Merge branch 'metrics' into 'master'

Add metrics reporting

See merge request ecohealthalliance/drake-gitlab-docker-example!1

.gitlab-ci.yml

@@ -33,6 +33,8 @@ run-drake:
     name: "$CI_JOB_NAME"
     paths:
       - artifacts/
+    reports:
+      metrics: artifacts/metrics.txt
   before_script:
     - Rscript -e "remotes::install_deps()"
   script:

README.md

@@ -8,6 +8,8 @@ Some key features:
 -   The build environment is defined in the project `Dockerfile` and packages required are in `DESCRIPTION`.
 -   Two jobs are defined in `.gitlab-ci.yml`. The first builds or updates the Docker image and is run only when `Dockerfile` or `DESCRIPTION` change.  The image is stored in GitLab's project-level image registry.  The second job builds the drake pipeline.
 -   Outputs from the drake pipeline (model objects, compiled reports, and a drake network graph) go into `artifacts` when built.  This directory is stored as an artifact with each GitLab build job, but `.gitignore`'d.
+-   A [metrics file](https://docs.gitlab.com/ee/ci/metrics_reports.html) is saved
+    on each run which can be read and reported by GitLab.
 -   The `.drake` directory is `.gitignore`'d but cached on GitLab between jobs so as to minimize build times.
 -   A `Makefile` defines a docker command so that `make` builds the Docker environment and runs the `drake` pipeline inside it. This facilitates running the dockerized pipeline locally.
 -   The RStudio project file (`.Rproj`) is configured so that `make.R` is run using "Build All" (Cmd+Shift+B) in the Rstudio build pane.

make.R

@@ -2,5 +2,13 @@
 
 library(drake)
 r_make()
+
+# Save a network graph
 visNetwork::visSave(r_vis_drake_graph(), here::here("artifacts", "drake_graph.html"))
 print(build_times(), n=50)
+
+# Save relevant metrics in OpenMetricc format
+# See https://prometheus.io/docs/instrumenting/exposition_formats/#text-based-format
+# https://docs.gitlab.com/ee/ci/metrics_reports.html
+cat("build_time_seconds ", round(sum(build_times()$elapsed), 2),
+    file = here::here("artifacts", "metrics.txt"))