Phawula. transl.: umbhali wenqaku - u-Erkan Erol, injineli evela kwi-SAP - wabelane ngesifundo sakhe seendlela zokusebenza kweqela kubectl exec, iqhelekile kuye wonke umntu osebenza noKubernetes. Uhamba kunye ne-algorithm yonke kunye noluhlu lwekhowudi yomthombo we-Kubernetes (kunye neeprojekthi ezinxulumene nazo), ezikuvumela ukuba uqonde isihloko ngokunzulu njengoko kufuneka.
Ngomnye uLwesihlanu, umntu endisebenza naye weza kum waza wabuza indlela yokwenza umyalelo kwipod usebenzisa . Khange ndikwazi ukumphendula ndavele ndaqaphela ukuba andazi kwanto ngemechanical operation kubectl exec. Ewe, ndinemibono ethile malunga nesakhiwo sayo, kodwa andizange ndiqiniseke nge-100% ngokuchaneka kwabo kwaye ngoko ke ndagqiba ekubeni ndiwuthathele ingqalelo lo mbandela. Emva kokufunda iiblogi, amaxwebhu kunye nekhowudi yomthombo, ndifunde izinto ezininzi ezintsha, kwaye kweli nqaku ndifuna ukwabelana ngezinto endizifumeneyo kunye nokuqonda. Ukuba kukho into engalunganga, nceda uqhagamshelane nam .
Ukulungiselela
Ukwenza iqela kwi-MacBook, ndiye ndabumba . Emva koko ndilungise iidilesi ze-IP zeendawo kwi-kubelet config, kuba useto olungagqibekanga aluzange luvumele kubectl exec. Unokufunda ngakumbi malunga nesizathu esiphambili soku .
- Nayiphi na imoto = iMacBook yam
- Master node IP = 192.168.205.10
- Indawo yabasebenzi IP = 192.168.205.11
- I-API yeseva ye-port = 6443
Izixhobo
- kubectl exec inkqubo: Xa siphumeza "kubectl exec..." inkqubo iqalisiwe. Oku kunokwenziwa kuwo nawuphi na umatshini onofikelelo kumncedisi we K8s API. Phawula Transl.
- : Icandelo kwi-master node enikezela ukufikelela kwi-Kubernetes API. Le yi-frontend yendiza yokulawula e-Kubernetes.
- : I-arhente esebenza kuyo yonke i-node kwiqela. Iqinisekisa ukusebenza kwezikhongozeli kwipod.
- (ixesha lokusetyenziswa komgqomo): Isoftware enoxanduva lokuqhuba izikhongozeli. Imizekelo: IDocker, CRI-O, ikhontenti...
- kernel: I-OS kernel kwindawo yabasebenzi; unoxanduva lolawulo lwenkqubo.
- joliswe kuyo (injongo) isitya: Isikhongozeli esiyinxalenye yepod kwaye sisebenza kwenye yeendawo zabasebenzi.
Into endiyifumeneyo
1. Umsebenzi wecala lomthengi
Yenza ipod kwindawo yegama default:
// any machine
$ kubectl run exec-test-nginx --image=nginxEmva koko senza umyalelo we-exec kwaye silinde imizuzwana engama-5000 ngokuqwalasela ngakumbi:
// any machine
$ kubectl exec -it exec-test-nginx-6558988d5-fgxgg -- sh
# sleep 5000Inkqubo ye-kubectl ibonakala (kunye pid=8507 kwimeko yethu):
// any machine
$ ps -ef |grep kubectl
501 8507 8409 0 7:19PM ttys000 0:00.13 kubectl exec -it exec-test-nginx-6558988d5-fgxgg -- shUkuba sijonga umsebenzi womnatha wenkqubo, siya kufumanisa ukuba inonxibelelwano kwi-api-server (192.168.205.10.6443):
// any machine
$ netstat -atnv |grep 8507
tcp4 0 0 192.168.205.1.51673 192.168.205.10.6443 ESTABLISHED 131072 131768 8507 0 0x0102 0x00000020
tcp4 0 0 192.168.205.1.51672 192.168.205.10.6443 ESTABLISHED 131072 131768 8507 0 0x0102 0x00000028Makhe sijonge ikhowudi. I-Kubectl yenza isicelo se-POST nge-exec subresource kwaye ithumela isicelo se-REST:
req := restClient.Post().
