agola/internal/services/executor/driver/k8s.go

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// Copyright 2019 Sorint.lab
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
// See the License for the specific language governing permissions and
// limitations under the License.
package driver
import (
"bytes"
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"context"
"encoding/json"
"fmt"
"io"
"path/filepath"
"regexp"
"strconv"
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"strings"
"time"
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"agola.io/agola/internal/common"
"agola.io/agola/internal/util"
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"github.com/docker/docker/pkg/archive"
uuid "github.com/satori/go.uuid"
"go.uber.org/zap"
errors "golang.org/x/xerrors"
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corev1 "k8s.io/api/core/v1"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
apilabels "k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/client-go/informers"
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"k8s.io/client-go/kubernetes"
"k8s.io/client-go/kubernetes/scheme"
corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
coordinationlistersv1 "k8s.io/client-go/listers/coordination/v1"
listerscorev1 "k8s.io/client-go/listers/core/v1"
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restclient "k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/remotecommand"
utilexec "k8s.io/utils/exec"
)
const (
mainContainerName = "maincontainer"
configMapName = "agola-executors-group"
executorLeasePrefix = "agola-executor-"
podNamePrefix = "agola-task-"
executorsGroupIDKey = labelPrefix + "executorsgroupid"
executorsGroupIDConfigMapKey = "executorsgroupid"
cmLeaseKey = labelPrefix + "lease"
renewExecutorLeaseInterval = 10 * time.Second
staleExecutorLeaseInterval = 1 * time.Minute
informerResyncInterval = 10 * time.Second
k8sLabelArchBeta = "beta.kubernetes.io/arch"
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)
type K8sDriver struct {
log *zap.SugaredLogger
restconfig *restclient.Config
client *kubernetes.Clientset
toolboxPath string
namespace string
executorID string
executorsGroupID string
useLeaseAPI bool
nodeLister listerscorev1.NodeLister
podLister listerscorev1.PodLister
cmLister listerscorev1.ConfigMapLister
leaseLister coordinationlistersv1.LeaseLister
k8sLabelArch string
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}
type K8sPod struct {
id string
namespace string
labels map[string]string
restconfig *restclient.Config
client *kubernetes.Clientset
initVolumeDir string
}
func NewK8sDriver(logger *zap.Logger, executorID, toolboxPath string) (*K8sDriver, error) {
kubeClientConfig := NewKubeClientConfig("", "", "")
kubecfg, err := kubeClientConfig.ClientConfig()
if err != nil {
return nil, err
}
kubecli, err := kubernetes.NewForConfig(kubecfg)
if err != nil {
return nil, fmt.Errorf("cannot create kubernetes client: %v", err)
}
namespace, _, err := kubeClientConfig.Namespace()
if err != nil {
return nil, err
}
d := &K8sDriver{
log: logger.Sugar(),
restconfig: kubecfg,
client: kubecli,
toolboxPath: toolboxPath,
namespace: namespace,
executorID: executorID,
k8sLabelArch: corev1.LabelArchStable,
}
serverVersion, err := d.client.Discovery().ServerVersion()
if err != nil {
return nil, err
}
sv, err := parseGitVersion(serverVersion.GitVersion)
// if server version parsing fails just warn but ignore it
if err != nil {
d.log.Warnf("failed to parse k8s server version: %v", err)
}
if sv != nil {
// for k8s version < v1.14.x use old arch label
if sv.Major == 1 && sv.Minor < 14 {
d.k8sLabelArch = k8sLabelArchBeta
}
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}
lists, err := d.client.Discovery().ServerPreferredResources()
if err != nil {
return nil, err
}
hasLeaseAPI := false
for _, list := range lists {
if len(list.APIResources) == 0 {
continue
}
if list.GroupVersion != "coordination.k8s.io/v1" {
continue
}
for _, apiResource := range list.APIResources {
