moby/daemon/commit.go

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package daemon // import "github.com/docker/docker/daemon"
import (
"fmt"
"runtime"
"strings"
"time"
"github.com/docker/docker/api/types/backend"
containertypes "github.com/docker/docker/api/types/container"
"github.com/docker/docker/builder/dockerfile"
"github.com/docker/docker/errdefs"
"github.com/pkg/errors"
)
// merge merges two Config, the image container configuration (defaults values),
// and the user container configuration, either passed by the API or generated
// by the cli.
// It will mutate the specified user configuration (userConf) with the image
// configuration where the user configuration is incomplete.
func merge(userConf, imageConf *containertypes.Config) error {
if userConf.User == "" {
userConf.User = imageConf.User
}
if len(userConf.ExposedPorts) == 0 {
userConf.ExposedPorts = imageConf.ExposedPorts
} else if imageConf.ExposedPorts != nil {
for port := range imageConf.ExposedPorts {
if _, exists := userConf.ExposedPorts[port]; !exists {
userConf.ExposedPorts[port] = struct{}{}
}
}
}
if len(userConf.Env) == 0 {
userConf.Env = imageConf.Env
} else {
for _, imageEnv := range imageConf.Env {
found := false
imageEnvKey := strings.Split(imageEnv, "=")[0]
for _, userEnv := range userConf.Env {
userEnvKey := strings.Split(userEnv, "=")[0]
if isWindows {
// Case insensitive environment variables on Windows
imageEnvKey = strings.ToUpper(imageEnvKey)
userEnvKey = strings.ToUpper(userEnvKey)
}
if imageEnvKey == userEnvKey {
found = true
break
}
}
if !found {
userConf.Env = append(userConf.Env, imageEnv)
}
}
}
if userConf.Labels == nil {
userConf.Labels = map[string]string{}
}
for l, v := range imageConf.Labels {
if _, ok := userConf.Labels[l]; !ok {
userConf.Labels[l] = v
}
}
if len(userConf.Entrypoint) == 0 {
if len(userConf.Cmd) == 0 {
userConf.Cmd = imageConf.Cmd
}
if userConf.Entrypoint == nil {
userConf.Entrypoint = imageConf.Entrypoint
}
}
Add support for user-defined healthchecks This PR adds support for user-defined health-check probes for Docker containers. It adds a `HEALTHCHECK` instruction to the Dockerfile syntax plus some corresponding "docker run" options. It can be used with a restart policy to automatically restart a container if the check fails. The `HEALTHCHECK` instruction has two forms: * `HEALTHCHECK [OPTIONS] CMD command` (check container health by running a command inside the container) * `HEALTHCHECK NONE` (disable any healthcheck inherited from the base image) The `HEALTHCHECK` instruction tells Docker how to test a container to check that it is still working. This can detect cases such as a web server that is stuck in an infinite loop and unable to handle new connections, even though the server process is still running. When a container has a healthcheck specified, it has a _health status_ in addition to its normal status. This status is initially `starting`. Whenever a health check passes, it becomes `healthy` (whatever state it was previously in). After a certain number of consecutive failures, it becomes `unhealthy`. The options that can appear before `CMD` are: * `--interval=DURATION` (default: `30s`) * `--timeout=DURATION` (default: `30s`) * `--retries=N` (default: `1`) The health check will first run **interval** seconds after the container is started, and then again **interval** seconds after each previous check completes. If a single run of the check takes longer than **timeout** seconds then the check is considered to have failed. It takes **retries** consecutive failures of the health check for the container to be considered `unhealthy`. There can only be one `HEALTHCHECK` instruction in a Dockerfile. If you list more than one then only the last `HEALTHCHECK` will take effect. The command after the `CMD` keyword can be either a shell command (e.g. `HEALTHCHECK CMD /bin/check-running`) or an _exec_ array (as with other Dockerfile commands; see e.g. `ENTRYPOINT` for details). The command's exit status indicates the health status of the container. The possible values are: - 0: success - the container is healthy and ready for use - 1: unhealthy - the container is not working correctly - 2: starting - the container is not ready for use yet, but is working correctly If the probe returns 2 ("starting") when the container has already moved out of the "starting" state then it is treated as "unhealthy" instead. For example, to check every five minutes or so that a web-server is able to serve the site's main page within three seconds: HEALTHCHECK --interval=5m --timeout=3s \ CMD curl -f http://localhost/ || exit 1 To help debug failing probes, any output text (UTF-8 encoded) that the command writes on stdout or stderr will be stored in the health status and can be queried with `docker inspect`. Such output should be kept short (only the first 4096 bytes are stored currently). When the health status of a container changes, a `health_status` event is generated with the new status. The health status is also displayed in the `docker ps` output. Signed-off-by: Thomas Leonard <thomas.leonard@docker.com> Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2016-04-18 09:48:13 +00:00
if imageConf.Healthcheck != nil {
if userConf.Healthcheck == nil {
userConf.Healthcheck = imageConf.Healthcheck
} else {
if len(userConf.Healthcheck.Test) == 0 {
userConf.Healthcheck.Test = imageConf.Healthcheck.Test
}
if userConf.Healthcheck.Interval == 0 {
userConf.Healthcheck.Interval = imageConf.Healthcheck.Interval
}
if userConf.Healthcheck.Timeout == 0 {
userConf.Healthcheck.Timeout = imageConf.Healthcheck.Timeout
}
if userConf.Healthcheck.StartPeriod == 0 {
