…29976)

Previously, the preview server docker image was based on Debian 8
(jessie). Recently, `jessie-updates` and `jessie-backborts` were removed
from the Debian mirrors ([more info][1]), thus breaking new builds of
the image.

Instead of updating `/etc/apt/sources.list` to remove the obsolete
sources, this commit upgrades to Debian 9 (stretch).

(The GCE VM running the preview server docker container was also
upgraded from Debian 8 to 9 this morning.)

---
Other changes:
- Removed dependency on `chkconfig`, which is not supported on Debian 9.
- Installing `nginx` from the regular repositories (instead of
  `*-backports).
- Upgraded to `pm2` v3, which can handle hooking itself up to system
  startup better (without `chkconfig` - see above).
- Updated tests to reflect the fact that `nginx` has dropped the reason
  phrase in response status lines for HTTP/2 (in compliance with
  [the spec][2]). (HTTP/1.1: `HTTP/1.1 200 OK` | HTTP/2: `HTTP/2 200`)

[1]: https://www.lucas-nussbaum.net/blog/?p=947
[2]: https://http2.github.io/http2-spec/#rfc.section.8.1.2.4

PR Close #29976

…er docker image (#29976)

This minimises the risk of unexpected failures due to breaking changes,
when building a new image (e.g. as a result of an unrelated config
change in Dockerfile).

PR Close #29976

…ver (#29976)

In #29926, the size of the build artifacts has increased due to turning
on differential loading (which generates an es2015/es5 pair for each JS
resource).

To avoid the preview server's rejecting the build artifacts (as in
[288181][1]), this commit increases the max allowed artifact size from
20MB to 25MB (current artifact size after #29926 is ~22MB).

[1]: https://circleci.com/gh/angular/angular/288181

PR Close #29976

…29976)

Previously, the preview server docker image was based on Debian 8
(jessie). Recently, `jessie-updates` and `jessie-backborts` were removed
from the Debian mirrors ([more info][1]), thus breaking new builds of
the image.

Instead of updating `/etc/apt/sources.list` to remove the obsolete
sources, this commit upgrades to Debian 9 (stretch).

(The GCE VM running the preview server docker container was also
upgraded from Debian 8 to 9 this morning.)

---
Other changes:
- Removed dependency on `chkconfig`, which is not supported on Debian 9.
- Installing `nginx` from the regular repositories (instead of
  `*-backports).
- Upgraded to `pm2` v3, which can handle hooking itself up to system
  startup better (without `chkconfig` - see above).
- Updated tests to reflect the fact that `nginx` has dropped the reason
  phrase in response status lines for HTTP/2 (in compliance with
  [the spec][2]). (HTTP/1.1: `HTTP/1.1 200 OK` | HTTP/2: `HTTP/2 200`)

[1]: https://www.lucas-nussbaum.net/blog/?p=947
[2]: https://http2.github.io/http2-spec/#rfc.section.8.1.2.4

PR Close #29976

…er docker image (#29976)

This minimises the risk of unexpected failures due to breaking changes,
when building a new image (e.g. as a result of an unrelated config
change in Dockerfile).

PR Close #29976

…ver (angular#29976)

In angular#29926, the size of the build artifacts has increased due to turning
on differential loading (which generates an es2015/es5 pair for each JS
resource).

To avoid the preview server's rejecting the build artifacts (as in
[288181][1]), this commit increases the max allowed artifact size from
20MB to 25MB (current artifact size after angular#29926 is ~22MB).

[1]: https://circleci.com/gh/angular/angular/288181

PR Close angular#29976

…ngular#29976)

Previously, the preview server docker image was based on Debian 8
(jessie). Recently, `jessie-updates` and `jessie-backborts` were removed
from the Debian mirrors ([more info][1]), thus breaking new builds of
the image.

Instead of updating `/etc/apt/sources.list` to remove the obsolete
sources, this commit upgrades to Debian 9 (stretch).

(The GCE VM running the preview server docker container was also
upgraded from Debian 8 to 9 this morning.)

---
Other changes:
- Removed dependency on `chkconfig`, which is not supported on Debian 9.
- Installing `nginx` from the regular repositories (instead of
  `*-backports).
- Upgraded to `pm2` v3, which can handle hooking itself up to system
  startup better (without `chkconfig` - see above).
- Updated tests to reflect the fact that `nginx` has dropped the reason
  phrase in response status lines for HTTP/2 (in compliance with
  [the spec][2]). (HTTP/1.1: `HTTP/1.1 200 OK` | HTTP/2: `HTTP/2 200`)

[1]: https://www.lucas-nussbaum.net/blog/?p=947
[2]: https://http2.github.io/http2-spec/#rfc.section.8.1.2.4

PR Close angular#29976

…er docker image (angular#29976)

This minimises the risk of unexpected failures due to breaking changes,
when building a new image (e.g. as a result of an unrelated config
change in Dockerfile).

PR Close angular#29976