if apiResource.Kind == "Lease" {
hasLeaseAPI = true
}
}
}
d.useLeaseAPI = hasLeaseAPI
executorsGroupID, err := d.getOrCreateExecutorsGroupID(context.TODO())
if err != nil {
return nil, err
}
d.executorsGroupID = executorsGroupID
ctx := context.TODO()
factory := informers.NewSharedInformerFactoryWithOptions(d.client, informerResyncInterval, informers.WithNamespace(d.namespace))
nodeInformer := factory.Core().V1().Nodes()
d.nodeLister = nodeInformer.Lister()
go nodeInformer.Informer().Run(ctx.Done())
podInformer := factory.Core().V1().Pods()
d.podLister = podInformer.Lister()
go podInformer.Informer().Run(ctx.Done())
if d.useLeaseAPI {
leaseInformer := factory.Coordination().V1().Leases()
d.leaseLister = leaseInformer.Lister()
go leaseInformer.Informer().Run(ctx.Done())
} else {
cmInformer := factory.Core().V1().ConfigMaps()
d.cmLister = cmInformer.Lister()
go cmInformer.Informer().Run(ctx.Done())
}
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go func() {
for {
if err := d.updateLease(ctx); err != nil {
d.log.Errorf("failed to update executor lease: %+v", err)
}
select {
case <-ctx.Done():
return
default:
}
time.Sleep(renewExecutorLeaseInterval)
}
}()
go func() {
for {
if err := d.cleanStaleExecutorsLease(ctx); err != nil {
d.log.Errorf("failed to clean stale executors lease: %+v", err)
}
select {
case <-ctx.Done():
return
default:
}
time.Sleep(renewExecutorLeaseInterval)
}
}()
return d, nil
}
// NewKubeClientConfig return a kube client config that will by default use an
// in cluster client config or, if not available or overriden an external client
// config using the default client behavior used also by kubectl.
func NewKubeClientConfig(kubeconfigPath, context, namespace string) clientcmd.ClientConfig {
rules := clientcmd.NewDefaultClientConfigLoadingRules()
rules.DefaultClientConfig = &clientcmd.DefaultClientConfig
if kubeconfigPath != "" {
rules.ExplicitPath = kubeconfigPath
}
overrides := &clientcmd.ConfigOverrides{ClusterDefaults: clientcmd.ClusterDefaults}
if context != "" {
overrides.CurrentContext = context
}
if namespace != "" {
overrides.Context.Namespace = namespace
}
return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(rules, overrides)
}
func (d *K8sDriver) Setup(ctx context.Context) error {
return nil
}
func (d *K8sDriver) Archs(ctx context.Context) ([]common.Arch, error) {
// TODO(sgotti) use go client listers instead of querying every time
nodes, err := d.nodeLister.List(apilabels.SelectorFromSet(nil))
if err != nil {
return nil, err
}
archsMap := map[common.Arch]struct{}{}
archs := []common.Arch{}
for _, node := range nodes {
archsMap[common.ArchFromString(node.Status.NodeInfo.Architecture)] = struct{}{}
}
for arch := range archsMap {
archs = append(archs, arch)
}
return archs, nil
}
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func (d *K8sDriver) ExecutorGroup(ctx context.Context) (string, error) {
return d.executorsGroupID, nil
}
func (d *K8sDriver) GetExecutors(ctx context.Context) ([]string, error) {
return d.getLeases((ctx))
}
// executorsGroups gets or creates (if it doesn't exists) a configmap under
// the k8s namespace where the executorsgroup id is saved. The executorsgroupid
// is unique per k8s namespace and is shared by all the executors accessing this
// namespace
func (d *K8sDriver) getOrCreateExecutorsGroupID(ctx context.Context) (string, error) {
cmClient := d.client.CoreV1().ConfigMaps(d.namespace)
// pod and secret name, based on pod id
cm, err := cmClient.Get(configMapName, metav1.GetOptions{})
if err != nil {
if !apierrors.IsNotFound(err) {
return "", err
}
} else {
return cm.Data[executorsGroupIDConfigMapKey], nil
}
executorsGroupID := uuid.NewV4().String()
cm = &corev1.ConfigMap{
ObjectMeta: metav1.ObjectMeta{
Name: configMapName,
},
Data: map[string]string{executorsGroupIDConfigMapKey: executorsGroupID},
}
if _, err = cmClient.Create(cm); err != nil {
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return "", err
}
return executorsGroupID, nil
