ContainerImage.Pinniped/internal/concierge/server/server.go

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2021-01-07 22:58:09 +00:00
// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package server is the command line entry point for pinniped-concierge.
package server
import (
"context"
"fmt"
"io"
Switch to a slimmer distroless base image. At a high level, it switches us to a distroless base container image, but that also includes several related bits: - Add a writable /tmp but make the rest of our filesystems read-only at runtime. - Condense our main server binaries into a single pinniped-server binary. This saves a bunch of space in the image due to duplicated library code. The correct behavior is dispatched based on `os.Args[0]`, and the `pinniped-server` binary is symlinked to `pinniped-concierge` and `pinniped-supervisor`. - Strip debug symbols from our binaries. These aren't really useful in a distroless image anyway and all the normal stuff you'd expect to work, such as stack traces, still does. - Add a separate `pinniped-concierge-kube-cert-agent` binary with "sleep" and "print" functionality instead of using builtin /bin/sleep and /bin/cat for the kube-cert-agent. This is split from the main server binary because the loading/init time of the main server binary was too large for the tiny resource footprint we established in our kube-cert-agent PodSpec. Using a separate binary eliminates this issue and the extra binary adds only around 1.5MiB of image size. - Switch the kube-cert-agent code to use a JSON `{"tls.crt": "<b64 cert>", "tls.key": "<b64 key>"}` format. This is more robust to unexpected input formatting than the old code, which simply concatenated the files with some extra newlines and split on whitespace. - Update integration tests that made now-invalid assumptions about the `pinniped-server` image. Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-07-26 16:18:43 +00:00
"os"
"time"
"github.com/spf13/cobra"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/runtime/serializer"
genericapiserver "k8s.io/apiserver/pkg/server"
genericoptions "k8s.io/apiserver/pkg/server/options"
Switch to a slimmer distroless base image. At a high level, it switches us to a distroless base container image, but that also includes several related bits: - Add a writable /tmp but make the rest of our filesystems read-only at runtime. - Condense our main server binaries into a single pinniped-server binary. This saves a bunch of space in the image due to duplicated library code. The correct behavior is dispatched based on `os.Args[0]`, and the `pinniped-server` binary is symlinked to `pinniped-concierge` and `pinniped-supervisor`. - Strip debug symbols from our binaries. These aren't really useful in a distroless image anyway and all the normal stuff you'd expect to work, such as stack traces, still does. - Add a separate `pinniped-concierge-kube-cert-agent` binary with "sleep" and "print" functionality instead of using builtin /bin/sleep and /bin/cat for the kube-cert-agent. This is split from the main server binary because the loading/init time of the main server binary was too large for the tiny resource footprint we established in our kube-cert-agent PodSpec. Using a separate binary eliminates this issue and the extra binary adds only around 1.5MiB of image size. - Switch the kube-cert-agent code to use a JSON `{"tls.crt": "<b64 cert>", "tls.key": "<b64 key>"}` format. This is more robust to unexpected input formatting than the old code, which simply concatenated the files with some extra newlines and split on whitespace. - Update integration tests that made now-invalid assumptions about the `pinniped-server` image. Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-07-26 16:18:43 +00:00
"k8s.io/client-go/pkg/version"
"k8s.io/client-go/rest"
"k8s.io/component-base/logs"
"k8s.io/klog/v2"
"go.pinniped.dev/internal/certauthority/dynamiccertauthority"
"go.pinniped.dev/internal/concierge/apiserver"
conciergescheme "go.pinniped.dev/internal/concierge/scheme"
"go.pinniped.dev/internal/config/concierge"
"go.pinniped.dev/internal/controller/authenticator/authncache"
"go.pinniped.dev/internal/controllerinit"
"go.pinniped.dev/internal/controllermanager"
"go.pinniped.dev/internal/crypto/ptls"
"go.pinniped.dev/internal/downward"
"go.pinniped.dev/internal/dynamiccert"
"go.pinniped.dev/internal/here"
"go.pinniped.dev/internal/issuer"
"go.pinniped.dev/internal/kubeclient"
"go.pinniped.dev/internal/plog"
"go.pinniped.dev/internal/registry/credentialrequest"
)
// App is an object that represents the pinniped-concierge application.
type App struct {
cmd *cobra.Command
// CLI flags
configPath string
downwardAPIPath string
}
// New constructs a new App with command line args, stdout and stderr.
