How to serialize anchor instruction from non-anchor contract - solana

Question

I am trying to invoke Anchor-contract from a regular solana contract and i am keep getting the error
Program log: AnchorError occurred. Error Code: InstructionMissing. Error Number: 100. Error Message: 8 byte instruction identifier not provided.
This is my instruction
#[derive(Debug, BorshDeserialize, BorshSerialize, PartialEq)]
pub enum ConfigInstruction {
Initialize,
}
pub fn initialize(
program_id: &Pubkey,
config: &Pubkey,
authority: &Pubkey,
) -> Instruction {
let accounts = vec![
AccountMeta::new(*config, true),
AccountMeta::new(*authority, true),
AccountMeta::new_readonly(system_program::id(), false),
];
Instruction::new_with_borsh(
*program_id,
&ConfigInstruction::Initialize,
accounts,
)
}
Seems like anchor is waiting a 8-byte long encoded instruction. While borsh serializes it to a vector with size 1. Any idea what am i doing wrong?

Answer 1

Really took some time to sort this out. Posting so this might be helpful for someone else.
So in order to use anchor's instruction for non-anchor contract you need to import InstructionData trait
use anchor_lang::InstructionData;
You instructions will be available using
use your_anchor_program::instruction::CamelCaseInstructionName
Create instruction as usual
Instruction {
program_id: *program_id,
accounts: vec![
...
],
data: CamelCaseInstructionName.data(),
}