refactor: inefficiency in generated Containerfile

src/template.rs

@@ -14,6 +14,7 @@ use typed_builder::TypedBuilder;
 use crate::module_recipe::Recipe;
 
 pub const DEFAULT_CONTAINERFILE: &str = include_str!("../templates/Containerfile.tera");
+pub const EXPORT_SCRIPT: &str = include_str!("../templates/export.sh");
 
 #[derive(Debug, Clone, Args, TypedBuilder)]
 pub struct TemplateCommand {
@@ -119,7 +120,9 @@ impl TemplateCommand {
                         }
                         None => Err("Arg containerfile wasn't a string".into()),
                     },
-                    None => Err("Needs the argument 'containerfile'".into()),
+                    None => {
+                        Err("Needs the argument 'containerfile' for print_containerfile()".into())
+                    }
                 }
             },
         );
@@ -134,7 +137,7 @@ impl TemplateCommand {
                         Ok(s) => Ok(s.into()),
                         Err(e) => Err(format!("Unable to serialize: {e}").into()),
                     },
-                    None => Err("Needs the argument 'module'".into()),
+                    None => Err("Needs the argument 'module' for print_module_context()".into()),
                 }
             },
         );
@@ -162,7 +165,7 @@ impl TemplateCommand {
                             Err(_) => Err(format!("Unable to deserialize file {file}").into()),
                         }
                     }
-                    None => Err("Needs the argument 'file'".into()),
+                    None => Err("Needs the argument 'file' for get_module_from_file()".into()),
                 }
             },
         );
@@ -177,6 +180,32 @@ impl TemplateCommand {
             },
         );
 
+        debug!("Registering function `print_script`");
+        tera.register_function(
+            "print_script",
+            |args: &HashMap<String, tera::Value>| -> tera::Result<tera::Value> {
+                trace!("tera fn print_script({args:#?})");
+
+                let escape_script = |script_contents: &str| {
+                    format!(
+                        "\"{}\"",
+                        script_contents
+                            .replace('\n', "\\n")
+                            .replace('\"', "\\\"")
+                            .replace('$', "\\$")
+                    )
+                };
+
+                match args.get("script") {
+                    Some(x) => match x.as_str().unwrap_or_default() {
+                        "export" => Ok(escape_script(EXPORT_SCRIPT).into()),
+                        _ => Err(format!("Script {x} doesn't exist").into()),
+                    },
+                    None => Err("Needs the argument 'script' for 'print_script()'".into()),
+                }
+            },
+        );
+
         Ok((tera, context))
     }
 }

templates/Containerfile.tera

@@ -29,9 +29,7 @@ COPY --from=ghcr.io/ublue-os/bling:latest /modules /tmp/modules/
 # Custom modules overwrite defaults
 COPY modules /tmp/modules/
 
-RUN echo "#!/usr/bin/env bash" >> /tmp/exports.sh
-RUN echo 'get_yaml_array() { readarray "$1" < <(echo "$3" | yq -I=0 "$2"); }; export -f get_yaml_array' >> /tmp/exports.sh
-RUN chmod +x /tmp/exports.sh
+RUN printf {{ print_script(script = "export") }} >> /tmp/exports.sh && chmod +x /tmp/exports.sh
 
 ARG CONFIG_DIRECTORY="/tmp/config"
 ARG IMAGE_NAME="{{ name }}"
@@ -44,8 +42,7 @@ ARG BASE_IMAGE="{{ base_image }}"
 {{ print_containerfile(containerfile = c ) }}
 			{%- endfor %}
 		{%- else %}
-RUN chmod +x /tmp/modules/{{ module.type }}/{{ module.type }}.sh
-RUN source /tmp/exports.sh && OS_VERSION="$(grep -Po '(?<=VERSION_ID=)\d+' /usr/lib/os-release)" /tmp/modules/{{ module.type }}/{{ module.type }}.sh '{{ print_module_context(module = module) }}'
+RUN chmod +x /tmp/modules/{{ module.type }}/{{ module.type }}.sh && source /tmp/exports.sh && /tmp/modules/{{ module.type }}/{{ module.type }}.sh '{{ print_module_context(module = module) }}'
 		{%- endif %}
 	{%- elif module["from-file"] %}
 		{%- set extra_module = get_module_from_file(file = module["from-file"]) %}

templates/export.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+get_yaml_array() { 
+  readarray "$1" < <(echo "$3" | yq -I=0 "$2")
+} 
+
+export -f get_yaml_array
+export OS_VERSION=$(grep -Po '(?<=VERSION_ID=)\d+' /usr/lib/os-release)