Python Hints

Python hints

Untrusted target

If you get untrusted cert error when trying to download library because your firewall, you can do this (only if you really trust the source).

python -m pip install --upgrade pip --trusted-host files.pythonhosted.org --trusted-host pypi.org

You can also put the untrusted cert in the location defined by this environment variable: REQUESTS_CA_BUNDLE

Working with venv

1. Create a new environment, this will create a directory named some_name from where you execute this

python -m venv some_name

You should see Include, Lib, and Scripts folders and pyvenv.cfg file in this directory

2. Go into that directory then activate the environment

./Scripts/activate

3. Now you should see (some_name) in from of your prompt. Any python code (and Pip) action taken here is isolated to this venv. 

4. To exit just type deactivate from this directory

Sorting a List of Dictionary

sorted(ListOfDict, key=(lambda item: item['SomeKeyName']))

Run Terraform in Docker

How to run terraform in container!

I am running this from Docker Desktop 2.3.0.2. on Windows 10. I am on my work network which brings special certificate issue.

Going to use this official Hashicorp Terraform Image.

Creating New Image to incorporate your certificate

Create a new dockerfile and insert following. Be sure to have your PEM file in the same directory. 

##Pull down the latest version of terraform from Hashi
FROM hashicorp/terraform:light
##Need this else you get cert trust error
COPY "myWork.pem" "/usr/local/share/ca-certificates/"
##Need this to apply the new cert (above) on this box
##https://manpages.ubuntu.com/manpages/xenial/man8/update-ca-certificates.8.html#name
RUN "/usr/sbin/update-ca-certificates"

##Need this so that it runs terraform upon launch
ENTRYPOINT ["/bin/terraform"]

Run following command to build your image

docker build -t terraform:latest .

Now you should bee a new image...

docker image ls

Create a terraform launcher

Now you can launch this image every time you want to invoke Terraform. 

docker run --rm -it terraform:latest -version

But that's not very helpful. So we'll need to attach some volumes to make this useful. See this link for details. This is a little more useful call to this image from docker

docker run --rm -it -e TF_LOG=%debugVar% -e TF_CLI_CONFIG_FILE=%TF_CLI_CONFIG_FILE_NEW% -v %cd%:/data -v %tf_config%:/terraform -w /data -v /var/run/docker.sock:/var/run/docker.sock -v /var/lib/docker:/var/lib/docker terraform:latest %newarg%

Now we'll make this into a Batch Script and ensure it's accessible from %PATH%. You can also create an Alias if you have permission to edit Registry. 

This Batch Script is gonna add some extra features

• Enable toggling Debug at will
• Ability to pass in Terraform Config
• Ability to write and read back credential via Terraform Login

@echo off
:dockerizedTerraform
setlocal enabledelayedexpansion
:: Initiall set this to 0, remember /A means this is number type
set /A debug = 0
::Set all the incoming argument into another variable, didn't know how to work with %*
set "args=%*"
::loop through the arguments, when something we want to is found, flag it
:: if there are more special flags we need to catch then just them here
:: be sure to put quote around both side of comparison
for %%x in (%*) do (
  if "%%x" == "-debug" set /A debug = 1
)
:: If debug flag was set to 1 then remove -debug from the args
if %debug%==1 (
  set "newarg=%args:-debug= %"
  set "debugVar=DEBUG"
) else (
  set "newarg=%args%"
  set "debugVar= "
)
:: use -e for passing in environment variables to Docker container
::Need to pass in environment variable for the token file
:: but we need to mount the volume and pass in the remote-end equivalent 
FOR %%i IN ("%TF_CLI_CONFIG_FILE%") DO (
  :: get the folder path
  set "tf_config=%%~di%%~pi"
  :: get the file name and extension
  set "tf_config_file=%%~ni%%~xi"
)
::This will be the mount point for the terraform configuration file
set "TF_CONFIG_PATH=terraform"
::THis will be the new config file location in the remote-end
set "TF_CLI_CONFIG_FILE_NEW=/%TF_CONFIG_PATH%/%tf_config_file%"

docker run --rm -it -e TF_LOG=%debugVar% -e TF_CLI_CONFIG_FILE=%TF_CLI_CONFIG_FILE_NEW% -v %cd%:/data -v %tf_config%:/terraform -w /data -v /var/run/docker.sock:/var/run/docker.sock -v /var/lib/docker:/var/lib/docker terraform:latest %newarg%

You can download the files here.

How to get your PEM