dApp Manager

dapp-manager is a purposefully minimalistic manager for decentralized applications running on Golem. It works together with the dapp-runner.

While the responsibility of the latter is to run a single Golem application (which may consist of multiple services), dapp-manager takes care of spawning, interacting with, and stopping the running instances of the dapp-runner.

Ensure you have curl available on your system.

curl --version

If not, please install it using the instructions appropriate for your system from here.

You should have python and pip installed.

As the dapp-manager uses the dapp-runner, which in turn requires a properly configured yagna service, you'll need to have it set up.

Please follow the Yagna installation instruction tutorial and ensure that your yagna is up and running.

Query yagna with:

yagna app-key list

If the above command doesn't give you any 32-char keys, just create your app key:

yagna app-key create requestor

and copy the value output by this command.

Set the YAGNA_APPKEY in your environment, e.g. with:

export YAGNA_APPKEY=insert-your-32-char-app-key-here

First, ensure you have Python 3.8 or later:

python3 --version

If your Python version is older, consider using pyenv to install and use multiple versions..

Once your python interpreter reports a version 3.8 or later, you can set up your virtual environment:

python3 -m venv ~/.envs/dapp-manager
source ~/.envs/dapp-manager/bin/activate

Install dapp-manager with a simple:

pip install dapp-manager

curl https://raw.githubusercontent.com/golemfactory/dapp-store/81e3f50aba90a84d335a26cb9cc2ea778193be11/apps/todo-app.yaml > app.yaml

curl https://raw.githubusercontent.com/golemfactory/dapp-runner/main/configs/default.yaml > config.yaml

dapp-manager start --config config.yaml app.yaml

The app is started in a background dapp-runner process, and you're returned an application ID in the form of a hexadecimal string. You can use this ID to query the state and other output streams using dapp-manager's read command.

Most importantly, you may query the data stream with:

dapp-manager read --follow <the-hex-string> data

waiting for the following line:

{"web": {"local_proxy_address": "http://localhost:8080"}}

Once you get it, you can access the launched app by following that link.

In case something goes amiss, dapp-manager will output: App <the-hex-string> is not running.

Whatever the reason, you can still query the various streams of a terminated dapp by adding the --no-ensure-alive option, e.g.:

dapp-manager read <the-hex-string> --no-ensure-alive stderr

Usage: dapp-manager [OPTIONS] COMMAND [ARGS]...

Options:
  --help  Show this message and exit.

Commands:
  autocomplete  Enable CLI shell completion for the given shell.
  kill          Stop the given app forcibly.
  list          List known app IDs (both active and dead).
  prune         Remove data for non-running apps.
  read          Read output from the given app.
  start         Start a new app using the provided descriptor and config...
  stop          Stop the given app gracefully.

The start command launches a new instance of the dapp-runner in a background process and returns the hexadecimal string that is the identifier of the running dapp-runner instance.

Usage: dapp-manager start [OPTIONS] DESCRIPTORS...

  Start a new app using the provided descriptor and config files.

Options:
  -c, --config PATH  Path to the file containing yagna-specific config.
                     [required]
  --help             Show this message and exit.

Importantly, it requires a config file which contains the parameters used to connect to the yagna service and initialize the requestor engine.

Of course, it also requires one or more descriptor files that are used by the dapp-runner to deploy the specified applications on Golem.

The stop and kill commands terminate the given dapp-runner instance, the main difference being the signal that's sent to do that. Essentially, stop should be enough and should give the dapp-runner a chance to shut the app down gracefully, correctly terminating the services, closing the agreements, and paying for them.

In case stop is stuck for whatever reason, you might want to resort to kill which terminates the dapp-runner immediately without allowing for any graceful shutdown.

The list command shows the identifiers of all the previously-started apps, whether they're still running or not.

prune causes dapp-manager to remove the data for those apps that it had previously identified as defunct. Consequently, those apps will no longer appear on the list.

Unless an app has been explicitly stopped with a stop or kill command, the dapp-manager will not purge it until it has had a chance to notice the termination, e.g. by issuing a read command to the defunct app.

The read command outputs the full contents of the specified stream. There are five streams as specified by the usage below:

Usage: dapp-manager read [OPTIONS] APP_ID [state|data|log|stdout|stderr]

  Read output from the given app.

Options:
  --ensure-alive / --no-ensure-alive
  -f, --follow
  --help                          Show this message and exit.

By default, the stream will only be output if the app is currently running. Otherwise, you'll get the App <the-hex-string> is not running. message and no stream.

If you wish to query a stream of a terminated app, add the --no-ensure-alive parameter to the specific read command.

This program supports shell completion for all of its commands, as well as existing dApp IDs (where applicable).

To enable completion, use the autocomplete command with your shell of choice:

• bash:

  dapp-manager autocomplete bash

• zsh:

  dapp-manager autocomplete zsh

• fish:

  dapp-manager autocomplete fish

The completion functions are defined in dapp_manager/autocomplete/scripts.

Should the entrypoint name ever change, those files will need to be updated as well.