Configurable Environment Variables

Added a FromStr implementation to debian::MultiarchName Implment functionality to load the environment variables associate with packages from the project.toml file use PACKAGE_ENV_VARS constand to map default env vars to be defined if the package is in the project.toml file - these can be overwritten by the values in the project.toml file define the package_env_vars before the env vars in the project.toml file update README to reflect the PACKAGE_ENV_VARS testing the buildpack, added a variable for skipped_packages. Will incorporate that into install_packages move the env logic into configure_layer_environment. Iterate through the skipped_packages to make sure all the env vars are set and the post install command are run flushed out a test in order to accomindate the new parameters passed to configure_layer_environment finished the test for skipped packages update the unit test to use a fixture to create the env correctly use a fixture for the test project.toml file; update the README
heroku · Jan 10, 2025 · 933ea9d · 933ea9d
1 parent 6f8a70e
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diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -26,17 +26,19 @@ reqwest-retry = "0.7"
 serde = { version = "1", features = ["derive"] }
 sequoia-openpgp = { version = "1", default-features = false, features = ["crypto-rust", "allow-experimental-crypto", "allow-variable-time-crypto"] }
 sha2 = "0.10"
-tokio = { version = "1", default-features = false, features = ["rt-multi-thread", "time"] }
+tempfile = "3"
+tokio = { version = "1", default-features = false, features = ["rt-multi-thread", "time", "macros"] }
 tokio-tar = "0.3"
 tokio-util = { version = "0.7", default-features = false, features = ["compat", "io"] }
 toml_edit = "0.22"
 walkdir = "2"
+libcnb-package = "0.26.0"
 
 [dev-dependencies]
+libcnb-package = "0.26.0"
 libcnb-test = "=0.26.0"
 regex = "1"
 strip-ansi-escapes = "0.2"
-tempfile = "3"
 buildpacks-deb-packages = { path = "." }
 
 [lints.rust]

diff --git a/README.md b/README.md
@@ -51,6 +51,25 @@ The configuration for this buildpack must be added to the project descriptor fil
 project using the `com.heroku.buildpacks.deb-packages` table. The list of packages to install must be
 specified there. See below for the [configuration schema](#schema) and an [example](#example).
 
+### Configuring Environment Variables
+
+You can configure environment variables for the packages installed by this buildpack by defining them in the `project.toml` file. The environment variables are specified under the `env` key for each package.  There can be more than one environment variable defined for each package.
+
+During the build process, the buildpack will read the `project.toml` file and apply the specified environment variables. The `{install_dir}` placeholder will be replaced with the actual paths so the variables are available at both `build` and `launch` phases using [layer environment variables][cnb-environment].
+
+### Default Package Environment Variables
+The buildpack includes a set of default environment variables for each package, known as `PACKAGE_ENV_VARS`. These default environment variables are applied during the build process. However, you can override these default values by specifying environment variables in the project.toml file.
+
+If a package is listed in the project.toml file with environment variables under the env key, those variables will take precedence over the default `PACKAGE_ENV_VARS`.
+
+### Executing Commands After Package Installation
+
+You can specify commands to be executed after the installation of each package by defining them in the project.toml file under the commands key for each package. These commands will be executed in the order they are listed.
+
+## Environment Variables and Post-Install Commands for Skipped Packages
+
+Even if a package is skipped, the environment variables and post-install commands defined for that package will still be applied and executed. This ensures that any necessary configuration or setup steps are performed, even if the package itself is not installed.
+
 #### Example
 
 ```toml
@@ -61,10 +80,20 @@ schema-version = "0.2"
 # buildpack configuration goes here
 [com.heroku.buildpacks.deb-packages]
 install = [
-    # string version of a dependency to install
-    "package-name",
-    # inline-table version of a dependency to install
-    { name = "package-name", skip_dependencies = true, force = true }
+  # basic package with some dependencies
+  "libgwenhywfar79",
+  # child package of "libgwenhywfar79" so we should get a warning that it was already installed by the previous entry
+  "libgwenhywfar-data",
+  # package with child dependencies skipped so no "libxmlsec1" or "libxmlsec1-openssl" will be installed
+  { name = "xmlsec1", skip_dependencies = true },
+  # a package already installed on the system
+  "wget",
+  # libvips is a virtual package which is only provided by libvips42 so no need to halt and ask the user which implementing package to install
+  "libvips",
+  # curl is already on the system so we're going to force it to be installed
+  { name = "curl", force = true },
+  # git needs to have environment variables set and post installation commands run
+  { name = "git", env = {"GIT_EXEC_PATH" = "{install_dir}/usr/lib/git-core", "GIT_TEMPLATE_DIR" = "{install_dir}/usr/share/git-core/templates"}, commands = ["echo 'Git installed successfully'", "git --version"]},
 ]
 ```
 
@@ -97,6 +126,14 @@ install = [
 
               If set to `true`, the package will be installed even if it's already installed on the system.
 