Resource("pods").
Name(pod.Name).
Namespace(pod.Namespace).
SubResource("exec")
req.VersionedParams(&corev1.PodExecOptions{
Container: containerName,
Command: p.Command,
Stdin: p.Stdin,
Stdout: p.Out != nil,
Stderr: p.ErrOut != nil,
TTY: t.Raw,
}, scheme.ParameterCodec)
return p.Executor.Execute("POST", req.URL(), p.Config, p.In, p.Out, p.ErrOut, t.Raw, sizeQueue)()
2. Umsebenzi kwicala le-master node
Sinokujonga isicelo kwicala le-api-server:
handler.go:143] kube-apiserver: POST "/api/v1/namespaces/default/pods/exec-test-nginx-6558988d5-fgxgg/exec" satisfied by gorestful with webservice /api/v1
upgradeaware.go:261] Connecting to backend proxy (intercepting redirects) https://192.168.205.11:10250/exec/default/exec-test-nginx-6558988d5-fgxgg/exec-test-nginx?command=sh&input=1&output=1&tty=1
Headers: map[Connection:[Upgrade] Content-Length:[0] Upgrade:[SPDY/3.1] User-Agent:[kubectl/v1.12.10 (darwin/amd64) kubernetes/e3c1340] X-Forwarded-For:[192.168.205.1] X-Stream-Protocol-Version:[v4.channel.k8s.io v3.channel.k8s.io v2.channel.k8s.io channel.k8s.io]]Qaphela ukuba isicelo se-HTTP siquka isicelo sokutshintsha iprotocol. ikuvumela ukuba uphindaphinde i-stdin/stdout/stderr/spdy-impazamo "imisinga" ngaphezulu koqhagamshelwano lwe-TCP enye.
Iseva ye-API ifumana isicelo kwaye isiguqulele kuyo PodExecOptions:
// PodExecOptions is the query options to a Pod's remote exec call
type PodExecOptions struct {
metav1.TypeMeta
// Stdin if true indicates that stdin is to be redirected for the exec call
Stdin bool
// Stdout if true indicates that stdout is to be redirected for the exec call
Stdout bool
// Stderr if true indicates that stderr is to be redirected for the exec call
Stderr bool
// TTY if true indicates that a tty will be allocated for the exec call
TTY bool
// Container in which to execute the command.
Container string
// Command is the remote command to execute; argv array; not executed within a shell.
Command []string
}()
Ukwenza iintshukumo ezifunekayo, i-api-server kufuneka yazi ukuba yeyiphi ipod ekufuneka iqhagamshelane nayo:
// ExecLocation returns the exec URL for a pod container. If opts.Container is blank
// and only one container is present in the pod, that container is used.
func ExecLocation(
getter ResourceGetter,
connInfo client.ConnectionInfoGetter,
ctx context.Context,
name string,
opts *api.PodExecOptions,
) (*url.URL, http.RoundTripper, error) {
return streamLocation(getter, connInfo, ctx, name, opts, opts.Container, "exec")
}()
Ewe kunjalo, idatha malunga nesiphelo ithathwa kulwazi malunga node:
nodeName := types.NodeName(pod.Spec.NodeName)
if len(nodeName) == 0 {
// If pod has not been assigned a host, return an empty location
return nil, nil, errors.NewBadRequest(fmt.Sprintf("pod %s does not have a host assigned", name))
}
nodeInfo, err := connInfo.GetConnectionInfo(ctx, nodeName)()
Uxolo! I kubelet ngoku inezibuko (node.Status.DaemonEndpoints.KubeletEndpoint.Port), apho iseva ye-API inokunxibelelana khona:
// GetConnectionInfo retrieves connection info from the status of a Node API object.