func New(ctx context.Context, args []string, stdout, stderr io.Writer) *App {
app := &App{}
app.addServerCommand(ctx, args, stdout, stderr)
return app
}
// Run the server.
func (a *App) Run() error {
return a.cmd.Execute()
}
// Create the server command and save it into the App.
func (a *App) addServerCommand(ctx context.Context, args []string, stdout, stderr io.Writer) {
cmd := &cobra.Command{
Use: "pinniped-concierge",
Long: here.Doc(`
pinniped-concierge provides a generic API for mapping an external
credential from somewhere to an internal credential to be used for
authenticating to the Kubernetes API.`),
RunE: func(cmd *cobra.Command, args []string) error { return a.runServer(ctx) },
Args: cobra.NoArgs,
}
cmd.SetArgs(args)
cmd.SetOut(stdout)
cmd.SetErr(stderr)
addCommandlineFlagsToCommand(cmd, a)
a.cmd = cmd
}
// Define the app's commandline flags.
func addCommandlineFlagsToCommand(cmd *cobra.Command, app *App) {
cmd.Flags().StringVarP(
&app.configPath,
"config",
"c",
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"pinniped.yaml",
"path to configuration file",
)
cmd.Flags().StringVar(
&app.downwardAPIPath,
"downward-api-path",
"/etc/podinfo",
"path to Downward API volume mount",
)
plog.RemoveKlogGlobalFlags()
}
// Boot the aggregated API server, which will in turn boot the controllers.
func (a *App) runServer(ctx context.Context) error {
// Read the server config file.
cfg, err := concierge.FromPath(a.configPath)
if err != nil {
return fmt.Errorf("could not load config: %w", err)
}
// Discover in which namespace we are installed.
podInfo, err := downward.Load(a.downwardAPIPath)
if err != nil {
return fmt.Errorf("could not read pod metadata: %w", err)
}
// Initialize the cache of active authenticators.
authenticators := authncache.New()
// This cert provider will provide certs to the API server and will
// be mutated by a controller to keep the certs up to date with what
// is stored in a k8s Secret. Therefore it also effectively acting as
// an in-memory cache of what is stored in the k8s Secret, helping to
// keep incoming requests fast.
dynamicServingCertProvider := dynamiccert.NewServingCert("concierge-serving-cert")
// This cert provider will be used to provide the Kube signing key to the
// cert issuer used to issue certs to Pinniped clients wishing to login.
dynamicSigningCertProvider := dynamiccert.NewCA("concierge-kube-signing-cert")
// This cert provider will be used to provide the impersonation proxy signing key to the
// cert issuer used to issue certs to Pinniped clients wishing to login.
impersonationProxySigningCertProvider := dynamiccert.NewCA("impersonation-proxy-signing-cert")
// Get the "real" name of the login concierge API group (i.e., the API group name with the
// injected suffix).
scheme, loginGV, identityGV := conciergescheme.New(*cfg.APIGroupSuffix)
// Prepare to start the controllers, but defer actually starting them until the
// post start hook of the aggregated API server.
buildControllers, err := controllermanager.PrepareControllers(
&controllermanager.Config{
ServerInstallationInfo: podInfo,
APIGroupSuffix: *cfg.APIGroupSuffix,
NamesConfig: &cfg.NamesConfig,
Labels: cfg.Labels,
KubeCertAgentConfig: &cfg.KubeCertAgentConfig,
DiscoveryURLOverride: cfg.DiscoveryInfo.URL,
DynamicServingCertProvider: dynamicServingCertProvider,
DynamicSigningCertProvider: dynamicSigningCertProvider,
ImpersonationSigningCertProvider: impersonationProxySigningCertProvider,
ServingCertDuration: time.Duration(*cfg.APIConfig.ServingCertificateConfig.DurationSeconds) * time.Second,
ServingCertRenewBefore: time.Duration(*cfg.APIConfig.ServingCertificateConfig.RenewBeforeSeconds) * time.Second,
AuthenticatorCache: authenticators,
// This port should be safe to cast because the config reader already validated it.
