Deploy to Google Cloud Storage (GCS) with wercker

Apr 28, 2016
3 minutes read

Wercker and the deploy steps

There are several deploy steps for the wercker CI service, but none of them worked for me, because they seemed to be outdated when dealing with authorization. But due to the flexibility of wercker to choose whatever docker container you want, I found a simple and straight forward solution.

tl;dr: The solution

I assume you use a static site generator like hexo or hugo. You can find an example wercker build step in my hexo tutorial (ignore the deploy part).


  • A Google Cloud account
  • A service account key (json file)
  • A Google Cloud Storage Bucket

Target Environment Variables

GOOGLE_JSON: The Service account key json file downloaded from google WITHOUT new lines \n GOOGLE_ACCOUNT: The email you find in the Service account key json file GOOGLE_BUCKET: Your bucket’s name

Deploy Step in wercker.yml

    id: google/cloud-sdk
    tag: latest
    - script:
      name: activate service account
      code: |
        echo $GOOGLE_JSON >> secret.json
        CLOUDSDK_PYTHON_SITEPACKAGES=1 gcloud auth activate-service-account $GOOGLE_ACCOUNT --key-file secret.json
    - script:
      name: upload to gs
      code: |
	    # Sync
        gsutil -m rsync -r -d public gs://$GOOGLE_BUCKET
        # Create gz files
        gsutil -m cp -r -z html,css,js,xml,txt,json,map,svg public/* gs://$GOOGLE_BUCKET

My Way to Find The Solution

1. Docker and How to Fix Dependency Problems

At first I wanted to run all gcloud or gsutil installation like I do it on my Mac (gcloud auth), but I had to deal with some dependency problems using the python:latest container for the wercker deploy. But as a heavy user of wercker, I know that I can use whatever container I want, so I searched the docker hub for a good image and found: google/cloud-sdk created by google itself. The dependency problems are gone!

2. Test it locally

I started to test it locally. So I started the docker container

# Pull and start
docker run -d --name gcloud-config google/cloud-sdk
# Prepare all keys
docker exec -it gcloud-config bash
# In docker paste the json file data to env
export GOOGLE_JSON='<json_filedata>' # Important here: plain copy paste. no changes!
export GOOGLE_ACCOUNT=<jsons_account>
export GOOGLE_BUCKET=<bucket>
# Run auth
echo $GOOGLE_JSON >> secret.json
CLOUDSDK_PYTHON_SITEPACKAGES=1 gcloud auth activate-service-account $GOOGLE_ACCOUNT --key-file secret.json
# Works fine: Sync now
gsutil -m rsync -r -d public gs://$GOOGLE_BUCKET
gsutil -m cp -r -z html,css,js,xml,txt,json,map,svg public/* gs://$GOOGLE_BUCKET

Wow. Works like a charm. Easy and without any dependency problems.

Fix it in wercker

If you read headlines you already know that you can’t copy-paste here. Because I did it, and it failed. I copied the env vars and created a wercker.yml with the steps. The error is not helpful:

ERROR: gcloud crashed (Error): []

If you would like to report this issue, please run the following command: gcloud feedback

After several retries, I remembered, that you need to be careful with env vars and newlines. So I removed them from the wercker target vars and a green success button!

Important Info

  • Remove \n from env vars (in wercker): cat secret.json | sed ':a;N;$!ba;s/\n/ /g'
  • Always try to use docker as your package/dependency manager

Useful gsutil stuff

I use the Google Cloud Storage as my static site hoster and therefor need to make the bucket content public reabadle:

# Make existent files public
gsutil -m acl set -R -a public-read gs://<bucket>
# Make public by default
gsutil setdefacl public-read gs://<bucket>
# Set index and error site
gsutil web set -m index.html -e 404.html gs://<bucket>

You take a look in this websites repo for a production example.

Further reading:

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