func (k *NodeConnectionInfoGetter) GetConnectionInfo(ctx context.Context, nodeName types.NodeName) (*ConnectionInfo, error) {
node, err := k.nodes.Get(ctx, string(nodeName), metav1.GetOptions{})
if err != nil {
return nil, err
}
// Find a kubelet-reported address, using preferred address type
host, err := nodeutil.GetPreferredNodeAddress(node, k.preferredAddressTypes)
if err != nil {
return nil, err
}
// Use the kubelet-reported port, if present
port := int(node.Status.DaemonEndpoints.KubeletEndpoint.Port)
if port <= 0 {
port = k.defaultPort
}
return &ConnectionInfo{
Scheme: k.scheme,
Hostname: host,
Port: strconv.Itoa(port),
Transport: k.transport,
}, nil
}()
Ukusuka kumaxwebhu :
Olu qhakamshelwano lwenziwa kwi-kubelet's HTTPS endpoint. Ngokungagqibekanga, i-apiserver ayiqinisekisi isatifikethi se-kubelet, esenza uxhulumaniso lube sesichengeni kuhlaselo lwendoda-phakathi-phakathi (MITM) kwaye engakhuselekanga ngokusebenza kuthungelwano olungathembekanga kunye/okanye lukawonke-wonke.
Ngoku iseva ye-API iyayazi isiphelo kwaye iseka unxibelelwano:
// Connect returns a handler for the pod exec proxy
func (r *ExecREST) Connect(ctx context.Context, name string, opts runtime.Object, responder rest.Responder) (http.Handler, error) {
execOpts, ok := opts.(*api.PodExecOptions)
if !ok {
return nil, fmt.Errorf("invalid options object: %#v", opts)
}
location, transport, err := pod.ExecLocation(r.Store, r.KubeletConn, ctx, name, execOpts)
if err != nil {
return nil, err
}
return newThrottledUpgradeAwareProxyHandler(location, transport, false, true, true, responder), nil
}()
Makhe sibone okwenzekayo kwi-master node.
Okokuqala, sifumanisa i-IP yenode yabasebenzi. Kwimeko yethu yi-192.168.205.11:
// any machine
$ kubectl get nodes k8s-node-1 -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-node-1 Ready <none> 9h v1.15.3 192.168.205.11 <none> Ubuntu 16.04.6 LTS 4.4.0-159-generic docker://17.3.3Emva koko seta i-kubelet port (10250 kwimeko yethu):
// any machine
$ kubectl get nodes k8s-node-1 -o jsonpath='{.status.daemonEndpoints.kubeletEndpoint}'
map[Port:10250]
Ngoku lixesha lokujonga inethiwekhi. Ngaba kukho uxhumano kwi-node yomsebenzi (192.168.205.11)? Yi! Ukuba ubulala inkqubo exec, izakunyamalala, ke ndiyazi ukuba uxhulumaniso lusekwe ngumncedisi we api njengesiphumo somyalelo ophunyeziweyo.
// master node
$ netstat -atn |grep 192.168.205.11
tcp 0 0 192.168.205.10:37870 192.168.205.11:10250 ESTABLISHED
β¦
Udibaniso phakathi kwe-kubectl kunye ne-api-server lusavuliwe. Ukongeza, kukho olunye uxhulumaniso oludibanisa i-api-server kunye ne kubelet.
3. Umsebenzi kwindawo yabasebenzi
Ngoku masiqhagamshele kwindawo yabasebenzi kwaye sibone ukuba kwenzeka ntoni kuyo.
Okokuqala, siyabona ukuba uxhulumaniso kuyo lusekwa (umgca wesibini); 192.168.205.10 yi-IP ye-master node:
// worker node
$ netstat -atn |grep 10250
tcp6 0 0 :::10250 :::* LISTEN
tcp6 0 0 192.168.205.11:10250 192.168.205.10:37870 ESTABLISHED
Kuthekani ngeqela lethu sleep? Khawuleza, ukhona naye!
