= yaml = title: The Device Manager layout: tutorial wherein: you learn about running applications with the device manager prerequisites: {scenario: b} sort: 51 toc: true = yaml =
In the basics tutorial, you ran the fortune server as a background process from the terminal.
In this tutorial, you‘ll learn how to use the device manager to run your server remotely (however, the device manager you’ll be running as part of the tutorial is running on the same computer to keep things simple).
We'll be using default credentials for all the commands and servers we start from the terminal. Recall that tutorial is the blessing name for these credentials:
export V23_CREDENTIALS="$V_TUT/cred/basics"
"${V_BIN}/principal" dump -s
The device manager is a Vanadium application that runs on a device and is responsible for installing and running other Vanadium applications on behalf of users.
The first step is to install and start a device manager on your computer (taking care first to clean up any previous ones). The device manager uses the security agent introduced in the agent tutorial to manage principals for itself and all the applications run under it.
The device manager has a built-in mount table, which we can us for service discovery (as we learned in the mount table tutorial). So give it a fixed port.
export V23_DEVICE_DIR="$V_TUT/devmgr"
PORT_MT=24000
"${V_BIN}/deviced" stop 2>/dev/null
"${V_BIN}/deviced" uninstall --suid_helper="${V_BIN}/suidhelper"
V23_CREDENTIALS="" "${V_BIN}/deviced" install --suid_helper="${V_BIN}/suidhelper" --agent="${V_BIN}/agentd" -- --v23.tcp.address=":$PORT_MT" --name=""
V23_CREDENTIALS="" "${V_BIN}/deviced" start
Check that the device manager service is mounted in the mount table. This should print /localhost:24000/devmgr:
"${V_BIN}/namespace" glob "/localhost:$PORT_MT/*"
The device manager is currently unclaimed, meaning that it does not have a blessing (other than the one it generates for itself). The user must claim the device manager to unlock its functionality. Claiming involves conferring a blessing, which then becomes the device manager‘s default blessing. We’ll bless our device manager as hal, and verify that the device manager presents itself as tutorial/hal:
DEVICE_NAME=/localhost:$PORT_MT/devmgr
"${V_BIN}/device" claim "${DEVICE_NAME}/device" hal
"${V_BIN}/vrpc" identify "${DEVICE_NAME}/device"
We‘re now ready to deploy a Vanadium application on the device manager. We’ll use the fortune server as our application.
First, install the application, recording the installation name:
INSTALLATION_NAME=$( \
"${V_BIN}/device" install-local "${DEVICE_NAME}/apps" \
fortuneserver "${V_TUT}/bin/server" --service-name=myFortunes \
)
echo "Installed: ${INSTALLATION_NAME}"
Then create an instance of the application just installed and run it, providing the instance with a blessing called fortune. Record the instance name:
INSTANCE_NAME=$("${V_BIN}/device" instantiate "${INSTALLATION_NAME}" fortune)
"${V_BIN}/device" run "${INSTANCE_NAME}"
echo "Instantiated and started: ${INSTANCE_NAME}"
Verify that the fortune server app runs with the expected blessing name, tutorial/fortune:
"${V_BIN}/vrpc" identify "/localhost:$PORT_MT/myFortunes"
At this point, you can look at the log files from your server. To see what log files are available:
${V_BIN}/namespace glob "${INSTANCE_NAME}/logs/*"
You can use debug logs read to read any of these files. For example:
LOGFILE=`${V_BIN}/namespace glob "${INSTANCE_NAME}/logs/STDOUT-*"`
${V_BIN}/debug logs read $LOGFILE
As in the basics tutorial, use the client to make a call to the server:
"${V_TUT}/bin/client" --server "/localhost:$PORT_MT/myFortunes"
"${V_BIN}/device" kill "${INSTANCE_NAME}"
"${V_BIN}/deviced" stop
"${V_BIN}/deviced" uninstall --suid_helper="${V_BIN}/suidhelper"
You set up a device manager on your computer, and used the device command-line tool to install and start an application on it.