* libs/db: conditional compilation
For cleveldb: go build -tags cleveldb
For boltdb: go build -tags boltdb
Fixes#3611
* document db_backend param better
* remove deprecated LevelDBBackend
* update changelog
* add missing lines
* add new line
* fix TestRemoteDB
* add a line about boltdb tag
* Revert "remove deprecated LevelDBBackend"
This reverts commit 1aa85453f76605e0c4d967601bbe26240e668d51.
* make PR non breaking
* change DEPRECATED label format
https://stackoverflow.com/a/36360323/820520
* not related to linter: remove obsolete constants:
- `Insecure` and `Secure` and type `Security` are not used anywhere
* not related to linter: update example
- NewInsecure was deleted; change example to NewRemoteDB
* address: Binds to all network interfaces (gosec):
- bind to localhost instead of 0.0.0.0
- regenerate test key and cert for this purpose (was valid for ::) and
otherwise we would see:
transport: authentication handshake failed: x509: certificate is
valid for ::, not 127.0.0.1\"
(used https://github.com/google/keytransparency/blob/master/scripts/gen_server_keys.sh
to regenerate certs)
* use sha256 in tests instead of md5; time difference is negligible
* nolint usage of math/rand in test and add comment on its import
- crypto/rand is slower and we do not need sth more secure in tests
* enable linter in circle-ci
* another nolint math/rand in test
* replace another occurrence of md5
* consistent comment about importing math/rand
