bazel with protobuf / gRPC-gateway / golang - getting started - bazel

So I am trying to convert a monorepo of micro services (C#, Go, NodeJS) to use bazel. Just playing with it for now.
I focus on one go service to get started and isolated it as a WORKSPACE.
The go service is gRPC service that uses protobuf obviously, grpc-gateway with the protoc-gen-swagger and also protoc-gen-gorm (this one does not support bazel).
The code builds using a command like go build cmd/server/server.go
I am hoping to get some guidance on how to get started to build this project with all the dependencies.
I see several rules available for protobuf/go and I am not yet comfortable browsing through them or deciding which is better (i cannot get any to work due to grpc gateway or protoc gen gorm)
- https://github.com/stackb/rules_proto
- https://github.com/bazelbuild/rules_go
- https://github.com/stackb/rules_proto/tree/master/github.com/grpc-ecosystem/grpc-gateway
Code structure looks like this:
/repo
svc1
svc2
svc3
cmd/server
BUILD.bazel
server.go
pkg
contains folders and some go files and a BUILD.bazel in each
proto
BUILD.bazel
test.proto
WORKSPACE
BUILD.bazel
Right now I only work on svc3. Later i will probably move the WORKSPACE to the parent folder.
My WORKSPACE looks like this:
load("#bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
name = "io_bazel_rules_go",
sha256 = "96b1f81de5acc7658e1f5a86d7dc9e1b89bc935d83799b711363a748652c471a",
urls = [
"https://storage.googleapis.com/bazel-mirror/github.com/bazelbuild/rules_go/releases/download/0.19.2/rules_go-0.19.2.tar.gz",
"https://github.com/bazelbuild/rules_go/releases/download/0.19.2/rules_go-0.19.2.tar.gz",
],
)
load("#io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
go_rules_dependencies()
go_register_toolchains()
http_archive(
name = "bazel_gazelle",
urls = [
"https://storage.googleapis.com/bazel-mirror/github.com/bazelbuild/bazel-gazelle/releases/download/0.18.1/bazel-gazelle-0.18.1.tar.gz",
"https://github.com/bazelbuild/bazel-gazelle/releases/download/0.18.1/bazel-gazelle-0.18.1.tar.gz",
],
sha256 = "be9296bfd64882e3c08e3283c58fcb461fa6dd3c171764fcc4cf322f60615a9b",
)
load("#bazel_gazelle//:deps.bzl", "gazelle_dependencies", "go_repository")
gazelle_dependencies()
load("#bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
git_repository(
name = "com_google_protobuf",
commit = "09745575a923640154bcf307fba8aedff47f240a",
remote = "https://github.com/protocolbuffers/protobuf",
shallow_since = "1558721209 -0700",
)
load("#com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
protobuf_deps()
+ a bunch of go_repository() created by Gazelle
Running gazelle created a bunch of build.bazel files for my go project in each folder.
Next to the .proto, I have a generated build.bazel file:
load("#io_bazel_rules_go//go:def.bzl", "go_library")
load("#io_bazel_rules_go//proto:def.bzl", "go_proto_library")
proto_library(
name = "svc_proto",
srcs = ["test.proto"],
visibility = ["//visibility:public"],
deps = [
# the two github below are referenced as go_repository
"#com_github_infobloxopen_protoc_gen_gorm//options:proto_library", # not sure what to put after the colon
"#com_github_grpc_ecosystem_grpc_gateway//protoc-gen-swagger/options:proto_library",
"#go_googleapis//google/api:annotations_proto",
],
)
go_proto_library(
name = "svc_go_proto",
compilers = ["#io_bazel_rules_go//proto:go_grpc"],
importpath = "src/test/proto/v1",
proto = ":svc_proto",
visibility = ["//visibility:public"],
deps = [
"//github.com/infobloxopen/protoc-gen-gorm/options:go_default_library",
"//github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/options:go_default_library",
"#go_googleapis//google/api:annotations_go_proto",
],
)
go_library(
name = "go_default_library",
embed = [":svc_go_proto"],
importpath = "src/test/proto/v1",
visibility = ["//visibility:public"],
)
Now the questions:
not sure what to put to reference other proto files: "#com_github_infobloxopen_protoc_gen_gorm//options:proto_library" ? and not sure this is the best way to reference other external libraries from git.
if i build the above using bazel build //proto/v1:svc_proto, i get: no such target '#com_github_grpc_ecosystem_grpc_gateway//protoc-gen-swagger/options:proto_library': target 'proto_library' not declared in package 'protoc-gen-swagger/options'. Probably linked to 1.
i am not sure which rule to use. As I need grpc gateway, I guess i
need to exclusively use
https://github.com/stackb/rules_proto/tree/master/github.com/grpc-ecosystem/grpc-gateway
but i can't make them to work either.
I use statik (https://github.com/rakyll/statik) to package the
swagger file in go to server the swagger. Is there any alternative
or if not, how can i call a custom bash/command as part of the build
process in the chain?
In summary, I am pretty sure my BUILD.bazel file to build the proto and library is structured wrong and would appreciate some up-to-date guidance (github is full of repos that are outdated, using outdated rules or simply not working).

