ማስታወሻ. ትርጉምየጽሁፉ ደራሲ - ኤርካን ኤሮል, የ SAP መሐንዲስ - የቡድኑን የአሠራር ዘዴዎች ጥናቱን ያካፍላል. kubectl exec, ከ Kubernetes ጋር ለሚሰሩ ሁሉ በጣም የተለመዱ. እሱ ሙሉውን ስልተ ቀመር ከ Kubernetes ምንጭ ኮድ (እና ተዛማጅ ፕሮጄክቶች) ዝርዝሮች ጋር አብሮ ይሄዳል ፣ ይህም ርዕሱን እንደ አስፈላጊነቱ በጥልቀት እንዲገነዘቡ ያስችልዎታል።
አንድ አርብ፣ አንድ የሥራ ባልደረባዬ ወደ እኔ ቀረበና እንዴት ተጠቅሞ ትእዛዝ በፖድ ውስጥ እንደሚፈጸም ጠየቀኝ። . ለእሱ መልስ መስጠት አልቻልኩም እና በድንገት ስለ ሥራው አሠራር ምንም እንደማላውቅ ተረዳሁ kubectl exec. አዎን, ስለ መሳሪያው አንዳንድ ሀሳቦች ነበሩኝ, ነገር ግን ስለ ትክክለኛነታቸው 100% እርግጠኛ አልነበርኩም እና ስለዚህ ይህንን ችግር ለመፍታት ወሰንኩ. ብሎጎችን፣ ሰነዶችን እና የምንጭ ኮድን በማጥናቴ ብዙ ተምሬያለሁ፣ እና በዚህ ጽሑፍ ውስጥ ግኝቶቼን እና ግንዛቤዬን ማካፈል እፈልጋለሁ። የሆነ ችግር ካለ፣ እባክዎን በ ላይ ያግኙኝ። .
ዝግጅት
በማክቡክ ላይ ክላስተር ለመፍጠር፣ ዘጋሁት . ከዚያ ነባሪ ቅንጅቶች ስላልፈቀዱ በ kubelet'a config ውስጥ ያሉትን የአንጓዎቹን የአይፒ አድራሻዎች አስተካክያለሁ kubectl exec. ለዚህ ዋና ምክንያት የበለጠ ማንበብ ይችላሉ .
- ማንኛውም ማሽን = የእኔ MacBook
- ዋና መስቀለኛ መንገድ IP = 192.168.205.10
- የአይፒ ሰራተኛ መስቀለኛ መንገድ = 192.168.205.11
- የኤፒአይ አገልጋይ ወደብ = 6443
ክፍለ አካላት
- kubectl exec ሂደት: "kubectl exec..." ስናደርግ ሂደቱ ተጀምሯል. ይህንን የK8s API አገልጋይ መዳረሻ ባለው በማንኛውም ማሽን ላይ ማድረግ ይችላሉ። ማስታወሻ. ትርጉም: በተጨማሪ በኮንሶል ዝርዝሮች ውስጥ ደራሲው "ማንኛውም ማሽን" የሚለውን አስተያየት ይጠቀማል, ይህም የሚከተሉትን ትዕዛዞች ወደ ኩበርኔትስ በሚደርሱ ማሽኖች ላይ ሊፈጸሙ ይችላሉ.
- የኩበርኔትስ ኤፒአይ መዳረሻን የሚያቀርብ በዋናው መስቀለኛ መንገድ ላይ ያለ አካል። ይህ በኩበርኔትስ ውስጥ ላለው መቆጣጠሪያ አውሮፕላን የፊት ለፊት ጫፍ ነው።
- በክላስተር ውስጥ በእያንዳንዱ መስቀለኛ መንገድ ላይ የሚሰራ ወኪል። በፖዳው ውስጥ የእቃ መያዣዎችን ሥራ ያቀርባል.
- (የመያዣ ጊዜ)፡ ኮንቴይነሮችን ለማስኬድ ኃላፊነት ያለው ሶፍትዌር። ምሳሌዎች፡ ዶከር፣ CRI-O፣ በኮንቴይነር…
- ጥሬበሠራተኛው መስቀለኛ መንገድ ላይ የስርዓተ ክወና ከርነል; ለሂደቱ አስተዳደር ኃላፊነት ያለው.
- ዒላማ (ዒላማ) እቃ: የፖድ አካል የሆነ እና በአንዱ ሰራተኛ አንጓዎች ላይ የሚሰራ መያዣ.