}
func (d *K8sDriver) NewPod(ctx context.Context, podConfig *PodConfig, out io.Writer) (Pod, error) {
if len(podConfig.Containers) == 0 {
return nil, errors.Errorf("empty container config")
}
secretClient := d.client.CoreV1().Secrets(d.namespace)
podClient := d.client.CoreV1().Pods(d.namespace)
labels := map[string]string{}
labels[agolaLabelKey] = agolaLabelValue
labels[podIDKey] = podConfig.ID
labels[taskIDKey] = podConfig.TaskID
labels[executorIDKey] = d.executorID
labels[executorsGroupIDKey] = d.executorsGroupID
dockerconfigj, err := json.Marshal(podConfig.DockerConfig)
if err != nil {
return nil, err
}
// pod and secret name, based on pod id
name := podNamePrefix + podConfig.ID
// secret that hold the docker registry auth
secret := &corev1.Secret{
ObjectMeta: metav1.ObjectMeta{
Name: name,
Labels: labels,
},
Data: map[string][]byte{
".dockerconfigjson": dockerconfigj,
},
Type: corev1.SecretTypeDockerConfigJson,
}
_, err = secretClient.Create(secret)
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if err != nil {
return nil, err
}
pod := &corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
Namespace: d.namespace,
Name: name,
Labels: labels,
},
Spec: corev1.PodSpec{
ImagePullSecrets: []corev1.LocalObjectReference{{Name: name}},
// don't mount service account secrets or pods will be able to talk with k8s
// api
AutomountServiceAccountToken: util.BoolP(false),
InitContainers: []corev1.Container{
{
Name: "initcontainer",
Image: "busybox",
// wait for a file named /tmp/done and then exit
Command: []string{"/bin/sh", "-c", "while true; do if [[ -f /tmp/done ]]; then exit; fi; sleep 1; done"},
Stdin: true,
VolumeMounts: []corev1.VolumeMount{
{
Name: "agolavolume",
MountPath: podConfig.InitVolumeDir,
},
},
},
},
Containers: []corev1.Container{},
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Volumes: []corev1.Volume{
{
Name: "agolavolume",
VolumeSource: corev1.VolumeSource{
EmptyDir: &corev1.EmptyDirVolumeSource{},
},
},
},
},
}
// define containers
for cIndex, containerConfig := range podConfig.Containers {
var containerName string
if cIndex == 0 {
containerName = mainContainerName
} else {
containerName = fmt.Sprintf("service%d", cIndex)
}
c := corev1.Container{
Name: containerName,
Image: containerConfig.Image,
Command: containerConfig.Cmd,
Env: genEnvVars(containerConfig.Env),
Stdin: true,
WorkingDir: containerConfig.WorkingDir,
// by default always try to pull the image so we are sure only authorized users can fetch them
// see https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#alwayspullimages
ImagePullPolicy: corev1.PullAlways,
SecurityContext: &corev1.SecurityContext{
Privileged: &containerConfig.Privileged,
},
}
if cIndex == 0 {
// main container requires the initvolume containing the toolbox
c.VolumeMounts = []corev1.VolumeMount{
{
Name: "agolavolume",
MountPath: podConfig.InitVolumeDir,
ReadOnly: true,
},
}
}
pod.Spec.Containers = append(pod.Spec.Containers, c)
}
if podConfig.Arch != "" {
pod.Spec.NodeSelector = map[string]string{
d.k8sLabelArch: string(podConfig.Arch),
}
}
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pod, err = podClient.Create(pod)
if err != nil {
return nil, err
}
watcher, err := podClient.Watch(
metav1.SingleObject(pod.ObjectMeta),
)
if err != nil {
return nil, err
}
// wait for init container to be ready
for event := range watcher.ResultChan() {
switch event.Type {
case watch.Modified:
pod := event.Object.(*corev1.Pod)
if len(pod.Status.InitContainerStatuses) > 0 {
if pod.Status.InitContainerStatuses[0].State.Running != nil {
watcher.Stop()
}
}
case watch.Deleted:
return nil, errors.Errorf("pod %q has been deleted", pod.Name)
}
}
fmt.Fprintf(out, "init container ready\n")
coreclient, err := corev1client.NewForConfig(d.restconfig)
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if err != nil {
return nil, err
}
// get the pod arch
req := coreclient.RESTClient().
Post().
Namespace(pod.Namespace).
Resource("pods").
Name(pod.Name).
SubResource("exec").
