ocm-container

ocm-container

A quick environment for accessing OpenShift v4 clusters. Nothing fancy, gets the job done.

Related tools added to image:

aws
oc
ocm
omg
osdctl
pd
rosa
velero
yq

Features:

Does not mount any host filesystem objects as read/write, only uses read-only mounts, except for configurable mountpoints.
Uses ephemeral containers per cluster login, keeping seperate .kube configuration and credentials.
Credentials are destroyed on container exit (container has --rm flag set)
Displays current cluster-name, and OpenShift project (oc project) in bash PS1
Ability to login to private clusters without using a browser

OCM Container also includes multiple scripts for your ease of use. For a quick overview of what is available, run list-utils.

Installation:

clone this repo
./init.sh (repeat until all required fields are set)
./build.sh (while this is building you can run the rest in another tab until the final command)
optional: have local aws keys (put on ${HOME}/.aws)
optional: have local gcp keys (put on ${HOME}/.config/gcloud)
optional: add alias in ~/.bashrc
- alias ocm-container-stg="OCM_URL=stg ocm-container"
- alias ocm-container-local='OCM_CONTAINER_LAUNCH_OPTS="-v ${PWD}:/root/local -w /root/local" ocm-container'
optional: add your PagerDuty API token in $HOME/.config/pagerduty-cli/config.json
Connect to the VPN
ocm-container {cluster-name}

Build:

./build.sh

Build accepts the following flags:

  -h  --help      Show this message and exit
  -t  --tag       Build with a specific docker tag
  -x  --debug     Set the bash debug flag

You can also override the container build flags by separating them at the end of the command with --. Example:

./build.sh -t local-dev -- --no-cache

Use it:

ocm-container

With launch options:

OCM_CONTAINER_LAUNCH_OPTS="-v ~/work/myproject:/root/myproject" ocm-container
--
or
--
ocm-container -o "-v ~/work/myproject:/root/myproject"

Launch options provide you a way to add other volumes, add environment variables, or anything else you would need to do to run ocm-container the way you want to.

NOTE: Using the flag for launch options will then NOT use the environment variable OCM_CONTAINER_LAUNCH_OPTS

Automatic Login to a cluster:

ocm-container my-cluster-id

Example:

Public Clusters

$ ocm-container
[production] # ./login.sh
[production] # ocm cluster login test-cluster
Will login to cluster:
 Name: test-cluster
 ID: 01234567890123456789012345678901
Authentication required for https://api.test-cluster.shard.hive.example.com:6443 (openshift)
Username: my_user
Password:
Login successful.

You have access to 67 projects, the list has been suppressed. You can list all projects with 'oc projects'

Using project "default".
Welcome! See 'oc help' to get started.
[production] (test-cluster) #

Private clusters

This tool also can tunnel into private clusters.

$ ocm-container-stg
[staging] # ./login.sh
[staging] # ocm tunnel --cluster test-cluster -- --dns &
Will create tunnel to cluster:
 Name: test-cluster
 ID: 01234567890123456789012345678901

# /usr/bin/sshuttle --remote sre-user@ssh-url.test-cluster.mycluster.com 10.0.0.0/16 172.31.0.0/16 --dns
client: Connected.
[staging] # cluster-login -c 01234567890123456789012345678901
Login successful.

You have access to 67 projects, the list has been suppressed. You can list all projects with 'oc projects'

Using project "default".
Welcome! See 'oc help' to get started.
[staging] (test-cluster) #

Automatic Login

We've built in functionality to simplify the cluster login steps. Now within the contianer you can run sre-login cluster-id and it will refresh your ocm login, create a tunnel within the container if necessary, and then log-in to the cluster.

sre-login accepts both a cluster-name or a cluster-id. If the cluster-name is not unique, it will not ask which one, but display the clusters and exit.

Advanced scripting with ocm-container

We've recently added the ability to run a script within the container so that you can run ocm-container within a script.

Given the following shell script saved on the local machine in ~/myproject/in-container.sh:

cat ~/myproject/in-container.sh
#!/bin/bash

# source this so we get all of the goodness of ocm-container
source /root/.bashrc

# get the version of the cluster
oc version >> report.txt

We can run that on-container with the following script which runs on the host (~/myproject/on-host.sh):

cat ~/myproject/on-host.sh
#!/bin/bash

while read -r cluster_id
do
    echo "Cluster $cluster_id Information:" >> report.txt
    ocm-container -o "-v ${HOME}/myproject/script.sh:/root/script.sh -v ${HOME}/myproject/report.txt:/root/report.txt" -e /root/script.sh $cluster_id
    echo "----"
done < clusters.txt

Would loop through all clusters listed in clusters.txt and then run oc version on the cluster, and add the output into report.txt and then it would exit the container, and move to the next container and do the same.

Troubleshooting

SSH Config

If you're on a mac and you get an error similar to:

Cluster is internal. Initializing Tunnel... /root/.ssh/config: line 34: Bad configuration option: usekeychain

you might need to add something similar to the following to your ssh config:

$ cat ~/.ssh/config | head
IgnoreUnknown   UseKeychain,AddKeysToAgent
Host *
  <snip>
  UseKeychain yes

UseKeychain is a MacOS specific directive which may cause issues on the linux container that ocm-container runs within. Adding the IgnoreUnknown UseKeychain directive tells the ssh config to ignore that directive when it's unknown so it will not throw errors.

georgettica / ocm-container