ምን አገኘሁ
1. በደንበኛው በኩል ያለው እንቅስቃሴ
በስም ቦታ ውስጥ ፖድ ይፍጠሩ default:
// any machine
$ kubectl run exec-test-nginx --image=nginxከዚያ የ exec ትዕዛዙን እንፈጽማለን እና ለተጨማሪ ምልከታዎች 5000 ሰከንዶች እንጠብቃለን-
// any machine
$ kubectl exec -it exec-test-nginx-6558988d5-fgxgg -- sh
# sleep 5000የ kubectl ሂደት ይታያል (በእኛ ሁኔታ ከ pid=8507 ጋር)
// any machine
$ ps -ef |grep kubectl
501 8507 8409 0 7:19PM ttys000 0:00.13 kubectl exec -it exec-test-nginx-6558988d5-fgxgg -- shየሂደቱን የኔትወርክ እንቅስቃሴ ካረጋገጥን ከኤፒ-ሰርቨር (192.168.205.10.6443) ጋር ግንኙነት እንዳለው እናገኘዋለን።
// 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 0x00000028ኮዱን እንይ። Kubectl የPOST ጥያቄን ከexec ንዑስ ምንጭ ጋር ይፈጥራል እና የREST ጥያቄን ይልካል፡
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. ከዋናው መስቀለኛ መንገድ ጎን ያለው እንቅስቃሴ
በ api-server በኩል ያለውን ጥያቄ መመልከት እንችላለን፡-
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]]የኤችቲቲፒ ጥያቄ የፕሮቶኮል ለውጥ ጥያቄን እንደሚያካትት ልብ ይበሉ። የተለያዩ የ stdin/stdout/stderr/spdy-ስህተት "ዥረቶች" በአንድ TCP ግንኙነት ላይ እንዲባዙ ይፈቅዳል።
የኤፒአይ አገልጋይ ጥያቄውን ተቀብሎ ወደ ይለውጠዋል 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
}()
አስፈላጊዎቹን ድርጊቶች ለመፈጸም አፒ-አገልጋዩ የትኛውን ፖድ ማግኘት እንዳለበት ማወቅ አለበት፡-
// 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")
}()
በእርግጥ ፣ ስለ መጨረሻው ነጥብ ያለው መረጃ ስለ መስቀለኛ መንገድ ካለው መረጃ የተወሰደ ነው-
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)()
ሆሬ! ኩቤሌት አሁን ወደብ አለው (node.Status.DaemonEndpoints.KubeletEndpoint.Port) የኤፒአይ አገልጋይ የሚያገናኘው፡-
// 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
}()
ከሰነድ :
እነዚህ ግንኙነቶች በ kubelet HTTPS የመጨረሻ ነጥብ ላይ ይቋረጣሉ። በነባሪ፣ አፒሰርቨር የ kubelet ሰርተፍኬት አያረጋግጥም፣ ይህም ግንኙነቱን ለ"ሰው-በመካከለኛው ጥቃት"(MITM) እና ተጋላጭ ያደርገዋል። ደህንነቱ ያልተጠበቀ በማይታመን እና/ወይም የህዝብ አውታረ መረቦች ውስጥ ለመስራት።
አሁን የኤፒአይ አገልጋይ የመጨረሻ ነጥቡን ያውቃል እና ግንኙነት ይመሰርታል፡
// 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
}()
በማስተር መስቀለኛ መንገድ ላይ ምን እንደሚፈጠር እንይ.
በመጀመሪያ የስራ መስቀለኛ መንገድን IP ይወቁ. በእኛ ሁኔታ ይህ 192.168.205.11 ነው:
// 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://17.3.3ከዚያ የኩቤሌት ወደብ ያዘጋጁ (በእኛ ሁኔታ 10250)
// any machine
$ kubectl get nodes k8s-node-1 -o jsonpath='{.status.daemonEndpoints.kubeletEndpoint}'
map[Port:10250]
አሁን አውታረ መረቡን ለመሞከር ጊዜው አሁን ነው። ከሠራተኛው መስቀለኛ መንገድ (192.168.205.11) ጋር ግንኙነት አለ? ነው! ሂደቱን "ከገደሉ". exec, ይጠፋል, ስለዚህ ግንኙነቱ በ api-server የተቋቋመው በተፈፀመው የexec ትዕዛዝ ምክንያት መሆኑን አውቃለሁ.
// master node
$ netstat -atn |grep 192.168.205.11
tcp 0 0 192.168.205.10:37870 192.168.205.11:10250 ESTABLISHED
…
በ kubectl እና api-server መካከል ያለው ግንኙነት አሁንም ክፍት ነው። በተጨማሪም, api-server እና kubelet የሚያገናኝ ሌላ ግንኙነት አለ.