// worker node
$ ps -afx
...
31463 ? Sl 0:00 _ docker-containerd-shim 7d974065bbb3107074ce31c51f5ef40aea8dcd535ae11a7b8f2dd180b8ed583a /var/run/docker/libcontainerd/7d974065bbb3107074ce31c51
31478 pts/0 Ss 0:00 _ sh
31485 pts/0 S+ 0:00 _ sleep 5000
β¦Kodwa Linda: njani kubelet wayikhupha lento? I-kubelet inedaemon ebonelela ngokufikelela kwi-API ngezibuko kwizicelo ze-api-server:
// Server is the library interface to serve the stream requests.
type Server interface {
http.Handler
// Get the serving URL for the requests.
// Requests must not be nil. Responses may be nil iff an error is returned.
GetExec(*runtimeapi.ExecRequest) (*runtimeapi.ExecResponse, error)
GetAttach(req *runtimeapi.AttachRequest) (*runtimeapi.AttachResponse, error)
GetPortForward(*runtimeapi.PortForwardRequest) (*runtimeapi.PortForwardResponse, error)
// Start the server.
// addr is the address to serve on (address:port) stayUp indicates whether the server should
// listen until Stop() is called, or automatically stop after all expected connections are
// closed. Calling Get{Exec,Attach,PortForward} increments the expected connection count.
// Function does not return until the server is stopped.
Start(stayUp bool) error
// Stop the server, and terminate any open connections.
Stop() error
}()
I-Kubelet ibala isiphelo sempendulo yezicelo ze-exec:
func (s *server) GetExec(req *runtimeapi.ExecRequest) (*runtimeapi.ExecResponse, error) {
if err := validateExecRequest(req); err != nil {
return nil, err
}
token, err := s.cache.Insert(req)
if err != nil {
return nil, err
}
return &runtimeapi.ExecResponse{
Url: s.buildURL("exec", token),
}, nil
}()
Musa ukubhideka. Ayibuyiseli isiphumo somyalelo, kodwa isiphelo sonxibelelwano:
type ExecResponse struct {
// Fully qualified URL of the exec streaming server.
Url string `protobuf:"bytes,1,opt,name=url,proto3" json:"url,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_sizecache int32 `json:"-"`
}()
I-Kubelet isebenzisa ujongano RuntimeServiceClient, eyinxalenye yeNdlela yokuSebenza yeSikhongozeli (sibhale ngakumbi ngayo, umzekelo, - malunga. guqulela.):
Uluhlu olude oluvela kwi-cri-api kwi-kubernetes/kubernetes
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
type RuntimeServiceClient interface {
// Version returns the runtime name, runtime version, and runtime API version.
Version(ctx context.Context, in *VersionRequest, opts ...grpc.CallOption) (*VersionResponse, error)
// RunPodSandbox creates and starts a pod-level sandbox. Runtimes must ensure
// the sandbox is in the ready state on success.
RunPodSandbox(ctx context.Context, in *RunPodSandboxRequest, opts ...grpc.CallOption) (*RunPodSandboxResponse, error)
// StopPodSandbox stops any running process that is part of the sandbox and
// reclaims network resources (e.g., IP addresses) allocated to the sandbox.
// If there are any running containers in the sandbox, they must be forcibly
// terminated.
// This call is idempotent, and must not return an error if all relevant
// resources have already been reclaimed. kubelet will call StopPodSandbox
// at least once before calling RemovePodSandbox. It will also attempt to
// reclaim resources eagerly, as soon as a sandbox is not needed. Hence,
// multiple StopPodSandbox calls are expected.
StopPodSandbox(ctx context.Context, in *StopPodSandboxRequest, opts ...grpc.CallOption) (*StopPodSandboxResponse, error)
// RemovePodSandbox removes the sandbox. If there are any running containers
// in the sandbox, they must be forcibly terminated and removed.
