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XeteraXetera
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add custom 503 pages for when backends are down
1 parent e977957 commit 506a28a

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Lines changed: 226 additions & 0 deletions

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‎internal/xds/503-dashboard.html‎

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<!doctype html>
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<html>
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<head>
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<title>503 Dashboard Unavailable</title>
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<style>
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* {
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box-sizing: border-box;
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margin: 0;
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padding: 0;
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}
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body {
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font-family:
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system-ui,
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-apple-system,
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sans-serif;
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background: #0a0a0a;
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color: #e5e5e5;
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display: flex;
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align-items: center;
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justify-content: center;
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min-height: 100vh;
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padding: 1rem;
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}
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.container {
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text-align: center;
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max-width: 500px;
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}
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h1 {
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font-size: 4rem;
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color: #ef4444;
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margin-bottom: 1rem;
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}
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h2 {
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font-size: 1.5rem;
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margin-bottom: 1rem;
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color: #fff;
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}
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p {
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color: #b8b8b8;
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line-height: 1.6;
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}
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code {
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background: #262626;
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padding: 0.2rem 0.4rem;
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border-radius: 0.25rem;
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font-size: 0.9rem;
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}
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</style>
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</head>
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<body>
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<div class="container">
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<h1>503</h1>
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<h2>Dashboard Unavailable</h2>
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<p>
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The dashboard is down but envoy isn't. You might need to restart
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localproxy after force killing envoy with
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<code>sudo killall envoy</code>
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</p>
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</div>
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</body>
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</html>

‎internal/xds/503.html‎

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<!doctype html>
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<html>
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<head>
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<title>503 Service Unavailable</title>
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<style>
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* {
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box-sizing: border-box;
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margin: 0;
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padding: 0;
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}
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body {
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font-family:
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system-ui,
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-apple-system,
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sans-serif;
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background: #0a0a0a;
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color: #e5e5e5;
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display: flex;
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align-items: center;
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justify-content: center;
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min-height: 100vh;
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padding: 1rem;
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}
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.container {
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text-align: center;
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max-width: 500px;
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}
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h1 {
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font-size: 4rem;
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color: #ef4444;
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margin-bottom: 1rem;
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}
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h2 {
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font-size: 1.5rem;
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margin-bottom: 1rem;
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color: #fff;
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}
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p {
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color: #b8b8b8;
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line-height: 1.6;
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}
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</style>
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</head>
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<body>
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<div class="container">
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<h1>503</h1>
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<h2>Service Unavailable</h2>
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<p>
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The backend service is not responding. Please check that your
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application is running and try again.
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</p>
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</div>
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</body>
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</html>