VersionedParams(&corev1.PodExecOptions{
Container: "initcontainer",
Command: []string{"uname", "-m"},
Stdout: true,
Stderr: true,
TTY: false,
}, scheme.ParameterCodec)
exec, err := remotecommand.NewSPDYExecutor(d.restconfig, "POST", req.URL())
if err != nil {
return nil, errors.Errorf("failed to generate k8s client spdy executor for url %q, method: POST: %w", req.URL(), err)
}
stdout := bytes.Buffer{}
err = exec.Stream(remotecommand.StreamOptions{
Stdout: &stdout,
Stderr: out,
})
if err != nil {
return nil, errors.Errorf("failed to execute command on initcontainer: %w", err)
}
osArch := strings.TrimSpace(stdout.String())
var arch common.Arch
switch osArch {
case "x86_64":
arch = common.ArchAMD64
case "aarch64":
arch = common.ArchARM64
default:
return nil, errors.Errorf("unsupported pod arch %q", osArch)
}
// copy the toolbox for the pod arch
toolboxExecPath, err := toolboxExecPath(d.toolboxPath, arch)
if err != nil {
return nil, errors.Errorf("failed to get toolbox path for arch %q: %w", arch, err)
}
srcInfo, err := archive.CopyInfoSourcePath(toolboxExecPath, false)
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if err != nil {
return nil, err
}
srcInfo.RebaseName = "agola-toolbox"
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srcArchive, err := archive.TarResource(srcInfo)
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if err != nil {
return nil, err
}
defer srcArchive.Close()
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req = coreclient.RESTClient().
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Post().
Namespace(pod.Namespace).
Resource("pods").
Name(pod.Name).
SubResource("exec").
VersionedParams(&corev1.PodExecOptions{
Container: "initcontainer",
Command: []string{"tar", "xf", "-", "-C", podConfig.InitVolumeDir},
Stdin: true,
Stdout: true,
Stderr: true,
TTY: false,
}, scheme.ParameterCodec)
exec, err = remotecommand.NewSPDYExecutor(d.restconfig, "POST", req.URL())
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if err != nil {
return nil, errors.Errorf("failed to generate k8s client spdy executor for url %q, method: POST: %w", req.URL(), err)
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}
fmt.Fprintf(out, "extracting toolbox\n")
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err = exec.Stream(remotecommand.StreamOptions{
Stdin: srcArchive,
Stdout: out,
Stderr: out,
})
if err != nil {
return nil, errors.Errorf("failed to execute command on initcontainer: %w", err)
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}
fmt.Fprintf(out, "extracting toolbox done\n")
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req = coreclient.RESTClient().
Post().
Namespace(pod.Namespace).
Resource("pods").
Name(pod.Name).
SubResource("exec").
VersionedParams(&corev1.PodExecOptions{
Container: "initcontainer",
Command: []string{"touch", "/tmp/done"},
Stdout: true,
Stderr: true,
TTY: false,
}, scheme.ParameterCodec)
exec, err = remotecommand.NewSPDYExecutor(d.restconfig, "POST", req.URL())
if err != nil {
return nil, errors.Errorf("failed to generate k8s client spdy executor for url %q, method: POST: %w", req.URL(), err)
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}
err = exec.Stream(remotecommand.StreamOptions{
Stdout: out,
Stderr: out,
})
if err != nil {
return nil, errors.Errorf("failed to execute command on initcontainer: %w", err)
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}
watcher, err = podClient.Watch(
metav1.SingleObject(pod.ObjectMeta),
)
if err != nil {
return nil, err
}
// wait for pod to be initialized
for event := range watcher.ResultChan() {
switch event.Type {
case watch.Modified:
pod := event.Object.(*corev1.Pod)
if len(pod.Status.ContainerStatuses) > 0 {
if pod.Status.ContainerStatuses[0].State.Running != nil {
watcher.Stop()
}
}
case watch.Deleted:
return nil, errors.Errorf("pod %q has been deleted", pod.Name)
}
}
return &K8sPod{
id: pod.Name,
namespace: pod.Namespace,
restconfig: d.restconfig,
client: d.client,
initVolumeDir: podConfig.InitVolumeDir,
}, nil
}
func (d *K8sDriver) GetPods(ctx context.Context, all bool) ([]Pod, error) {
// get all pods for the executor group, also the ones managed by other executors in the same executor group
