go-env-template
A statically compilable templating application written in Golang. It uses Mustache for the templating, and gets all the template variables from the environment (e.g., Docker container).
The Goal
The purpose of this application is to be able to template a static website for use in a Docker container. Specifically, the Docker container will run using goStatic, however, some of the paths, or features of the site will need to be configured based on how it is deployed (e.g., Dev vs Prod, context path, etc). This is where go-env-template comes in. It can do a one-shot parse of the static site, and render the final product.
The key is that the application can be statically compiled, resulting in a 3MB file that can be dropped into a FROM scratch Docker container.
Usage
./go-env-template --help
Usage of ./go-env-template:
-ext string
The template extension to look for (default ".tmpl")
-path string
The path for the static files (default "/srv/http")
Building
For my own notes:
docker run -it -w /src/go-env-template -v $PWD:/src/go-env-template golang:latest /bin/bash
go get github.com/alexkappa/mustache
CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build
Example Usage
This is an example that builds a Docker container for a static website. It pulls in this tool, along with x for process hosting, and goStatic for web serving. It then processes the web content using the environment variables
Dockerfile:
# stage 0
FROM golang:latest as builder
RUN go get github.com/nigelsim/go-env-template
RUN go get github.com/pablo-ruth/go-init
FROM pierrezemb/gostatic
COPY --from=builder /go/bin/go-static-template /
COPY --from=builder /go/bin/go-init /
COPY dist/ /srv/http
COPY frontend-static/ /srv/http
ENTRYPOINT ["/go-init"]
CMD ["-pre", "/go-env-template /srv/http", "-main", "/goStatic --fallback index.html"]