Trouble with wasm in install_code : Management Canister

Developers
1

Supoose I am having 1000 canisters created using IC management canister with some actor class…
But Later on I need to redeploy those 1000 canisters code with some extra update function, In that case Im supposed to use IC.install_code method for all 1000 canister Ids …
Lets just say I looped over them and will be using install_code method for each canister Id…

await IC.install_code({
                arg = [0] : [Nat8];
                wasm_module = [];
                mode = #upgrade;
                canister_id = cid;
            });

Trouble Im having here is from where to get arg and wasm_module for new Code which i need to deploy… Suppose in some way I can create a .wasm file for new code , then how Im going to change it to

[Blob] or [Nat8] , to get it supported with install_code method…
I found a forum over this, but i didnt get the approach.

Please help with the above method, or you can let me know some more good method if there is one!!!

2

You can use DIDC to create the args Releases · dfinity/candid · GitHub.

You can read in the wasm as a file and pass it in just like any other blob.

//get arg blob from didc
const ARG_BLOB = Buffer.from('4449444c076c0690......', 'hex')

const ARG_ARR = ARG_BLOB.toJSON().data
const wasmPath = `/canister-3110-6.wasm`;

const data = fs.readFileSync(wasmPath);
 const size = await actor. install_code(ARG_ARR, Array.from(data), {upgrage:null}, canister_id);

I look forward to your cycle burn.

4 Likes
3

At the moment there is no good way to achieve this from Motoko, I’m afraid.

We have the forthcoming to_candid/from_candid primitives coming soon that will make argument construction easier, but the only install method we have at the moment is a fresh install via the class constructor.

There is a GH PR and issue below that discusses some ways forward but none are that satisfactory.

The solution I currently have in mind is an additional constructor with more install options, coupled with an opt-out dynamic check for interface compatibility during upgrade. Opt-out to allow for deliberate breaking change, when desired.

1 Like
4

One more doubt, while using didc encode ‘(“text”)’

Instead of text , I wanted to pass variable which contains that text, can i do that ? If Yes, Can you please tell me syntax for that , I tried every way, but i am not able to figure out a way !!

didc encode {some variable which contains text value}

5

Also, can you please provide me some link, how to deal with WASM, Array.data(wasm) is not working I guess. So please if you can elaborate how to deal with wasm. I tried to convert it to text , but not working.