gcloud cheatsheet for GKE

This is by no means comprehensive, it's just some things I've found useful.

Get installed and auth'd:

gcloud components install kubectl
gcloud auth application-default login

Creating a cluster with a specific version:

gcloud config set compute/zone us-west1-b
gcloud beta container clusters create permissions-test-cluster \
    --cluster-version=1.6.1 \
    --no-enable-legacy-authorization

Upgrading GKE:

# Get available versions
$ gcloud container get-server-config 
Fetching server config for us-west1-b
defaultClusterVersion: 1.5.7
defaultImageType: COS
validImageTypes:
- COS
- CONTAINER_VM
validMasterVersions:
- 1.6.4
- 1.5.7
validNodeVersions:
- 1.6.4
- 1.6.2
- 1.5.7
- 1.5.6
- 1.4.9

$ CLUSTER_NAME="testing"
$ CLUSTER_VERSION="1.6.4"

# Nodes
$ gcloud container clusters upgrade $CLUSTER_NAME --cluster-version=$CLUSTER_VERSION

# Master
$ gcloud container clusters upgrade $CLUSTER_NAME --master --cluster-version=$CLUSTER_VERSION

List containers in the google-containers project:

gcloud container images list --repository gcr.io/google-containers

Tags for a given container:

gcloud container images list-tags gcr.io/gke-release/auditproxy

Google gcloud tool cheatsheet

Some gcloud commands I've found useful:

# See config
gcloud config list

# Change default zone
gcloud config set compute/zone us-central1-a

# Copy a file, default zone
gcloud compute copy-files some/file.txt cloud-machine-name:~/

# Copy a file, specifying zone for machine
gcloud compute copy-files some/file.txt cloud-machine-name:~/ --zone=us-west1-a

# Forward a port with ssh
gcloud compute ssh client-machine-name -- -L 8080:localhost:8080

Mac OS X Sierra and SSH keys

With OS X Sierra Apple changed the ssh client key handling behavior. They aligned with OpenSSH behavior by not automatically loading passphrases from the keychain on login. More surprisingly, it now remembers your ssh key passphrase automatically by default. To disable this behavior you can add this to ~/.ssh/config:

Host *
    UseKeyChain no

As you can see in the radar report, deleting keys using "ssh-add -D" seems to be just as problematic and confusing as it is with gnome-keyring, i.e. "All identities removed" is a lie.

For deleting already saved passwords and re-instating the El-Cap ssh behavior see here.

Prevent system management from installing over a test package on Ubuntu

When you are testing a new package version it's annoying to have your system management come and install the old version over the top of your test one. There's a bunch of ways to stop this, the one I tend to use on Ubuntu is:

echo "package hold" | sudo dpkg --set-selections

To undo the hold and go back to normal:

echo "package install" | sudo dpkg --set-selections

Running modern python on Ubuntu LTS

The python version on your Ubunutu LTS may be slightly behind latest, or years behind, depending on the release cycle. Here's how to run a newer python without interfering with the system one.

Note that setting an install prefix is necessary to avoid making this the default system python (which will break cinnamon-settings apps as well as possibly other things). The prefix I chose puts it in a directory with my username.

Download the latest python source and install it:

sudo apt-get install build-essential libreadline-dev libsqlite3-dev
./configure --enable-ipv6 --enable-unicode=ucs4 --prefix=/usr/local/${USER}/
make
sudo make install

Your new python is now in /usr/local/${USER}/bin/python2.7. To use it, specify it in any virtualenvs you create. Make it an alias so you never forget:

alias virtualenv='virtualenv --python=/usr/local/${USER}/bin/python'

Run a different command on an existing docker container using exec

To run a previously created container with bash, start it as normal and then use exec (this assumes your original container can actually run successfully):

docker start [container id]
docker exec -it [container id] /bin/bash

Creating a Google Cloud service account that can only create new objects in a single bucket

I wanted a service account that can only create new objects in a single bucket, and have those objects be publicly readable by default. Use case is a travis deployer that publishes build artifacts.

1. create a service account. Currently this is under "IAM & Admin | Service Accounts" in the Google Cloud UI.
2. In the IAM screen your service account is over-privileged, you can remove all privileges from the account here (which causes it to disappear from the IAM list). We will grant it permission over the bucket only.
3. Create your bucket, then give the world access (you can also use AllUsers in the UI):

   gsutil defacl ch -u AllUsers:R gs://mybucket
   

4. Give your serviceaccount@projectname.iam.gserviceaccount.com writer access to the bucket. It seems there is no way to limit the permission to create only (options are read/write/owner).
5. Test the permissions of your service account:

   gcloud auth activate-service-account --key-file mysecretfile.json serviceaccountname
   gcloud auth list
   # Check your service account is the active account, then try copying to the bucket you authorized, and another bucket which should fail.
   gsutil cp test gs://mybucket
   gsutil cp test gs://someotherbucket
   

6. You can then set the default object permissions for the bucket via the UI so that new objects are world readable by default.