9 files changed, 127 insertions, 12 deletions
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 651e9d2c..32ed8625 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 * [#2111](https://github.com/clojure-emacs/cider/pull/2111): Add `cider-pprint-eval-last-sexp-to-comment` and `cider-pprint-eval-defun-to-comment`.
 * Add a REPL shortcut for `cider-repl-require-repl-utils` (this makes it easy to require common functions like `doc`, `source`, etc. in REPL buffers).
 * [#2112](https://github.com/clojure-emacs/cider/issues/2112): Add a new interactive command `cider-find-keyword` (bound to `C-c C-:`).
+* [#2144](https://github.com/clojure-emacs/cider/issues/2144): Create a Docker image to mimic the Travis environment
 
 ### Changes
 
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 00000000..58a1cb32
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,34 @@
+FROM travisci/ci-garnet:packer-1490989530
+
+RUN apt-get update -y \
+ && apt-get install -y \
+      autogen \
+      ca-certificates \
+      curl \
+      gcc \
+      git \
+      libgmp-dev \
+      m4 \
+      make \
+      pkg-config \
+      python \
+      ruby \
+      xz-utils
+
+USER travis
+ENV HOME=/home/travis
+ENV PATH="${HOME}/local/evm/bin:${HOME}/local/cask/bin:${HOME}/local/bin:${PATH}"
+
+ADD travis-ci/ ${HOME}/cider-setup/travis-ci/
+RUN echo ". ${HOME}/cider-setup/travis-ci/prompt.sh" >> ${HOME}/.bashrc
+
+RUN ${HOME}/cider-setup/travis-ci/install-gnutls.sh
+RUN ${HOME}/cider-setup/travis-ci/install-evm.sh
+RUN ${HOME}/cider-setup/travis-ci/install-cask.sh
+
+RUN evm install emacs-25.3-travis --use
+RUN evm install emacs-26-pretest-travis
+RUN evm install emacs-git-snapshot-travis
+
+WORKDIR /home/travis/cider
+CMD /bin/bash
diff --git a/doc/hacking_on_cider.md b/doc/hacking_on_cider.md
index 11c4e80f..c778a536 100644
--- a/doc/hacking_on_cider.md
+++ b/doc/hacking_on_cider.md
@@ -77,6 +77,72 @@ You can also check for the presence of byte-compilation warnings in batch mode:
 $ make test-bytecomp
 ```
 
+#### Running the tests in Travis CI
+
+If you prefer to see the full Travis test suite run successfully, the easiest
+way to achieve that is to create your own personal account on
+https://travis-ci.org. View your profile details on the Travis site, and toggle
+the switch to enable builds on your fork of the cider project.
+
+Subsequent pushes to your fork will generate a Travis build you can monitor for
+success or failure.
+
+#### Simulating the Travis tests locally in Docker
+
+If you prefer not to wait for Travis all the time, or if you need to debug
+something that fails in Travis but does not fail for you on your own machine,
+then you can also run the Travis tests manually in Docker.
+
+You will need to run some scripts to build and launch the Docker image.
+
+To build:
+```
+$ docker/build.sh
+```
+
+The build script uses a base image provided by the engineers at Travis. Note: the
+Travis docker image is currently more than 8GB, so be prepared with a good
+internet connection and time to spare.
+
+The resulting docker image is tagged simply `cider-travis`. You can run this
+image by hand, but there is a convenience script available:
+```
+$ docker/run.sh
+```
+
+This script launches a docker container and bind-mounts your cider project
+directory as `/home/travis/cider` such that you can instantly see any code
+changes reflected inside the docker environment.
+
+For instance, you can run tests on emacs 25.3
+```
+(emacs-25.3-travis) ~/cider$ make test
+```
+
+and then switch to emacs 26 and test again
+
+```
+(emacs-25.3-travis) ~/cider$ evm use emacs-26-pretest-travis
+(emacs-26-pretest-travis) ~/cider$ cask install
+(emacs-26-pretest-travis) ~/cider$ make test
+```
+
+You can test byte compilation too
+```
+(emacs-26-pretest-travis) ~/cider$ make test-bytecomp
+```
+
+When you are done working in docker, just `exit` the bash prompt, and the docker
+container will also exit. Note that `docker/run.sh` runs the container with
+`--rm`, meaning any changes to the docker container are discarded when the
+container exits.
