Replace vfsgen with embed for static web assets (prometheus#9719)

* remove vfsgen usages

Signed-off-by: Jan Fajerski <jfajersk@redhat.com>

* web: use embed package for static assets

This requires go 1.16.

Signed-off-by: Jan Fajerski <jfajersk@redhat.com>

* circleci: drop go generate in web/ui

Signed-off-by: Jan Fajerski <jfajersk@redhat.com>

* Makefile: compress web assets before build

This commit add compression before (and decompression after) prometheus
is build. This ensures that gzipped assets are embeded in the prometheus
binary, if the builtinassets build tag is passed. If the build tag is
not passed this step is still executed but has no effect.
All this is executed in a subshell so that we can run the decompress
step even if the build step fails, but retain the exit code of promu.
This cleanup could also cover interrupts, but I left that out for now.

Signed-off-by: Jan Fajerski <jfajersk@redhat.com>

* [FIXME]: add new module dependency on common/assets and temp replace

Signed-off-by: Jan Fajerski <jfajersk@redhat.com>

.circleci/config.yml

@@ -81,8 +81,6 @@ jobs:
           command: refreshenv
       - run:
           command: |
-            $env:GOARCH=""; $env:GOOS=""; cd web/ui; go generate
-            cd ../..
             $TestTargets = go list ./... | Where-Object { $_ -NotMatch "(github.com/prometheus/prometheus/discovery.*|github.com/prometheus/prometheus/config|github.com/prometheus/prometheus/web)"}
             go test $TestTargets -vet=off -v
           environment:

.gitignore

@@ -23,7 +23,6 @@ benchmark.txt
 
 npm_licenses.tar.bz2
 /web/ui/static/react
-/web/ui/assets_vfsdata.go
 
 /vendor
 /.build

Makefile

@@ -51,12 +51,6 @@ ui-lint:
 
 .PHONY: assets
 assets: ui-install ui-build
-	@echo ">> writing assets"
-	# Un-setting GOOS and GOARCH here because the generated Go code is always the same,
-	# but the cached object code is incompatible between architectures and OSes (which
-	# breaks cross-building for different combinations on CI in the same container).
-	cd $(UI_PATH) && GO111MODULE=$(GO111MODULE) GOOS= GOARCH= $(GO) generate -x -v $(GOOPTS)
-	@$(GOFMT) -w ./$(UI_PATH)
 
 .PHONY: test
 # If we only want to only test go code we have to change the test target

Makefile.common

@@ -238,8 +238,11 @@ endif
 
 .PHONY: common-build
 common-build: promu
-	@echo ">> building binaries"
-	GO111MODULE=$(GO111MODULE) $(PROMU) build --prefix $(PREFIX) $(PROMU_BINARIES)
+	@bash -c "trap 'echo \">> restoring assets\"; scripts/compress_assets.sh -d;' EXIT; \
+	          echo '>> compressing assets'; \
+	          scripts/compress_assets.sh; \
+	          echo '>> building binaries'; \
+	          GO111MODULE=$(GO111MODULE) $(PROMU) build --prefix $(PREFIX) $(PROMU_BINARIES)"
 
 .PHONY: common-tarball
 common-tarball: promu

go.mod

@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus
 
-go 1.14
+go 1.16
 
 require (
 	github.com/Azure/azure-sdk-for-go v58.3.0+incompatible
@@ -49,11 +49,11 @@ require (
 	github.com/prometheus/client_golang v1.11.0
 	github.com/prometheus/client_model v0.2.0
 	github.com/prometheus/common v0.32.1
+	github.com/prometheus/common/assets v0.1.0
 	github.com/prometheus/common/sigv4 v0.1.0
 	github.com/prometheus/exporter-toolkit v0.7.0
 	github.com/scaleway/scaleway-sdk-go v1.0.0-beta.7.0.20210223165440-c65ae3540d44
 	github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749
-	github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546
 	github.com/stretchr/testify v1.7.0
 	github.com/uber/jaeger-client-go v2.29.1+incompatible
 	github.com/uber/jaeger-lib v2.4.1+incompatible
@@ -117,3 +117,5 @@ exclude (
 	k8s.io/client-go v9.0.0+incompatible
 	k8s.io/client-go v9.0.0-invalid+incompatible
 )
+
+replace github.com/prometheus/common/assets => github.com/jan--f/common/assets v0.0.0-20211112085804-0bbedfb4d189

