dotcloud/docker

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

import (
    "encoding/json"
    "io"
    "runtime"

    "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/network"
    "github.com/docker/docker/pkg/sysinfo"
)

// ContainerDecoder implements httputils.ContainerDecoder
// calling DecodeContainerConfig.
type ContainerDecoder struct {
    GetSysInfo func() *sysinfo.SysInfo
}

// DecodeConfig makes ContainerDecoder to implement httputils.ContainerDecoder
func (r ContainerDecoder) DecodeConfig(src io.Reader) (*container.Config, *container.HostConfig, *network.NetworkingConfig, error) {
    var si *sysinfo.SysInfo
    if r.GetSysInfo != nil {
        si = r.GetSysInfo()
    } else {
        si = sysinfo.New()
    }

    return decodeContainerConfig(src, si)
}

// decodeContainerConfig decodes a json encoded config into a ContainerConfigWrapper
// struct and returns both a Config and a HostConfig struct, and performs some
// validation. Certain parameters need daemon-side validation that cannot be done
// on the client, as only the daemon knows what is valid for the platform.
// Be aware this function is not checking whether the resulted structs are nil,
// it's your business to do so
func decodeContainerConfig(src io.Reader, si *sysinfo.SysInfo) (*container.Config, *container.HostConfig, *network.NetworkingConfig, error) {
    var w container.CreateRequest
    if err := loadJSON(src, &w); err != nil {
        return nil, nil, nil, err
    }

    hc := w.HostConfig
    if hc == nil {
        // We may not be passed a host config, such as in the case of docker commit
        return w.Config, hc, w.NetworkingConfig, nil
    }

    // Make sure NetworkMode has an acceptable value. We do this to ensure
    // backwards compatible API behavior.
    //
    // TODO(thaJeztah): platform check may be redundant, as other code-paths execute this unconditionally. Also check if this code is still needed here, or already handled elsewhere.
    if runtime.GOOS != "windows" && hc.NetworkMode == "" {
        hc.NetworkMode = network.NetworkDefault
    }
    if err := validateNetMode(w.Config, hc); err != nil {
        return nil, nil, nil, err
    }
    if err := validateIsolation(hc); err != nil {
        return nil, nil, nil, err
    }
    if err := validateQoS(hc); err != nil {
        return nil, nil, nil, err
    }
    if err := validateResources(hc, si); err != nil {
        return nil, nil, nil, err
    }
    if err := validatePrivileged(hc); err != nil {
        return nil, nil, nil, err
    }
    if err := validateReadonlyRootfs(hc); err != nil {
        return nil, nil, nil, err
    }
    if w.Config != nil && w.Config.Volumes == nil {
        w.Config.Volumes = make(map[string]struct{})
    }
    return w.Config, hc, w.NetworkingConfig, nil
}

// loadJSON is similar to api/server/httputils.ReadJSON()
func loadJSON(src io.Reader, out interface{}) error {
    dec := json.NewDecoder(src)
    if err := dec.Decode(&out); err != nil {
        return invalidJSONError{Err: err}
    }
    if dec.More() {
        return validationError("unexpected content after JSON")
    }
    return nil
}