add rollout support to weaver kube (#32)

* add rollout support to weaver kube

In the current implementation, with weaver kube you have to pause the
world when you want to rollout a new version of the app.

In this PR we enable rolling upgrades, a deployment strategy that is
supported by Kubernetes.

In the near future, we might want to provide integration with argo
rollouts (or something else) to enable blue/green and canary
deployments.

Main changes:
* for each component that exports a listener, we create a deployment
  with an unique name; this doesn't change across rollouts, so a rolling
  update will update the existing pods one by one
* one a pod is updated to the new version, whenever it gets a request,
  it will only talk with other services within the same version
* for each public listener, the name should be unique and not deployment
  specific
* also, for jaeger and prometheus, we want unique instances that persist
  across multiple versions (and captures the metrics/traces for all the
  deployer versins of an app)
* Prometheus used to scrape an address that was passed to the pods to
  export metrics on; this doesn't really work across versions; so we
  change the prometheus config to scrape all pods based on a label (the
  label is based on the app name, so it scrapes all pods across all
  versions of the app)

Drawbacks of this approach (things that might not work):
* what if a listener moves between components
* what if a listener is dropped

For now, in all our examples we have a simple listener exported by main.
So we can restrict to be only one listener exported by main, and this
might cover most of the scenarios. However, how to handle listeners
across versions is something to think about.

* Fixed comments.

* Fixed last comments

go.mod

@@ -1,9 +1,9 @@
 module github.com/ServiceWeaver/weaver-kube
 
-go 1.20
+go 1.21
 
 require (
-	github.com/ServiceWeaver/weaver v0.17.1-0.20230720212036-7b261fed1c5f
+	github.com/ServiceWeaver/weaver v0.17.1-0.20230721230105-3d5e307bba63
 	github.com/google/uuid v1.3.0
 	go.opentelemetry.io/otel/exporters/jaeger v1.16.0
 	go.opentelemetry.io/otel/sdk v1.16.0

