Templatization of Dockerfile

1.14.5/bullseye/Dockerfile → Dockerfile

@@ -1,9 +1,9 @@
-FROM debian:bullseye-slim AS verify
+FROM debian:%{variant} AS verify
 
 WORKDIR /verify
 
 # Specify release variables
-ARG RLS_VERSION=1.14.5
+ARG RLS_VERSION=%{version}
 ARG RLS_OS=linux
 ARG RLS_LIB=gnu
 ARG RLS_ARCH=
@@ -27,10 +27,10 @@ ARG REPO_GITIAN_SIGS=https://github.com/dogecoin/gitian.sigs.git
 ARG REPO_DOGECOIN_CORE=https://github.com/dogecoin/dogecoin.git
 
 # Pinned known sha256sums
-RUN    echo f3bc387f393a0d55b6f653aef24febef6cb6f352fab2cbb0bae420bddcdacd1c  dogecoin-1.14.5-aarch64-linux-gnu.tar.gz > SHASUMS \
-    && echo dfdcdc6bb36076e7634cc8ed89138ec0383d73ba42b3e7ecfa9279b8949bce6b  dogecoin-1.14.5-arm-linux-gnueabihf.tar.gz >> SHASUMS \
-    && echo 7e7dd731ecfb2b78d6cc50d013ebf5faceeab50c59ffa2ab7551167b1bb81f08  dogecoin-1.14.5-i686-pc-linux-gnu.tar.gz >> SHASUMS \
-    && echo 17a03f019168ec5283947ea6fbf1a073c1d185ea9edacc2b91f360e1c191428e  dogecoin-1.14.5-x86_64-linux-gnu.tar.gz >> SHASUMS
+RUN    echo %{shasum_arm64}  %{file_arm64} > SHASUMS \
+    && echo %{shasum_armv7}  %{file_armv7} >> SHASUMS \
+    && echo %{shasum_386}  %{file_386} >> SHASUMS \
+    && echo %{shasum_amd64}  %{file_amd64} >> SHASUMS
 
 # install system requirements
 RUN apt update && apt install -y \

apply_templates.py

@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+
+"""
+Clean and generate all files for Dogecoin Core images using Dockerfile
+templates, copying entrypoint.py. Use a manifest (version.json)
+to create images tree structure.
+
+Use python variables in templates using DockerfileTemplate.delimiter `%`.
+Regular Dockerfile variable subsitution symbol `$` won't be alterate.
+
+Template instruction example:
+
+RUN FOO=%{bar}
+RUN FILENAME=%{var_1}-%var2
+"""
+
+from string import Template
+import shutil
+import json
+import os
+
+class DockerfileTemplate(Template):
+    """
+    Interface to generate Dockerfiles from base templates.
+
+    Enable 2 type of variable in Dockerfiles templates,
+    variables with `%` are used by python templates,
+    variable with `$` are regular variable used by Dockerfiles.
+
+    Example: `%version` or `%{version}`
+    """
+    delimiter = "%"
+
+def release_files(version_info):
+    """
+    Format version release files for all architectures with
+    respective checksum.
+
+    Prepare dictionnary for template arguments.
+    """
+    archs_list = version_info["arches"]
+
+    files = {}
+    for architecture, asset in archs_list.items():
+        #Remove 'arm/v7' slash, to use armv7 as python variable
+        architecture = architecture.replace("/", "")
+
+        #Store tar filename and checksum
+        files[f"file_{architecture}"] = asset['file']
+        files[f"shasum_{architecture}"] = asset['shasum']
+
+    return files
+
+def load_template(base):
+    """Load a Dockerfile base template"""
+    with open(base, encoding="utf8") as dockerfile_stream:
+        return DockerfileTemplate(dockerfile_stream.read())
+
+def render_dockerfile(template_vars):
+    """
+    Generate Dockerfile & entrypoint for a single image.
+    Save result in `version/variant` directory.
+    """
+    #Load base template used by the variant
+    template = load_template("Dockerfile")
+
+    #Replace python variable in the base template
+    dockerfile_content = template.substitute(template_vars)
+
+    #Define destination files
+    version = template_vars['version']
+    variant = template_vars['variant']
+
+    directory = os.path.join(version, variant)
+    dockerfile_path = os.path.join(directory, "Dockerfile")
+    entrypoint_path = os.path.join(directory, "entrypoint.py")
+
+    #Write Dockerfile and entrypoint for the image
+    os.makedirs(directory)
+
+    shutil.copy("entrypoint.py", entrypoint_path)
+    with open(dockerfile_path, "w", encoding="utf8") as dockerfile:
+        dockerfile.write(dockerfile_content)
+
+def generate_images_files():
+    """
+    Generate Dockerfile and entrypoint for all images according to
+    a manifest.
+    """
+    # Get manifest file for images versions/variant/architectures
+    with open("version.json", encoding="utf8") as versions_json:
+        manifest = json.load(versions_json)
+
+    for version in manifest:
+        #Clean previous images
+        shutil.rmtree(version, ignore_errors=True)
+
+        #Prepate template variables
+        template_vars = {"version" : version}
+        template_vars.update(release_files(manifest[version]))
+
+        #Generate image files for each variant of the version
+        for variant in manifest[version]['variants']:
+            template_vars['variant'] = variant
+            render_dockerfile(template_vars)
+
+if __name__ == "__main__":
+    generate_images_files()

version.json

@@ -0,0 +1,26 @@
+{
+    "1.14.5": {
+        "arches" : {
+            "amd64" : {
+                "file" : "dogecoin-1.14.5-x86_64-linux-gnu.tar.gz",
+                "shasum" : "17a03f019168ec5283947ea6fbf1a073c1d185ea9edacc2b91f360e1c191428e"
+            },
+            "386" : {
+                "file" : "dogecoin-1.14.5-i686-pc-linux-gnu.tar.gz",
+                "shasum" : "7e7dd731ecfb2b78d6cc50d013ebf5faceeab50c59ffa2ab7551167b1bb81f08"
+            },
+            "arm/v7" : {
+                "file" : "dogecoin-1.14.5-arm-linux-gnueabihf.tar.gz",
+                "shasum" : "dfdcdc6bb36076e7634cc8ed89138ec0383d73ba42b3e7ecfa9279b8949bce6b"
+            },
+            "arm64" : {
+                "file" : "dogecoin-1.14.5-aarch64-linux-gnu.tar.gz",
+                "shasum" : "f3bc387f393a0d55b6f653aef24febef6cb6f352fab2cbb0bae420bddcdacd1c"
+            }
+        },
+        "variants": [
+            "bullseye-slim",
+            "buster-slim"
+        ]
+    }
+}