Ubuntu PPA does not depend on wget.
The Ubuntu PPA does not depend on wget, and in minimal installs wget is not present (example: the official 14.04 Docker image).
This causes the install to fail with:
Setting up suricata (2.0.4-0ubuntu15) ...
Download and install the latest Emerging Threats Open ruleset
/var/lib/dpkg/info/suricata.postinst: 23: /var/lib/dpkg/info/suricata.postinst: /usr/bin/wget: not found
gzip: stdin: unexpected end of file
tar: Child returned status 1
tar: Error is not recoverable: exiting now
dpkg: error processing package suricata (--configure):
subprocess installed post-installation script returned error exit status 2
Processing triggers for libc-bin (2.19-0ubuntu6.4) ...
Processing triggers for ureadahead (0.100.0-16) ...
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)
2014/12/07 19:40:03 The command [/bin/sh -c apt-get -y install suricata] returned a non-zero code: 100