+            - `env` *__([inline-table][toml-inline-table], optional, default={})__*
+
+              A table of environment variables to set for the package. The keys are the variable names and the values are the variable values. The `{build_dir}` placeholder can be used in the values and will be replaced with the actual build directory path.
+
+            - `commands` *__([array][toml-array], optional, default=[])__*
+
+              A list of commands to execute after the package is installed. The commands will be executed in the order they are listed.
+
 > [!TIP]
 > Users of the [heroku-community/apt][classic-apt-buildpack] can migrate their Aptfile to the above configuration by
 > adding a `project.toml` file with:
@@ -199,9 +236,9 @@ For each package added after [determining the packages to install](#step-2-deter
 | `INCLUDE_PATH`       | `/<layer_dir>/usr/include/<arch>` <br> `/<layer_dir>/usr/include`                                                | header files     |
 | `CPATH`              | Same as `INCLUDE_PATH`                                                                                           | header files     |
 | `CPPPATH`            | Same as `INCLUDE_PATH`                                                                                           | header files     |
-
 | `PKG_CONFIG_PATH`    | `/<layer_dir>/usr/lib/<arch>/pkgconfig` <br> `/<layer_dir>/usr/lib/pkgconfig`                                    | pc files         |
 | `GIT_EXEC_PATH`    | `/<layer_dir>/app/.apt/usr/lib/git-core`                                    | git files         |
+
 ## Contributing
 
 Issues and pull requests are welcome. See our [contributing guidelines](./CONTRIBUTING.md) if you would like to help.
@@ -260,3 +297,20 @@ Issues and pull requests are welcome. See our [contributing guidelines](./CONTRI
 
 [toml-table]: https://toml.io/en/v1.0.0#table
 
+## Testing Locally
+
+To test the project locally, follow these steps:
+
+### Prerequisites
+
+Ensure you have the following installed:
+- Rust and Cargo: [Installation Guide](https://www.rust-lang.org/tools/install)
+- Docker (if applicable for your tests)
+- `cargo install libcnb-cargo`
+
+### Building the Project
+
+`cargo build` to build the project
+`cargo test` to run the automated tests
+`cargo test --test integration_test` to run integration tests
+`cargo libcnb package` builds an image of the buildpack that can be used with an application.  The output of this command shows usage of the generated image.
diff --git a/project.toml b/project.toml
@@ -3,6 +3,7 @@ schema-version = "0.2"
 
 [com.heroku.buildpacks.deb-packages]
 install = [
-  "git",
-  "systemd-cron"
+    { name = "git", env = {"GIT_EXEC_PATH" = "{install_dir}/usr/lib/git-core", "GIT_TEMPLATE_DIR" = "{install_dir}/usr/share/git-core/templates"}, commands = ["echo 'Git installed successfully'", "git --version"]},
+    { name = "babeld" },
+    { name = "ghostscript", skip_dependencies = true, force = true, env = {"GS_LIB" = "{install_dir}/var/lib/ghostscript"}, commands = ["echo 'Ghostscript installed successfully'", "gs --version"]},
 ]
diff --git a/src/config/buildpack_config.rs b/src/config/buildpack_config.rs
@@ -108,46 +108,138 @@ impl From<ConfigError> for libcnb::Error<DebianPackagesBuildpackError> {
 #[cfg(test)]
 mod test {
     use crate::debian::PackageName;
+    use std::collections::HashMap;
+    use indexmap::IndexSet;
+    use std::str::FromStr;
 
     use super::*;
 
     #[test]
-    fn test_deserialize() {
+    fn test_deserialize_basic() {
         let toml = r#"
 [_]
 schema-version = "0.2"
 