go.sum

@@ -1,8 +1,9 @@
 github.com/BurntSushi/toml v1.3.2 h1:o7IhLm0Msx3BaB+n3Ag7L8EVlByGnpq14C4YWiu/gL8=
 github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/DataDog/hyperloglog v0.0.0-20220804205443-1806d9b66146 h1:S5WsRc58vIeuhvbz0V0FKs19nTbh5z23DCutLIXJkFA=
-github.com/ServiceWeaver/weaver v0.17.1-0.20230720212036-7b261fed1c5f h1:vs6Dhz1TjPuNS2hcO4oiUVq8VxVJ9m0LGQbuoXuaPKw=
-github.com/ServiceWeaver/weaver v0.17.1-0.20230720212036-7b261fed1c5f/go.mod h1:/tJzitb+h8nLeHa4Mk7iIGU5ZV4OGB4C9IvIfD8n/1I=
+github.com/DataDog/hyperloglog v0.0.0-20220804205443-1806d9b66146/go.mod h1:hFPkswc42pKhRbeKDKXy05mRi7J1kJ2vMNbvd9erH0M=
+github.com/ServiceWeaver/weaver v0.17.1-0.20230721230105-3d5e307bba63 h1:BtZs3nXQVbsOFLu5mg2DwMKqKX8VHzw5y1C5xJ1ipQQ=
+github.com/ServiceWeaver/weaver v0.17.1-0.20230721230105-3d5e307bba63/go.mod h1:/tJzitb+h8nLeHa4Mk7iIGU5ZV4OGB4C9IvIfD8n/1I=
 github.com/antlr/antlr4/runtime/Go/antlr/v4 v4.0.0-20230305170008-8188dc5388df h1:7RFfzj4SSt6nnvCPbCqijJi1nWCd+TqAT3bYCStRC18=
 github.com/antlr/antlr4/runtime/Go/antlr/v4 v4.0.0-20230305170008-8188dc5388df/go.mod h1:pSwJ0fSY5KhvocuWSx4fz3BA8OrA1bQn+K1Eli3BRwM=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -11,6 +12,7 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/felixge/httpsnoop v1.0.3 h1:s/nj+GCswXYzN5v2DpNMuMQYe+0DDwt5WVCU6CWBdXk=
+github.com/felixge/httpsnoop v1.0.3/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
@@ -26,10 +28,12 @@ github.com/google/cel-go v0.17.1 h1:s2151PDGy/eqpCI80/8dl4VL3xTkqI/YubXLXCFw0mw=
 github.com/google/cel-go v0.17.1/go.mod h1:HXZKzB0LXqer5lHHgfWAnlYwJaQBDKMjxjulNQzhwhY=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/pprof v0.0.0-20230705174524-200ffdc848b8 h1:n6vlPhxsA+BW/XsS5+uqi7GyzaLa5MH7qlSLBZtRdiA=
+github.com/google/pprof v0.0.0-20230705174524-200ffdc848b8/go.mod h1:Jh3hGz2jkYak8qXPD19ryItVnUgpgeqzdkY/D0EaeuA=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
@@ -39,31 +43,38 @@ github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:C
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/lightstep/varopt v1.3.0 h1:H7OhtEBhYyDhoMu+wJGl4mTqM9TrYYdThG+xLGU3fZQ=
+github.com/lightstep/varopt v1.3.0/go.mod h1:3GP18zB7pfvbVUAnJ8xfvYjpwp0CF027QRD5FsfXau0=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-sqlite3 v1.14.16 h1:yOQRA0RpS5PFz/oikGwBEqvAWhWg5ufRz4ETLjwpU1Y=
+github.com/mattn/go-sqlite3 v1.14.16/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8 h1:KoWmjvw+nsYOo29YJK9vDA65RGE3NrOnUtO7a+RF9HU=
+github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8/go.mod h1:HKlIX3XHQyzLZPlr7++PzdhaXEj94dEiJgZDTsxEqUI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stoewer/go-strcase v1.2.0 h1:Z2iHWqGXH00XYgqDmNgQbIBxf3wrNq0F3feEy0ainaU=
 github.com/stoewer/go-strcase v1.2.0/go.mod h1:IBiWB2sKIp3wVVQ3Y035++gc+knqhUQag1KpM8ahLw8=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.8.3 h1:RP3t2pwF7cMEbC1dqtB6poj3niw/9gnV4Cjg5oW5gtY=
+github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.42.0 h1:pginetY7+onl4qN1vl0xW/V/v6OBZ0vVdH+esuJgvmM=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.42.0/go.mod h1:XiYsayHc36K3EByOO6nbAXnAWbrUxdjUROCEeeROOH8=
 go.opentelemetry.io/otel v1.16.0 h1:Z7GVAX/UkAXPKsy94IU+i6thsQS4nb7LviLpnaNeW8s=
 go.opentelemetry.io/otel v1.16.0/go.mod h1:vl0h9NUa1D5s1nv3A5vZOYWn8av4K8Ml6JDeHrT/bx4=
 go.opentelemetry.io/otel/exporters/jaeger v1.16.0 h1:YhxxmXZ011C0aDZKoNw+juVWAmEfv/0W2XBOv9aHTaA=
@@ -133,6 +144,7 @@ gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 k8s.io/api v0.26.2 h1:dM3cinp3PGB6asOySalOZxEG4CZ0IAdJsrYZXE/ovGQ=
 k8s.io/api v0.26.2/go.mod h1:1kjMQsFE+QHPfskEcVNgL3+Hp88B80uj0QtSOlj8itU=
 k8s.io/apimachinery v0.27.2 h1:vBjGaKKieaIreI+oQwELalVG4d8f3YAMNpWLzDXkxeg=
@@ -148,7 +160,9 @@ modernc.org/cc/v3 v3.40.0/go.mod h1:/bTg4dnWkSXowUO6ssQKnOV0yMVxDYNIsIrzqTFDGH0=
 modernc.org/ccgo/v3 v3.16.13 h1:Mkgdzl46i5F/CNR/Kj80Ri59hC8TKAhZrYSaqvkwzUw=
 modernc.org/ccgo/v3 v3.16.13/go.mod h1:2Quk+5YgpImhPjv2Qsob1DnZ/4som1lJTodubIcoUkY=
 modernc.org/ccorpus v1.11.6 h1:J16RXiiqiCgua6+ZvQot4yUuUy8zxgqbqEEUuGPlISk=
+modernc.org/ccorpus v1.11.6/go.mod h1:2gEUTrWqdpH2pXsmTM1ZkjeSrUWDpjMu2T6m29L/ErQ=
 modernc.org/httpfs v1.0.6 h1:AAgIpFZRXuYnkjftxTAZwMIiwEqAfk8aVB2/oA6nAeM=
+modernc.org/httpfs v1.0.6/go.mod h1:7dosgurJGp0sPaRanU53W4xZYKh14wfzX420oZADeHM=
 modernc.org/libc v1.22.5 h1:91BNch/e5B0uPbJFgqbxXuOnxBQjlS//icfQEGmvyjE=
 modernc.org/libc v1.22.5/go.mod h1:jj+Z7dTNX8fBScMVNRAYZ/jF91K8fdT2hYMThc3YjBY=
 modernc.org/mathutil v1.5.0 h1:rV0Ko/6SfM+8G+yKiyI830l3Wuz1zRutdslNoQ0kfiQ=
@@ -162,9 +176,11 @@ modernc.org/sqlite v1.24.0/go.mod h1:OrDj17Mggn6MhE+iPbBNf7RGKODDE9NFT0f3EwDzJqk
 modernc.org/strutil v1.1.3 h1:fNMm+oJklMGYfU9Ylcywl0CO5O6nTfaowNsh2wpPjzY=
 modernc.org/strutil v1.1.3/go.mod h1:MEHNA7PdEnEwLvspRMtWTNnp2nnyvMfkimT1NKNAGbw=
 modernc.org/tcl v1.15.2 h1:C4ybAYCGJw968e+Me18oW55kD/FexcHbqH2xak1ROSY=
+modernc.org/tcl v1.15.2/go.mod h1:3+k/ZaEbKrC8ePv8zJWPtBSW0V7Gg9g8rkmhI1Kfs3c=
 modernc.org/token v1.0.1 h1:A3qvTqOwexpfZZeyI0FeGPDlSWX5pjZu9hF4lU+EKWg=
 modernc.org/token v1.0.1/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=
 modernc.org/z v1.7.3 h1:zDJf6iHjrnB+WRD88stbXokugjyc0/pB91ri1gO6LZY=
+modernc.org/z v1.7.3/go.mod h1:Ipv4tsdxZRbQyLq9Q1M6gdbkxYzdlrciF2Hi/lS7nWE=
 sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd h1:EDPBXCAspyGV4jQlpZSudPeMmr1bNJefnuqLsRAsHZo=
 sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd/go.mod h1:B8JuhiUyNFVKdsE8h686QcCxMaH6HrOAZj4vswFpcB0=
 sigs.k8s.io/structured-merge-diff/v4 v4.2.3 h1:PRbqxJClWWYMNV1dhaG4NsibJbArud9kFxnAMREiWFE=