ImpersonationProxyServerPort: int(*cfg.ImpersonationProxyServerPort),
},
)
if err != nil {
return fmt.Errorf("could not prepare controllers: %w", err)
}
certIssuer := issuer.ClientCertIssuers{
dynamiccertauthority.New(dynamicSigningCertProvider), // attempt to use the real Kube CA if possible
dynamiccertauthority.New(impersonationProxySigningCertProvider), // fallback to our internal CA if we need to
}
// Get the aggregated API server config.
aggregatedAPIServerConfig, err := getAggregatedAPIServerConfig(
dynamicServingCertProvider,
authenticators,
certIssuer,
buildControllers,
*cfg.APIGroupSuffix,
*cfg.AggregatedAPIServerPort,
scheme,
loginGV,
identityGV,
)
if err != nil {
return fmt.Errorf("could not configure aggregated API server: %w", err)
}
// Complete the aggregated API server config and make a server instance.
server, err := aggregatedAPIServerConfig.Complete().New()
if err != nil {
return fmt.Errorf("could not create aggregated API server: %w", err)
}
// Run the server. Its post-start hook will start the controllers.
return server.GenericAPIServer.PrepareRun().Run(ctx.Done())
}
// Create a configuration for the aggregated API server.
func getAggregatedAPIServerConfig(
dynamicCertProvider dynamiccert.Private,
authenticator credentialrequest.TokenCredentialRequestAuthenticator,
issuer issuer.ClientCertIssuer,
buildControllers controllerinit.RunnerBuilder,
apiGroupSuffix string,
aggregatedAPIServerPort int64,
scheme *runtime.Scheme,
loginConciergeGroupVersion, identityConciergeGroupVersion schema.GroupVersion,
) (*apiserver.Config, error) {
codecs := serializer.NewCodecFactory(scheme)
// this is unused for now but it is a safe value that we could use in the future
defaultEtcdPathPrefix := fmt.Sprintf("/pinniped-concierge-registry/%s", apiGroupSuffix)
recommendedOptions := genericoptions.NewRecommendedOptions(
defaultEtcdPathPrefix,
codecs.LegacyCodec(loginConciergeGroupVersion, identityConciergeGroupVersion),
)
recommendedOptions.Etcd = nil // turn off etcd storage because we don't need it yet
recommendedOptions.SecureServing.ServerCert.GeneratedCert = dynamicCertProvider
// This port is configurable. It should be safe to cast because the config reader already validated it.
recommendedOptions.SecureServing.BindPort = int(aggregatedAPIServerPort)
// secure TLS for connections coming from and going to the Kube API server
// this is best effort because not all options provide the right hooks to override TLS config
// since our only client is the Kube API server, this uses the most secure TLS config
if err := ptls.SecureRecommendedOptions(recommendedOptions, kubeclient.Secure); err != nil {
return nil, fmt.Errorf("failed to secure recommended options: %w", err)
}
serverConfig := genericapiserver.NewRecommendedConfig(codecs)
// Note that among other things, this ApplyTo() function copies
// `recommendedOptions.SecureServing.ServerCert.GeneratedCert` into
// `serverConfig.SecureServing.Cert` thus making `dynamicCertProvider`
// the cert provider for the running server. The provider will be called
// by the API machinery periodically. When the provider returns nil certs,
// the API server will return "the server is currently unable to
// handle the request" error responses for all incoming requests.
// If the provider later starts returning certs, then the API server
// will use them to handle the incoming requests successfully.
