I needed a minimal installation of hashicorp/terraform, downloaded and verified from the official Terraform downloads page. This serves as a simple, containerized installation source.
Please notice that the examples below do not specify image tags which means the Docker client will assume latest
.
The Terraform executable is statically compiled and set as the image entry ENTRYPOINT
with help
as the default CMD
:
# this container is not shipped with ca-certificates, so let's set those up.
# (supporting version check, plugin discovery+download, provider api interactions ...)
docker container run --rm -it -v ca-certificates:/etc/ssl/certs alpine apk add --no-cache ca-certificates
# now we can invoke terraform
docker container run --rm -it -v ca-certificates:/etc/ssl/certs -v /tmp -v $PWD:$PWD -w $PWD overneath/terraform # [init|plan|apply|destroy|...]
Usage: terraform [-version] [-help] <command> [args]
The available commands for execution are listed below.
The most common, useful commands are shown first, followed by
less common or more advanced commands. If you're just getting
started with Terraform, stick with the common commands. For the
other commands, please read the help and docs before usage.
Common commands:
apply Builds or changes infrastructure
console Interactive console for Terraform interpolations
destroy Destroy Terraform-managed infrastructure
env Workspace management
fmt Rewrites config files to canonical format
get Download and install modules for the configuration
graph Create a visual graph of Terraform resources
import Import existing infrastructure into Terraform
init Initialize a Terraform working directory
output Read an output from a state file
plan Generate and show an execution plan
providers Prints a tree of the providers used in the configuration
refresh Update local state file against real resources
show Inspect Terraform state or plan
taint Manually mark a resource for recreation
untaint Manually unmark a resource as tainted
validate Validates the Terraform files
version Prints the Terraform version
workspace Workspace management
All other commands:
0.12upgrade Rewrites pre-0.12 module source code for v0.12
debug Debug output management (experimental)
force-unlock Manually unlock the terraform state
push Obsolete command for Terraform Enterprise legacy (v1)
state Advanced state management
docker container run --rm -it -v ca-certificates:/etc/ssl/certs -v /tmp overneath/terraform -version
Terraform v0.12.5
Note the -v /tmp
is important because the current default behavior of Terraform is to exec
itself to capture logs.
Running vanilla Terraform in a container lacking a /tmp
directory will error, e.g.:
docker container run --rm -it -v ca-certificates:/etc/ssl/certs overneath/terraform -version
Couldn't setup logging tempfile: open /tmp/terraform-log076603776: no such file or directory
To install into an image via Dockerfile
:
COPY --from=overneath/terraform /opt/local/ /usr/local/
To install into a container via docker volume
leveraging (the default) nocopy=false
behavior:
# this only works if the volume `terraform-files` does not already exist or it is empty
docker container run --rm --mount source=terraform-files,destination=/opt/local,volume-nocopy=false overneath/terraform
docker container run --rm -it --volume terraform-files:/usr/local alpine terraform help