// This call is idempotent, and must not return an error if the sandbox has
// already been removed.
RemovePodSandbox(ctx context.Context, in *RemovePodSandboxRequest, opts ...grpc.CallOption) (*RemovePodSandboxResponse, error)
// PodSandboxStatus returns the status of the PodSandbox. If the PodSandbox is not
// present, returns an error.
PodSandboxStatus(ctx context.Context, in *PodSandboxStatusRequest, opts ...grpc.CallOption) (*PodSandboxStatusResponse, error)
// ListPodSandbox returns a list of PodSandboxes.
ListPodSandbox(ctx context.Context, in *ListPodSandboxRequest, opts ...grpc.CallOption) (*ListPodSandboxResponse, error)
// CreateContainer creates a new container in specified PodSandbox
CreateContainer(ctx context.Context, in *CreateContainerRequest, opts ...grpc.CallOption) (*CreateContainerResponse, error)
// StartContainer starts the container.
StartContainer(ctx context.Context, in *StartContainerRequest, opts ...grpc.CallOption) (*StartContainerResponse, error)
// StopContainer stops a running container with a grace period (i.e., timeout).
// This call is idempotent, and must not return an error if the container has
// already been stopped.
// TODO: what must the runtime do after the grace period is reached?
StopContainer(ctx context.Context, in *StopContainerRequest, opts ...grpc.CallOption) (*StopContainerResponse, error)
// RemoveContainer removes the container. If the container is running, the
// container must be forcibly removed.
// This call is idempotent, and must not return an error if the container has
// already been removed.
RemoveContainer(ctx context.Context, in *RemoveContainerRequest, opts ...grpc.CallOption) (*RemoveContainerResponse, error)
// ListContainers lists all containers by filters.
ListContainers(ctx context.Context, in *ListContainersRequest, opts ...grpc.CallOption) (*ListContainersResponse, error)
// ContainerStatus returns status of the container. If the container is not
// present, returns an error.
ContainerStatus(ctx context.Context, in *ContainerStatusRequest, opts ...grpc.CallOption) (*ContainerStatusResponse, error)
// UpdateContainerResources updates ContainerConfig of the container.
UpdateContainerResources(ctx context.Context, in *UpdateContainerResourcesRequest, opts ...grpc.CallOption) (*UpdateContainerResourcesResponse, error)
// ReopenContainerLog asks runtime to reopen the stdout/stderr log file
// for the container. This is often called after the log file has been
// rotated. If the container is not running, container runtime can choose
// to either create a new log file and return nil, or return an error.
// Once it returns error, new container log file MUST NOT be created.
ReopenContainerLog(ctx context.Context, in *ReopenContainerLogRequest, opts ...grpc.CallOption) (*ReopenContainerLogResponse, error)
// ExecSync runs a command in a container synchronously.
ExecSync(ctx context.Context, in *ExecSyncRequest, opts ...grpc.CallOption) (*ExecSyncResponse, error)
// Exec prepares a streaming endpoint to execute a command in the container.
Exec(ctx context.Context, in *ExecRequest, opts ...grpc.CallOption) (*ExecResponse, error)
// Attach prepares a streaming endpoint to attach to a running container.
Attach(ctx context.Context, in *AttachRequest, opts ...grpc.CallOption) (*AttachResponse, error)
// PortForward prepares a streaming endpoint to forward ports from a PodSandbox.
PortForward(ctx context.Context, in *PortForwardRequest, opts ...grpc.CallOption) (*PortForwardResponse, error)
// ContainerStats returns stats of the container. If the container does not
// exist, the call returns an error.
ContainerStats(ctx context.Context, in *ContainerStatsRequest, opts ...grpc.CallOption) (*ContainerStatsResponse, error)
// ListContainerStats returns stats of all running containers.
ListContainerStats(ctx context.Context, in *ListContainerStatsRequest, opts ...grpc.CallOption) (*ListContainerStatsResponse, error)
// UpdateRuntimeConfig updates the runtime configuration based on the given request.