‎internal/xds/snapshot.go‎

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Original file line numberDiff line numberDiff line change
@@ -1,10 +1,12 @@
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package xds
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import (
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_ "embed"
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"fmt"
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"net"
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"time"
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accesslog "github.com/envoyproxy/go-control-plane/envoy/config/accesslog/v3"
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cluster "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3"
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core "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
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endpoint "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
@@ -21,8 +23,15 @@ import (
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"github.com/envoyproxy/go-control-plane/pkg/resource/v3"
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"google.golang.org/protobuf/types/known/anypb"
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"google.golang.org/protobuf/types/known/durationpb"
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"google.golang.org/protobuf/types/known/wrapperspb"
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)
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//go:embed 503.html
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var error503HTML string
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//go:embed 503-dashboard.html
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var error503DashboardHTML string
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2635
type Protocol string
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const (
@@ -89,12 +98,112 @@ func (b *SnapshotBuilder) Build(routes []Route, httpsRedirect bool) (*cache.Snap
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9099
routerFilter, _ := anypb.New(&router.Router{})
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statusCode503Filter := &accesslog.AccessLogFilter{
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FilterSpecifier: &accesslog.AccessLogFilter_StatusCodeFilter{
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StatusCodeFilter: &accesslog.StatusCodeFilter{
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Comparison: &accesslog.ComparisonFilter{
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Op: accesslog.ComparisonFilter_EQ,
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Value: &core.RuntimeUInt32{
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DefaultValue: 503,
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RuntimeKey: "local_reply_503",
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},
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},
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},
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},
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}
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dashboardHostFilter := &accesslog.AccessLogFilter{
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FilterSpecifier: &accesslog.AccessLogFilter_OrFilter{
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OrFilter: &accesslog.OrFilter{
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Filters: []*accesslog.AccessLogFilter{
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{
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FilterSpecifier: &accesslog.AccessLogFilter_HeaderFilter{
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HeaderFilter: &accesslog.HeaderFilter{
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Header: &route.HeaderMatcher{
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Name: ":authority",
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HeaderMatchSpecifier: &route.HeaderMatcher_ExactMatch{
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ExactMatch: "localhost",
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},
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},
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},
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},
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},
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{
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FilterSpecifier: &accesslog.AccessLogFilter_HeaderFilter{
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HeaderFilter: &accesslog.HeaderFilter{
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Header: &route.HeaderMatcher{
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Name: ":authority",
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HeaderMatchSpecifier: &route.HeaderMatcher_ExactMatch{
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ExactMatch: "proxy.localhost",
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},
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},
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},
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},
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},
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{
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FilterSpecifier: &accesslog.AccessLogFilter_HeaderFilter{
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HeaderFilter: &accesslog.HeaderFilter{
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Header: &route.HeaderMatcher{
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Name: ":authority",
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HeaderMatchSpecifier: &route.HeaderMatcher_ExactMatch{
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ExactMatch: "proxy.internal",
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},
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},
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},
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},
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},
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},
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},
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},
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}
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localReplyConfig := &hcm.LocalReplyConfig{
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Mappers: []*hcm.ResponseMapper{
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{
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Filter: &accesslog.AccessLogFilter{
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FilterSpecifier: &accesslog.AccessLogFilter_AndFilter{
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AndFilter: &accesslog.AndFilter{
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Filters: []*accesslog.AccessLogFilter{
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statusCode503Filter,
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dashboardHostFilter,
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},
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},
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},
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},
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StatusCode: wrapperspb.UInt32(503),
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Body: &core.DataSource{
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Specifier: &core.DataSource_InlineString{InlineString: error503DashboardHTML},
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},
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BodyFormatOverride: &core.SubstitutionFormatString{
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ContentType: "text/html; charset=UTF-8",
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Format: &core.SubstitutionFormatString_TextFormat{
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TextFormat: "%LOCAL_REPLY_BODY%",
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},
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},
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},
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{
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Filter: statusCode503Filter,
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StatusCode: wrapperspb.UInt32(503),
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Body: &core.DataSource{
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Specifier: &core.DataSource_InlineString{InlineString: error503HTML},
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},
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BodyFormatOverride: &core.SubstitutionFormatString{
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ContentType: "text/html; charset=UTF-8",
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Format: &core.SubstitutionFormatString_TextFormat{
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TextFormat: "%LOCAL_REPLY_BODY%",
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},
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},
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},
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},
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}
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httpsHcm := &hcm.HttpConnectionManager{
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CodecType: hcm.HttpConnectionManager_AUTO,
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StatPrefix: "https_ingress",
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StreamIdleTimeout: durationpb.New(0),
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RequestTimeout: durationpb.New(0),
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RequestHeadersTimeout: durationpb.New(0),
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LocalReplyConfig: localReplyConfig,
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RouteSpecifier: &hcm.HttpConnectionManager_Rds{
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Rds: &hcm.Rds{
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ConfigSource: &core.ConfigSource{
@@ -119,6 +228,7 @@ func (b *SnapshotBuilder) Build(routes []Route, httpsRedirect bool) (*cache.Snap
119228
StreamIdleTimeout: durationpb.New(0),
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RequestTimeout: durationpb.New(0),
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RequestHeadersTimeout: durationpb.New(0),
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LocalReplyConfig: localReplyConfig,
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RouteSpecifier: &hcm.HttpConnectionManager_Rds{
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Rds: &hcm.Rds{
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ConfigSource: &core.ConfigSource{
@@ -387,6 +497,7 @@ func (b *SnapshotBuilder) Build(routes []Route, httpsRedirect bool) (*cache.Snap
387497
StreamIdleTimeout: durationpb.New(0),
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RequestTimeout: durationpb.New(0),
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RequestHeadersTimeout: durationpb.New(0),
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LocalReplyConfig: localReplyConfig,
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RouteSpecifier: &hcm.HttpConnectionManager_Rds{
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Rds: &hcm.Rds{
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ConfigSource: &core.ConfigSource{

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