Add command line option to print build info

Like commit sha1, rustc version used to build the app, host and target
triplets, etc.

.github/workflows/ci.yaml

@@ -190,6 +190,14 @@ jobs:
           command: build
           args: --release --target=${{ matrix.rust_target_arch }}
 
+      - name: Run app with --build-info
+        uses: actions-rs/cargo@v1
+        if: matrix.cross == false
+        with:
+          use-cross: ${{ matrix.cross }}
+          command: run
+          args: --release --target=${{ matrix.rust_target_arch }} -- --build-info
+
       - name: Create staging archive
         id: create_staging_archive
         uses: ./.github/actions/create_archive

Cargo.toml

@@ -9,6 +9,7 @@ license = "MIT"
 keywords = ["dyndns", "digitalocean"]
 exclude = ["/ci/*", "/.github/*"]
 publish = false
+build = "build.rs"
 
 [[bin]]
 name = "do_ddns"
@@ -35,5 +36,9 @@ signal-hook = { version = "0.3", features = ["extended-siginfo"] }
 toml = "0.5"
 trust-dns-resolver = "0.20"
 
+[build-dependencies]
+anyhow = "1.0"
+vergen = "6"
+
 [dev-dependencies]
 tempfile = "3"

TODO.md

@@ -4,4 +4,3 @@
 * Add support for detecting systemd notify socket to remove timestamp from logs
 * Deduplicate `from_x` code in ConfigValueBuilder
 * Add systemd sample configuration
-* Embed commit SHA1 into help text.

build.rs

@@ -0,0 +1,16 @@
+use anyhow::Result;
+use vergen::{vergen, Config, SemverKind, TimestampKind};
+
+fn main() -> Result<()> {
+    let mut config = Config::default();
+    // Enable build date generation
+    *config.build_mut().kind_mut() = TimestampKind::All;
+
+    // Change the SEMVER output to the lightweight variant
+    *config.git_mut().semver_kind_mut() = SemverKind::Lightweight;
+    // Add a `-dirty` flag to the SEMVER output
+    *config.git_mut().semver_dirty_mut() = Some("-dirty");
+
+    // Generate the instructions
+    vergen(config)
+}

src/build_info.rs

@@ -0,0 +1,62 @@
+use crate::config_consts::BUILD_INFO;
+use clap::ArgMatches;
+
+fn print_build_info() {
+    println!(
+        "
+Build date:          {}
+Build timestamp:     {}
+Build version:       {}
+Commit SHA:          {:?}
+Commit timestamp:    {:?}
+Commit branch:       {:?}
+Commit SemVer:       {:?}
+Rust channel:        {}
+Rust commit date:    {}
+Rust commit SHA:     {}
+Rust host triple:    {}
+Rust llvm version:   {}
+Rust version:        {}
+Cargo target triple: {}
+Cargo profile:       {}
+Cargo features:      {}
+Host platform:       {}
+Host OS:             {}
+Host memory:         {}
+Host CPU:            {}
+Host CPU core count: {}
+Host CPU brand:      {}
+",
+        env!("VERGEN_BUILD_DATE"),
+        env!("VERGEN_BUILD_TIMESTAMP"),
+        env!("VERGEN_BUILD_SEMVER"),
+        option_env!("VERGEN_GIT_SHA"),
+        option_env!("VERGEN_GIT_COMMIT_TIMESTAMP"),
+        option_env!("VERGEN_GIT_BRANCH"),
+        option_env!("VERGEN_GIT_SEMVER_LIGHTWEIGHT"),
+        env!("VERGEN_RUSTC_CHANNEL"),
+        env!("VERGEN_RUSTC_COMMIT_DATE"),
+        env!("VERGEN_RUSTC_COMMIT_HASH"),
+        env!("VERGEN_RUSTC_HOST_TRIPLE"),
+        env!("VERGEN_RUSTC_LLVM_VERSION"),
+        env!("VERGEN_RUSTC_SEMVER"),
+        env!("VERGEN_CARGO_TARGET_TRIPLE"),
+        env!("VERGEN_CARGO_PROFILE"),
+        env!("VERGEN_CARGO_FEATURES"),
+        env!("VERGEN_SYSINFO_NAME"),
+        env!("VERGEN_SYSINFO_OS_VERSION"),
+        env!("VERGEN_SYSINFO_TOTAL_MEMORY"),
+        env!("VERGEN_SYSINFO_CPU_VENDOR"),
+        env!("VERGEN_SYSINFO_CPU_CORE_COUNT"),
+        env!("VERGEN_SYSINFO_CPU_BRAND"),
+    );
+}
+
+pub fn print_build_info_if_requested(clap_matches: &ArgMatches<'static>) -> bool {
+    if clap_matches.is_present(BUILD_INFO) {
+        print_build_info();
+        true
+    } else {
+        false
+    }
+}