feat: Add environment variable expansion in top-level recipe fields

.github/workflows/test.yml

@@ -169,6 +169,45 @@
           COSIGN_PRIVATE_KEY: ${{ secrets.TEST_SIGNING_SECRET }}
         run: just test-empty-files-build
 
+  env-expand-build:
+    timeout-minutes: 60
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read # read repo contents
+      packages: write # write test package to ghcr
+      id-token: write # docker auth
+
+    steps:
+      - name: Maximize build space
+        uses: ublue-os/remove-unwanted-software@cc0becac701cf642c8f0a6613bbdaf5dc36b259e # v9
+
+      - uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
+        with:
+          install: true
+
+      - uses: actions-rust-lang/setup-rust-toolchain@150fca883cd4034361b621bd4e6a9d34e5143606 # v1.15.4
+
+      # Setup repo and add caching
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+          ref: ${{ inputs.ref }}
+          repository: ${{ inputs.repo }}
+
+
+      - uses: extractions/setup-just@f8a3cce218d9f83db3a2ecd90e41ac3de6cdfd9b # v3
+
+      - name: Run Build
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_PR_EVENT_NUMBER: ${{ inputs.pr_event_number }}
+          COSIGN_PRIVATE_KEY: ${{ secrets.TEST_SIGNING_SECRET }}
+        run: just test-env-expansion-build
+
   bluefin-build:
     timeout-minutes: 60
     runs-on: ubuntu-latest

integration-tests/test-repo/recipes/recipe-env-expansion.yml

@@ -0,0 +1,12 @@
+---
+# yaml-language-server: $schema=https://schema.blue-build.org/recipe-v1.json
+name: cli/test-${NAME_EXT:-env-expansion}
+description: This is my personal OS image. ${DESC_EXT}
+base-image: ${BASE_REGISTRY:-quay.io}/fedora/fedora-bootc
+blue-build-tag: none
+cosign-version: none
+image-version: ${VERSION}
+stages:
+  - from-file: stages.yml
+modules:
+  - from-file: common.yml

justfile

@@ -166,6 +166,18 @@ test-empty-files-build: generate-test-secret install-debug-all-features
     {{ should_push }} \
     -vv
 
+test-env-expansion-build: generate-test-secret install-debug-all-features
+  cd integration-tests/test-repo \
+  && DESC_EXT="Test description" \
+  VERSION="43" \
+  bluebuild build \
+    --retry-push \
+    -B docker \
+    -S sigstore \
+    {{ should_push }} \
+    -vv \
+    recipes/recipe-env-expansion.yml
+
 test-bluefin-build: generate-test-secret install-debug-all-features
   cd integration-tests/test-repo \
   && bluebuild build \

recipe/src/recipe.rs

@@ -6,7 +6,8 @@ use std::{
 };
 
 use blue_build_utils::{
-    constants::COSIGN_IMAGE_VERSION, container::Tag, platform::Platform, secret::Secret,
+    constants::COSIGN_IMAGE_VERSION, container::Tag, env_str::EnvString, platform::Platform,
+    secret::Secret,
 };
 use bon::Builder;
 use cached::proc_macro::cached;
@@ -24,21 +25,22 @@ use crate::{Module, ModuleExt, StagesExt, maybe_version::MaybeVersion};
 /// base image to assist with building the Containerfile
 /// and tagging the image appropriately.
 #[derive(Default, Serialize, Clone, Deserialize, Debug, Builder)]
-#[builder(on(String, into))]
+#[allow(clippy::duplicated_attributes)]
+#[builder(on(EnvString, into), on(String, into))]
 pub struct Recipe {
     /// The name of the user's image.
     ///
     /// This will be set on the `org.opencontainers.image.title` label.
-    pub name: String,
+    pub name: EnvString,
 
     /// The description of the user's image.
     ///
     /// This will be set on the `org.opencontainers.image.description` label.
-    pub description: String,
+    pub description: EnvString,
 
     /// The base image from which to build the user's image.
     #[serde(alias = "base-image")]
-    pub base_image: String,
+    pub base_image: EnvString,
 
     /// The version/tag of the base image.
     #[serde(alias = "image-version")]

src/commands/generate.rs

@@ -249,11 +249,11 @@ pub fn generate_default_labels(recipe: &Recipe) -> Result<BTreeMap<String, Strin
             ),
             (
                 "org.opencontainers.image.title".to_string(),
-                recipe.name.clone(),
+                recipe.name.to_string(),
             ),
             (
                 "org.opencontainers.image.description".to_string(),
-                recipe.description.clone(),
+                recipe.description.to_string(),
             ),
             ("org.opencontainers.image.source".to_string(), source),
             (

utils/Cargo.toml

@@ -15,6 +15,7 @@ constcat = "0.6.1"
 directories = "6.0.0"
 docker_credential = "1.3.2"
 process_control = { version = "4.2.2", features = ["crossbeam-channel"] }
+shellexpand = "3.1.2"
 
 bon.workspace = true
 cached.workspace = true

utils/src/container.rs

@@ -11,7 +11,7 @@ use miette::miette;
 use oci_client::Reference;
 use serde::{Deserialize, Serialize};
 