 [com.heroku.buildpacks.deb-packages]
 install = [
     "package1",
-    { name = "package2" },
-    { name = "package3", skip_dependencies = true, force = true },
+    { name = "package2", env = {"ENV_VAR_1" = "VALUE_1"}, commands = ["command1", "command2"] },
+    { name = "package3", skip_dependencies = true, force = true, env = {"ENV_VAR_2" = "VALUE_2", "ENV_VAR_3" = "VALUE_3"}, commands = ["command3"] },
 ]
         "#
         .trim();
+
         let config = BuildpackConfig::from_str(toml).unwrap();
-        assert_eq!(
-            config,
-            BuildpackConfig {
-                install: IndexSet::from([
-                    RequestedPackage {
-                        name: PackageName::from_str("package1").unwrap(),
-                        skip_dependencies: false,
-                        force: false,
-                    },
-                    RequestedPackage {
-                        name: PackageName::from_str("package2").unwrap(),
-                        skip_dependencies: false,
-                        force: false,
-                    },
-                    RequestedPackage {
-                        name: PackageName::from_str("package3").unwrap(),
-                        skip_dependencies: true,
-                        force: true,
-                    }
-                ])
-            }
-        );
+
+        let expected_config = BuildpackConfig {
+            install: IndexSet::from([
+                RequestedPackage {
+                    name: PackageName::from_str("package1").unwrap(),
+                    skip_dependencies: false,
+                    force: false,
+                    env: None,
+                    commands: vec![],
+                },
+                RequestedPackage {
+                    name: PackageName::from_str("package2").unwrap(),
+                    skip_dependencies: false,
+                    force: false,
+                    env: Some(HashMap::from([
+                        ("ENV_VAR_1".to_string(), "VALUE_1".to_string()),
+                    ])),
+                    commands: vec!["command1".to_string(), "command2".to_string()],
+                },
+                RequestedPackage {
+                    name: PackageName::from_str("package3").unwrap(),
+                    skip_dependencies: true,
+                    force: true,
+                    env: Some(HashMap::from([
+                        ("ENV_VAR_2".to_string(), "VALUE_2".to_string()),
+                        ("ENV_VAR_3".to_string(), "VALUE_3".to_string()),
+                    ])),
+                    commands: vec!["command3".to_string()],
+                },
+            ]),
+        };
+
+        assert_eq!(config, expected_config);
+    }
+
+    #[test]
+    fn test_deserialize_with_env() {
+        let toml = r#"
+[_]
+schema-version = "0.2"
+
+[com.heroku.buildpacks.deb-packages]
+install = [
+    { name = "package1", env = {"ENV_VAR_1" = "VALUE_1"} },
+]
+        "#
+        .trim();
+
+        let config = BuildpackConfig::from_str(toml).unwrap();
+
+        let expected_config = BuildpackConfig {
+            install: IndexSet::from([
+                RequestedPackage {
+                    name: PackageName::from_str("package1").unwrap(),
+                    skip_dependencies: false,
+                    force: false,
+                    env: Some(HashMap::from([("ENV_VAR_1".to_string(), "VALUE_1".to_string())])),
+                    commands: vec![],
+                },
+            ]),
+        };
+
+        assert_eq!(config, expected_config);
+    }
+
+    #[test]
+    fn test_deserialize_with_commands() {
+        let toml = r#"
+[_]
+schema-version = "0.2"
+
+[com.heroku.buildpacks.deb-packages]
+install = [
+    { name = "package1", commands = ["echo 'Hello, world!'"] },
+]
+        "#
+        .trim();
+
+        let config = BuildpackConfig::from_str(toml).unwrap();
+
+        let expected_config = BuildpackConfig {
+            install: IndexSet::from([
+                RequestedPackage {
+                    name: PackageName::from_str("package1").unwrap(),
+                    skip_dependencies: false,
+                    force: false,
+                    env: None,
+                    commands: vec!["echo 'Hello, world!'".to_string()],
+                },
+            ]),
+        };
+
+        assert_eq!(config, expected_config);
+    }
+
+    #[test]
+    fn test_deserialize_invalid_config() {
+        let toml = r#"
+[_]
+schema-version = "0.2"
+
+[com.heroku.buildpacks.deb-packages]
+install = [
+    { name = 123 },
+]
+        "#
+        .trim();
+
+        let result = BuildpackConfig::from_str(toml);
+        assert!(result.is_err());
     }
 
     #[test]