build: fix CentOS build image

[taiki45]

Description:
Current CentOS build image is broken since bazel 0.27.0 released due to its unintentional incompatible change. While the bazel team tries releasing the fixed one, we can just pin the bazel version in our CentOS image until the fixed version is released. bazelbuild/bazel#8652

Risk Level: Low
Testing: manual testing

~/.ghq/github.com/envoyproxy/envoy fix-centos-build-image
✔ docker run -it envoyproxy/envoy-build-centos:`git rev-parse HEAD` bazel version
Extracting Bazel installation...
WARNING: --batch mode is deprecated. Please instead explicitly shut down your Bazel server using the command "bazel shutdown".
Build label: 0.26.1
Build target: bazel-out/k8-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Thu Jun 6 11:05:05 2019 (1559819105)
Build timestamp: 1559819105
Build timestamp as int: 1559819105

Docs Changes: N/A
Release Notes: N/A
[Optional Fixes #Issue]
[Optional Deprecated:]

Signed-off-by: Taiki Ono taiki@tetrate.io

[htuch]

Can we just wait it out? Bazel team say they are doing the new build, can we get an ETA from them?

[taiki45]

Yes, we can also wait for that release. I thought this is a trivial fix and it's better than leaving the build image broken (probably for days though).

[taiki45]

hmm, +1 to waiting for the release.