go.sum

@@ -348,7 +348,6 @@ github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:ma
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
-github.com/creack/pty v1.1.11 h1:07n33Z8lZxZ2qwegKbObQohDhXDQxiMMz1NOUGYlesw=
 github.com/creack/pty v1.1.11/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/cyberdelia/templates v0.0.0-20141128023046-ca7fffd4298c/go.mod h1:GyV+0YP4qX0UQ7r2MoYZ+AvYDp12OF5yg4q8rGnyNh4=
 github.com/cyphar/filepath-securejoin v0.2.2/go.mod h1:FpkQEhXnPnOthhzymB7CGsFk2G9VLXONKD9G7QGMM+4=
@@ -854,6 +853,8 @@ github.com/influxdata/tdigest v0.0.0-20181121200506-bf2b5ad3c0a9/go.mod h1:Js0mq
 github.com/influxdata/tdigest v0.0.2-0.20210216194612-fc98d27c9e8b/go.mod h1:Z0kXnxzbTC2qrx4NaIzYkE1k66+6oEDQTvL95hQFh5Y=
 github.com/influxdata/usage-client v0.0.0-20160829180054-6d3895376368/go.mod h1:Wbbw6tYNvwa5dlB6304Sd+82Z3f7PmVZHVKU637d4po=
 github.com/j-keck/arping v0.0.0-20160618110441-2cf9dc699c56/go.mod h1:ymszkNOg6tORTn+6F6j+Jc8TOr5osrynvN6ivFWZ2GA=
+github.com/jan--f/common/assets v0.0.0-20211112085804-0bbedfb4d189 h1:zm38/UrVgy0o0/4D7mV+rtVZs1FjlEzZyIP/Y82eoh0=
+github.com/jan--f/common/assets v0.0.0-20211112085804-0bbedfb4d189/go.mod h1:D17UVUE12bHbim7HzwUvtqm6gwBEaDQ0F+hIGbFbccI=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
 github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
@@ -1215,7 +1216,6 @@ github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749 h1:bUGsEnyNbVPw06B
 github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749/go.mod h1:ZY1cvUeJuFPAdZ/B6v7RHavJWZn2YPVFQ1OSXhCGOkg=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/shurcooL/vfsgen v0.0.0-20181202132449-6a9ea43bcacd/go.mod h1:TrYk7fJVaAttu97ZZKrO9UbRa8izdowaMIZcxYMbVaw=
-github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546 h1:pXY9qYc/MP5zdvqWEUH6SjNiu7VhSjuVFTFiTcphaLU=
 github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546/go.mod h1:TrYk7fJVaAttu97ZZKrO9UbRa8izdowaMIZcxYMbVaw=
 github.com/simonpasquier/klog-gokit v0.3.0 h1:TkFK21cbwDRS+CiystjqbAiq5ubJcVTk9hLUck5Ntcs=
 github.com/simonpasquier/klog-gokit v0.3.0/go.mod h1:+SUlDQNrhVtGt2FieaqNftzzk8P72zpWlACateWxA9k=
@@ -1431,7 +1431,6 @@ golang.org/x/exp v0.0.0-20191129062945-2f5052295587/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
-golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6 h1:QE6XYQK6naiK1EPAe1g/ILLxN5RBoH5xkJk3CqlMI/Y=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
 golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
@@ -1785,10 +1784,8 @@ golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8T
 gonum.org/v1/gonum v0.0.0-20180816165407-929014505bf4/go.mod h1:Y+Yx5eoAFn32cQvJDxZx5Dpnq+c3wtXuadVZAcxbbBo=
 gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca/go.mod h1:Y+Yx5eoAFn32cQvJDxZx5Dpnq+c3wtXuadVZAcxbbBo=
 gonum.org/v1/gonum v0.6.0/go.mod h1:9mxDZsDKxgMAuccQkewq682L+0eCu4dCN2yonUJTCLU=
-gonum.org/v1/gonum v0.8.2 h1:CCXrcPKiGGotvnN6jfUsKk4rRqm7q09/YbKb5xCEvtM=
 gonum.org/v1/gonum v0.8.2/go.mod h1:oe/vMfY3deqTw+1EZJhuvEW2iwGF1bW9wwu7XCu0+v0=
 gonum.org/v1/netlib v0.0.0-20181029234149-ec6d1f5cefe6/go.mod h1:wa6Ws7BG/ESfp6dHfk7C6KdzKA7wR7u/rKwOGE66zvw=
-gonum.org/v1/netlib v0.0.0-20190313105609-8cb42192e0e0 h1:OE9mWmgKkjJyEmDAAtGMPjXu+YNeGvK9VTSHY6+Qihc=
 gonum.org/v1/netlib v0.0.0-20190313105609-8cb42192e0e0/go.mod h1:wa6Ws7BG/ESfp6dHfk7C6KdzKA7wR7u/rKwOGE66zvw=
 gonum.org/v1/plot v0.0.0-20190515093506-e2840ee46a6b/go.mod h1:Wt8AAjI+ypCyYX3nZBvf6cAIx93T+c/OS2HFAYskSZc=
 google.golang.org/api v0.0.0-20160322025152-9bf6e6e569ff/go.mod h1:4mhQ8q/RsB7i+udVvVy5NUi08OU8ZlA0gRVgrF7VFY0=

