remove(cmd): Remove `zebrad download` command, because it no longer does anything (#7819)

* Remove the `zebrad download` command

* Reorder command.rs imports

* Remove zcash-params/Dockerfile and the main Dockerfile commands that use it

* Stop building zcash-params Docker images in CI

* Update CHANGELOG for `zebrad download` removal

* Clarify why the image is smaller

Co-authored-by: Marek <mail@marek.onl>

---------

Co-authored-by: Marek <mail@marek.onl>

.github/workflows/sub-build-zcash-params.yml

@@ -1,45 +0,0 @@
-name: Build zcash-params
-
-# Ensures that only one workflow task will run at a time. Previous deployments, if
-# already in process, won't get cancelled. Instead, we let the first to complete
-# then queue the latest pending workflow, cancelling any workflows in between
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: false
-
-on:
-  workflow_dispatch:
-    inputs:
-      no_cache:
-        description: 'Disable the Docker cache for this build'
-        required: false
-        type: boolean
-        default: false
-
-  push:
-    branches:
-      - 'main'
-    paths:
-      # parameter download code
-      - 'zebra-consensus/src/primitives/groth16/params.rs'
-      - 'zebra-consensus/src/router.rs'
-      - 'zebrad/src/commands/download.rs'
-      - 'zebrad/src/commands/start.rs'
-      # workflow definitions
-      - 'docker/zcash-params/Dockerfile'
-      - '.dockerignore'
-      - '.github/workflows/sub-build-zcash-params.yml'
-      - '.github/workflows/sub-build-docker-image.yml'
-
-jobs:
-  build:
-    name: Build Zcash Params Docker
-    uses: ./.github/workflows/sub-build-docker-image.yml
-    with:
-      dockerfile_path: ./docker/zcash-params/Dockerfile
-      dockerfile_target: release
-      image_name: zcash-params
-      no_cache: ${{ inputs.no_cache || false }}
-      rust_backtrace: full
-      rust_lib_backtrace: full
-      rust_log: info

CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 
 ## [Zebra 1.4.0](https://github.com/ZcashFoundation/zebra/releases/tag/v1.4.0) - TODO: DATE
 
-Zebra's mining RPCs are now available in release builds. TODO: rest of intro
+Zebra's mining RPCs are now available in release builds. Our Docker images are significantly smaller,
+because the smaller Zcash verification parameters are now built into the `zebrad` binary.
+TODO: rest of intro
 
 This release contains the following changes:
 
@@ -21,10 +23,12 @@ read our [mining blog post](https://zfnd.org/experimental-mining-support-in-zebr
 Please [let us know](https://github.com/ZcashFoundation/zebra/issues/new?assignees=&labels=C-enhancement%2CS-needs-triage&projects=&template=feature_request.yml&title=feature%3A+)
 if your mining pool needs extra RPC methods or fields.
 
-### Parameters in Binary
+### Zcash Parameters in `zebrad` Binary
 
 `zebrad` now bundles zk-SNARK parameters directly into its binary. This increases the binary size
-by a few megabytes, but these parameters do not need to be downloaded or stored separately.
+by a few megabytes, but reduces the size of the Docker image by around 600 MB because
+the parameters don't contain the Sprout proving key anymore. The `zebrad download`
+command does nothing, so it has been removed.
 
 Previously, parameters were stored by default in these locations:
 

docker/Dockerfile

@@ -95,9 +95,7 @@ ENV CARGO_HOME="/opt/zebrad/.cargo/"
 # We also download needed dependencies for tests to work, from other images.
 # An entrypoint.sh is only available in this step for easier test handling with variables.
 FROM deps AS tests
-# TODO: do not hardcode the user /root/ even though is a safe assumption
-# Pre-download Zcash Sprout, Sapling parameters and Lightwalletd binary
-COPY --from=us-docker.pkg.dev/zfnd-dev-zebra/zebra/zcash-params:edge /root/.zcash-params /root/.zcash-params
+
 COPY --from=us-docker.pkg.dev/zfnd-dev-zebra/zebra/lightwalletd:edge /opt/lightwalletd /usr/local/bin
 
 # cargo uses timestamps for its cache, so they need to be in this order:
@@ -176,11 +174,10 @@ RUN chmod u+x /entrypoint.sh
 # This stage is only used when deploying nodes or when only the resulting zebrad binary is needed
 #
 # To save space, this step starts from scratch using debian, and only adds the resulting
-# binary from the `release` stage, and the Zcash Sprout & Sapling parameters from ZCash
+# binary from the `release` stage
 FROM debian:bullseye-slim AS runtime
 COPY --from=release /opt/zebrad/target/release/zebrad /usr/local/bin
 COPY --from=release /entrypoint.sh /
-COPY --from=us-docker.pkg.dev/zfnd-dev-zebra/zebra/zcash-params:edge /root/.zcash-params /root/.zcash-params
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \

