Continued improvements

* Remove legacy Store upload credentials

These have not been needed since 5d7969a.

* Work around dev part dependency failure case

Get pip to install certbot from its VCS repository directly during the
build of the nginx and apache plugin parts.

This works around issue #12 when it affects the interaction between the
apache or nginx plugin and certbot itself.

It does not work around the case where the same problem occurs in the
interaction between certbot and acme. This looks harder to work around
because pip's VCS URL handling doesn't appear to include a facility to
install from a subdirectory of a git repository and this is where the
acme source is located.

* Switch to using lxd for the snapcraft run

The Docker image is 16.04 only. Before we can switch to 18.04, we need
to remove Docker, which means using the snapcraft snap using Travis' new
snap support, and then using the lxd functionality in snapcraft so that
it is enabled to build in the appropriate environment.

* Switch build to use core 18

Fixes: #14

* Move constraints into a list

This seems to be a requirement either either newer snapcraft, snapcraft
in lxd or in the move to core18 (it isn't clear to me which). This fixes
the error:

Failed to load plugin: properties failed to load for certbot: The 'constraints' property does not match the required schema: '$SNAPCRAFT_PART_SRC/constraints.txt' is not of type 'array'

* version-script -> snapcraftctl set-version

The use of version-script seems to break with either newer snapcraft,
snapcraft with lxd or core18 (it's not clear to me which). The breakage
is related to "parts/certbot/src" not being found. This can be fixed
with $SNAPCRAFT_PART_SRC, but this doesn't seem to be defined at
"version-script time".

However https://snapcraft.io/docs/deprecation-notices/dn10 deprecates
the use of version-script, and if we convert to the recommended new way,
then we use override-pull instead and $SNAPCRAFT_PART_SRC is defined
there, so this conveniently fixes both problems at once.

* Do not explicitly install snapd

Since this is now handled by the Travis addon, we do not need to do it
explicitly.

snap/.travis.yml

@@ -1,12 +1,15 @@
 language: python
 before_install:
-  - sudo -E apt-get -yq --no-install-suggests --no-install-recommends install nginx-light snapd python3-venv
+  - sudo -E apt-get -yq --no-install-suggests --no-install-recommends install nginx-light python3-venv
   - sudo -E /etc/init.d/nginx stop
 install:
+  - sudo /snap/bin/lxd.migrate -yes
+  - sudo /snap/bin/lxd waitready
+  - sudo /snap/bin/lxd init --auto
   - git clone https://github.com/certbot/certbot.git certbot --branch master
   - certbot/tools/strip_hashes.py certbot/letsencrypt-auto-source/pieces/dependency-requirements.txt > certbot/constraints.txt
 before_script:
-  - docker run -v $(pwd):$(pwd) -t snapcore/snapcraft sh -c "apt-get update -qq && apt-get install -qq git && cd $(pwd) && snapcraft"
+  - sudo snapcraft --use-lxd
 script:
   - sudo snap install --dangerous --classic *.snap
   - sudo bash test.sh
@@ -21,3 +24,10 @@ notifications:
   email:
     recipients: [robie.basak@canonical.com]
     on_failure: change
+addons:
+  snaps:
+    - name: snapcraft
+      channel: stable
+      classic: true
+    - name: lxd
+      channel: stable

snap/snapcraft.yaml

@@ -1,6 +1,4 @@
 name: certbot
-version: script
-version-script: cd parts/certbot/src && git describe|sed s/^v//
 summary: Automatically configure HTTPS using Let's Encrypt
 description: |
  The objective of Certbot, Let's Encrypt, and the ACME (Automated
@@ -17,6 +15,8 @@ description: |
    - Help you revoke the certificate if that ever becomes necessary.
 confinement: classic
 grade: devel
+base: core18
+adopt-info: certbot
 
 apps:
   certbot:
@@ -47,26 +47,31 @@ parts:
     plugin: python
     source: certbot
     source-subdir: acme
-    constraints: $SNAPCRAFT_PART_SRC/constraints.txt
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
     python-version: python3
   certbot:
     plugin: python
     source: certbot
-    constraints: $SNAPCRAFT_PART_SRC/constraints.txt
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
     python-version: python3
     after: [acme]
+    override-pull: |
+        snapcraftctl pull
+        snapcraftctl set-version `cd $SNAPCRAFT_PART_SRC && git describe|sed s/^v//`
   certbot-apache:
     plugin: python
     source: certbot
     source-subdir: certbot-apache
-    constraints: $SNAPCRAFT_PART_SRC/constraints.txt
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
     python-version: python3
     after: [python-augeas, certbot]
     stage-packages: [libaugeas0]
+    python-packages: ['git+https://github.com/certbot/certbot.git']  # workaround for #12
   certbot-nginx:
     plugin: python
     source: certbot
     source-subdir: certbot-nginx
-    constraints: $SNAPCRAFT_PART_SRC/constraints.txt
+    constraints: [$SNAPCRAFT_PART_SRC/constraints.txt]
     python-version: python3
     after: [certbot]
+    python-packages: ['git+https://github.com/certbot/certbot.git']  # workaround for #12