+
+So for example, by default, the docker image pre-installs only the most recent
+releases of emacs 25, emacs 26, and a recent snapshot of the emacs git
+repository. The `evm` tool is available should you need to install some other
+specific build. However additional versions of emacs will be discarded when
+you exit the docker container.
+
 ## Hacking on cider-nrepl
 
 ### Obtaining the code
diff --git a/docker/build.sh b/docker/build.sh
new file mode 100755
index 00000000..67c48bb6
--- /dev/null
+++ b/docker/build.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+docker build -t cider-travis .
+
diff --git a/docker/run.sh b/docker/run.sh
new file mode 100755
index 00000000..33ff3e2f
--- /dev/null
+++ b/docker/run.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+docker run -it --rm -v `pwd`:/home/travis/cider cider-travis bash
+
diff --git a/travis-ci/install-cask.sh b/travis-ci/install-cask.sh
index 3f4ae446..fc2438b6 100755
--- a/travis-ci/install-cask.sh
+++ b/travis-ci/install-cask.sh
@@ -1,14 +1,13 @@
-#!/bin/bash
+#!/bin/bash -x
 
 # Install cask for Travis CI
 # or if already installed, then check for updates
 
-set -x
-
 WORKDIR=${HOME}/local
 CASKDIR=$WORKDIR/cask
+SCRIPTDIR=`dirname $(readlink -f $0)`
 
-. travis-ci/retry.sh
+. $SCRIPTDIR/retry.sh
 
 cask_upgrade_cask_or_reset() {
     cask upgrade-cask || { rm -rf $HOME/.emacs.d/.cask && false; }
@@ -30,4 +29,7 @@ fi
 # Install dependencies for cider as descriped in ./Cask
 # Effect is identical to "make elpa", but here we can retry
 # in the event of network failures.
-travis_retry cask_install_or_reset && touch elpa-emacs
+if [ -f Cask ]
+then
+    travis_retry cask_install_or_reset && touch elpa-emacs
+fi
diff --git a/travis-ci/install-evm.sh b/travis-ci/install-evm.sh
index f3481071..ef9bb979 100755
--- a/travis-ci/install-evm.sh
+++ b/travis-ci/install-evm.sh
@@ -1,14 +1,13 @@
-#!/bin/bash
+#!/bin/bash -x
 
 # Install evm for Travis CI
 # or if already installed, then check for updates
 
-set -x
-
 WORKDIR=${HOME}/local
 EVMDIR=$WORKDIR/evm
+SCRIPTDIR=`dirname $(readlink -f $0)`
 
-. travis-ci/retry.sh
+. $SCRIPTDIR/retry.sh
 
 if [ -d $EVMDIR ]
 then
diff --git a/travis-ci/install-gnutls.sh b/travis-ci/install-gnutls.sh
index 121dbfdf..bd3316b4 100755
--- a/travis-ci/install-gnutls.sh
+++ b/travis-ci/install-gnutls.sh
@@ -1,11 +1,9 @@
-#!/bin/bash
+#!/bin/bash -x
 
 # Setup a newer gnutls-cli on Travis CI
 # We need this as long as the Travis workers are Ubuntu 14.04
 # and the TLS cert chain on elpa.gnu.org is out-of-order
 
-set -x
-
 # adjust these versions as needed
 export NETTLE_VERSION=3.4
 export GNUTLS_VERSION=3.5.16
@@ -14,6 +12,12 @@ export WORKDIR=${HOME}/local/
 export LD_LIBRARY_PATH=${WORKDIR}/lib/
 export PKG_CONFIG_PATH=${WORKDIR}/lib/pkgconfig/
 
+# make sure workdir exists
+if [ ! -d ${WORKDIR} ]
+then
+    mkdir $WORKDIR
+fi
+
 # exit if the cache is valid and up-to-date
 if [ -f ${WORKDIR}/bin/gnutls-cli ] && \
    [ -f ${WORKDIR}/nettle-${NETTLE_VERSION}.tar.gz ] && \
diff --git a/travis-ci/prompt.sh b/travis-ci/prompt.sh
new file mode 100644
index 00000000..ef95931c
--- /dev/null
+++ b/travis-ci/prompt.sh
@@ -0,0 +1 @@
+export PS1="(\$(sed -ne 's/^.*\(emacs-.*-travis\).*$/\1/p' ~/local/evm/.config)) \w$ "