So far we've seen how the FROM command in Earthly has the ability to reference another target's image as its base image, like in the case below where the +build target uses the image from the +deps target.
VERSION 0.6
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
deps:
COPY go.mod go.sum ./
RUN go mod download
# Output these back in case go mod download changes them.
SAVE ARTIFACT go.mod AS LOCAL go.mod
SAVE ARTIFACT go.sum AS LOCAL go.sum
build:
FROM +deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-example
But FROM also has the ability to import targets from Earthfiles in different directories. Let's say we have a directory structure like this.
We can use a target in the Earthfile in /services/service-one from inside the Earthfile in the root of our directory. NOTE: relative paths must use ./ or ../.
./services/service-one/Earthfile
VERSION 0.6
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
deps:
COPY go.mod go.sum ./
RUN go mod download
# Output these back in case go mod download changes them.
SAVE ARTIFACT go.mod AS LOCAL go.mod
SAVE ARTIFACT go.sum AS LOCAL go.sum
./Earthfile
build:
FROM ./services/service-one+deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-example
This code tells FROM that there is another Earthfile in the services/service-one directory and that the Earthfile contains a target called +deps. In this case, if we were to run +build Earthly is smart enough to go into the subdirectory, run the +deps target in that Earthfile, and then use it as the base image for +build.
build:
FROM github.com/example/project+remote-target
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-example
Importing Whole Projects
In addition to importing single targets from other files, we can also import an entire Earthfile with the IMPORT command. This is helpful if there are several targets in a separate Earthfile that you want access to in your current file. It also allows you to create an alias.
VERSION 0.6
IMPORT ./services/service-one AS my_service
FROM golang:1.15-alpine3.13
WORKDIR /go-workdir
build:
FROM my_service+deps
COPY main.go .
RUN go build -o output/example main.go
SAVE ARTIFACT output/example AS LOCAL local-output/go-example
In this example, we assume there is a ./services/service-one directory that contains its own Earthfile. We import it and then use the AS keyword to give it an alias.
Then, in our +build target we can inherit from any target in the imported Earthfile by passing alias+target-name. In this case the Earthfile in the service directory has a target named +deps.
VERSION 0.6
FROM node:13.10.1-alpine3.11
WORKDIR /js-example
build:
FROM ./services/service-one+deps
COPY src src
RUN mkdir -p ./dist && cp ./src/index.html ./dist/
RUN npx webpack
SAVE ARTIFACT dist /dist AS LOCAL dist
docker:
FROM +deps
ARG tag='latest'
COPY +build/dist ./dist
EXPOSE 8080
ENTRYPOINT ["/js-example/node_modules/http-server/bin/http-server", "./dist"]
SAVE IMAGE js-example:$tag
VERSION 0.6
FROM openjdk:8-jdk-alpine
RUN apk add --update --no-cache gradle
WORKDIR /java-example
build:
FROM ./services/service-one+deps
COPY src src
RUN gradle build
RUN gradle install
SAVE ARTIFACT build/install/java-example/bin AS LOCAL build/bin
SAVE ARTIFACT build/install/java-example/lib AS LOCAL build/lib
docker:
COPY +build/bin bin
COPY +build/lib lib
ARG tag='latest'
ENTRYPOINT ["/java-example/bin/java-example"]
SAVE IMAGE java-example:$tag
VERSION 0.6
FROM python:3
WORKDIR /code
build:
FROM ./services/service-one+deps
COPY src src
SAVE ARTIFACT src /src
docker:
COPY +deps/wheels wheels
COPY +build/src src
COPY requirements.txt ./
ARG tag='latest'
RUN pip install --no-index --find-links=wheels -r requirements.txt
ENTRYPOINT ["python3", "./src/hello.py"]
SAVE IMAGE python-example:$tag
We can also reference an Earthfile in another repo, which works in a similar way. If the reference does not begin with one of /, ./, or ../, then earthly treats it as a repository. See for details.