-use crate::platform::Platform;
+use crate::{env_str::EnvString, platform::Platform};
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ContainerId(pub String);
@@ -274,7 +274,7 @@ impl PartialEq<Reference> for ImageRef<'_> {
 }
 
 #[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Tag(String);
+pub struct Tag(EnvString);
 
 impl Tag {
     #[must_use]
@@ -283,15 +283,18 @@ impl Tag {
     }
 }
 
+fn eval_tag(haystack: &EnvString) -> bool {
+    regex!(r"[\w][\w.-]{0,127}").is_match(haystack)
+}
+
 impl FromStr for Tag {
     type Err = miette::Error;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let regex = regex!(r"[\w][\w.-]{0,127}");
-        regex
-            .is_match(s)
-            .then(|| Self(s.into()))
-            .ok_or_else(|| miette!("Invalid tag: {s}"))
+        let expanded = EnvString::from(s);
+        eval_tag(&expanded)
+            .then(|| Self(expanded.clone()))
+            .ok_or_else(|| miette!("Invalid tag: {expanded}"))
     }
 }
 
@@ -317,24 +320,27 @@ impl<'de> Deserialize<'de> for Tag {
     where
         D: serde::Deserializer<'de>,
     {
-        Self::from_str(&String::deserialize(deserializer)?).map_err(serde::de::Error::custom)
+        let expanded = EnvString::deserialize(deserializer)?;
+        eval_tag(&expanded)
+            .then(|| Self(expanded.clone()))
+            .ok_or_else(|| serde::de::Error::custom(format!("Invalid tag: {expanded}")))
     }
 }
 
 impl Default for Tag {
     fn default() -> Self {
-        Self(String::from("latest"))
+        Self(String::from("latest").into())
     }
 }
 
 impl From<Tag> for String {
     fn from(value: Tag) -> Self {
-        value.0
+        value.0.to_string()
     }
 }
 
 impl From<&Tag> for String {
     fn from(value: &Tag) -> Self {
-        value.0.clone()
+        value.0.to_string()
     }
 }

utils/src/env_str.rs

@@ -0,0 +1,98 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, Default, Eq)]
+pub struct EnvString {
+    unexpanded: String,
+    expanded: String,
+}
+
+impl<'de> Deserialize<'de> for EnvString {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let unexpanded = String::deserialize(deserializer)?;
+        let expanded = shellexpand::env(&unexpanded)
+            .map_err(serde::de::Error::custom)?
+            .into();
+
+        Ok(Self {
+            unexpanded,
+            expanded,
+        })
+    }
+}
+
+impl Serialize for EnvString {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(&self.unexpanded)
+    }
+}
+
+impl std::fmt::Display for EnvString {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.expanded)
+    }
+}
+
+impl std::ops::Deref for EnvString {
+    type Target = str;
+
+    fn deref(&self) -> &Self::Target {
+        self.expanded.as_str()
+    }
+}
+
+impl From<String> for EnvString {
+    fn from(value: String) -> Self {
+        Self::from(value.as_str())
+    }
+}
+
+impl From<&String> for EnvString {
+    fn from(value: &String) -> Self {
+        Self::from(value.as_str())
+    }
+}
+
+/// Context function for env var expansion.
+/// If the variable doesn't exist, return None to prevent expansion.
+fn context(var: &str) -> Option<String> {
+    crate::get_env_var(var).ok()
+}
+
+impl From<&str> for EnvString {
+    fn from(value: &str) -> Self {
+        Self {
+            unexpanded: value.to_string(),
+            expanded: shellexpand::env_with_context_no_errors(&value, context).to_string(),
+        }
+    }
+}
+
+impl From<EnvString> for String {
+    fn from(value: EnvString) -> Self {
+        value.expanded
+    }
+}
+
+impl PartialEq for EnvString {
+    fn eq(&self, other: &Self) -> bool {
+        self.expanded.eq(&other.expanded)
+    }
+}
+
+impl Ord for EnvString {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.expanded.cmp(&other.expanded)
+    }
+}
+
+impl PartialOrd for EnvString {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}

utils/src/lib.rs

@@ -3,6 +3,7 @@ pub mod command_output;
 pub mod constants;
 pub mod container;
 pub mod credentials;
+pub mod env_str;
 mod macros;
 pub mod platform;
 pub mod secret;