/gotool v1.0.0
go: finding github.com/konsorten/go-windows-terminal-sequences v1.0.1
go: finding github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515
go: finding github.com/kr/pretty v0.1.0
go: finding github.com/kr/pty v1.1.8
go: finding github.com/kr/text v0.1.0
go: finding github.com/magiconair/properties v1.8.0
go: finding github.com/mattn/go-colorable v0.1.6
go: finding github.com/mattn/go-isatty v0.0.12
go: finding github.com/mattn/go-runewidth v0.0.8
go: finding github.com/matttproud/golang_protobuf_extensions v1.0.1
go: finding github.com/mitchellh/go-homedir v1.1.0
go: finding github.com/mitchellh/go-ps v1.0.0
go: finding github.com/mitchellh/mapstructure v1.1.2
go: finding github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223
go: finding github.com/oklog/ulid v1.3.1
go: finding github.com/opentracing/basictracer-go v1.0.0
go: finding github.com/opentracing/opentracing-go v1.1.0
go: finding github.com/pelletier/go-buffruneio v0.2.0
go: finding github.com/pelletier/go-toml v1.2.0
go: finding github.com/pkg/errors v0.9.1
go: finding github.com/pmezard/go-difflib v1.0.0
go: finding github.com/prometheus/client_golang v0.9.3
go: finding github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4
go: finding github.com/prometheus/common v0.4.0
go: finding github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084
go: finding github.com/prometheus/tsdb v0.7.1
go: finding github.com/pulumi/pulumi/sdk v1.13.1
go: finding github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af
go: finding github.com/russross/blackfriday/v2 v2.0.1
go: finding github.com/sergi/go-diff v1.0.0
go: finding github.com/shurcooL/sanitized_anchor_name v1.0.0
go: finding github.com/sirupsen/logrus v1.4.1
go: finding github.com/soheilhy/cmux v0.1.4
go: finding github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72
go: finding github.com/spf13/afero v1.1.2
go: finding github.com/spf13/cast v1.3.1
go: finding github.com/spf13/cobra v0.0.6
go: finding github.com/spf13/jwalterweatherman v1.0.0
go: finding github.com/spf13/pflag v1.0.3
go: finding github.com/spf13/viper v1.4.0
go: finding github.com/src-d/gcfg v1.4.0
go: finding github.com/stretchr/objx v0.2.0
go: finding github.com/stretchr/testify v1.5.1
go: finding github.com/texttheater/golang-levenshtein v0.0.0-20191208221605-eb6844b05fc6
go: finding github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5
go: finding github.com/uber/jaeger-client-go v2.22.1+incompatible
go: finding github.com/uber/jaeger-lib v2.2.0+incompatible
go: finding github.com/ugorji/go v1.1.4
go: finding github.com/xanzy/ssh-agent v0.2.1
go: finding github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2
go: finding github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77
go: finding go.etcd.io/bbolt v1.3.2
go: finding go.uber.org/atomic v1.4.0
go: finding go.uber.org/multierr v1.1.0
go: finding go.uber.org/zap v1.10.0
go: finding golang.org/x/crypto v0.0.0-20200317142112-1b76d66859c6
go: finding golang.org/x/exp v0.0.0-20190121172915-509febef88a4
go: finding golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3
go: finding golang.org/x/net v0.0.0-20200301022130-244492dfa37a
go: finding golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
go: finding golang.org/x/sync v0.0.0-20190423024810-112230192c58
go: finding golang.org/x/sys v0.0.0-20200317113312-5766fd39f98d
go: finding golang.org/x/text v0.3.2
go: finding golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
go: finding golang.org/x/tools v0.0.0-20190729092621-ff9f1409240a
go: finding google.golang.org/appengine v1.4.0
go: finding google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55
go: finding google.golang.org/grpc v1.28.0
go: finding gopkg.in/alecthomas/kingpin.v2 v2.2.6
go: finding gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127
go: finding gopkg.in/cheggaaa/pb.v1 v1.0.28
go: finding gopkg.in/resty.v1 v1.12.0
go: finding gopkg.in/src-d/go-billy.v4 v4.3.2
go: finding gopkg.in/src-d/go-git-fixtures.v3 v3.5.0
go: finding gopkg.in/src-d/go-git.v4 v4.13.1
go: finding gopkg.in/warnings.v0 v0.1.2
go: finding gopkg.in/yaml.v2 v2.2.8
go: finding honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc
go: finding sourcegraph.com/sourcegraph/appdash v0.0.0-20190731080439-ebfcffb1b5c0
Finished installing dependencies

Your new project is ready to go! ✨

To perform an initial deployment, run 'pulumi up'

E2E automated setup including plugin acquisition:

Evans-MBP:newtest evanboyle$ pulumi new
Please choose a template: Show additional templates
Please choose a template: aws-go                     A minimal AWS Go Pulumi program
This command will walk you through creating a new Pulumi project.

Enter a value or leave blank to accept the (default), and press <ENTER>.
Press ^C at any time to quit.

project name: abfdf
project description: (A minimal AWS Go Pulumi program) sds
Created project 'abfdf'

Please enter your desired stack name.
To create a stack in an organization, use the format <org-name>/<stack-name> (e.g. `acmecorp/dev`).
stack name: (dev) 
Created stack 'dev'

aws:region: The AWS region to deploy into: (us-east-1) 
Saved config

Installing dependencies...

go: finding github.com/pulumi/pulumi-aws/sdk v1.28.0
Finished installing dependencies

Your new project is ready to go! ✨

To perform an initial deployment, run 'pulumi up'

Evans-MBP:newtest evanboyle$ pulumi up
Previewing update (dev):
[resource plugin aws-1.28.0] installing
Downloading plugin: 64.58 MiB / 64.58 MiB [=========================] 100.00% 7s
Moving plugin... done.
     Type                 Name       Plan       
 +   pulumi:pulumi:Stack  abfdf-dev  create     
 +   └─ aws:s3:Bucket     my-bucket  create     
 
Resources:
    + 2 to create

Do you want to perform this update? yes
Updating (dev):
     Type                 Name       Status      
 +   pulumi:pulumi:Stack  abfdf-dev  created     
 +   └─ aws:s3:Bucket     my-bucket  created     
 
Outputs:
    bucketName: "my-bucket-5627649"

Resources:
    + 2 created

Duration: 12s

Permalink: https://app.pulumi.com/EvanBoyle/abfdf/dev/updates/1
Evans-MBP:newtest evanboyle$ 

[lukehoban]

For the use case that's new in this PR - do we really want to be looking in CWD or $GOPATH/bin for go itself? I would have though we could have just directly used exec.LookPath for that. It appears that we do just that for finding npm/yarn as well in the equivalent codepath there. The goal of FindExecutable is different - about finding user binaries.

Not a big deal though.

[EvanBoyle]

I agree we could probably change this. I'm not really concerned as we've been using this same code to find the go binary from within the go language host for quite some time (go run, more recently go list) and haven't seen any issues.