UpdateRuntimeConfig(ctx context.Context, in *UpdateRuntimeConfigRequest, opts ...grpc.CallOption) (*UpdateRuntimeConfigResponse, error)
// Status returns the status of the runtime.
Status(ctx context.Context, in *StatusRequest, opts ...grpc.CallOption) (*StatusResponse, error)
}
()
Isebenzisa nje i-gRPC ukubiza indlela ngeNdlela yokuSebenza yeSikhongozeli:
type runtimeServiceClient struct {
cc *grpc.ClientConn
}()
func (c *runtimeServiceClient) Exec(ctx context.Context, in *ExecRequest, opts ...grpc.CallOption) (*ExecResponse, error) {
out := new(ExecResponse)
err := c.cc.Invoke(ctx, "/runtime.v1alpha2.RuntimeService/Exec", in, out, opts...)
if err != nil {
return nil, err
}
return out, nil
}()
Ixesha lokuSebenza komgqomo linoxanduva lokuphumeza RuntimeServiceServer:
Uluhlu olude oluvela kwi-cri-api kwi-kubernetes/kubernetes
// RuntimeServiceServer is the server API for RuntimeService service.
type RuntimeServiceServer interface {
// Version returns the runtime name, runtime version, and runtime API version.
Version(context.Context, *VersionRequest) (*VersionResponse, error)
// RunPodSandbox creates and starts a pod-level sandbox. Runtimes must ensure
// the sandbox is in the ready state on success.
RunPodSandbox(context.Context, *RunPodSandboxRequest) (*RunPodSandboxResponse, error)
// StopPodSandbox stops any running process that is part of the sandbox and
// reclaims network resources (e.g., IP addresses) allocated to the sandbox.
// If there are any running containers in the sandbox, they must be forcibly
// terminated.
// This call is idempotent, and must not return an error if all relevant
// resources have already been reclaimed. kubelet will call StopPodSandbox
// at least once before calling RemovePodSandbox. It will also attempt to
// reclaim resources eagerly, as soon as a sandbox is not needed. Hence,
// multiple StopPodSandbox calls are expected.
StopPodSandbox(context.Context, *StopPodSandboxRequest) (*StopPodSandboxResponse, error)
// RemovePodSandbox removes the sandbox. If there are any running containers
// in the sandbox, they must be forcibly terminated and removed.
// This call is idempotent, and must not return an error if the sandbox has
// already been removed.
RemovePodSandbox(context.Context, *RemovePodSandboxRequest) (*RemovePodSandboxResponse, error)
// PodSandboxStatus returns the status of the PodSandbox. If the PodSandbox is not
// present, returns an error.
PodSandboxStatus(context.Context, *PodSandboxStatusRequest) (*PodSandboxStatusResponse, error)
// ListPodSandbox returns a list of PodSandboxes.
ListPodSandbox(context.Context, *ListPodSandboxRequest) (*ListPodSandboxResponse, error)
// CreateContainer creates a new container in specified PodSandbox
CreateContainer(context.Context, *CreateContainerRequest) (*CreateContainerResponse, error)
// StartContainer starts the container.
StartContainer(context.Context, *StartContainerRequest) (*StartContainerResponse, error)
// StopContainer stops a running container with a grace period (i.e., timeout).
// This call is idempotent, and must not return an error if the container has
// already been stopped.
// TODO: what must the runtime do after the grace period is reached?
StopContainer(context.Context, *StopContainerRequest) (*StopContainerResponse, error)
// RemoveContainer removes the container. If the container is running, the
// container must be forcibly removed.
// This call is idempotent, and must not return an error if the container has
// already been removed.
RemoveContainer(context.Context, *RemoveContainerRequest) (*RemoveContainerResponse, error)
// ListContainers lists all containers by filters.
ListContainers(context.Context, *ListContainersRequest) (*ListContainersResponse, error)
// ContainerStatus returns status of the container. If the container is not
// present, returns an error.
