| # Copyright 2017 The Bazel Authors. All rights reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| # Rules for templating / files layout |
| |
| def _expand_template_impl(ctx): |
| """Simply spawn the template-engine in a rule.""" |
| variables = [ |
| "--variable=%s=%s" % (k, ctx.attr.substitutions[k]) |
| for k in ctx.attr.substitutions |
| ] |
| if not ctx.attr.escape_xml: |
| variables += ["--noescape_xml"] |
| d = {str(ctx.attr.deps[i].label): ctx.files.deps[i].path |
| for i in range(0, len(ctx.attr.deps))} |
| imports = ["--imports=%s=%s" % (k, d[k]) for k in d] |
| imports += ["--imports=%s=%s" % (k, d[str(ctx.label.relative(ctx.attr.deps_aliases[k]))]) |
| for k in ctx.attr.deps_aliases] |
| ctx.action( |
| executable = ctx.executable._engine, |
| arguments = [ |
| "--executable" if ctx.attr.executable else "--noexecutable", |
| "--template=%s" % ctx.file.template.path, |
| "--output=%s" % ctx.outputs.out.path, |
| ] + variables + imports, |
| inputs = [ctx.file.template] + ctx.files.deps, |
| outputs = [ctx.outputs.out], |
| ) |
| |
| expand_template = rule( |
| attrs = { |
| "template": attr.label( |
| mandatory = True, |
| allow_files = True, |
| single_file = True, |
| ), |
| "deps": attr.label_list(default = [], allow_files = True), |
| "deps_aliases": attr.string_dict(default = {}), |
| "substitutions": attr.string_dict(mandatory = True), |
| "out": attr.output(mandatory = True), |
| "executable": attr.bool(default = True), |
| "escape_xml": attr.bool(default = True), |
| "_engine": attr.label( |
| default = Label("//templating:template_engine"), |
| executable = True, |
| cfg="host"), |
| }, |
| implementation = _expand_template_impl, |
| ) |
| """Expand a jinja2 template file. |
| |
| This rules expands the file given in template, into the file given by out. |
| |
| Args: |
| template: The template file to expand. |
| deps: additional files to expand, they will be accessible as imports[label] |
| in the template environment. If a file ends with .tpl, it is considered |
| a template itself and will be expanded. |
| deps_aliases: a dictionary of name to label. Each label in that dictionary |
| should be present in the deps attribute, and will be make accessible as |
| imports[name] in the template environment. |
| substitutions: a dictionary of key => values that will appear as variables.key |
| in the template environment. |
| out: the name of the output file to generate. |
| executable: mark the result as excutable if set to True. |
| """ |
| |
| def strip_prefix(path, prefixes): |
| for prefix in prefixes: |
| if path.startswith(prefix): |
| return path[len(prefix):] |
| return path |
| |
| def _dest_path(f, strip_prefixes): |
| """Returns the short path of f, stripped of strip_prefixes.""" |
| return strip_prefix(f.short_path, strip_prefixes) |
| |
| def _format_path(path_format, path): |
| dirsep = path.rfind("/") |
| dirname = path[:dirsep] if dirsep > 0 else "" |
| basename = path[dirsep+1:] if dirsep > 0 else path |
| extsep = basename.rfind(".") |
| extension = basename[extsep+1:] if extsep > 0 else "" |
| basename = basename[:extsep] if extsep > 0 else basename |
| return path_format.format( |
| path=path, |
| dirname=dirname, |
| basename=basename, |
| extension=extension |
| ) |
| |
| def _append_inputs(args, inputs, f, path, path_format): |
| args.append("--file=%s=%s" % ( |
| f.path, |
| _format_path(path_format, path) |
| )) |
| inputs.append(f) |
| |
| def _merge_files_impl(ctx): |
| """Merge a list of config files in a tar ball with the correct layout.""" |
| output = ctx.outputs.out |
| build_tar = ctx.executable._build_tar |
| inputs = [] |
| args = [ |
| "--output=" + output.path, |
| "--directory=" + ctx.attr.directory, |
| "--mode=0644", |
| ] |
| variables = [ |
| "--variable=%s=%s" % (k, ctx.attr.substitutions[k]) |
| for k in ctx.attr.substitutions |
| ] |
| for f in ctx.files.srcs: |
| path = _dest_path(f, ctx.attr.strip_prefixes) |
| if path.endswith(ctx.attr.template_extension): |
| path = path[:-4] |
| f2 = ctx.new_file(ctx.label.name + "/" + path) |
| ctx.action( |
| executable = ctx.executable._engine, |
| arguments = [ |
| "--template=%s" % f.path, |
| "--output=%s" % f2.path, |
| "--noescape_xml", |
| ] + variables, |
| inputs = [f], |
| outputs = [f2], |
| ) |
| _append_inputs(args, inputs, f2, path, ctx.attr.path_format) |
| else: |
| _append_inputs(args, inputs, f, path, ctx.attr.path_format) |
| ctx.action( |
| executable = build_tar, |
| arguments = args, |
| inputs = inputs, |
| outputs = [output], |
| mnemonic="MergeFiles" |
| ) |
| |
| merge_files = rule( |
| attrs = { |
| "srcs": attr.label_list(allow_files=True), |
| "template_extension": attr.string(default=".tpl"), |
| "directory": attr.string(default="/"), |
| "strip_prefixes": attr.string_list(default=[]), |
| "substitutions": attr.string_dict(default={}), |
| "path_format": attr.string(default="{path}"), |
| "_build_tar": attr.label( |
| default=Label("@bazel_tools//tools/build_defs/pkg:build_tar"), |
| cfg="host", |
| executable=True, |
| allow_files=True), |
| "_engine": attr.label( |
| cfg="host", |
| default = Label("//templating:template_engine"), |
| executable = True), |
| }, |
| outputs = {"out": "%{name}.tar"}, |
| implementation = _merge_files_impl, |
| ) |
| """Merge a set of files in a single tarball. |
| |
| This rule merge a set of files into one tarball, each file will appear in the |
| tarball as a file determined by path_format, strip_prefixes and directory. |
| |
| Outputs: |
| <name>.tar: the tarball containing all the files in srcs. |
| |
| Args: |
| srcs: The list of files to merge. If a file is ending with ".tpl" (see |
| template_extension), it will get expanded like a template passed to |
| expand_template. |
| template_extension: extension of files to be considered as template, ".tpl" |
| by default. |
| directory: base directory for all the files in the resulting tarball. |
| strip_prefixes: list of prefixes to strip from the path of the srcs to obtain |
| the final path (see path_format). |
| substitutions: map of substitutions to make available during template |
| expansion. Values of that map will be available as "variables.name" in |
| the template environment. |
| path_format: format of the final files. Each file will appear in the final |
| tarball under "{directory}/{path_format}" where the following string of |
| path_format are replaced: |
| {path}: path of the input file, removed from prefixes and suffixes, |
| {dirname}: directory name of path, |
| {basename}: base filename of path, |
| {extension}: extension of path |
| """ |