3. በሠራተኛ መስቀለኛ መንገድ ላይ ያለ እንቅስቃሴ
አሁን ከሰራተኛው መስቀለኛ መንገድ ጋር እንገናኝ እና በእሱ ላይ ምን እየተፈጠረ እንዳለ ይመልከቱ።
በመጀመሪያ ደረጃ, ከእሱ ጋር ያለው ግንኙነት እንዲሁ የተመሰረተ መሆኑን እናያለን (ሁለተኛ መስመር); 192.168.205.10 የዋናው መስቀለኛ መንገድ አይፒ ነው፡-
// 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
ስለ ቡድናችንስ? sleep? ሁሬ፣ እሷም እዚያ ነች!
// 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
…ቆይ ግን ኩበሌት ይህን እንዴት አነሳው? Kubelet ለኤፒ አገልጋይ ጥያቄዎች በወደብ በኩል የኤፒአይ መዳረሻን የሚከፍት ዴሞን አለው።
// 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
}()
ኩቤሌት የexec ጥያቄዎችን የምላሽ የመጨረሻ ነጥብ ያሰላል፡-
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
}()
ግራ አትጋቡ። የትዕዛዙን ውጤት አይመልስም ፣ ግን የግንኙነቱ የመጨረሻ ነጥብ
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:"-"`
}()
ኩቤሌት በይነገጽ ይተገብራል። RuntimeServiceClientየኮንቴይነር Runtime በይነገጽ አካል የሆነው (ስለ እሱ የበለጠ ጽፈናል ፣ ለምሳሌ ፣ - በግምት. መተርጎም):
ረጅም ዝርዝር ከcri-api በkubernetes/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)
}
()
ዘዴውን በኮንቴይነር አሂድ ጊዜ በይነገጽ ለመጥራት gRPCን ብቻ ይጠቀማል፡-
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
}()
ኮንቴይነር Runtime ለትግበራው ተጠያቂ ነው። RuntimeServiceServer:
ረጅም ዝርዝር ከcri-api በkubernetes/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)
}
()
ከሆነ፣ በ kubelet እና በኮንቴይነር አሂድ ጊዜ መካከል ያለውን ግንኙነት ማየት አለብን፣ አይደል? እንፈትሽ።
ይህንን ትእዛዝ ከexec ትዕዛዝ በፊት እና በኋላ ያሂዱ እና ልዩነቱን ይመልከቱ። በእኔ ሁኔታ ልዩነቱ፡-
// worker node
$ ss -a -p |grep kubelet
...
u_str ESTAB 0 0 * 157937 * 157387 users:(("kubelet",pid=5714,fd=33))
...እም… አዲስ የዩኒክስ ሶኬት ግንኙነት በኩቤሌት (pid=5714) እና ባልታወቀ ነገር መካከል። ምን ሊሆን ይችላል? ልክ ነው፣ ዶከር ነው (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))
...እንደምታስታውሱት፣ ትዕዛዛችንን የሚያስፈጽም ይህ የዶከር ዴሞን ሂደት (pid=1186) ነው።
// 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. በመያዣው ውስጥ ያለው እንቅስቃሴ የአሂድ ጊዜ
ምን እየተካሄደ እንዳለ ለመረዳት የCRI-O ምንጭ ኮድን እንመርምር። በዶከር ውስጥ, አመክንዮው ተመሳሳይ ነው.
ለትግበራው ኃላፊነት ያለው አገልጋይ አለ። 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
}()
በሰንሰለቱ መጨረሻ ላይ የእቃ መያዣው የሩጫ ጊዜ በሠራተኛው መስቀለኛ መንገድ ላይ ትዕዛዙን ይፈጽማል-
// 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
}()
በመጨረሻም ከርነል ትእዛዞቹን ይፈጽማል፡-
አስታዋሾች
- የኤ.ፒ.አይ. አገልጋይ ከ kubelet ጋር ግንኙነት መጀመር ይችላል።
- የሚከተሉት ግንኙነቶች መስተጋብራዊ exec ክፍለ ጊዜ መጨረሻ ድረስ ይቆያሉ:
- በ kubectl እና api-server መካከል;
- በ api-server እና kubectl መካከል;
- በ kubelet እና በእቃ መጫኛ ጊዜ መካከል.
- Kubectl ወይም api-server በሠራተኛ ኖዶች ላይ ምንም ነገር ማሄድ አይችሉም። ኩቤሌት መሮጥ ይችላል፣ ነገር ግን ለእነዚህ ድርጊቶች ከመያዣው የሩጫ ጊዜ ጋር ይገናኛል።
መርጃዎች
- ውይይት "»በ kubernetes-dev;
- አንቀፅ "";
- ውይይት "» በአገልጋይ ስህተት ላይ።
PS ከተርጓሚ
በብሎጋችን ላይ ያንብቡ፡-
- "Kubectl Run ን ሲሮጡ በኩበርኔትስ ውስጥ ምን ይከሰታል?" и ;
- «";
- «";
- «».
ምንጭ: hab.com