userConf.Healthcheck.StartPeriod = imageConf.Healthcheck.StartPeriod
}
Add support for user-defined healthchecks This PR adds support for user-defined health-check probes for Docker containers. It adds a `HEALTHCHECK` instruction to the Dockerfile syntax plus some corresponding "docker run" options. It can be used with a restart policy to automatically restart a container if the check fails. The `HEALTHCHECK` instruction has two forms: * `HEALTHCHECK [OPTIONS] CMD command` (check container health by running a command inside the container) * `HEALTHCHECK NONE` (disable any healthcheck inherited from the base image) The `HEALTHCHECK` instruction tells Docker how to test a container to check that it is still working. This can detect cases such as a web server that is stuck in an infinite loop and unable to handle new connections, even though the server process is still running. When a container has a healthcheck specified, it has a _health status_ in addition to its normal status. This status is initially `starting`. Whenever a health check passes, it becomes `healthy` (whatever state it was previously in). After a certain number of consecutive failures, it becomes `unhealthy`. The options that can appear before `CMD` are: * `--interval=DURATION` (default: `30s`) * `--timeout=DURATION` (default: `30s`) * `--retries=N` (default: `1`) The health check will first run **interval** seconds after the container is started, and then again **interval** seconds after each previous check completes. If a single run of the check takes longer than **timeout** seconds then the check is considered to have failed. It takes **retries** consecutive failures of the health check for the container to be considered `unhealthy`. There can only be one `HEALTHCHECK` instruction in a Dockerfile. If you list more than one then only the last `HEALTHCHECK` will take effect. The command after the `CMD` keyword can be either a shell command (e.g. `HEALTHCHECK CMD /bin/check-running`) or an _exec_ array (as with other Dockerfile commands; see e.g. `ENTRYPOINT` for details). The command's exit status indicates the health status of the container. The possible values are: - 0: success - the container is healthy and ready for use - 1: unhealthy - the container is not working correctly - 2: starting - the container is not ready for use yet, but is working correctly If the probe returns 2 ("starting") when the container has already moved out of the "starting" state then it is treated as "unhealthy" instead. For example, to check every five minutes or so that a web-server is able to serve the site's main page within three seconds: HEALTHCHECK --interval=5m --timeout=3s \ CMD curl -f http://localhost/ || exit 1 To help debug failing probes, any output text (UTF-8 encoded) that the command writes on stdout or stderr will be stored in the health status and can be queried with `docker inspect`. Such output should be kept short (only the first 4096 bytes are stored currently). When the health status of a container changes, a `health_status` event is generated with the new status. The health status is also displayed in the `docker ps` output. Signed-off-by: Thomas Leonard <thomas.leonard@docker.com> Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2016-04-18 09:48:13 +00:00
if userConf.Healthcheck.Retries == 0 {
userConf.Healthcheck.Retries = imageConf.Healthcheck.Retries
}
}
}
if userConf.WorkingDir == "" {
userConf.WorkingDir = imageConf.WorkingDir
}
if len(userConf.Volumes) == 0 {
userConf.Volumes = imageConf.Volumes
} else {
for k, v := range imageConf.Volumes {
userConf.Volumes[k] = v
}
}
if userConf.StopSignal == "" {
userConf.StopSignal = imageConf.StopSignal
}
return nil
}
// CreateImageFromContainer creates a new image from a container. The container
// config will be updated by applying the change set to the custom config, then
// applying that config over the existing container config.
func (daemon *Daemon) CreateImageFromContainer(name string, c *backend.CreateImageConfig) (string, error) {
start := time.Now()
container, err := daemon.GetContainer(name)
if err != nil {
return "", err
}
// It is not possible to commit a running container on Windows
if isWindows && container.IsRunning() {
return "", errors.Errorf("%+v does not support commit of a running container", runtime.GOOS)
}
if container.IsDead() {
err := fmt.Errorf("You cannot commit container %s which is Dead", container.ID)
return "", errdefs.Conflict(err)
}
if container.IsRemovalInProgress() {
err := fmt.Errorf("You cannot commit container %s which is being removed", container.ID)
return "", errdefs.Conflict(err)
}
if c.Pause && !container.IsPaused() {
daemon.containerPause(container)
defer daemon.containerUnpause(container)
}
if c.Config == nil {
c.Config = container.Config
}
newConfig, err := dockerfile.BuildFromConfig(c.Config, c.Changes, container.OS)
if err != nil {
return "", err
}
if err := merge(newConfig, container.Config); err != nil {
return "", err
}
id, err := daemon.imageService.CommitImage(backend.CommitConfig{
Author: c.Author,
Comment: c.Comment,
Config: newConfig,
ContainerConfig: container.Config,
ContainerID: container.ID,
ContainerMountLabel: container.MountLabel,
ContainerOS: container.OS,
ParentImageID: string(container.ImageID),
})
if err != nil {
return "", err
}
var imageRef string
if c.Repo != "" {
imageRef, err = daemon.imageService.TagImage(string(id), c.Repo, c.Tag)
if err != nil {
return "", err
}
}
daemon.LogContainerEventWithAttributes(container, "commit", map[string]string{
"comment": c.Comment,
"imageID": id.String(),
"imageRef": imageRef,
})
containerActions.WithValues("commit").UpdateSince(start)
return id.String(), nil
}