if err := recommendedOptions.ApplyTo(serverConfig); err != nil {
return nil, fmt.Errorf("failed to apply recommended options: %w", err)
}
apiServerConfig := &apiserver.Config{
GenericConfig: serverConfig,
ExtraConfig: apiserver.ExtraConfig{
Authenticator: authenticator,
Issuer: issuer,
BuildControllersPostStartHook: buildControllers,
Scheme: scheme,
NegotiatedSerializer: codecs,
LoginConciergeGroupVersion: loginConciergeGroupVersion,
IdentityConciergeGroupVersion: identityConciergeGroupVersion,
},
}
return apiServerConfig, nil
}
Switch to a slimmer distroless base image. At a high level, it switches us to a distroless base container image, but that also includes several related bits: - Add a writable /tmp but make the rest of our filesystems read-only at runtime. - Condense our main server binaries into a single pinniped-server binary. This saves a bunch of space in the image due to duplicated library code. The correct behavior is dispatched based on `os.Args[0]`, and the `pinniped-server` binary is symlinked to `pinniped-concierge` and `pinniped-supervisor`. - Strip debug symbols from our binaries. These aren't really useful in a distroless image anyway and all the normal stuff you'd expect to work, such as stack traces, still does. - Add a separate `pinniped-concierge-kube-cert-agent` binary with "sleep" and "print" functionality instead of using builtin /bin/sleep and /bin/cat for the kube-cert-agent. This is split from the main server binary because the loading/init time of the main server binary was too large for the tiny resource footprint we established in our kube-cert-agent PodSpec. Using a separate binary eliminates this issue and the extra binary adds only around 1.5MiB of image size. - Switch the kube-cert-agent code to use a JSON `{"tls.crt": "<b64 cert>", "tls.key": "<b64 key>"}` format. This is more robust to unexpected input formatting than the old code, which simply concatenated the files with some extra newlines and split on whitespace. - Update integration tests that made now-invalid assumptions about the `pinniped-server` image. Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-07-26 16:18:43 +00:00
func main() error { // return an error instead of klog.Fatal to allow defer statements to run
Switch to a slimmer distroless base image. At a high level, it switches us to a distroless base container image, but that also includes several related bits: - Add a writable /tmp but make the rest of our filesystems read-only at runtime. - Condense our main server binaries into a single pinniped-server binary. This saves a bunch of space in the image due to duplicated library code. The correct behavior is dispatched based on `os.Args[0]`, and the `pinniped-server` binary is symlinked to `pinniped-concierge` and `pinniped-supervisor`. - Strip debug symbols from our binaries. These aren't really useful in a distroless image anyway and all the normal stuff you'd expect to work, such as stack traces, still does. - Add a separate `pinniped-concierge-kube-cert-agent` binary with "sleep" and "print" functionality instead of using builtin /bin/sleep and /bin/cat for the kube-cert-agent. This is split from the main server binary because the loading/init time of the main server binary was too large for the tiny resource footprint we established in our kube-cert-agent PodSpec. Using a separate binary eliminates this issue and the extra binary adds only around 1.5MiB of image size. - Switch the kube-cert-agent code to use a JSON `{"tls.crt": "<b64 cert>", "tls.key": "<b64 key>"}` format. This is more robust to unexpected input formatting than the old code, which simply concatenated the files with some extra newlines and split on whitespace. - Update integration tests that made now-invalid assumptions about the `pinniped-server` image. Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-07-26 16:18:43 +00:00
logs.InitLogs()
defer logs.FlushLogs()
// Dump out the time since compile (mostly useful for benchmarking our local development cycle latency).
var timeSinceCompile time.Duration
if buildDate, err := time.Parse(time.RFC3339, version.Get().BuildDate); err == nil {
timeSinceCompile = time.Since(buildDate).Round(time.Second)
}
klog.Infof("Running %s at %#v (%s since build)", rest.DefaultKubernetesUserAgent(), version.Get(), timeSinceCompile)
ctx := genericapiserver.SetupSignalContext()
return New(ctx, os.Args[1:], os.Stdout, os.Stderr).Run()
}
func Main() {
if err := main(); err != nil {
Switch to a slimmer distroless base image. At a high level, it switches us to a distroless base container image, but that also includes several related bits: - Add a writable /tmp but make the rest of our filesystems read-only at runtime. - Condense our main server binaries into a single pinniped-server binary. This saves a bunch of space in the image due to duplicated library code. The correct behavior is dispatched based on `os.Args[0]`, and the `pinniped-server` binary is symlinked to `pinniped-concierge` and `pinniped-supervisor`. - Strip debug symbols from our binaries. These aren't really useful in a distroless image anyway and all the normal stuff you'd expect to work, such as stack traces, still does. - Add a separate `pinniped-concierge-kube-cert-agent` binary with "sleep" and "print" functionality instead of using builtin /bin/sleep and /bin/cat for the kube-cert-agent. This is split from the main server binary because the loading/init time of the main server binary was too large for the tiny resource footprint we established in our kube-cert-agent PodSpec. Using a separate binary eliminates this issue and the extra binary adds only around 1.5MiB of image size. - Switch the kube-cert-agent code to use a JSON `{"tls.crt": "<b64 cert>", "tls.key": "<b64 key>"}` format. This is more robust to unexpected input formatting than the old code, which simply concatenated the files with some extra newlines and split on whitespace. - Update integration tests that made now-invalid assumptions about the `pinniped-server` image. Signed-off-by: Matt Moyer <moyerm@vmware.com>
2021-07-26 16:18:43 +00:00
klog.Fatal(err)
}
}