ContainerStatus(context.Context, *ContainerStatusRequest) (*ContainerStatusResponse, error)
// UpdateContainerResources updates ContainerConfig of the container.
UpdateContainerResources(context.Context, *UpdateContainerResourcesRequest) (*UpdateContainerResourcesResponse, error)
// ReopenContainerLog asks runtime to reopen the stdout/stderr log file
// for the container. This is often called after the log file has been
// rotated. If the container is not running, container runtime can choose
// to either create a new log file and return nil, or return an error.
// Once it returns error, new container log file MUST NOT be created.
ReopenContainerLog(context.Context, *ReopenContainerLogRequest) (*ReopenContainerLogResponse, error)
// ExecSync runs a command in a container synchronously.
ExecSync(context.Context, *ExecSyncRequest) (*ExecSyncResponse, error)
// Exec prepares a streaming endpoint to execute a command in the container.
Exec(context.Context, *ExecRequest) (*ExecResponse, error)
// Attach prepares a streaming endpoint to attach to a running container.
Attach(context.Context, *AttachRequest) (*AttachResponse, error)
// PortForward prepares a streaming endpoint to forward ports from a PodSandbox.
PortForward(context.Context, *PortForwardRequest) (*PortForwardResponse, error)
// ContainerStats returns stats of the container. If the container does not
// exist, the call returns an error.
ContainerStats(context.Context, *ContainerStatsRequest) (*ContainerStatsResponse, error)
// ListContainerStats returns stats of all running containers.
ListContainerStats(context.Context, *ListContainerStatsRequest) (*ListContainerStatsResponse, error)
// UpdateRuntimeConfig updates the runtime configuration based on the given request.
UpdateRuntimeConfig(context.Context, *UpdateRuntimeConfigRequest) (*UpdateRuntimeConfigResponse, error)
// Status returns the status of the runtime.
Status(context.Context, *StatusRequest) (*StatusResponse, error)
}
()
Ukuba kunjalo, kufuneka sibone unxibelelwano phakathi kwe-kubelet kunye ne-runtime yesikhongozeli, akunjalo? Makhe sijonge.
Sebenzisa lo myalelo ngaphambi nasemva komyalelo we-exec kwaye ujonge umahluko. Kwimeko yam umahluko kukuba:
// worker node
$ ss -a -p |grep kubelet
...
u_str ESTAB 0 0 * 157937 * 157387 users:(("kubelet",pid=5714,fd=33))
...Hmmm... Udibaniso olutsha olusebenzisa iisokethi ze-unix phakathi kwe-kubelet (pid=5714) kunye nento engaziwayo. Inokuba yintoni? Kulungile, yiDocker (pid=1186)!
// worker node
$ ss -a -p |grep 157387
...
u_str ESTAB 0 0 * 157937 * 157387 users:(("kubelet",pid=5714,fd=33))
u_str ESTAB 0 0 /var/run/docker.sock 157387 * 157937 users:(("dockerd",pid=1186,fd=14))
...Njengoko ukhumbula, le yinkqubo ye-docker daemon (pid=1186) eyenza umyalelo wethu:
// worker node
$ ps -afx
...
1186 ? Ssl 0:55 /usr/bin/dockerd -H fd://
17784 ? Sl 0:00 _ docker-containerd-shim 53a0a08547b2f95986402d7f3b3e78702516244df049ba6c5aa012e81264aa3c /var/run/docker/libcontainerd/53a0a08547b2f95986402d7f3
17801 pts/2 Ss 0:00 _ sh
17827 pts/2 S+ 0:00 _ sleep 5000
...4. Umsebenzi kwisikhongozeli sexesha lokuqhuba
Makhe sihlolisise ikhowudi yomthombo we-CRI-O ukuze siqonde ukuba kuqhubeka ntoni. Kwi-Docker ingqiqo iyafana.
