Reenvisioning SSH with ShellHub

Starting Up

After running the command to bring up the resources listed in the ShellHub Docker Compose configuration, you'll see lots of Docker-esque output as containers are created and started. After putting the kettle on and coming back a few minutes later, you should be greeted with some logging information, right at the end of the output:

Creating shellhub-v002_emq_1... done
Creating shellhub-v002_ssh_1... done
Creating shellhub-v002_ws_1... done
Creating shellhub-v002_gateway_1 ... done

To check whether the installation was successful, run the following command to see which containers are now running:

$ docker ps

The seven containers that run a ShellHub server are shown in Figure 2. They include a MongoDB container and containers running from images with names such as:

shellhubio/shellhub-gateway:v0.0.4
shellhubio/shellhub-ws:v0.0.4
shellhubio/shellhub-ssh:v0.0.4
shellhubio/shellhub-ui:v0.0.4
shellhubio/shellhub-api:v0.0.4
Figure 2: Seven containers are running the ShellHub server, courtesy of Docker Compose's ShellHub config.

The next step is adding a user to our shiny, new ShellHub server. From the same directory as in the cloned GitHub repository, run the following command:

$ ./bin/add-user chrisbinnie nothingtoseehere
User added: chrisbinnie
Tenant ID: fca338ad-8801-4a91-8487-5de263dadbd2

The username in this case is chrisbinnie and the password is nothingtoseehere.

Connecting

The moment of truth has arrived. Open up a browser and navigate to the following HTTP page:

http://localhost/login

Figure 3 shows the slick-looking login screen that awaits.

Figure 3: Happiness is a login screen that accepts your username and password.

Figure 4 shows the main window that appears once you have logged in. On the left-hand side are a few options; the rest of the screen shows you the status of devices that are connected to your ShellHub server.

Figure 4: A dashboard view, once logged in, courtesy of the nicely designed ShellHub UI.

I'll cheat a little here in order to stay focused on the dashboard and the UI. Instead of installing a ShellHub agent (the equivalent of the SSH client) on another device, I'll install it on the ShellHub server itself and then explain what to do with other machines later on.

The process of installing a ShellHub agent is remarkably simple. Click the ADD DEVICE link on the dashboard, and you'll be presented with a curl command, as shown in Figure 5.

Figure 5: Simplicity incarnate. Run this command to register a device you want SSH access to with ShellHub. Note that localhost needs changing; I'll come back to that later.

This command essentially passes a tenant ID to ShellHub and then asks the localhost (the ShellHub server name, which I'll change in a minute) to install the ShellHub agent so that it can be accessed over SSH.

Then check the ShellHub dashboard again to see if the ShellHub agent has been registered. Figure 6 shows that a device is registered to the ShellHub server successfully.

Figure 6: Excellent, I've connected a client (the ShellHub agent) to the ShellHub server. What was previously shown as 0 devices now shows as 1.

Oh So Pretty

The View All Devices link in Figure 6 lets you open the Devices dialog (Figure 7). The command-line icon in lower-right corner of the Devices dialog lets you open an SSH prompt. As you can see in Figure 7, devices are referenced by MAC address, but you have the option of giving each device a handy nickname.

Figure 7: After clicking on the View All Devices section shown in Figure 6, you're presented with the ability to open up an SSH prompt.

If you click the little shell prompt icon, you'll be prompted for a username and password. These credentials are for the machine's users directly and not the ShellHub server's usernames.

Figure 8 shows that the browser-based SSH client works well (I'm using Google Chrome on Linux Mint).

Figure 8: Running the top command in a terminal window, within a Browser tab sitting atop a desktop environment.

Note that the SSHID column in Figure  7 allows you to SSH directly over the command line to a machine connected to ShellHub. Simply click the copy box and then enter the credentials. See the project docs for more on connecting to another device [6] .

From the command line, the connections launched through the ShellHub GUI to devices on the LAN have the following format:

$ ssh <USER>@<SSHID>

For example:

$ ssh linux-user.3c-6a-a7-15-23-7c@localhost

With a little trial and error, you should be able to quickly get used to the format of the SSH command from all popular SSH clients. If you want to connect a device later on but aren't sure of the ID of that ShellHub's agent, the docs suggest running this command:

$ docker exec shellhub agent info

Then look for the sshid entry in the JSON that is output:

sshid: "namespace.device_name@address"

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