Related

Bazel: How to pass relative path of a file as an "args" to java_binary?

I have a file hello.txt that lives in src/main/resources folder.
I am using a java_binary rule and need to pass this hello.txt file as an argument.
java_binary(
name = "Hello",
srcs = glob(["src/main/java/**"]),
args = ["/Users/jdoe/repo1/libraries/myproj/src/main/resources/hello.txt"],
deps = [...],
)
The above works when I provide the full path, however it fails if I try with a relative path like src/main/resources/hello.txt.
How do I provide a relative path to the args attribute?
Your binary depends on the resource file hello.txt, but Bazel is not aware of this. Make hello.txt a data dependency of your java_binary, i. e. add the attribute data = ["src/main/resources/hello.txt"]. Bazel runs your executable in a sandbox, i.e. somewhere where your hello.txt is not present. The data dependency makes sure that the file is copied to the place where it is needed.

How to access node_modules folder after running yarn_install (or npm_install ) in rules_nodejs bazel?

I'm relatively new to Bazel but this has taken longer than I felt it should. I am doing yarn_install in my workspace, and I am just trying to reference the installed node_modules so that I can put them in my new docker container.
Workspace
yarn_install(
name = "npm",
package_json = "//:package.json",
yarn_lock = "//:yarn.lock",
)
BUILD.bazel
load("#io_bazel_rules_docker//nodejs:image.bzl", "nodejs_image")
nodejs_image(
name = "webapi_image",
# gets all the files in my directory
data = glob(
[
"**/*",
],
# references the node modules, but doesn't work :(
) + ["#npm//node_modules"],
entry_point = "//:app.js",
)
I've been able to get specific packages (i.e. #npm//express) but if I try to access node_modules then I just get
no such package '#npm//node_modules': Package is considered deleted due to --deleted_packages and referenced by '//:webapi_image'
I'm not sure I totally understand why I can access individual packages (i.e. #npm//express) but not node_modules (i.e. #npm//node_modules).
but after bumping around, I found if I just use the structure #npm//:node_modules, then it works finally.

How to I set an ENV VAR in my WORKSPACE in Bazel

I am trying to use Bazel with Pybind, and it requires that I set the following variables:
"""Repository rule for Python autoconfiguration.
`python_configure` depends on the following environment variables:
* `PYTHON_BIN_PATH`: location of python binary.
* `PYTHON_LIB_PATH`: Location of python libraries.
"""
https://github.com/pybind/pybind11_bazel/blob/master/python_configure.bzl
I dont want to have to pass it in manually when building my libraries, how can i hardcode these env vars in my WORKSPACE?
To (always) set environmental variable for a repository rule consumption, you case use --repo_env command line option. And if you want to include those with every invocation in your workspace, you can set add these flags to your .bazelrc file therein.
Now the wisdom of doing that could be questioned. If it's actually a project (repo) and not build host configuration, it would probably make more sense, be more targeted and more explicit, if it was an attribute of the given rule which was then checked in with the rest of the build configuration.
And looking at the name, there may be another question about specifying python configuration (from outside the bazel build) instead of actually using correctly resolved python toolchain (but there I have to say have no background in what the given rule is about and what is it trying to accomplish to render judgment, this is just a general comment).
To address your comment... I don't what other factors make it "not accept" or what exactly does that actually look like, but if I have this mini-example:
.
├── BUILD
├── WORKSPACE
└── customrule.bzl
Where customrule.bzl reads:
def _run_me(repo_ctx):
repo_ctx.file(
"WORKSPACE",
'workspace(name = "{}")\n'.format(repo_ctx.name),
executable = False,
)
repo_ctx.file(
"BUILD",
'exports_files(["var.sh"], visibility=["//visibility:public"])',
executable = False,
)
repo_ctx.file(
"var.sh",
"echo {}\n".format(repo_ctx.os.environ.get("var1")),
executable = True,
)
wsrule = repository_rule(
implementation = _run_me,
environ = ["var1"],
)
The WORKSPACE is:
load(":customrule.bzl", "wsrule")
wsrule(
name = "extdep"
)
And BUILD:
sh_binary(
name = "tgt",
srcs = ["#extdep//:var.sh"],
)
Then I do get:
$ bazel run --repo_env var1=val1 tgt
val1
and:
$ bazel run --repo_env var1=val2 tgt
val2
I.e. this is a way to pass variables to a repo rule and it does (as such) work.
If you absolutely know, you must call a build with some variable set to certain value (which as mentioned above is itself a requirement that is worth closer examination) and you want these to be associated with the project / repo. You can always check in a build.sh or any such file that wraps your bazel call to be exactly what it must be. But again, this looks more likely to not be really entirely "The Right Thing" to do or want.