internal/impl/babysitter.go

@@ -28,7 +28,7 @@ import (
 	"github.com/ServiceWeaver/weaver/runtime/envelope"
 	"github.com/ServiceWeaver/weaver/runtime/logging"
 	"github.com/ServiceWeaver/weaver/runtime/metrics"
-	imetrics "github.com/ServiceWeaver/weaver/runtime/prometheus"
+	"github.com/ServiceWeaver/weaver/runtime/prometheus"
 	"github.com/ServiceWeaver/weaver/runtime/protos"
 	"github.com/ServiceWeaver/weaver/runtime/traces"
 	"github.com/google/uuid"
@@ -82,7 +82,7 @@ func RunBabysitter(ctx context.Context) error {
 	}
 
 	// Create the trace exporter.
-	collector := name{cfg.Deployment.App.Name, jaegerAppName, cfg.Deployment.Id[:8]}.DNSLabel()
+	collector := name{cfg.Deployment.App.Name, jaegerAppName}.DNSLabel()
 	endpoint := fmt.Sprintf("http://%s:%d/api/traces", collector, jaegerCollectorPort)
 	traceExporter, err :=
 		jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(endpoint)))
@@ -127,7 +127,7 @@ func RunBabysitter(ctx context.Context) error {
 		// Read the metrics.
 		metrics := b.readMetrics()
 		var b bytes.Buffer
-		imetrics.TranslateMetricsToPrometheusTextFormat(&b, metrics, r.Host, prometheusEndpoint)
+		prometheus.TranslateMetricsToPrometheusTextFormat(&b, metrics, r.Host, prometheusEndpoint)
 		w.Write(b.Bytes()) //nolint:errcheck // response write error
 	})
 	go func() {