asteris-llc/converge

// Copyright © 2016 Asteris, LLC
//
// 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.

// +build !solaris

package image

import (
    "fmt"

    "github.com/asteris-llc/converge/resource"
    "github.com/asteris-llc/converge/resource/docker"
    "golang.org/x/net/context"
)

// Image is responsible for pulling docker images
type Image struct {
    // name of the image
    Name string `export:"name"`

    // tag of the image
    Tag string `export:"tag"`

    client docker.APIClient
}

// Check system for presence of docker image
func (i *Image) Check(context.Context, resource.Renderer) (resource.TaskStatus, error) {
    status := resource.NewStatus()
    repoTag := i.RepoTag()
    image, err := i.client.FindImage(repoTag)
    if err != nil {
        status.Level = resource.StatusFatal
        return status, err
    }

    var original string
    if image != nil {
        original = repoTag
    }

    status.AddDifference("image", original, repoTag, "<image-missing>")
    status.RaiseLevelForDiffs()

    return status, nil
}

// Apply pulls a docker image
func (i *Image) Apply(context.Context) (resource.TaskStatus, error) {
    if err := i.client.PullImage(i.Name, i.Tag); err != nil {
        return &resource.Status{
            Level:  resource.StatusFatal,
            Output: []string{err.Error()},
        }, err
    }
    return &resource.Status{}, nil
}

// SetClient injects a docker api client
func (i *Image) SetClient(client docker.APIClient) {
    i.client = client
}

// RepoTag builds a repo tag used to identify a specific docker image
func (i *Image) RepoTag() string {
    var tag string
    if i.Tag != "" {
        tag = i.Tag
    } else {
        tag = "latest"
    }
    return fmt.Sprintf("%s:%s", i.Name, tag)
}