faucet-common-snowflake 1.0.3

Shared configuration types for the faucet-stream Snowflake source and sink connectors
Documentation

faucet-common-snowflake

Crates.io Docs.rs MSRV License

Shared Snowflake authentication types and SQL REST API header helpers. Part of the faucet-stream ecosystem.

This is an internal building block: it holds the one piece of configuration the Snowflake source and sink must agree on — how a request authenticates against the Snowflake SQL REST API — so both connectors mint identical Authorization / X-Snowflake-Authorization-Token-Type headers from one place instead of duplicating the JWT logic.

What it provides

SnowflakeAuth

The authentication method for a Snowflake connector. It serializes as the project-wide adjacently-tagged shape — { type: <method>, config: { … } }, snake_case discriminators — and derives Serialize, Deserialize, and JsonSchema so it round-trips through YAML/JSON configs and CLI schema introspection. Its Debug impl masks every credential as "***".

type config fields Notes
key_pair user: String, private_key_pem: String RSA key-pair JWT auth. A fresh RS256 JWT is minted locally per request (1-hour expiry); the issuer carries the SHA-256 fingerprint of the derived public key, which Snowflake requires. Accepts PKCS#8 (BEGIN PRIVATE KEY) or PKCS#1 (BEGIN RSA PRIVATE KEY) PEM. Stateless — cannot be sourced from a shared auth: { ref } provider.
oauth token: String OAuth2 bearer token from an external IdP. Can be supplied via a shared auth: { ref } provider.

Helper functions

Function Returns Purpose
authorization_header(auth, account) -> Result<String, FaucetError> Bearer {jwt} for KeyPair; Snowflake Token="{token}" for OAuth Builds the Authorization header value for a SQL REST API request. account (e.g. "xy12345.us-east-1") is uppercased into the JWT iss/sub claims.
snowflake_token_type(auth) -> &'static str KEYPAIR_JWT or OAUTH The matching X-Snowflake-Authorization-Token-Type header value.
credential_to_auth(cred) -> Result<SnowflakeAuth, FaucetError> SnowflakeAuth::OAuth { token } Maps a faucet_core::Credential from a shared AuthProvider onto SnowflakeAuth. Bearer/Token → OAuth; Basic/Header → FaucetError::Auth (key-pair JWT can't come from a provider).

Who should depend on this

Most users don't — it is re-exported by the connectors:

Depend on it directly only if you are building a third-party Snowflake connector and want to accept the same auth config shape and produce correct request headers.

Installation

cargo add faucet-common-snowflake

Usage

In a config (the wire shape SnowflakeAuth deserializes from):

# Key-pair JWT
auth:
  type: key_pair
  config:
    user: SVC_FAUCET
    private_key_pem: ${file:./rsa_key.p8}

# OAuth bearer
auth:
  type: oauth
  config:
    token: ${env:SNOWFLAKE_OAUTH_TOKEN}

In Rust, build the two headers a SQL REST API call needs:

use faucet_common_snowflake::{SnowflakeAuth, authorization_header, snowflake_token_type};

let auth = SnowflakeAuth::OAuth { token: "ey...".into() };
let account = "xy12345.us-east-1";

let authorization = authorization_header(&auth, account)?;      // Snowflake Token="ey..."
let token_type = snowflake_token_type(&auth);                   // "OAUTH"

let resp = client
    .post(format!("https://{account}.snowflakecomputing.com/api/v2/statements"))
    .header("Authorization", authorization)
    .header("X-Snowflake-Authorization-Token-Type", token_type)
    .json(&body)
    .send()
    .await?;
# Ok::<(), faucet_core::FaucetError>(())

Troubleshooting / FAQ

Symptom Likely cause / fix
401 from Snowflake with a key-pair JWT The registered public key must match the private key in private_key_pem. The iss claim is {ACCOUNT}.{USER}.SHA256:<fingerprint>; verify the fingerprint matches openssl rsa -pubout … | openssl dgst -sha256 -binary | base64.
FaucetError::Auth("invalid RSA private key: …") private_key_pem isn't valid PKCS#8 or PKCS#1 PEM. Generate an RSA key in PEM form (encrypted keys are not supported — decrypt first).
FaucetError::Auth("Snowflake auth provider must yield a bearer/token credential") A shared auth: { ref } provider returned a Basic/Header credential. Only OAuth bearer/token credentials work; use inline key_pair for JWT auth.
A private key showed up in logs It shouldn't — SnowflakeAuth's Debug masks all credentials as "***". File an issue if you see one leak.

See also

License

Licensed under either of:

at your option.