dotcloud/docker

package client // import "github.com/docker/docker/client"

import (
    "context"
    "encoding/json"
    "net/http"
    "net/url"

    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/registry"
    "github.com/docker/docker/api/types/swarm"
    "github.com/docker/docker/api/types/versions"
)

// ServiceUpdate updates a Service. The version number is required to avoid conflicting writes.
// It should be the value as set *before* the update. You can find this value in the Meta field
// of swarm.Service, which can be found using ServiceInspectWithRaw.
func (cli *Client) ServiceUpdate(ctx context.Context, serviceID string, version swarm.Version, service swarm.ServiceSpec, options types.ServiceUpdateOptions) (swarm.ServiceUpdateResponse, error) {
    response := swarm.ServiceUpdateResponse{}

    // Make sure we negotiated (if the client is configured to do so),
    // as code below contains API-version specific handling of options.
    //
    // Normally, version-negotiation (if enabled) would not happen until
    // the API request is made.
    if err := cli.checkVersion(ctx); err != nil {
        return response, err
    }

    query := url.Values{}
    if options.RegistryAuthFrom != "" {
        query.Set("registryAuthFrom", options.RegistryAuthFrom)
    }

    if options.Rollback != "" {
        query.Set("rollback", options.Rollback)
    }

    query.Set("version", version.String())

    if err := validateServiceSpec(service); err != nil {
        return response, err
    }

    // ensure that the image is tagged
    var resolveWarning string
    switch {
    case service.TaskTemplate.ContainerSpec != nil:
        if taggedImg := imageWithTagString(service.TaskTemplate.ContainerSpec.Image); taggedImg != "" {
            service.TaskTemplate.ContainerSpec.Image = taggedImg
        }
        if options.QueryRegistry {
            resolveWarning = resolveContainerSpecImage(ctx, cli, &service.TaskTemplate, options.EncodedRegistryAuth)
        }
    case service.TaskTemplate.PluginSpec != nil:
        if taggedImg := imageWithTagString(service.TaskTemplate.PluginSpec.Remote); taggedImg != "" {
            service.TaskTemplate.PluginSpec.Remote = taggedImg
        }
        if options.QueryRegistry {
            resolveWarning = resolvePluginSpecRemote(ctx, cli, &service.TaskTemplate, options.EncodedRegistryAuth)
        }
    }

    headers := http.Header{}
    if versions.LessThan(cli.version, "1.30") {
        // the custom "version" header was used by engine API before 20.10
        // (API 1.30) to switch between client- and server-side lookup of
        // image digests.
        headers["version"] = []string{cli.version}
    }
    if options.EncodedRegistryAuth != "" {
        headers[registry.AuthHeader] = []string{options.EncodedRegistryAuth}
    }
    resp, err := cli.post(ctx, "/services/"+serviceID+"/update", query, service, headers)
    defer ensureReaderClosed(resp)
    if err != nil {
        return response, err
    }

    err = json.NewDecoder(resp.body).Decode(&response)
    if resolveWarning != "" {
        response.Warnings = append(response.Warnings, resolveWarning)
    }

    return response, err
}