docker/zcash-params/Dockerfile

@@ -1,19 +0,0 @@
-# This image is for caching Zcash Sprout and Sapling parameters.
-# We don't test it automatically in CI due to download server rate-limiting.
-# To manually run it on the PR branch before merging, go to:
-# https://github.com/ZcashFoundation/zebra/actions/workflows/zcash-params.yml
-
-FROM debian:bullseye-slim AS release
-
-# Just use the precompiled zebrad binary from a recent release image.
-#
-# It doesn't matter what build or commit of Zebra we use, because it just calls into the
-# zcash_proofs download code. (Which doesn't change much.)
-# Test image zebrad binaries would also work, but it's harder to get a recent tag for them.
-#
-# Compiling the download-params example using `cargo ` is another alternative:
-# `cargo run --locked --release --features default-docker --example download-params`
-COPY --from=zfnd/zebra:latest /usr/local/bin/zebrad /usr/local/bin
-
-# Pre-download Zcash Sprout and Sapling parameters
-RUN zebrad download

zebrad/src/commands.rs

@@ -1,7 +1,16 @@
 //! Zebrad Subcommands
 
+use std::path::PathBuf;
+
+use abscissa_core::{config::Override, Command, Configurable, FrameworkError, Runnable};
+
+use crate::config::ZebradConfig;
+
+pub use self::{entry_point::EntryPoint, start::StartCmd};
+
+use self::{copy_state::CopyStateCmd, generate::GenerateCmd, tip_height::TipHeightCmd};
+
 mod copy_state;
-mod download;
 mod entry_point;
 mod generate;
 mod start;
@@ -10,18 +19,7 @@ mod tip_height;
 #[cfg(test)]
 mod tests;
 
-use self::ZebradCmd::*;
-use self::{
-    copy_state::CopyStateCmd, download::DownloadCmd, generate::GenerateCmd,
-    tip_height::TipHeightCmd,
-};
-
-pub use self::{entry_point::EntryPoint, start::StartCmd};
-
-use crate::config::ZebradConfig;
-
-use abscissa_core::{config::Override, Command, Configurable, FrameworkError, Runnable};
-use std::path::PathBuf;
+use ZebradCmd::*;
 
 /// Zebrad Configuration Filename
 pub const CONFIG_FILE: &str = "zebrad.toml";
@@ -33,10 +31,6 @@ pub enum ZebradCmd {
     // TODO: hide this command from users in release builds (#3279)
     CopyState(CopyStateCmd),
 
-    // The `download` subcommand
-    /// Pre-download required Zcash Sprout and Sapling parameter files
-    Download(DownloadCmd),
-
     /// Generate a default `zebrad.toml` configuration
     Generate(GenerateCmd),
 
@@ -60,7 +54,7 @@ impl ZebradCmd {
             CopyState(_) | Start(_) => true,
 
             // Utility commands that don't use server components
-            Download(_) | Generate(_) | TipHeight(_) => false,
+            Generate(_) | TipHeight(_) => false,
         }
     }
 
@@ -74,14 +68,14 @@ impl ZebradCmd {
             Start(_) => true,
 
             // Utility commands
-            CopyState(_) | Download(_) | Generate(_) | TipHeight(_) => false,
+            CopyState(_) | Generate(_) | TipHeight(_) => false,
         }
     }
 
     /// Returns true if this command should ignore errors when
     /// attempting to load a config file.
     pub(crate) fn should_ignore_load_config_error(&self) -> bool {
-        matches!(self, ZebradCmd::Generate(_) | ZebradCmd::Download(_))
+        matches!(self, ZebradCmd::Generate(_))
     }
 
     /// Returns the default log level for this command, based on the `verbose` command line flag.
@@ -96,7 +90,7 @@ impl ZebradCmd {
             Generate(_) | TipHeight(_) => true,
 
             // Commands that generate informative logging output by default.
-            CopyState(_) | Download(_) | Start(_) => false,
+            CopyState(_) | Start(_) => false,
         };
 
         if only_show_warnings && !verbose {
@@ -113,7 +107,6 @@ impl Runnable for ZebradCmd {
     fn run(&self) {
         match self {
             CopyState(cmd) => cmd.run(),
-            Download(cmd) => cmd.run(),
             Generate(cmd) => cmd.run(),
             Start(cmd) => cmd.run(),
             TipHeight(cmd) => cmd.run(),

zebrad/src/commands/download.rs

@@ -1,35 +0,0 @@
-//! `download` subcommand - pre-download required parameter files
-//!
-//! `zebrad download` automatically downloads required parameter files the first time it is run.
-//!
-//! This command should be used if you're launching lots of `zebrad start` instances for testing,
-//! or you want to include the parameter files in a distribution package.
-
-use abscissa_core::{Command, Runnable};
-
-/// Pre-download required Zcash Sprout and Sapling parameter files
-#[derive(Command, Debug, Default, clap::Parser)]
-pub struct DownloadCmd {}
-
-impl DownloadCmd {
-    /// Download the Sapling and Sprout Groth16 parameters if needed,
-    /// check they were downloaded correctly, and load them into Zebra.
-    ///
-    /// # Panics
-    ///
-    /// If the downloaded or pre-existing parameter files are invalid.
-    fn download_and_check(&self) {
-        // The lazy static initializer does the download, if needed,
-        // and the file hash checks.
-        lazy_static::initialize(&zebra_consensus::groth16::GROTH16_PARAMETERS);
-    }
-}
-
-impl Runnable for DownloadCmd {
-    /// Run the download command.
-    fn run(&self) {
-        info!("checking if Zcash Sapling and Sprout parameters have been downloaded");
-
-        self.download_and_check();
-    }
-}