labels := map[string]string{executorsGroupIDKey: d.executorsGroupID}
k8sPods, err := d.podLister.List(apilabels.SelectorFromSet(labels))
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if err != nil {
return nil, err
}
pods := make([]Pod, len(k8sPods))
for i, k8sPod := range k8sPods {
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labels := map[string]string{}
// keep only labels starting with our prefix
for n, v := range k8sPod.Labels {
if strings.HasPrefix(n, labelPrefix) {
labels[n] = v
}
}
pods[i] = &K8sPod{
id: k8sPod.Name,
namespace: k8sPod.Namespace,
labels: labels,
restconfig: d.restconfig,
client: d.client,
}
}
return pods, nil
}
func (p *K8sPod) ID() string {
return p.id
}
func (p *K8sPod) ExecutorID() string {
return p.labels[executorIDKey]
}
func (p *K8sPod) TaskID() string {
return p.labels[taskIDKey]
}
func (p *K8sPod) Stop(ctx context.Context) error {
d := int64(0)
secretClient := p.client.CoreV1().Secrets(p.namespace)
if err := secretClient.Delete(p.id, &metav1.DeleteOptions{GracePeriodSeconds: &d}); err != nil {
return err
}
podClient := p.client.CoreV1().Pods(p.namespace)
if err := podClient.Delete(p.id, &metav1.DeleteOptions{GracePeriodSeconds: &d}); err != nil {
return err
}
return nil
}
func (p *K8sPod) Remove(ctx context.Context) error {
return p.Stop(ctx)
}
type K8sContainerExec struct {
endCh chan error
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stdin io.WriteCloser
}
func (p *K8sPod) Exec(ctx context.Context, execConfig *ExecConfig) (ContainerExec, error) {
endCh := make(chan error)
coreclient, err := corev1client.NewForConfig(p.restconfig)
if err != nil {
return nil, err
}
// k8s pod exec api doesn't let us define the workingdir and the environment.
// Use a toolbox command that will set them up and then exec the real command.
envj, err := json.Marshal(execConfig.Env)
if err != nil {
return nil, err
}
cmd := []string{filepath.Join(p.initVolumeDir, "agola-toolbox"), "exec", "-e", string(envj), "-w", execConfig.WorkingDir, "--"}
cmd = append(cmd, execConfig.Cmd...)
req := coreclient.RESTClient().
Post().
Namespace(p.namespace).
Resource("pods").
Name(p.id).
SubResource("exec").
VersionedParams(&corev1.PodExecOptions{
Container: mainContainerName,
Command: cmd,
Stdin: execConfig.AttachStdin,
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Stdout: execConfig.Stdout != nil,
Stderr: execConfig.Stderr != nil,
TTY: execConfig.Tty,
}, scheme.ParameterCodec)
exec, err := remotecommand.NewSPDYExecutor(p.restconfig, "POST", req.URL())
if err != nil {
return nil, err
}
reader, writer := io.Pipe()
var stdin io.Reader
if execConfig.AttachStdin {
stdin = reader
}
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go func() {
err := exec.Stream(remotecommand.StreamOptions{
Stdin: stdin,
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Stdout: execConfig.Stdout,
Stderr: execConfig.Stderr,
Tty: execConfig.Tty,
})
endCh <- err
}()
return &K8sContainerExec{
stdin: writer,
endCh: endCh,
}, nil
}
func (e *K8sContainerExec) Wait(ctx context.Context) (int, error) {
err := <-e.endCh
var exitCode int
if err != nil {
switch err := err.(type) {
case utilexec.ExitError:
exitCode = err.ExitStatus()
default:
return -1, err
}
}
return exitCode, nil
}
func (e *K8sContainerExec) Stdin() io.WriteCloser {
return e.stdin
}
func genEnvVars(env map[string]string) []corev1.EnvVar {
envVars := make([]corev1.EnvVar, 0, len(env))
for n, v := range env {
envVars = append(envVars, corev1.EnvVar{Name: n, Value: v})
}
return envVars
}
type serverVersion struct {
Major int
Minor int
}
// k8s version is in this format: v0.0.0(-master+$Format:%h$)
var gitVersionRegex = regexp.MustCompile("v([0-9]+).([0-9]+).[0-9]+.*")
func parseGitVersion(gitVersion string) (*serverVersion, error) {
parsedVersion := gitVersionRegex.FindStringSubmatch(gitVersion)
if len(parsedVersion) != 3 {
return nil, fmt.Errorf("cannot parse git version %s", gitVersion)
}
sv := &serverVersion{}
var err error
sv.Major, err = strconv.Atoi(parsedVersion[1])
if err != nil {
return nil, err
}
sv.Minor, err = strconv.Atoi(parsedVersion[2])
if err != nil {
return nil, err
}
return sv, nil
}