Bazel get location of external dependency as command line arg for py_binary

I need the path to external (or internal) dependency to pass it as an argument to a function inside. We need the location to the folder, not specific files. Also, sometimes, we need the path to the folder where a shared library, generated by cc_library.
Python file
import cppyy
cppyy.add_include_path('path/to/external/dependency/1')
cppyy.add_library_path('path/to/another/external/dependency/2')
cppyy.add_include_path('path/to/another/internal/dependency')
cppyy.include('file/in/external/dependency')
BUILD file
py_binary(
name = "sample",
srcs = ["sample.py"],
deps = [
"#cppyy_archive//:cppyy",
],
data = [
"#external-dependency//location:target",
"//internal-dependency/location:target2"
]
)
From https://docs.bazel.build/versions/master/external.html#layout:
You can see the external directory by running:
ls $(bazel info output_base)/external
How the paths in external actually look like really depends on the rule used for the archive.
For example, if it's declared using an http_file in the WORKSPACE file:
load("#bazel_tools//tools/build_defs/repo:http.bzl", "http_file")
http_file(
name = "fenix",
urls = ["https://github.com/mozilla-mobile/fenix/archive/v76.0.0-beta.2.tar.gz"],
sha256 = "94050c664e5ec5b66cd2ca9f6a8b898987ab63d9602090533217df1a3f2dc5a9"
)
You will find that v76.0.0-beta.2.tar.gz file as external/fenix/file/downloaded:
user#host:~$ file $(bazel info output_base)/external/fenix/file/downloaded
/home/user/.cache/bazel/_bazel_user/761044447e04744e746cd54d0b4b5056/external/fenix/file/downloaded: gzip compressed data, from Unix, original size modulo 2^32 15759360

Read file content in WORKSPACE

I'm using container_pull in my WORKSPACE file. (It's part of bazel docker rules)
Here is what it looks like:
container_pull(
name = "base-image",
registry = "registry:9999",
repository = "base-image",
digest = "sha256:e6f44554a270025c578c0f91160d809735c2589baae80bafcdeebefb0c0b04b6",
tag = "1.1.0"
)
Howeve, there is a file containing the version of base-image, and I want it to be read from that file, instead of hardcoding in WORKSPACE.
How can I read a file content in WORKSPACE?
There's no direct way to read a file from the workspace file. The container_pull rule would have to add support for reading from a file.
A workaround is to put the file that contains the information into .bzl format, and load that from the workspace file.
Something like this:
versions.bzl:
BASE_IMAGE_VERSION = "1.1.0"
WORKSPACE:
load("//:versions.bzl", "BASE_IMAGE_VERSION")
container_pull(
name = "base-image",
registry = "registry:9999",
repository = "base-image",
digest = "sha256:e6f44554a270025c578c0f91160d809735c2589baae80bafcdeebefb0c0b04b6",
tag = BASE_IMAGE_VERSION,
)
Bazel does a similar thing in its own workspace file:
https://github.com/bazelbuild/bazel/blob/669a1a2634bdf267f890cf88833c9712d4e75016/WORKSPACE#L589

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