Rename cli command to exec and document it

The `cli` word, to me, implies too much that it's run via a shell, which
it isn't. Renaming to `exec` resolves that.

CHANGELOG.md

@@ -14,6 +14,7 @@ bugs in actually-released versions.
 - Database integrity tests. These are always run at startup of Flamenco Manager, and by default run periodically every hour. This can be configured by adding/changing the `database_check_period: 1h` setting in `flamenco-manager.yaml`. Setting it to `0` will disable the periodic check. When a database consistency error is found, Flamenco Manager will immediately shut down.
 - Workers can be marked as 'restartable' by using the `-restart-exit-code N` commandline option. More info in the [Worker Actions documentation](https://flamenco.blender.org/usage/worker-actions/).
 - Worker name can be configured via `flamenco_worker.yaml` via `worker_name = "somename"`.
+- Add worker command `exec` for executing arbitrary executables.
 - Upgrade bundled FFmpeg from 5.0 to 5.1.
 - Rename the add-on download to `flamenco-addon.zip` (it used to be `flamenco3-addon.zip`). It still contains the same files as before, and in Blender the name of the add-on has not changed.
 - Improve speed of queueing up >100 simultaneous job deletions.

internal/worker/command_exe.go

@@ -81,7 +81,7 @@ func NewCommandExecutor(cli CommandLineRunner, listener CommandListener, timeSer
 		// misc
 		"echo":  ce.cmdEcho,
 		"sleep": ce.cmdSleep,
-		"cli":   ce.cmdCLI,
+		"exec":  ce.cmdExec,
 
 		// blender
 		"blender-render": ce.cmdBlenderRender,

internal/worker/command_exec.go

@@ -14,17 +14,17 @@ import (
 	"projects.blender.org/studio/flamenco/pkg/api"
 )
 
-type CliParams struct {
+type ExecParams struct {
 	exe  string   // Executable to run.
 	args []string // Arguments for the executable.
 }
 
-// cmdCLI runs an arbitrary executable with arguments.
+// cmdExec runs an arbitrary executable with arguments.
-func (ce *CommandExecutor) cmdCLI(ctx context.Context, logger zerolog.Logger, taskID string, cmd api.Command) error {
+func (ce *CommandExecutor) cmdExec(ctx context.Context, logger zerolog.Logger, taskID string, cmd api.Command) error {
 	cmdCtx, cmdCtxCancel := context.WithCancel(ctx)
 	defer cmdCtxCancel()
 
-	execCmd, err := ce.cmdCLICommand(cmdCtx, logger, taskID, cmd)
+	execCmd, err := ce.cmdExecCommand(cmdCtx, logger, taskID, cmd)
 	if err != nil {
 		return err
 	}
@@ -43,13 +43,13 @@ func (ce *CommandExecutor) cmdCLI(ctx context.Context, logger zerolog.Logger, ta
 	return nil
 }
 
-func (ce *CommandExecutor) cmdCLICommand(
+func (ce *CommandExecutor) cmdExecCommand(
 	ctx context.Context,
 	logger zerolog.Logger,
 	taskID string,
 	cmd api.Command,
 ) (*exec.Cmd, error) {
-	parameters, err := cmdCLIParams(logger, cmd)
+	parameters, err := cmdExecParams(logger, cmd)
 	if err != nil {
 		return nil, err
 	}
@@ -70,9 +70,9 @@ func (ce *CommandExecutor) cmdCLICommand(
 	return execCmd, nil
 }
 
-func cmdCLIParams(logger zerolog.Logger, cmd api.Command) (CliParams, error) {
+func cmdExecParams(logger zerolog.Logger, cmd api.Command) (ExecParams, error) {
 	var (
-		parameters CliParams
+		parameters ExecParams
 		ok         bool
 	)
 

web/project-website/content/usage/jobs-tasks-commands/commands.md

@@ -62,6 +62,31 @@ Copies a file from one location to another.
 | `src`     | `string` | Path of the file to copy. Must be an absolute path.                               |
 | `dest`    | `string` | Destination to copy it to. Must be an absolute path. This path may not yet exist. |
 
+## Misc: `exec`
+
+Run an executable. This can be any executable. The command succeeds when the
+executable exit status is `0`, and fails otherwise. The executable needs to stop
+running (or fork) in order for the Worker to consider the command 'done'.
+
+The executable is run directly, and *not* via a shell invocation. To run a shell
+command, use something like `{exe: "/bin/bash", args: ["-c", "echo", "hello
+world"]}`.
+
+
+{{< hint type=info >}}
+If there is a specific command for the functionality you need, like
+`blender-render` or `ffmpeg`, use those commands instead. They are aware of
+cross-platform differences, and know more about the program they are running.
+For example, the `blender-render` command sends rendered images to the Manager
+to show in the web interface, and `ffmpeg` will change its commandline arguments
+depending on the platform it runs on.
+{{< /hint >}}
+
+| Parameter | Type       | Description            |
+|-----------|------------|------------------------|
+| `exec`    | `string`   | The executable to run. |
+| `args`    | `[]string` | Commandline arguments. |
+
 ## Misc: `echo`
 
 Writes a message to the task log.