-
Notifications
You must be signed in to change notification settings - Fork 2k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
HostVolumePlugin interface and implementations
* mkdir: HostVolumePluginMkdir: just creates a directory * example-host-volume: HostVolumePluginExternal: mkfs and mount loopback
- Loading branch information
Showing
5 changed files
with
233 additions
and
96 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,165 @@ | ||
| package hostvolumemanager | ||
|
|
||
| import ( | ||
| "bytes" | ||
| "context" | ||
| "encoding/json" | ||
| "fmt" | ||
| "io" | ||
| "os" | ||
| "os/exec" | ||
| "path/filepath" | ||
|
|
||
| "github.com/hashicorp/go-hclog" | ||
| cstructs "github.com/hashicorp/nomad/client/structs" | ||
| ) | ||
|
|
||
| type HostVolumePlugin interface { | ||
| Version(ctx context.Context) (string, error) // TODO(db): semver? | ||
| Create(ctx context.Context, req *cstructs.ClientHostVolumeCreateRequest) (*hostVolumePluginCreateResponse, error) | ||
| Delete(ctx context.Context, req *cstructs.ClientHostVolumeDeleteRequest) error | ||
| // TODO(db): update? resize? ?? | ||
| } | ||
|
|
||
| type hostVolumePluginCreateResponse struct { | ||
| Path string `json:"path"` | ||
| SizeBytes int64 `json:"bytes"` | ||
| Context map[string]string `json:"context"` // metadata | ||
| } | ||
|
|
||
| var _ HostVolumePlugin = &HostVolumePluginMkdir{} | ||
|
|
||
| type HostVolumePluginMkdir struct { | ||
| ID string | ||
| TargetPath string | ||
|
|
||
| log hclog.Logger | ||
| } | ||
|
|
||
| func (p *HostVolumePluginMkdir) Version(_ context.Context) (string, error) { | ||
| return "0.0.1", nil | ||
| } | ||
|
|
||
| func (p *HostVolumePluginMkdir) Create(_ context.Context, | ||
| req *cstructs.ClientHostVolumeCreateRequest) (*hostVolumePluginCreateResponse, error) { | ||
|
|
||
| path := filepath.Join(p.TargetPath, req.ID) | ||
| p.log.Debug("CREATE: default host volume plugin", "target_path", path) | ||
|
|
||
| err := os.Mkdir(path, 0o700) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| return &hostVolumePluginCreateResponse{ | ||
| Path: path, | ||
| SizeBytes: 0, | ||
| Context: map[string]string{}, | ||
| }, nil | ||
| } | ||
|
|
||
| func (p *HostVolumePluginMkdir) Delete(_ context.Context, req *cstructs.ClientHostVolumeDeleteRequest) error { | ||
| path := filepath.Join(p.TargetPath, req.ID) | ||
| p.log.Debug("DELETE: default host volume plugin", "target_path", path) | ||
| return os.RemoveAll(path) | ||
| } | ||
|
|
||
| var _ HostVolumePlugin = &HostVolumePluginExternal{} | ||
|
|
||
| type HostVolumePluginExternal struct { | ||
| ID string | ||
| Executable string | ||
| TargetPath string | ||
|
|
||
| log hclog.Logger | ||
| } | ||
|
|
||
| func (p *HostVolumePluginExternal) Version(_ context.Context) (string, error) { | ||
| return "0.0.1", nil | ||
| } | ||
|
|
||
| func (p *HostVolumePluginExternal) Create(ctx context.Context, | ||
| req *cstructs.ClientHostVolumeCreateRequest) (*hostVolumePluginCreateResponse, error) { | ||
|
|
||
| stdin, err := json.Marshal(req) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| stdout, _, err := p.runPlugin(ctx, "create", req.ID, stdin, []string{ | ||
| "NODE_ID=" + req.NodeID, | ||
| "VOLUME_NAME=" + req.Name, | ||
| fmt.Sprintf("CAPACITY_MIN_BYTES=%d", req.RequestedCapacityMinBytes), | ||
| fmt.Sprintf("CAPACITY_MAX_BYTES=%d", req.RequestedCapacityMaxBytes), | ||
| }) | ||
| if err != nil { | ||
| return nil, fmt.Errorf("error creating volume %q with plugin %q: %w", req.ID, req.PluginID, err) | ||
| } | ||
|
|
||
| var pluginResp hostVolumePluginCreateResponse | ||
| err = json.Unmarshal(stdout, &pluginResp) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| return &pluginResp, nil | ||
| } | ||
|
|
||
| func (p *HostVolumePluginExternal) Delete(ctx context.Context, | ||
| req *cstructs.ClientHostVolumeDeleteRequest) error { | ||
|
|
||
| stdin, err := json.Marshal(req) | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
|
||
| _, _, err = p.runPlugin(ctx, "delete", req.ID, stdin, []string{}) | ||
| if err != nil { | ||
| return fmt.Errorf("error deleting volume %q with plugin %q: %w", req.ID, req.PluginID, err) | ||
| } | ||
| return nil | ||
| } | ||
|
|
||
| func (p *HostVolumePluginExternal) runPlugin(ctx context.Context, op, volID string, | ||
| stdin []byte, env []string) (stdout, stderr []byte, err error) { | ||
|
|
||
| p.log.Debug("running host volume plugin", | ||
| "operation", op, | ||
| "volume_id", volID, | ||
| "stdin", string(stdin), | ||
| ) | ||
|
|
||
| path := filepath.Join(p.TargetPath, volID) | ||
| // set up plugin execution | ||
| cmd := exec.CommandContext(ctx, p.Executable, op, path) | ||
|
|
||
| // plugins may read the full json from stdin, | ||
| cmd.Stdin = bytes.NewReader(stdin) | ||
| // and/or environment variables for basic features. | ||
| cmd.Env = append([]string{ | ||
| "OPERATION=" + op, | ||
| "HOST_PATH=" + path, | ||
| }, env...) | ||
|
|
||
| var errBuf bytes.Buffer | ||
| cmd.Stderr = io.Writer(&errBuf) // TODO(db): surely a better way to capture stderr... | ||
|
|
||
| // run the command and capture output | ||
| stdout, err = cmd.Output() | ||
| stderr, _ = io.ReadAll(&errBuf) | ||
|
|
||
| logArgs := []any{ | ||
| "operation", op, | ||
| "volume_id", volID, | ||
| "stdout", string(stdout), | ||
| "stderr", string(stderr), | ||
| } | ||
|
|
||
| if err != nil { | ||
| logArgs = append(logArgs, []any{"err", err}...) | ||
| p.log.Error("error with plugin", logArgs...) | ||
| return stdout, stderr, err | ||
| } else { | ||
| p.log.Debug("plugin ran", logArgs...) | ||
| } | ||
| return stdout, stderr, nil | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters