allow multistage docker (#84)

* feat Add `append` parameter to `write()` to allow appending to file instead of overwriting

* feat allow multistage dockerfile

Author: VincentGuyader

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: dockerfiler
 Title: Easy Dockerfile Creation from R
-Version: 0.2.4
+Version: 0.2.4.9000
 Authors@R: c(
     person("Colin", "Fay", , "contact@colinfay.me", role = c("cre", "aut"),
            comment = c(ORCID = "0000-0001-7343-1846")),

NEWS.md

@@ -1,3 +1,7 @@
+# dockerfiler 0.2.4.9xxx
+
+- allow multistage dockerfile creation
+
 # dockerfiler 0.2.4
 
 - remove native pipe thanks to @HenningLorenzen-ext-bayer, this enable to use of older R versions

R/add.R

@@ -31,19 +31,22 @@ add_add <- function(
   glue("ADD {from} {to}")
 }
 
-add_copy <- function(
-  from,
-  to,
-  force = TRUE
-) {
+add_copy <- function(from,
+                     to,
+                     stage = NULL,
+                     force = TRUE) {
   if (!force) {
-    warn_if_not(
-      normalizePath(from),
-      file.exists,
-      "The file `from` doesn't seem to exists"
-    )
+    warn_if_not(normalizePath(from),
+                file.exists,
+                "The file `from` doesn't seem to exists")
+  }
+
+  if (is.null(stage)) {
+    glue("COPY {from} {to}")
+  } else {
+    glue("COPY --from={stage} {from} {to}")
+
   }
-  glue("COPY {from} {to}")
 }
 
 add_workdir <- function(where) {

R/dockerfile.R

@@ -39,9 +39,10 @@ self$Dockerfile <- c(self$Dockerfile, add_add(from, to, force))
 #' @param from The source file.
 #' @param to The destination file.
 #' @param force If TRUE, overwrite the destination file.
+#' @param stage Optional. Name of the build stage (e.g., `"builder"`) to copy files from. This corresponds to the `--from=` part in a Dockerfile COPY instruction (e.g., `COPY --from=builder /source /dest`). If `NULL`, the `--from=` argument is omitted.
 #' @return the Dockerfile object, invisibly.
-COPY = function(from, to, force = TRUE) {
-self$Dockerfile <- c(self$Dockerfile, add_copy(from, to, force))
+COPY = function(from, to, stage= NULL , force = TRUE) {
+self$Dockerfile <- c(self$Dockerfile, add_copy(from, to, stage, force))
 },
 #' @description
 #' Add a WORKDIR command.
@@ -162,9 +163,10 @@ cat(self$Dockerfile, sep = "\n")
 #' @description
 #' Write the Dockerfile to a file.
 #' @param as The file to write to.
+#' @param append boolean, if TRUE append to file.
 #' @return used for side effect
-write = function(as = "Dockerfile") {
-base::write(self$Dockerfile, file = as)
+write = function(as = "Dockerfile", append = FALSE) {
+base::write(self$Dockerfile, file = as, append = append)
 },
 #' @description
 #' Switch commands.

man/Dockerfile.Rd

@@ -0,0 +1,27 @@
+test_that("Dockerfile COPY with build stage works correctly", {
+  # Création des deux étapes du Dockerfile
+  stage_1 <- Dockerfile$new(FROM = "alpine", AS = "builder")
+  stage_1$RUN('echo "coucou depuis le builder" > /coucou')
+
+  stage_2 <- Dockerfile$new(FROM = "ubuntu")
+  stage_2$COPY(from = "/coucou", to = "/truc.txt", force = TRUE, stage = "builder")
+  stage_2$RUN("cat /truc.txt")
+
+  tmpfile <- tempfile(fileext = ".Dockerfile")
+  stage_1$write(as = tmpfile)
+  stage_2$write(as = tmpfile, append = TRUE)
+
+  docker_lines <- readLines(tmpfile)
+
+  expect_length(docker_lines, 5)
+
+  expect_equal(docker_lines[1], "FROM alpine AS builder")
+  expect_equal(docker_lines[2], 'RUN echo "coucou depuis le builder" > /coucou')
+  expect_equal(docker_lines[3], "FROM ubuntu")
+  expect_equal(docker_lines[4], "COPY --from=builder /coucou /truc.txt")
+  expect_equal(docker_lines[5], "RUN cat /truc.txt")
+
+  expect_true(any(grepl("COPY --from=builder", docker_lines)))
+  expect_true(any(grepl("/coucou", docker_lines)))
+  expect_true(any(grepl("/truc.txt", docker_lines)))
+})