open-nomad/client/getter/getter.go

140 lines
3.2 KiB
Go

package getter
import (
"fmt"
"net/url"
"path/filepath"
"strings"
"sync"
gg "github.com/hashicorp/go-getter"
"github.com/hashicorp/nomad/nomad/structs"
)
var (
// getters is the map of getters suitable for Nomad. It is initialized once
// and the lock is used to guard access to it.
getters map[string]gg.Getter
lock sync.Mutex
// supported is the set of download schemes supported by Nomad
supported = []string{"http", "https", "s3", "hg", "git"}
)
const (
// gitSSHPrefix is the prefix for dowwnloading via git using ssh
gitSSHPrefix = "git@github.com:"
)
// EnvReplacer is an interface which can interpolate environment variables and
// is usually satisfied by env.TaskEnv.
type EnvReplacer interface {
ReplaceEnv(string) string
}
// getClient returns a client that is suitable for Nomad downloading artifacts.
func getClient(src string, mode gg.ClientMode, dst string) *gg.Client {
lock.Lock()
defer lock.Unlock()
// Return the pre-initialized client
if getters == nil {
getters = make(map[string]gg.Getter, len(supported))
for _, getter := range supported {
if impl, ok := gg.Getters[getter]; ok {
getters[getter] = impl
}
}
}
return &gg.Client{
Src: src,
Dst: dst,
Mode: mode,
Getters: getters,
}
}
// getGetterUrl returns the go-getter URL to download the artifact.
func getGetterUrl(taskEnv EnvReplacer, artifact *structs.TaskArtifact) (string, error) {
source := taskEnv.ReplaceEnv(artifact.GetterSource)
// Handle an invalid URL when given a go-getter url such as
// git@github.com:hashicorp/nomad.git
gitSSH := false
if strings.HasPrefix(source, gitSSHPrefix) {
gitSSH = true
source = source[len(gitSSHPrefix):]
}
u, err := url.Parse(source)
if err != nil {
return "", fmt.Errorf("failed to parse source URL %q: %v", artifact.GetterSource, err)
}
// Build the url
q := u.Query()
for k, v := range artifact.GetterOptions {
q.Add(k, taskEnv.ReplaceEnv(v))
}
u.RawQuery = q.Encode()
// Add the prefix back
url := u.String()
if gitSSH {
url = fmt.Sprintf("%s%s", gitSSHPrefix, url)
}
return url, nil
}
// GetArtifact downloads an artifact into the specified task directory.
func GetArtifact(taskEnv EnvReplacer, artifact *structs.TaskArtifact, taskDir string) error {
url, err := getGetterUrl(taskEnv, artifact)
if err != nil {
return newGetError(artifact.GetterSource, err, false)
}
// Download the artifact
dest := filepath.Join(taskDir, artifact.RelativeDest)
// Convert from string getter mode to go-getter const
mode := gg.ClientModeAny
switch artifact.GetterMode {
case structs.GetterModeFile:
mode = gg.ClientModeFile
case structs.GetterModeDir:
mode = gg.ClientModeDir
}
if err := getClient(url, mode, dest).Get(); err != nil {
return newGetError(url, err, true)
}
return nil
}
// GetError wraps the underlying artifact fetching error with the URL. It
// implements the RecoverableError interface.
type GetError struct {
URL string
Err error
recoverable bool
}
func newGetError(url string, err error, recoverable bool) *GetError {
return &GetError{
URL: url,
Err: err,
recoverable: recoverable,
}
}
func (g *GetError) Error() string {
return g.Err.Error()
}
func (g *GetError) IsRecoverable() bool {
return g.recoverable
}