capriott/MachineConfigAnalyzer

A tool to decode and compare the contents of MachineConfig(s) in OpenShift4.

This script can take one of three options:

• decode: Takes multiple MachineConfig YAML files to decode them.
• compare: Takes two MachineConfig YAML files, decode and compare between their contents
• extract: Specify the full file path to be extracted from the MachineConfig files instead of extracting everything from the MC
• help: Gives a brief description about this tool

Using decode operation:

Assuming I have generated a YAMl file using the following command:

# oc get mc <name> -o yaml > mc-file.yaml

Normally, this file is encoded and it is difficult to read the configuration file(s) contents directly from it.

You can use this tool to separate between these configuration files and decode it into a readable format:

# ./mca.sh decode mc-file.yaml

The decode option can work with multiple MachineConfig files at the same time. It will create a directory with the name metdata.name-metadata.creationTimestamp that are extraced from the YAML file, for example:

# ./mca.sh decode mc-file1.yaml mc-file2.yaml mc-file3.yaml

# ls
-rw-r--r--. 1 user user 117349 Sep 24 14:41 mc-file1.yaml
drwxrwxr-x. 3 user user   4096 Sep 27 20:13 rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z
-rw-r--r--. 1 user user 117349 Sep 24 14:41 mc-file2.yaml
drwxrwxr-x. 3 user user   4096 Sep 27 20:13 rendered-master-3130d4b00faa48cef9b9b50252bcbbbbb-2020-01-09T11:26:25Z
-rw-r--r--. 1 user user 117349 Sep 24 14:41 mc-file3.yaml
drwxrwxr-x. 3 user user   4096 Sep 27 20:13 rendered-master-3130d4b00faa48cef9b9b50252bcccccc-2020-09-15T11:26:25Z

Under the new diretory you will find the decoded configuration files, for example:

# ls -lh rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/
...
-rw-rw-r--. 1 user user  272 Sep 27 21:14 sdn.conf
-rw-rw-r--. 1 user user 5.9K Sep 27 21:14 storage.conf
-rw-rw-r--. 1 user user 1.4K Sep 27 21:14 tokenize-signer.sh

It will also extract the services configurations .spec.config.systemd.units under service-units subdirectory.

# ls -lh rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/service-units/
-rw-rw-r--. 1 user user 1.2K Sep 30 21:03 kubelet.service
-rw-rw-r--. 1 user user  661 Sep 30 21:03 machine-config-daemon-firstboot.service
-rw-rw-r--. 1 user user  596 Sep 30 21:03 machine-config-daemon-firstboot-v42.service
-rw-rw-r--. 1 user user  636 Sep 30 21:03 machine-config-daemon-host.service

Using compare operation:

Assuming you have generated MachineConfig YAMl files using the following command:

# oc get mc <name> -o yaml > mc-file1.yaml
# oc get mc <another name> -o yaml > mc-file2.yaml

You can compare between their contents as follows:

# ./mca.sh compare mc-file1.yaml mc-file2.yaml

It will show unique files in each machineConfig and also common files with different contents, for example:

# ./mca.sh compare mc-file1.yaml mc-file2.yaml
checking differences between mc-file1.yaml and mc-file2.yaml MachineConfig files

.... decoding mc-file1.yaml

.... decoding mc-file2.yaml

Unique files existing only in mc-file1.yaml MachineConfig:

Only in rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/: etcd.conf
Only in rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/: etcd-generate-certs.yaml.template
...
Only in rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/: tokenize-signer.sh

Unique files existing only in mc-file2.yaml MachineConfig:

Only in rendered-master-3130d4b00faa48cef9b9b50252bcbbbbb-2020-01-09T11:26:25Z/: 99-kni.conf
Only in rendered-master-3130d4b00faa48cef9b9b50252bcbbbbb-2020-01-09T11:26:25Z/: config.hcl.tmpl
...
Only in rendered-master-3130d4b00faa48cef9b9b50252bcbbbbb-2020-01-09T11:26:25Z/: sshd_config

Files existing in both MachineConfig files mc-file1.yaml and mc-file2 .yaml but differ in contents:
ca.crt
cleanup-cni.conf
crio.conf
kubelet-ca.crt
kubelet.conf
openshift-config-user-ca-bundle.crt
root-ca.crt
sdn.conf

Using extract operation:

Gives you the ability to extract specific configuration file(s) from the MachineCOnfig YAML file and decode it.

# ./mca.sh extract <MachineCOnfig file> <configuration file1 path>...

For example:

# ./mca.sh extract mc-file1.yaml /etc/crio/crio.conf /wrong/file /etc/kubernetes/ca.crt

/etc/crio/crio.conf got extracted
WARNING: /wrong/file doesn't exist in May19.yaml MahineConfig
/etc/kubernetes/ca.crt got extracted
Check extracted configuration files under rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/

# ls rendered-master-3130d4b00faa48cef9b9b50252bcaaaaa-2019-03-07T11:26:25Z/
crio.conf
ca.crt

Notes:

• machineConfig files should be in YAML format "for now".
• compare operation will first decode, even if decode operation was already done.
• This tool uses yq to filter YAML outputs, it can be installed by running the following command:

# pip install yq

limitations:

- Services units data are in clear text, so I am still working on a away to exclude and separate them - Some configurations are encoded using base64 and it will require to be decoded separatly, I am also working on it