Kukho umncedisi onoxanduva lokuphunyezwa RuntimeServiceServer:
// Server implements the RuntimeService and ImageService
type Server struct {
config libconfig.Config
seccompProfile *seccomp.Seccomp
stream StreamService
netPlugin ocicni.CNIPlugin
hostportManager hostport.HostPortManager
appArmorProfile string
hostIP string
bindAddress string
*lib.ContainerServer
monitorsChan chan struct{}
defaultIDMappings *idtools.IDMappings
systemContext *types.SystemContext // Never nil
updateLock sync.RWMutex
seccompEnabled bool
appArmorEnabled bool
}()
// Exec prepares a streaming endpoint to execute a command in the container.
func (s *Server) Exec(ctx context.Context, req *pb.ExecRequest) (resp *pb.ExecResponse, err error) {
const operation = "exec"
defer func() {
recordOperation(operation, time.Now())
recordError(operation, err)
}()
resp, err = s.getExec(req)
if err != nil {
return nil, fmt.Errorf("unable to prepare exec endpoint: %v", err)
}
return resp, nil
}()
Ekupheleni kwekhonkco, ixesha lokuqhuba isikhongozeli liphumeza umyalelo kwindawo yabasebenzi:
// ExecContainer prepares a streaming endpoint to execute a command in the container.
func (r *runtimeOCI) ExecContainer(c *Container, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize) error {
processFile, err := prepareProcessExec(c, cmd, tty)
if err != nil {
return err
}
defer os.RemoveAll(processFile.Name())
args := []string{rootFlag, r.root, "exec"}
args = append(args, "--process", processFile.Name(), c.ID())
execCmd := exec.Command(r.path, args...)
if v, found := os.LookupEnv("XDG_RUNTIME_DIR"); found {
execCmd.Env = append(execCmd.Env, fmt.Sprintf("XDG_RUNTIME_DIR=%s", v))
}
var cmdErr, copyError error
if tty {
cmdErr = ttyCmd(execCmd, stdin, stdout, resize)
} else {
if stdin != nil {
// Use an os.Pipe here as it returns true *os.File objects.
// This way, if you run 'kubectl exec <pod> -i bash' (no tty) and type 'exit',
// the call below to execCmd.Run() can unblock because its Stdin is the read half
// of the pipe.
r, w, err := os.Pipe()
if err != nil {
return err
}
go func() { _, copyError = pools.Copy(w, stdin) }()
execCmd.Stdin = r
}
if stdout != nil {
execCmd.Stdout = stdout
}
if stderr != nil {
execCmd.Stderr = stderr
}
cmdErr = execCmd.Run()
}
if copyError != nil {
return copyError
}
if exitErr, ok := cmdErr.(*exec.ExitError); ok {
return &utilexec.ExitErrorWrapper{ExitError: exitErr}
}
return cmdErr
}()
Ekugqibeleni, i-kernel iphumeza imiyalelo:
Izikhumbuzo
- Umncedisi we API unokuqalisa umdibaniso kwi kubelet.
- Olu qhakamshelwano lulandelayo luyaqhuba de kuphele iseshoni ye-interactive exec:
- phakathi kwe-kubectl kunye ne-api-server;
- phakathi kwe-api-server kunye ne-kubectl;
- phakathi kwe-kubelet kunye nexesha lokuqhuba lesikhongozeli.
- I-Kubectl okanye i-api-server ayinakuqhuba nantoni na kwiindawo zabasebenzi. I-Kubelet inokubaleka, kodwa iphinda inxibelelane nexesha lokuqhuba isikhongozeli ukwenza ezo zinto.
Izibonelelo
- Ingxoxo "" kwi kubernetes-dev;
- Inqaku "";
- Ingxoxo ""kwiFault yomncedisi.
PS evela kumguquleli
Funda nakwibhlog yethu:
- "Kwenzeka ntoni eKubernetes xa ubaleka kubectl run?" ΠΈ ;
- Β«";
- Β«";
- «».
umthombo: www.habr.com