ResiLien
/
terraform
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

📚 pg backend technical design & clarifications

This commit is contained in:
Mars Hall 2018-10-14 12:34:34 -07:00 committed by Mars Hall
parent 6d7e8268e7
commit 2831459ca2
1 changed files with 27 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
website/docs/backends/types/pg.html.md
View File

@ -8,11 +8,11 @@ description: |-
# pg
**Kind: Standard with locking**
**Kind: Standard (with locking)**
Stores the state in a [Postgres database](https://www.postgresql.org) using two tables, `states` and `locks`.
Stores the state in a [Postgres database](https://www.postgresql.org) version 9.5 or newer.
Supports Postgres version 10 and newer.
This backend supports [state locking](/docs/state/locking.html).
## Example Configuration
@ -24,18 +24,13 @@ terraform {
}
```
This assumes we have a database created called `terraform_backend`. The
Terraform state is stored in a self-managed schema, by default
`terraform_remote_backend`.
Before initializing the backend with `terraform init`, the database must already exist.
Note that for the access credentials we recommend using a
[partial configuration](/docs/backends/config.html).
We recommend using a [partial configuration](/docs/backends/config.html#partial-configuration) for the `conn_str` variable, because it typically contains access credentials that should not be committed to source control.
## Using the pg remote state
## Example Referencing
To make use of the pg remote state we can use the
[`terraform_remote_state` data
source](/docs/providers/terraform/d/remote_state.html).
To make use of the pg remote state we can use the [`terraform_remote_state` data source](/docs/providers/terraform/d/remote_state.html).
```hcl
data "terraform_remote_state" "network" {
@ -46,24 +41,28 @@ data "terraform_remote_state" "network" {
}
```
The `terraform_remote_state` data source will return all of the root module
outputs defined in the referenced remote state (but not any outputs from
nested modules unless they are explicitly output again in the root). An
example output might look like:
```
data.terraform_remote_state.network:
id = 2018-10-11 01:57:59.780010914 +0000 UTC
backend = pg
config.% = 1
config.conn_str = postgres://localhost/terraform_backend
```
## Configuration variables
## Configuration Variables
The following configuration options or environment variables are supported:
* `conn_str` - (Required) Postgres connection string; a `postgres://` URL
* `lock` - Use locks to synchronize state access, default `true`
* `schema_name` - Name of the automatically managed Postgres schema to store locks & state.
* `schema_name` - Name of the automatically-managed Postgres schema to store locks & state, default `terraform_remote_backend`.
## Technical Design
Postgres version 9.5 or newer is required to support the "ON CONFLICT" upsert syntax and *jsonb* data type.
This backend creates two tables, **states** and **locks**, in the automatically-managed Postgres schema configured by the `schema_name` variable.
Both tables are keyed by the [workspace](/docs/state/workspaces.html) name. If workspaces are not in use, the name `default` is used.
The **states** table contains:
* the workspace `name` key as *text* with a unique index
* the Terraform state `data` JSON as *text*.
The **locks** table contains:
* the workspace `name` key as *text* with a unique index
* the lock's `info` JSON as *jsonb*.