Thursday, 27 July 2017

Accessing Pivotal Cloud Foundry droplet file system when "cf ssh" isn't enabled

In order to view your application layout you can simply use "cf ssh" to log into the container and then view the files created as part of the droplet. The problem is "cf ssh" isn't always enabled bye the Ops team so what is your alternative in cloud foundry?

You can use "cf curl" to invoke an endpoint using the application GUID as shown in the steps below.

** cf ssh demo **

pasapicella@pas-macbook:~/temp/droplets$ cf ssh pas-swagger-demo
vcap@ef9e4e93-0df9-47a7-5351-dccf:~$ ls -lartF
total 16
-rw-r--r-- 1 vcap vcap  675 Apr  9  2014 .profile
-rw-r--r-- 1 vcap vcap 3637 Apr  9  2014 .bashrc
-rw-r--r-- 1 vcap vcap  220 Apr  9  2014 .bash_logout
drwxr-xr-x 2 vcap vcap    6 Jun 14 03:32 deps/
drwxr-xr-x 1 vcap root   72 Jun 14 03:32 app/
-rw-r--r-- 1 vcap vcap 1087 Jun 14 03:32 staging_info.yml
drwxr-xr-x 2 vcap vcap    6 Jun 14 03:32 logs/
drwx------ 1 vcap vcap   76 Jun 14 03:32 ./
drwxr-xr-x 1 root root   18 Jul 26 23:45 ../
drwxr-xr-x 4 vcap vcap   92 Jul 26 23:48 tmp/
vcap@ef9e4e93-0df9-47a7-5351-dccf:~$

** Steps **


1. Download droplet as follows

Format:

   cf curl /v2/apps/`cf app {appname} --guid`/droplet/download > droplet.tar.gz

Example:

pasapicella@pas-macbook:~/temp/droplets$ cf curl /v2/apps/`cf app pas-swagger-demo --guid`/droplet/download > droplet.tar.gz

To determine the app name you can either use Applications manager UI or use "cf apps" to get the app name


2. This will take some time due to the size of the droplet but when done verify you have this on the file system

pasapicella@pas-macbook:~/temp/droplets$ ls -la
total 150736
drwxr-xr-x   3 pasapicella  staff       102 Jul 27 14:20 .
drwxr-xr-x  23 pasapicella  staff       782 Jul 27 14:19 ..
-rw-r--r--   1 pasapicella  staff  77173173 Jul 27 14:23 droplet.tar.gz

3. Gunzip followed by tar -xvf and you will then have a file system replicator of what your application droplet looks like in CF

pasapicella@pas-macbook:~/temp/droplets$ d
total 313408
drwxr-xr-x   2 pasapicella  staff         68 Jun 14 13:32 deps/
drwxr-xr-x   6 pasapicella  staff        204 Jun 14 13:32 app/
drwxr-xr-x   2 pasapicella  staff         68 Jun 14 13:32 tmp/
-rw-r--r--   1 pasapicella  staff       1087 Jun 14 13:32 staging_info.yml
drwxr-xr-x   2 pasapicella  staff         68 Jun 14 13:32 logs/
drwxr-xr-x  23 pasapicella  staff        782 Jul 27 14:19 ../
-rw-r--r--   1 pasapicella  staff  160460800 Jul 27 14:23 droplet.tar
drwxr-xr-x   8 pasapicella  staff        272 Jul 27 14:25 ./


You really only want to do this to see how your application was staged on the file system as the buildpack may have changed some files or added files based on what you deployed. This is not how you would debug an application but rather view what the file system looks like for your application itself and what content exists in the files should the buildpack have changed file content for example.

No comments: