session-24.txt

state and remote state
-----------------------
terraform --> IaaC, declarative
whatever we write we will get
shell is imperative
terraform is idempotent also

there is something called state...

whatever we declared terraform should create

declared state[terraform files] == actual state[resources inside provider i.e AWS]/Created infra

I ran, terraform created infrastructure
I run once again, How terraform will understand what infra it is already created?

terraform.tfstate is the file that terraform tracks the actual infra

I deleted manually inside AWS. but it exists in terraform.tfstate

Refreshing state
----------------
it will check terraform.tfstate against AWS...

terraform files[declared state] = AWS infra[actual state] --> false -->

terraform responsibility is to create the infra equivalent to terraform files...


terraform.tfstate, declared state, actual state, refresh

in colloboration environment
remote state
--------------
duplicate resources or errors, locking

1 person is creating infra through terraform, can we ask other person also do same thing?
5min..

there should be some locking mechanism, when one person is creating infra. it should be locked until it is completed

daws78s.doc, daws78s.doc.lock(1kb)
.lock file --> means someone opened, others are not allowed to edit

local state vs remote state
----------------------------
1. there is a chance you delete/edit the file...
2. it will not work in colloboration environment
3. there is a chance multiple persons apply/edit the infra

centralise repo --> github

S3 remote state
----------------
s3 bucket can be locked with dynamodb table..


for loop
-----------------
count --> list
for --> maps
dynamic

create sg that opens 22,80,8080,3306