A tiny single-file Go client for Bazel Remote Execution API v2.

The Bazel Remote Execution protocol turns out to be a surprisingly nice “universal remote runner” for retro platforms. With a compatible server (see my excitoon/buildpot repository), you can offload execution to old/slow systems — starting with Windows NT 3.1 and likely even older — and still drive the workflow from a modern machine.

This is useful for:

• running command-line tools that are awkward or impossible to run on modern hardware/OSes
• keeping classic compilers and toolchains alive (some are still genuinely useful and deserve not to be forgotten)

It:

• computes the most common directory among input files (input prefix)
• uploads inputs to the remote CAS under paths relative to that prefix
• runs a command remotely
• downloads declared output files and writes them into the current directory, preserving paths relative to the most common output directory (output prefix)

go build -o bazz .

./bazz \
  -address executor.example.com:8980 \
  -tls-certificate ca.pem \
  -instance my-instance \
  -input /abs/path/work/src/a.txt -input /abs/path/work/src/b.txt \
  -output /abs/path/work/out/result.bin -output /abs/path/work/out/logs/build.log \
  -environment FOO=bar -environment BAZ=qux \
  -- \
  sh -lc 'cat a.txt b.txt > ../out/result.bin; echo ok > ../out/logs/build.log'

Notes:

• If -tls-certificate is omitted, the client uses insecure gRPC (plaintext).
• -instance is optional; many deployments require it.
• Inputs must be files (directories aren’t supported).
• Outputs must be listed explicitly; the client requests them via Command.output_paths.

• -address: remote executor gRPC address (required)

• -instance: instance name (optional)

• -tls-certificate: CA cert to trust (optional)

• -tls-server-name: TLS server name override (optional)

• -tls-insecure-skip-verify: skip hostname/SAN verification (helps CN-only certs; insecure)

• -input: input file path (repeatable or comma-separated)

• -output: expected output file path (repeatable or comma-separated)

• -environment: environment variable KEY=VALUE (repeatable)

• -working-directory: remote working directory relative to input root (optional)

• -timeout: execution timeout (default 10m)

• -dry-run: print computed prefixes and planned command without network calls