scripts/compress_assets.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+#
+# [de]compress static assets
+
+find web/ui/templates web/ui/static -type f -exec gzip "$@" {} \;

web/ui/README.md

@@ -1,11 +1,12 @@
 ## Overview
-
-The `ui` directory contains static files and templates used in the web UI. For easier distribution they are statically
-compiled into the Prometheus binary using the vfsgen library (c.f. Makefile).
-
-During development it is more convenient to always use the files on disk to directly see changes without recompiling. To
-make this work, remove the `builtinassets` build tag in the `flags` entry in `.promu.yml`, and then `make build` (or
-build Prometheus using
+The `ui` directory contains static files and templates used in the web UI. For
+easier distribution they are compressend (c.f. Makefile) and statically compiled 
+into the Prometheus binary using the embed package.
+
+During development it is more convenient to always use the files on disk to 
+directly see changes without recompiling.
+To make this work, remove the `builtinassets` build tag in the `flags` entry
+in `.promu.yml`, and then `make build` (or build Prometheus using
 `go build ./cmd/prometheus`).
 
 This will serve all files from your local filesystem. This is for development purposes only.

web/ui/doc.go → web/ui/assets_embed.go

@@ -1,4 +1,4 @@
-// Copyright 2018 The Prometheus Authors
+// Copyright 2021 The Prometheus Authors
 // Licensed 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
@@ -11,14 +11,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package ui provides the assets via a virtual filesystem.
+//go:build builtinassets
+// +build builtinassets
+
 package ui
 
 import (
-	// The blank import is to make Go modules happy.
-	_ "github.com/shurcooL/httpfs/filter"
-	_ "github.com/shurcooL/httpfs/union"
-	_ "github.com/shurcooL/vfsgen"
+	"embed"
+	"github.com/prometheus/common/assets"
+	"net/http"
 )
 
-//go:generate go run assets_generate.go
+//go:embed static templates
+var EmbedFS embed.FS
+
+var Assets = http.FS(assets.New(EmbedFS))