See what a plan changes

The Terraform page in the console draws the resources of a Terraform folder or plan, and the references between them. With a plan, it also shows what the plan does to each resource.

You need pogi running, and a folder or a plan.json. To make a plan, see Price a plan.

Open the pageCopy Anchor Link

1. Choose Terraform in the console sidebar, under Tools, or open http://localhost:7644/_pogi/terraform.
2. Choose a folder or a plan: Choose folder, Choose plan.json, or drop one on the page. Try a sample uses a built-in stack.

pogi keeps the last stack that loaded, in memory and never on disk. A reload, the Cost page's Terraform tab and the Terraform page all show the same stack. If a new folder fails to load, the old stack stays. The Cost page's Terraform tab has the table and the totals, and an Open diagram link to the Terraform page.

pogi draws the diagram on the server, so the same files always give the same picture. It shows:

• One box per resource, with its type and its monthly cost. A resource with count or for_each is one box marked ×N.
• A lane per cloud, and a dashed band for each module.
• Arrows run from a resource to the ones that use it, so foundations such as a network sit on the left.
• A "?" or a "+" on a cost means a price is missing: "?" when no price is known, "+" when the cost is at least that much.
• Not shown: data sources, because they cost nothing and their arrows add noise.

A module with more than 40 resources starts as one box. Click it to draw it in full.

Group by networkCopy Anchor Link

Group by above the diagram offers Module (the default) or Network. Network draws frames in place of module bands:

• AWS: a VPC, with its subnets inside.
• Azure: a virtual network, with its subnets inside.
• Google Cloud: a network, with its subnetworks inside.

A box sits in the innermost frame among the resources it refers to directly, for example through subnet_id.

• If it refers to two subnets of one network, it sits in the network's frame.
• If it refers to two different networks, or to none, it sits in its cloud's lane, outside the frames.
• A collapsed module is a box in the lane too.

A network or a subnet is a frame, not a box. Its label selects it like a box, and no arrow runs from a frame to what is inside it. Other arrows stay, and end at the frame's label.

Read the change viewCopy Anchor Link

Open a plan.json. Each box takes the color of what the plan does to it:

The line above the diagram counts them, for example "3 to create, 1 to replace, 4 affected". The table has an action for each row and a before and after price. The totals at the top show the cost before the plan, after it, and the change.

If the plan changes resources pogi can't price, a banner lists them and says the change doesn't count them.

See what depends on a resourceCopy Anchor Link

Click a box. The boxes and arrows that depend on it, directly or through others, stay bright, and the rest fade. A bar under the diagram names the box, and a panel beside it shows the resource: its type, file and line, price lines and notes.

To clear the selection, click the same box again, click empty space, choose Clear or Close, or press Esc. Pan, zoom and the selected box stay when you change a variable file or the grouping.

Read the two kinds of lineCopy Anchor Link

A solid arrow means "depends on": it runs from a resource to one whose Terraform code refers to it.

A dotted line means "data flows": events or messages move from one resource to another, for example from an SNS topic to the queue that subscribes to it. The dashes move the way the data flows.

pogi draws a line, and no box, for a resource that only wires two others together:

• an SNS subscription
• a Lambda event source mapping
• an S3 bucket notification
• an EventBridge target
• a Pub/Sub or Event Grid subscription

Click the line to see that resource in the side panel. Two cases still get a box. A pull subscription (Pub/Sub, Service Bus) holds messages, so it stays a box, with a line from its topic. If pogi can't tell which resource is the source and which is the target, it also draws a box.

If the stack is also running in pogi, moving dots show the lines that carried traffic in the last 10 seconds. Dots in the error color show failed deliveries. pogi matches a line to a running resource by the ARN (the ID AWS gives a resource) or id in the files, or by its name and region. It never guesses: a name that fits two resources lights nothing.

The dots refresh without redrawing, so pan, zoom and the selection stay. The SVG and PNG exports show the dotted lines, still. With reduced motion turned on in your system, the lines stay dotted and still and the dots are hidden.

Pan and zoomCopy Anchor Link

• Drag to pan. Scroll to zoom at the pointer.
• +, − and Fit are above the diagram.
• With the diagram focused, the arrow keys pan, + and - zoom, 0 fits it, and Tab moves between boxes. Enter selects one.

Draw it from the command lineCopy Anchor Link

pogi tf diagram [path] sends a folder or a plan.json to the running pogi and opens the Terraform page in your browser. With no path it uses the current folder.

pogi tf diagram ./infra
pogi tf diagram plan.json --group network
pogi tf diagram ./infra --no-open   # prints the address, does not open the browser

To get a file instead of a page, add -o. This needs no running pogi:

pogi tf diagram ./infra -o diagram.svg

Without -o, if pogi isn't running, the command stops with pogi isn't running at http://localhost:7644; start it with `pogi start`, or write a file with -o. For every flag, see the CLI reference.

ExportCopy Anchor Link

Above the diagram, choose:

• SVG for the diagram as a file. It uses the light theme, whatever the console shows.
• PNG for the same picture as an image.
• JSON or Markdown for the estimate. These are the same as pogi cost --format json and --format markdown.

Files are named pogi-terraform-diagram.svg, pogi-terraform-diagram.png, pogi-terraform-cost.json and pogi-terraform-cost.md.

See alsoCopy Anchor Link

• Estimate Terraform cost
• How Terraform cost works