DINGHY

What ?

Send cargo test or cargo bench to your phone. Painlessly.

It is not a way to build portable apps, merely a way to run simple piece of code and grab their output.

The purpose here is to make it easier for teams to unit-test and bench their libraries on more platforms. We want to get Rust everywhere right ?

Getting started

Depending on what is your target (iOS or Android) and your workstation, setting up Dinghy can be more or less easy. See the setup sections for that.

If you've never used cross compiling before, you'll probaby want to pick a toolchain or two...

rustup target install aarch64-apple-ios
rustup target install armv7-apple-ios
rustup target install arm-linux-androideabi

Let's install dinghy...

cargo install dinghy

And... stop here. Unfortunately, there is a bit of stuff to do by hand before the fun stuff come.

Android setup

TODO (but if you're on a mac, chances are it already works).

iOS setup

On iOS, things are made complicated by the fact that there is no way to run a naked executable: you need to make it an app, and sign it before sending it to your phone. Setting up app signature requires some manipulations that we could not find a way to dispense with through XCode. The good news is, this is a constant time thing: you'll have do it once in a while, but it will cover all your Rust projects.

Ho, and we don't need a paying account.

Creating a signing id

You may skip most of this section if you're already setup to ship code to your phone.

• You'll need an Apple ID. Chances are you already have one, but you can an account there: https://appleid.apple.com/account .
• Go to XCode > Preferences > Accounts, and make sure your Apple ID is listed, or add it (+ bottom well-hidden bottom left).
• View Details (bottom right this time)
• Click the "Create" button in front of "iOS Development" in the top half of this windows.
• We're done here.

Creating a certificate

• Plug-in your iPhone (or the device you want to run test on).
• Fire up XCode, and /create a new XCode project/.
• Pick /iOS/, /Single view application/.
• Options box:
  • Make the bundle identifier some.unique.domainame.Dinghy.
  • So Product Name is Dinghy, and Organization identifier is something that will be unique and looks like a domain name in reverse.
  • Pick your team.
  • Leave the rest alone
• Save it somewhere.
• You should get the dreadful projects settings. The only thing that is relevant is the "Signing" bit.
  • If you see your Team there, and nothing red or yellows shows up, then you're OK. In some cases, you have to push the "repair" button to actually obtain a certificate from Apple.

If you're using a Apple ID free account, you will need to come back once a week to refresh the certificate (aka "repair"). Paying account generate longer living certificates, so you need this less often.

Trust the certificate on your phone

On top of project window, make the target "Dinghy>Your Device", and run the project (play button). Xcode should ask you to go to your phone settings and Trust the certificate. It's in the Preferences > General > [your dev account name].

At this point, we're ready to roll.

Debugging tips

If you got lost somewhere, here are a few hints to help you make sense of what is happening. This is more or less what Dinghy use when fishing for your signing identity.

security find-identity -p codesigning

Shows you the codesigning identities available where you are. You should see one or more identities line, made of a long capitalize hex identifier, followed by a "name". The name is very structured: For iOS development , its starts with the string "iPhone Developer: ", followed by an email (for an Apple Id account) or the name of your team. Then comes the developer identifier in parenthesis.

security find-certificate -a -c "name" -p | openssl x509 -text

"name" is the identity name (the string between double quotes) from the command before.

Shows you a certificate that makes the developer a part of a Team. The certificate is signed and issued by Apple (Issuer:), but the interesting part is the Subject line: CN= is the same developer name string, and OU= is the actual Team identifier.

Look for provisioning certificates

Last but not least, we need one more certificate that proves that you and your team has the right to deploy an App (identified by the bundle id we have chosen while creating the project) on one (or more) devices.

These certificates are in Library/MobileDevice/Provisioning\ Profiles.

To read them, you'll need to do

security cms -D -i  ~/Library/MobileDevice/Provisioning\ Profiles\....mobileprovision

The more interesting keys here are TeamIdentifier, ProvisionedDevices which are relatively explicit, and the Entitlements dictionary. These entitlements specify what the certificate is valid for, that is, signing an app identified by a name.

Dinghy will actually scan this directory to find one that it can use (this is where the app name being "Dinghy" plays a role).

Phew.

command line arguments on aarch64

• there is a bug somewhere, probably in the standard library, that prevents command line to be received by the executable.

Enjoy

Now, you can go to your favourite Rust project. For a first try, I suggest you consider something without too many exotic external dependencies.

Then... instead of doing cargo test, try cargo dinghy test.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.